FOOD. SCiENCE AND. YOU: A PROJECT DEVELOPED FOR YOUTH Thesis for the Degree of M. S. MiCl-EJGAN STATE UNIVERSITY MARILYN- MOOK 1973 ABSTRACT FOOD SCIENCE AND YOU: A PROJECT DEVELOPED FOR YOUTH By Marilyn Mook A new 4-H projecT, "Food Science and You," has been developed for use wiTh older 4-H members and adulTs. The projecT maTerials consisT of a book of experimenTs, a record book, and a slide series wiTh narraTive. The book of experimenTs includes simple experiences which TesT some of The principles of food preparaTion, food sTorage and food handling. The experimenTs have visually deTecTable resuITs, and use uTensils and ingredienTs found in The average kiTchen. For each experimenT, The principle To be TesTed is sTaTed firsT, followed by a lisT of The equip- menT and ingredienTs required. The procedure is ouTlined, and a shorT explanaTion of The anTicipaTed resulTs is given. The record book facili- TaTes mainTaining a wriTTen record of The experimenTal procedure, The re— sulTs, and The way The member shared his new knowledge. The slide series provides a visual demonsTraTion of The funcTion of an excess and a de- ficiency or lack of The ingredienTs in a one-egg buTTer cake sysTem. TwenTy-five young people were asked To evaluaTe The experimenTs and reTurn The quesTionnaire. TwenTy 4-H'ers ranging in age from nine To l6 years evaluaTed The experimenTs and reTurned The quesTionnaire. FiTTeen adulT 4-H leaders also evaluaTed The experimenTs. All The adulTs and I9 of The young people received The projecT enThusiasTically. They enjoyed doing The experimenTs and would like To TesT more experimenTs. The adulTs and young people also indicaTed ThaT They would be able To use Their new knowledge in fuTure work wiTh food. FOOD SCIENCE AND YOU: A PROJECT DEVELOPED FOR YOUTH By Marilyn Mook A THESIS SubmlTTed To Michigan STaTe UnlversiTy ln parTlal fulfillmenT of The requlremenTs for The degree of MASTER OF SCIENCE DeparTmenT of Food Science and Human NuTriTion l973 hfi ACKNOWLEDGEMENTS I wish To Thank The members of The graduaTe commiTTee for Their supporT. Special Thanks go To my major professor, Dr. Mary Zabik, for her Time and in‘eresT in planning and direcTing my course work and wriTing. Dr. Dena CederquisT, Dr. PorTia Morris and Dr. Carroll Wamhoff also gave me encouragemenT during This endeavor. RecogniTion is also due To Mrs. HesTer Fillmore and her Happy HusTlers 4-H club for Their evaluaTion of The experimenTs in "Food Science and You." Personal Thanks also go To Bonnie Gregg and Claudia Arnold for Their assisTance in Typing 3rd priufirg This Thesis. TABLE OF CONTENTS INTRODUCTION AND LITERATURE REVIEW DEVELOPMENTAL PROCEDURE ExperimenT Book Record Book Visual Learning Aids Preliminary EvaluaTion RESULTS AND DISCUSSION Food Science and You ProjecT EvaluaTions Discussion SUMMARY AND CONCLUSIONS LIST OF REFERENCES APPENDICES Appendix A...ExperimenT Book Appendix B...Record Book Appendix C...NarraTive Appendix D...QuesTionnaire Page 22 25 27 30 32 85 95 97 LIST OF TABLES Page Responses of 4-H youTh To quesTionnaire evaluaTing 24 "Food Science and You." ReacTions of 4-H leaders To experimenTs on measuring, 25 ingredienT funcTion and gluTen developmenT. INTRODUCTION AND LITERATURE REVIEW 4-H YouTh DevelopmenT, The youTh program of CooperaTive ExTension Service, maximizes The ToTal poTenTial of young people. 4-H has been recognized for iTs conTribuTion To The developmenT of social responsibil- iTy and personaliTy Through "real-life" experiences. Through projecTs in science and Technology, 4-H Teaches The scienTific process of de- cision-making, and sTimuIaTes creaTive InTeracTion. Ideally, 4-H fosTers invenTiveness and emphasizes beTTer planning of whaT is To be learned, so ThaT The parTIcipanT may begin To seT up his own life goals (I). In l9l5, Michigan AgriculTural College firsT published a bulieTin (2) ouTIIning six club projecTs for boys and six for girls. The boys' projecTs were corn, poTaToes, apples, IivesTock, poulTry, and markeT gardening. The projecTs for girls included housekeeping, garmenT- making, canning and markeTing, gardening and canning, poulTry, and markeT gardening. These projecTs were designed To help The boys and girls acquire These skills. The bulIeTin sTaTes ThaT boys' and girls' club work "reinforces The school aT iTs weakesT poInT; uniTes The home and school; is The kind of educaTion ThaT fiTs for The duTies of life; Teaches in Terms of acTion; keeps boys and girls on The farm; viTalizes home and school work; and makes beTTer ciTizens." ExTension's youTh program conTinues To do many of These Things for young people, buT The Type of skills TaughT changes as The populaTion 2 changes from rural To urban. Michigan is becoming an urban sTaTe. Michigan's meTropolITan area increased l4.l% or 850,000 people in The Ten-year period from I960 To I970. The non-meTropolITan area increased II.I% or 200,000 people in The same Time span. 0f Michigan's 8.8 mil— lion people, 6.8 live In meTropolITan areas. The Trend Toward popula- Tion cenTralIzaTion conTInues, wiTh nearly half of Michigan's residenTs living In The DeTroiT area of Wayne, Oakland and Macomb counTies (3). Major popuIaTIon shifTs To a highly urban and rural non-farm majorITy have resulTed In corresponding shIfTs in needs and InTeresTs among young people. Along wiTh popuIaTIon shifTs have come Tremendous advances In science and Technology (4). UnTII a few years ago, 4-H food and nuTriTion projecTs in Michigan, as well as In oTher sTaTes, promoTed food preparaTIon. ProjecT parTi- pranTs learned cooking skills, and were expecTed To pracTIce unTII They ‘ could make perfecT cookies or pIe crusT or bread. WITh The developmenT of food Technology and The refinemenT of The disTrIbuTion and markeTIng process, The food IndusTry Is able To provide prepared, pro-packaged and parTIally prepared foods aT low cosT To The consumer. Examples of perfecT cookies, pie crusT and bread may be found In supermarkeTs, and IT Is no longer necessary To bake These ITems aT home. The beglnnlng of The shifT To The "why's" of food preparaTion raTher Than The "how's" began In I964 (5). A UnITed STaTes DeparTmenT of AgriculTure publicaTIon urged ExTension workers and leaders To InTe- graTe more science InTo The Iearnlng experiences of 4-H members and adulTs. The publicaTIon sTaTed ThaT IncorporaTlng science Is one major way of having an up-To-daTe and forward-looking program. Science In foods means undersTandIng The properTIes and characTerisTIcs of foods 3 as well as The proper means of preparing Them. The Michigan foods projecT bulleTins were revised To include more of The "why's" or sci- enTific aspecTs of food preparaTion (6, 7, 8). One chapTer of a bul- IeTin published in I965 is devoTed enTirely To ExperimenTal Foods (9). The nexT sTep was To prepare an enTire projecT on The scienTific aspecTs of food. A few sTaTes have already published bulIeTins in food science (I0, Il, I2, l3, l4, l5). AIThough These buIIeTins have noT been revised since They were wriTTen, They have been used successfully in sTaTe-wide youTh programs. "Exploring Dairy Food Science," from The NaTional 4-H Service CommiTTee, presenTs Techniques and ideas for dairy foods demonsTraTions. Members are urged To use foods from The Milk Group in new and creaTive ways for planning and preparing meals for Their families. A few experi- menTs on making buTTer, making coTTage cheese, and cooking wiTh cheese are provided for The members To use (l6). Colorado's publicaTion, "4-H Food Science," presenTs 25 experimenTs designed To demonsTraTe The changes ThaT Take place in cooking because of The properTies of The food. ExperimenTs are designed To demonsTraTe The effecT of cooking on The flavor, color and TexTure of vegeTables; The effecT of cooking TemperaTure on The TexTure of meaT and eggs; and The effecT of faT on The body, TexTure and flavor of ice cream (I5). "AdvenTures in Food Science" from California provides I8 experimenTs which show how sclenTIfic projecTs may be carried ouT wiTh food. Exper- imenTers may TesT various foods for sTarch, TesT The effecT of enzymes on proTein, and TesT differenT meThods of cooking vegeTables To deTermine The effecT on color, flavor and TexTure. Members and leaders may Then undersTand some of The reasons for Their own food preparaTion successes or failures (IS). A series of IeaerTs also TiTIed "AdvenTures in Food Science" was published in Florida. These leafleTs include Two or Three exper- imenTs on color in vegeTables, color changes In meaTs, Ieavening, gela- Tin, emulsions, and vegeTabIe cellulose. The projecT leaerTs are designed To acquainT The experimenTer wiTh scienTific principles To improve The use of food in everyday meal preparaTion (l2). Pennsylvania has Two publicaTions, "Fun wiTh Food Science" and "Food Science for Teen Leaders." "Fun wiTh Food Science," a projecT for younger members, has Three suggesTed experimenTs. The experimenTs provide informaTion To demonsTraTe ThaT scienTific facTs may be applied To daily food preparaTion (II). "Food Science for Teen Leaders" is a book of acTIviTies demonsTraT- ing chemisTry of food. ParTicipanTs conducT experimenTs on The effecT of oxidaTion, heaT, pH and enzymes in food preparaTion (l0). "AdvenTures in Food-NuTriTion" from SouTh Carolina is also a book of experimenTs in food chemisTry. The members learn The major and minor consTiTuenTs of milk; The naTure and properTies of TaTs, proTeIns, lacTose, wheaT gluTen and Ieavening agenTs; and color changes in cured meaTs, TruiTs and vegeTables (I4). AlThough These sTaTes have had 4-H Food Science projecTs, Michigan did noT have a projecT of This Type. EnrollmenT of older Teens in 4—H youTh programs has been decreasing (I7). In The I960 fiscal year I3,400 youhg people aged l6 To l8 were parTicipaTing in 4-H. By I965 enrollmenT had dropped To Il,I00, and in The I972 fiscal year, 8,600 young people in The I6 To l8-year age range were members of 4-H. A projecT promoTIng The food science aspecT of food and nuTriTion could help mainTain inTeresT 5 and parTIcipaTion of older Teens enrolled in The 4-H food and nuTri- Tion projecT area. A food science projecT would emphasize The scienTific aspecTs raTher Than The meThods of food preparaTion. A projecT which uses simple experimenTs To TesT The principles of food preparaTion, food sTorage and food handling would have appeal To boTh boys and girls in The food and nuTriTion projecT area, as well as oTher projecT areas. The food science projecT could be considered a science experience as well as a foods projecT. In parTicipaTing in This projecT, young people will learn some of The principles of food preparaTion, food sTorage and food handling. They will learn ThaT The componenTs of food sysTems work TogeTher To produce desired resulTs, and They will be encouraged To share Their new knowledge wiTh oThers in some creaTive way. AfTer The experimenT book is developed, The experimenTs will be evaluaTed by a selecTed group of young people and adulT leaders. The parTicipanTs will compleTe and reTurn a quesTionnaire afTer They have concluded The experimenTs. Included in The quesTionnaire will be The age of The member, place of residence, if he liked doing The experimenTs, whaT he learned, if he could share his new knowledge wiTh oThers, and if he would like To parTicipaTe in furTher experimenTs. CommenTs and sug- gesTions will also be soliciTed aT The end of The quesTionnaire. In addiTion To The experimenT book, a record book will be included To faciliTaTe daTa collecTing in These scienTific experiences. In The record book, The parTicipanT will noTe The Time The experimenT Took, whaT principle was TesTed, whaT resulTs were obTained, whaT he learned from This experimenT, and how he shared This knowledge. A series of slides and narraTive will be developed ThaT visually 6 demonsTraTe The funcTion of ingredienTs in a one-egg buTTer cake sysTem. The slides will poinT ouT The effecT of an excess and a deficiency or lack of each ingredienT on The appearance of The cakes. These slides will be used for educaTionaI and promoTional experiences for 4-H members and leaders in Michigan. DEVELOPMENTAL PROCEDURE The purpose of This sTudy was To develop and To obTain a prelimi- nary evaluaTion of a learning projecT In food science for 4-H youTh. The projecT, "Food Science and You," consisTs of a book of experimenTs, a record book, and a seT of slides wiTh narraTive. The objechves of This projecT are To TesT some of The principles of food preparaTion, food sTorage and food handling; To learn ThaT The componenTs of a food sysTem work TogeTher To produce desired resulTs; and To share knowledge In a creaTive way. IT is hoped ThaT Through parTicipaTing In This pro- jecT, young people and Their leaders will realize ThaT food preparaTion is based on scienTiflc principles, and will undersTand ThaT The prepara- Tion of food is more Than a skill. ExperimenT Book The experimenT book includes l00 experimenTs TesTing some of The principles of food preparaTion, food sTorage and food handling (Appendix A). ExperimenTs in measuring, ingredienT funcTion, proTeins, carbohydraTes, faTs, freezing, and microbiology were developed. All of The experimenTs were pre-TesTed by The wriTer before inclusion in The experimenT book. The principles To be TesTed were firsT deTermined, Then experimenTs were selecTed To demonsTraTe These principles. The criTerIa for The ex- perimenTs were: (I) The experimenT should require The use of IngredienTs and uTensils found in The home kiTchen or readily available; (2) The ouTcome of The experimenT should be readily and easily discernible; (3) The principle TesTed should be applicable To ordinary food preparaTion 7 slTuaTions. Many of The experimenTs were adapTed from Those used in Three under- graduaTe classes in The DeparTmenT of Food Science and Human NuTriTion aT Michigan STaTe UniversiTy. Two of The classes, ExperimenTal Foods 403 and ExperimenTal Foods 404, provided The basis for The experimenTs on food sTorage and a majoriTy of The experimenTs on food preparaTion. For The experimenTs on food handling, experimenTs were adapTed and sim- plified from some of Those used in Food Microbiology 440. 0Ther experi- menTs were adapTed from The IaboraTory manuals (I8, l9) for Food Prep- araTion l00 and Food PreparaTion 200. Some of The experimenTs used in ExperimenTal Foods 403 and 404 classes indicaTed The use of measuremenT of ingredienTs by weighT raTher Than volume, and heaTing To TemperaTures expressed in cenTigrade raTher Than FahrenheiT. To be included in "Food Science and You," The experi- menTs were changed To require volumes of household uniTs, and TemperaTures in FahrenheiT readings or a visually described end poinT. The wriTer pre-TesTed all of The planned experimenTs. Several of The experimenTs which were originally planned were discarded before pre- TesTing. Some were changed afTer pre-TesTing To insure reproducible re- sulTs by The 4-H'ers. Many of The experimenTs require The use of half- baTches or half-recipes in order To conserve ingredienTs and To have Shaller amounTs of The experimenTaI sample. ExperimenTs on The funcTion of sugar, acid, pecTin and cooking Time on The formaTion of jelly were discarded because of The difficulTy encounTered in obTaining accuraTe TemperaTure readings using half-baTches of jelly. The experimenT on The coagulaTion of milk proTein by rennin was also discarded because rennin TableTs are noT available in mosT of The areas of Michigan. 9 The experimenT on The funcTion of excess sugar in a cake sysTem was also changed. IT was originally planned To use double The amounT of sugar, buT The sugar Tenderized The gluTen in The sysTem To The poinT where The baTTer ran over The pan during baking and burned onTo The floor of The oven. The amounT of exTra sugar added To The cake sysTem was decreased To The poinT where The cake baTTer rose To The edge of The pan, raTher Than running over The pan. The experimenT on The funcTion of excess baking powder In a cake sysTem required Three Times The amounT raTher Than Twice added To The cake sysTem in order To produce a visually accepTable producT. The cooking Time allowed in The experimenT on The heaT TreaTmenT of shellfish was also increased considerably. The ori- ginal Time of heaTing produced Toughenlng ThaT was discernible only by Trained people. In order To provide a dramaTic demonsTraTion of heaT Toughenlng proTein, The ToTal cooking Time was doubled. In The experi- menT on The developmenT of gluTen by liquid and manipuiaTion, The muffin baTTer was originally sTirred a ToTal of 75 sTrokes. This was increased To a ToTaI of I05 sTrokes, so ThaT The experimenTer would be beTTer able To see The changes in baTTer TexTure as The experimenT pro- grassed. Each experimenT as wriTTen in The experimenT book has The same formaT: (I) presenTaTion of The principle To be TesTed; (2) equipmenT and ingredienTs required To perform The TesT; (3) ouTIine of The experi- menTal procedure; (4) descripTion of The anTicipaTed ouTcomes of The experimenT; (5) explanaTion of The experimenTaI findings. IO Record Book A record book was developed To accompany The projecT (Appendix B), adapTed from one used wiTh Colorado's 4-H Food Science projecT (20). Since record-keeping is a parT of any scienTific experience, The book was designed To faciliTaTe keeping accuraTe noTes of The experimenTal procedure and resulTs. For each experimenT, The member records The daTe on which he compleTed The experimenT; The Time required for compleTion; The principle TesTed; The way The experimenT was designed; The resulTs; The applicaTion of whaT has been learned; and ways The member has shared or hopes To share his new knowledge. One page of The record book is compleTed, so ThaT The inenbers may undersTand more easily how To use The record book. Visual Learning Aids A seT of slides and accompanying narraTive (Appendix C), visually poinTing ouT The funcTion of ingredienTs in a baked producT, was developed as a learning aid as well as a promoTional device. The ingredienTs de- monsTraTed are flour, sugar, salT, baking powder, egg, shorTening and liquid. The slides show The effecT of an excess and a deficiency or lack of each ingredienT on The appearance of a one-egg buTTer cake. The slides and narraTive may be used To sTimuIaTe inTeresT in The new 4-H food science projecT, as well as To presenT a visual explanaTion of The funcTion of various ingredienTs in a cake sysTem. These learning aids will be available on a loan basis for anyone To use, Through The counTy exTension offices. Preliminary EvaluaTion The experimenT book and record book were presenTed aT 4-H foods ll leaders' meeTings in EaTon, Oakland and Kalamazoo counTies early in The summer of I972. Some 4-H members were presenT aT The meeTings. The projecT, "Food Science and You," was inTroduced as a new foods projecT in Michigan, and some of The experimenTs were explained. The leaders were asked if some of The members In Their clubs mighT wish To be among The firsT To use The new food science projecT. Those leaders inTeresTed were given addiTional informaTion and copies of The projecT book and record book. The names and addresses of The leaders, as well as The number of copies of The maTerials They requesTed, were Taken in order To send The follow-up quesTionnaire. The quesTionnaire (Appendix D) gaThered informaTion on The age of The member; where he lived (ciTy or counTry); whaT experimenTs he con- ducTed; whaT he learned; if he was able To share his new knowledge wiTh oThers; if he liked doing The experimenTs; and whaT commenTs or suggesTions he had for oTher young people who mighT parTicipaTe in This projecT. SixTy—five copies of The experimenT book and record book were disTri— buTed in The Three counTies. AfTer Two monThs, quesTionnaires were mailed To The leaders along wiTh self-addressed franked envelopes wiTh enclosure slips for ease in reTurning The quesTionnaires. The Two-monTh Time lapse was allowed To give leaders Time To organize Their clubs, disTribuTe The new projecT maTerials, explain The projecT, and for members To compleTe The experimenTs They chose. No quesTionnaires were reTurned, despiTe IeTTers To The leaders and counTy 4-H sTaff indicaTing ThaT The daTa on The quesTionnaires were needed. If is possible ThaT leaders losT inTeresT in The new food science projecT, or felT uncomforTable wiTh if if They were noT able To answer members' quesTions. The meeTings aT which The projecT was presenTed were primarily I2 for adulT leaders, so The members did nOT hear The original explanaTion of The projecT and experimenTs. No daTe for The reTurn of The quesTion- naires was given To The leaders aT The meeTings early in summer. Early in The fall of I972, The 4-H sTaff of Ingham CounTy was re- quesTed To indicaTe a 4-H leader and club who would be inTeresTed In TesTing The new food science projecT. The experimenT book and record book were given To selecTed members of The Happy HusTiers 4-H Club of STockbridge, Michigan. Members who had shown inTeresT in The new projecT aT The club's organizaTional meeTing were given addiTional informaTion and insTrucTion. TwenTy-five members ranging in age from nine To l6 years agreed To compleTe assigned experimenTs by The requesTed deadline, compleTe The record book, and reTurn The quesTionnaire. The members were given The quesTionnaires and self-addressed franked envelopes wiTh enclosure slips aT The Time of The organizaTional meeTing. They also received a wriTTen explanaTion of The projecT and whaT Their respon- sibiliTy was in reTurning The quesTionnaire. FifTeen adulT 4-H foods leaders In Big Rapids, Michigan also TesTed selecTed experimenTs. These leaders, parTicipaTing in a leadership de- velopmenT workshop, compleTed experimenTs on liquid and dry measuring, 23nd The funcTion of ingredienTs. The adulTs also compleTed a shorT quesTionnaire, which gaThered informaTion on whaT experimenTs They TesTed; If‘ They enjoyed doing The experimenTs; whaT They learned; If They could Share Their knowledge wiTh oThers; and commenTs and suggesTions for im- Pt‘oving The experimenTs for use wiTh young people. The adulTs were given T11e3 quesTionnaires aT The beginning of The workshop, and They Turned Them In before They IefT. RESULTS AND DISCUSSION Food Science and You One hundred experimenTs are included in The experimenT book (Ap- pendix A). The experimenTs require The use of ingredienTs and uTensils found in The average kiTchen, and are designed To resulT in readily de- TecTable ouTcomes. These experimenTs allow The parTicipanT To TesT some of The principles of food preparation, food sTorage and food handling. For ease in selecTing The experimenTs, They have been grouped ac- cording To caTegories. The experimenTs differ in The degree of difficulTy in order To meeT The needs of varying age groups. Various levels of accomplishmenTs are expecTed from The members in The differenT cafe- gories of experimenTs. The formaT for each experimenT is idenTical. The principle To be TesTed is presenTed firsT. A lisT of The equipmenT and ingredienTs re- quired To compleTe The experimenT follows. Then, The experimenTal procedure is ouTlined, and The anTicipaTed ouTcome is described. Finally, an explan- aTion of The experimenTaI findings is given. For example: one principle To be TesTed sTaTes, "Qualify of shell eggs deTerioraTes wiTh aging and is dependenT upon sTorage condiTions." Eggs are sTored in The refrigeraTor in a covered conTainer, in The re- frigeraTor uncovered, and uncovered aT room TemperaTure. One egg from each group is broken ouT afTer one day or sTorage, Then Three days, and finally seven days. During sTorage, The air cell of The egg becomes larger, The whiTe l3 l4 becomes Thinner, The yolk increases in size and iTs viTelline membrane weakens, and The egg becomes more alkaline. When The egg is laid no air cell is presenT. As The conTenTs cool, shrinkage occurs and air is drawn in Through The porous shell, creaTing an air space aT The large end of The egg. The air cell increases in size during aging because The egg loses moisTure Through The shell. WaTer conTinues To evaporaTe as aging progresses, and This evaporaTion is acceleraTed aT higher TemperaTures and if The egg is noT covered during sTorage. The amounT of Thick whiTe decreases during sTorage. Of The more Than l5 proTeins in egg whiTe, ovomucin is The proTein ThoughT To be responsible for Thick whiTe. Ovomucin is a mucoproTein, and more mucin is found in Thick whiTe Than in Thin whiTe. The increase in Thinning is correlaTed wiTh an increase in The alkaliniTy of The egg. Alkaline hydrolysis of The disulfide bonds of The ovomucin may be The reason for The increase in Thin whiTe. When an older egg is broken ouT onTo a flaT surface, The whiTe does noT sTand up and if spreads ouT over a wider area Than a fresher egg. During sTorage, The egg also becomes more alkaline. Carbonic acid in The egg breaks down To form carbon dioxide. The carbon dioxide passes Through The shell unTil equilibrium wiTh The ambienT air is reached, and The pH of The egg Increases. The egg, when laid, has a pH of abouT 7.6. During The firsT few days The pH increases rapidly, To abouT 8.9. AfTer furTher sTorage The alkaliniTy of The egg whiTe increases To abouT 9.4. AT higher sTorage TemperaTures, carbon dioxide is losT aT a more rapid raTe Than if The egg is sTored aT lower TemperaTures. The yolk increases in size because waTer moves from The whiTe Through IS The viTelline membrane surrounding The yolk. The greaTer osmoTic pressure ‘in The yolk draws The waTer Through The membrane. Because The yolk size Increases The viTelline membrane sTreTches and becomes more fragile. In some eggs sTored for a long period of Time, The yolk will break when The shell is cracked because of The fragiliTy of This membrane. The yolk becomes less viscous and is flaTTer Than The yolk of a fresh egg when broken ouT. The yolk may also move away from The cenTer Toward The shell wall, and may aTTach iTself To The shell. This may be easily seen in exTremely old eggs which are hard-cooked. AlThough The experimenTers cannoT see all of These processes of aging, They may see some of The resulTs of The increased deTerioraTion in The qualiTy of shell eggs sTored under differenT condiTions. The amounT of Thin whiTe may be deTermined by measuring The spread of The whiTe afTer The egg has been broken ouT onTo a flaT surface. The yolk of an old egg is also flaTTer and larger Than ThaT of a fresh egg. The size of The air cell may be noTed by hard-cooking The egg, peeling off The shell, and noTing The flaTness of The egg aT The large end. This flaTness is an indicaTion of The air cell. In hard-cooked eggs, experi- menTers may also noTe The posiTion of The yolk. In older eggs, The yolk may be very close To The side of The shell, or even aTTached To The shell. In The secTion on measuring, The members learn ThaT measuring cups and measuring spoons are sTandardized, whereas Tea cups, coffee cups and Table flaTware cannoT be relied on for accuraTe measure. SifTed flour and firmly packed brown sugar give more reproducible resulTs Than un- sifTed flour and non-packed brown sugar. SifTing of flour and packing of brown sugar insures ThaT The densiTy of These ingredienTs will be consTanT when They are used in food preparaTion, and The volume of The I6, amounT required will be correcT for The food sysTem in which These in- gredienTs are used. There are several secTions on The funcTions of ingredienTs in food sysTems. In The secTion on £1915, The experimenTs are designed To illusTraTe The relaTive gluTen sTrengThs of differenT flours and grains. WheaT flour conTains Two proTeins, gluTenin and gliadin. TogeTher wiTh liquid, These Two proTeins form gluTen. Cake flour has The lowesT gluTen sTrengTh because if is milled primarily from sofT wheaT which conTains more sTarch and less proTein. Bread flour has The mosT gluTen because iT is milled from hard wheaT, which has more proTein and less sTarch. All-purpose flour from Michigan has a high gluTen sTrengTh also. There is a high proporTion of hard wheaT flour in The mixTure as Michigan raises hard wheaT. The proTeins in flour TogeTher wiTh moisTure and manipulaTion fonh The gluTen framework for baked producTs. Over-manipulaTion or over-sTirring develops The gluTen To The poinT where Tunnels form in The baked lTem. Excessive manipulaTion causes The gluTen sTrands To collapse. The secTion on sgga:_provides experimenTs To demonsTraTe ThaT sugar conTribuTes To browning, Tenderness and flavor in baked iTems. The heaT of baking caramelizes The sugar, causing The Top crusT To Turn brown. Excess sugar in baked producTs causes Tenderness because The sugar Takes up The moisTure presenT, leaving Too liTTle liquid To combine wiTh The gluTen in The flour. As sugar is increased, a sweeTer flavor resulTs in The finished baked producT. Sugar also conTribuTes To The firmness of cornsTarch pudding. Excess sugar compeTes wiTh The cornsTarch for The moisTure presenT. The sugar binds The moisTure so ThaT There is noT enough liquid To mix wiTh l7 The cornsTarch and form a gel of The desired sTrengTh. In a gelaTin gel, The presence of sugar also resulTs in a sofTer producT. The liquid is Taken up by The sugar and Too liTTle moisTure is available for The gelaTin To form The proper sTrucTure. In fudge, sugar conTribuTes To The firmness of The producT. When excess<33rn syrup is added To The fudge mixTure,'The producT is sofTer Than desirable because The inverT sugar in The corn syrup inTerferes wiTh The crysTallizaTion of The sugar. In The leavening secTion The experimenTs demonsTraTe how carbon dioxide is liberaTed from The various Ieavening agenTs. WiTh The appli- caTion of heaT, baking powder releases carbon dioxide when mixed wiTh liquid. Baking soda liberaTes carbon dioxide in The presence of heaT when mixed wiTh acid subsTances such as vinegar and orange juice. Baking soda is alkaline in naTure; baking powder is a mixTure of acid and al- kaline maTerials. Baking soda is used in baked iTems which have oTher ingredienTs which are decidedly acid, such as sour milk, buTTermilk, or molasses. YeasT yields carbon dioxide in The presence of sugar, liquid and heaT. Liquid rehydraTes The yeasT. The sugar provides food for The yeasT planTs To grow and produce carbon dioxide. Baking powder is The Ieavening agenT in many baked iTems. A lack of baking powder resulTs in a cake ThaT does noT rise, and excess baking fixawder resulTs in a cake ThaT is very porous. The carbon dioxide forms very large air cells, and may sTreTch The gluTen sTrands Too much so ThaT They collapse. The cake may be sunken in The middle. If parTicipanTs selecT experimenTs from The sal:_secTion, They learn SaI‘T's role in conTribuTing flavor To cakes. EIiminaTion of The saIT l8 resulTs in a cake ThaT has liTTle flavor. Excess salT in a cake re- sulTs in a decidedly salTy TasTe. SalT waTer causes raw vegeTables To become limp and sofT because of osmoTic pressure. WaTer in The cells of The vegeTable is drawn ouT by The concenTraTed salT soluTion. The sTabiliTy of an egg whiTe foam is also decreased by The addiTion of salT. Upon sTanding, The foam exhibiTs a greaTer amounT of leakage Than an egg whiTe foam beaTen wiThouT The addiTion of saIT. The secTion on eggs provides experimenTs ThaT demonsTraTe The funcTion of egg in a cake sysTem. Egg adds some proTein for sTrucTure, and The leciThin in The yolk probably helps To emulsify The mixTure. An excess amounT of egg Tends To decrease The volume of The finished cake, and To make The crumb Tough. Too liTTle egg resulTs in a cake wiTh a dry crumb because less liquid is presenT when The egg is omiTTed. Eggs coagulaTe when heaTed because of The denaTuraTion of The pro- Teins. The applicaTion of Too much heaT, Too long a cooking Time, or boTh, resulT in an overcooked and Toughened egg. The leciThin in egg yolk, in addiTion To emulsifying cake baTTer, also helps To form a mayonnaise emulsion. WiThouT egg yolk, no emulsion is formed in a mayonnaise mixTure. An emulsion does form when whole egg is used, buT The mixTure is sofTer Than desirable because The egg yolk has been diluTed by The egg whiTe. ExperimenTs on iEIE demonsTraTe ThaT faT conTribuTes Tenderness, moisTness and flavor To cakes. WiTh an excessive amounT of faT The crumb is greasy, The volume may be small, and The cake Is crumbly and T00 Tender. A lack of faT In a cake sysTem resulTs in a cake ThaT is dry and slighTIy 113ugh. BuTTer and margarine add Their disTincTive flavors when used in cakes. Solid and liquid faTs have differenT smoke poinTs. BuTTer has The lowesT smoke poinT because of The wafer which is presenT naTurally in buTTer. Solid shorTenings have a higher smoke poinT, buT lower Than oils. The emulsifiers, which have been added To solid shorTenings To improve Their baking qualiTies, lower The smoke poinT. As oil has no emulsi- fiers added, The smoke poinT is The highesT of The Three faTs. Frying in faT heaTed To a TemperaTure higher Than ThaT recommended resulTs in food ThaT is burned on The ouTside and underdone in The cenTer. Food fried in faT heaTed To Too low a TemperaTure is grease-soaked. FaT is one phase of food emulsions. In a permanenT emulsion such as mayonnaise, The leciThin in egg yolk keeps The dropleTs of oil from coalescing. In a Temporary emulsion such as French-Type salad dressing, The spices and seasonings help keep The oil dropleTs separaTed during and shorle afTer agiTaTion of The mixTure. In The secTion on building a muffin, The experimenTers learn The funcTions of The various ingredienTs and amounTs of IngredienTs in a muffin sysTem. In This series of experimenTs, The 4—H'er begins wiTh flour, waTer and salT; he adds oTher ingredienTs, one aT a Time, in succeeding experimenTs, unTil The muffin sysTem is compleTe. If members selecT experimenTs in The secTion on baking soda, They learn ThaT alkali in The form of baking soda sofTens vegeTable TexTure. ITmaaddiTion of baking soda To The cooking waTer for vegeTables will hasTen The sofTening process. This pracTice will, however, desTroy much Of The Thiamine presenT in The vegeTable. Baking soda also causes anTho- xanThins To Turn brown, orange or yellow. ExperimenTs on acid demonsTraTe ThaT acid hydrolyzes gelaTin 20 proTeins. When acid is added To a gelaTin sol, The gelaTin absorbs more waTer, resulTing in a sofTer gel. An acid marinade used for soaking some meaTs will resulT in a more Tender cuT afTer cooking. Acid also makes anThocyanins redder, and alkali Turns These pigmenTs purple or blue. The reacTion is reversible, and acid added To food ThaT has become bluish from an alkaline reacTion reTurns The red color. Chlor— ophyll Turns To pheophyTin in The presence of acid. This olive green color resulTs when green vegeTables are cooked in a covered conTainer. The volaTile planT acids cannoT excape and pheophyTin forms. ExperimenTs in The secTion on cornsTarch are designed To illusTraTe The effecT of several ingredienTs on The firmness of a cornsTarch gel. Sugar makes The gel sofT or Tender because of The compeTiTion for The liquid by The sugar and cornsTarch. Sugar binds The waTer presenT and noT enough is available To form a gel of The proper consisTency. Addi- Tional liquid makes The gel sofTer because There is Too much liquid for The sugar and sTarch To absorb. Acid added To The mixTure resulTs in a sofTer gel because The sTarch polymers are broken, and They are noT able To bind The proper amounT of liquid. FaT added To The cornsTarch pud- ding inTerferes wiTh gelaTion and makes The gel sligthy sofTer wiTh a silky mouTh feel. An increase in The concenTraTion of cornsTarch in- creases The firmness of The gel. There are more sTarch granules To bind The available liquid, and The gel is firmer Than desired. The sTrengTh of a cornsTarch gel is weakened by sTirring afTer The gel has been formed. The walls of The sTarch granules are broken and The liquid is released, Thus making The mixTure Thinner. The gel is also sofTer when The mixTure lNas been heaTed aT a slower raTe, such as over hoT waTer, raTher Than over d i recT heaT. 2i The egg whiTe experimenTs help The parTicipanT learn whaT affecTs The sTabiliTy of an egg whiTe foam. OverheaTing decreases sTabiliTy, as Too much air is incorporaTed, sTreTching The albumen unTil iT is Thin and loses elasTlciTy. Liquid added To egg whiTe during beaTing decreases The sTabiliTy of The foam because The proTein is diluTed and loses iTs elasTlciTy. Sugar and acid increase The sTabiliTy of The foam. A longer Time is required for beaTing To highesT volume when sugar is added To The egg whiTe foam. Sugar reTards The denaTuraTion of The egg whiTe proTeins. Acid in The form of cream of TarTar also increases The beaT- ing Time required, buT makes The foam more sTable. in The secTion on proTein The experimenTers learn ThaT muscle pro- Teins are Toughened by The applicaTion of high heaT and exTended heaTing Times. Excessive heaT TreaTmenT causes The proTeins To shrink and in- creases drip loss. The surface of The meaT becomes dry and Tough. Casein, one of The proTeins in milk, is coagulaTed by The addiTion of acid. The curdled appearance ThaT resulTs when acid is mixed wiTh milk indicaTes ThaT The casein has been coagulaTed. The skin on The Top of heaTed milk is lacToglobulin; The scum which forms on The sides and boTTom of The pan is IacTalbumin. The sTrengTh of a gelaTin gel is dependenT on many facTors. In- creasing The concenTraTlon of gelaTin resulTs in a sTIff gel, because more gelaTin ls available To blnd The liquid presenT. AddiTional liquid de— creases The gel sTrengTh because There is Too much liquid for The gela- Tin To absorb. Enzymes presenT in The mixTure hydrolyze The proTeins and no gel ls formed. A gel which Is formed aT a higher TemperaTure, Sanh as room TemperaTure, will be sofTer Than one formed aT refrigeraTor Tetnperafure. However, The gel formed aT The higher TemperaTure will noT 22 melT as rapidly as The one formed aT The lower TemperaTure. The secTion on sTorage includes experimenTs ThaT demonsTraTe how correcT wrapping helps foods mainTain Their qualiTy. The experimenTs on refrigeraTor sTorage show ThaT fresh shell eggs lose moisTure and qualiTy when sTored uncovered in The refrigeraTor. The freezing ex— perimenTs show The members ThaT various wraps differ in Their abiliTy To prevenT food from drying. As freezer air is dry air, food To be held in freezer sTorage should be wrapped in moisTure-vapor-proof packaging in order To mainTain highesT qualiTy. ExperimenTs in The secTion on microbiology show The members ThaT proper handling of food and uTensils reduces The possibiliTy of microbial growTh. In compleTing These experimenTs, The parTicipanTs conTaminaTe prepoured agar plaTes wiTh The mishandled food and uTensils. The plaTes are Then incubaTed aT room TemperaTure for Three days, and The members compare The microbial growTh on The plaTes conTaminaTed wiTh The mishandled maTerials wiTh Those conTaminaTed by properly handled iTems. ProjecT EvaluaTions ATTemst To evaluaTe The experimenTs and record book wiTh leaders and members in EaTon, Oakland and Kalamazoo counTies were noT successful. AlThough 65 copies of The experimenT book and record book were disTrIbuTed, no response was derived from The Three counTies. OuesTionnaIres and follow-up IeTTers were mailed To The leaders who had requesTed The ex— perimenT books, buT no quesTionnaires were reTurned. A second aTTempT To evaluaTe The experimenT and record books was Inade wiTh one 4-H club in Ingham CounTy. Ybung people from The STock- tn‘idge, Michigan Happy HusTiers 4—H club were InTeresTed In evaluaTing Tine new food science projecT. Of The 25 members who had agreed To 23 compleTe The experimenTs, 20 reTurned The quesTionnaire (Appendix D). Table I shows The responses of The young people who reTurned The quesTion- naires. One was nine years old, five were l2, four were l3, Three were I4, four were l5 and Three were l6 years o-d. Twelve of The parTicipanTs lived in The counTry and eighT lived in The ciTy. FourTeen enjoyed doing The experimenTs, one did noT, and five felT ThaT The experience was 50-50. Seven were Teen leaders and I3 were noT, buT l9 of The 20 felT They could use Their new knowledge wiTh oTher members and in Their fuTure work wiTh food. NineTeen of The 20 also indicaTed ThaT They would like To parTicipaTe In more experimenTs. The members of The STockbridge club has been assigned specific ex- perimenTs To compleTe; however, noT all of The young people conducTed The experimenTs assigned To Them. All of The experimenTs were TesTed excepT numbers 87, 88, 89 and 90 dealing wiTh refrigeraTor and freezer sTorage (Appendix A). These experimenTs were noT done because The Time for compleTlon of some is more Than The four weeks allowed for TesTing, and probably These experimenTs were omiTTed because They are near The back of The book. The experimenTs on measuring and Those on The funcTion of ingredienrs were done by several members of The experimenTal group. These are simple experimenTs, require IITTIe Time, and are aT The fronT of The book. There appeared To be no correlaTIon beTween The ages of The young People and wheTher or noT They enjoyed parTicipaTing In The experience. The few who IndicaTed ThaT The experimenTs were 50-50 had compleTed many fMDre experimenTs Than They had been asked To do. Since They were asked To compleTe The projecT In four weeks, faTigue may have conTribuTed To u¢cca+ec ece; mmc_mcco_+mo:c mN +0 0Nm 24 _ m_ _ m. m_ N m _ e. N_ m 0N m_m+OH o m o m _ N o o m m o m o_ _ m _ m _ m N _ _ N N e m. o m o m _ N o o m _ N m e_ o e o e e o _ o m m _ e m. o m o m m o N o m N m m N_ l i l l l l l l l l l l __ l i l i l l l l l l l l o_ o _ o _ _ o o o _ _ o _ m 02 we» 02 we» oz mm> Omlom oz mm> >c+caoo >+~o m+cma_o_+cma choe 0e 0+ +cm3 Nemeo_30cx em: 0+ m_n< Neeeme_ camp N+oewoLa m_c+ >0ficm mocmn_mem +0 .02 em< :30» can moco_om nook: mc_+m:_m>e oc_mcco_+moac 0+ mc+30> Inc +0 mechQmom ._ m_anl 25 Their reacTion. FifTeen adulT leaders of 4-H foods clubs TesTed experimenTs l Through l7 and experimenT 57 (Appendix A) aT a one-day workshop in Big Rapids, Michigan. These experimenTs involve liquid and dry measuring, The funcTion of ingredienTs in a cake sysTem, and The effecT of manipula- Tion on gluTen developmenT. The adulTs compleTed a quesTionnaire (Appendix D) abouT The experience before leaving The workshop. Table 2 shows The reacTions of These lead- ers To The experience. Table 2. ReacTions of 4-H leaders To experimenTs on measuring, ingred- IenT funcTion and gluTen developmenT No. of leaders Enjoy This experience? Able To use knowledge? Yes No Yes No _#A l5 I5 0 I5 0 All of The adulTs indicaTed ThaT They enjoyed compleTing The ex- perimenTs, and ThaT They were pleased wiTh The new approach To foods projecTs. They all felT ThaT They could use Their new knowledge and could share iT wiTh The members of Their own clubs. The leaders also viewed The slide series on The funcTion of IngredienTs In a cake sysTem. Several asked when if would be available for loan. Discussion AlThough This projecT was designed for older Teens The young people evaluaTing The experimenTs ranged in age from nine To l6 years, wiTh The median age l4 years. Only one of The young people IndicaTed ThaT she did noT enjoy parTicipaTing In The experience, and was noT inTeresTed in compleTing 26 more experimenTs. She was The club leader's daughTer, and alThough she had never been enrolled In a foods projecT she compleTed experimenTs on gelaTin and measuring. The members shared Their new knowledge wiTh Their families and friends. They had noT yeT shared This knowledge wiTh oTher members of The club and communiTy because only four weeks were allowed To compleTe The experimenTs and reTurn The quesTionnaires. None of The members had suggesTions for changing The experimenTs. A few made commenTs ThaT The experimenTs were fun To do; The direcTIons were clear; and The experimenTs would be fun To compleTe wiTh a group of oTher young people. The 4-H leaders also had no suggesTions for changes In any of The experimenTs or dIrecTIons. They indicaTed ThaT They would be able To use The experimenTs wiTh The members of Their own clubs, and ThaT Their members would be InTeresTed In The new food science projecT. SUMMARY AND CONCLUSION A 4-H learning projecT in food science was developed for use wiTh older members and leaders. The projecT consisTs of a book of experi- menTs, a record book, and a slide series wiTh narraTive. The experimenT book includes l00 experimenTs which TesT some of The principles of food preparaTion, food sTorage and food handling. The experimenTs require The use of ingredienTs and uTensils found in The average kiTchen, have visually discernible resulTs, and can be applied To everyday food sITuaTIons. The formaT for each experimenT Is IdenTIcal. The principle To be TesTed ls given firsT, Then a lisT of The equipmenT and ingredienTs required To compleTe The experimenT. The experimenTal procedure Is ouTlined, and The anTicipaTed resulTs are given. An explanaTion of The reasons The resulTs can be expecTed compleTes The formaT. The record book provides an appropriaTe form for noTing The progress of The scienTific experimenTs. The member is able To record The resulTs of The experimenT, whaT he learned, and how he shared or plans To share his new knowledge wiTh oThers. I The slide series and narraTive is a visual presenTaTion of The funcTion of The various ingredienTs in a one-egg buTTer cake sysTem. The slides depicT The appearance of cakes prepared wiTh an excess and a deficiency or lack of each ingredienT. The IngredienTs demonsTraTed are flour, sugar, salT, baking powder, shorTening, egg and liquid. ATTemst To evaluaTe The experimenT and record books wiTh leaders and members In Three Michigan counTies were noT successful. However, 27 28 20 young people from one 4-H club and IS adulT 4-H foods leaders agreed To evaluaTe The experimenTs. The 4-H members were assigned experimenTs To compleTe so ThaT each experimenT would be evaluaTed, buT The ex- perimenTs on food sTorage were noT compleTed. The adulT leaders evaluaTed selecTed experimenTs on liquid and dry measuring, The funcTion of in- gredienTs, and The effecT of manipulaTion on gluTen developmenT. All of The adulTs and I9 of The young people indicaTed ThaT They enjoyed doing The experimenTs, would be able To use Their new knowledge wiTh oThers, and would like To parTicipaTe in more experimenTs. "Food Science and You" should be TesTed and evaluaTed wITh a larger group of young people and adulTs. Since The projecT was designed for older Teens, a greaTer efforT mighT be made To seek ouT This audience for parTicipaTion in The projecT. As IT was assumed ThaT boys would be inTeresTed in a food science projecT, a parTicular efforT should be made To conTacT boys and Involve Them in This new projecT. The group of young people and adulTs who evaluaTed The experimenis were a biased sample, as boTh groups were involved in foods, eITher as members of 4-H foods projecTs or as leaders of foods clubs. A more accuraTe indicaTion of inTeresT mighT be demonsTraTed by using a random sample of young people and adulTs from all 4-H projecT areas, or a group of young people and adulTs noT involved in The 4—H program. The evaluaTing groups were noT represenTaTive of The Michigan 4-H audience. The young people were members of one club in one counTy, and The leaders were Those who had elecTed To parTicipaTe in The food sci- ence porTIon of a leader-Training workshop. "Food Science and You" will be inTroduced To ExTension 4-H YouTh AgenTs and 4-H foods leaders and members in The spring of I973. The 29 InTroducTion and explanaTion of The projecT will be-parT of The agenda for The annual fOods leader-Training workshops which will be held In several areas of The sTaTe. ExTension 4-H YouTh AgenTs will be inTro- duced To "Food Science and You" aT The annual sTaTewide spring conference. L I ST OF REFERENCES 30 LIST of References ExTension SubcommiTTee on 4-H YouTh DevelopmenT. ReporT and Recom- mendaTions of an Expanded 4-H Program. SubmiTTed To The ExTension CommiTTee on OrganizaTion and Policy. Chicago, I966. Michigan AgriculTural College. Club BulleTin #l. ExTension Divi- sion, l9l5. Michigan STaTe UniversiTy. PopulaTion GrowTh and RedisTribuTion. AgriculTure ExperimenT STaTion, EasT Lansing, l97l. Ad Hoc CommiTTee for lnTensive STudy and Special ConsideraTion To The FuTure DirecTion of 4-H and OTher YouTh ExTension Program Dev- elopmenT. ExTension YouTh Programs in The 20Th CenTury: A PbsITion Paper. WashingTon, D. C., I965. UniTed STaTes DeparTmenT of AgriculTure, Federal ExTension Service. Science in Food and NuTriTion: A Guide for ExTension Workers. Wash- ingTon, D. C., I964. Brink, Muriel S. Food For Fun. ExTension 4-H BulleTin I55A. Michigan STaTe UniversiTy, EasT Lansing, I967. Brink, Muriel S. The Young Chef. ExTension 4-H BulleTin I55E. Michigan STaTe UniversiTy, EasT Lansing, l966. Brink, Muriel S. loday's Girl, Tomorrow's Homemaker. ExTension 4-H BulleTin I55D. Michigan STaTe UniversiTy, EasT Lansing, I966. Brink, Muriel S. Exploring Foods and NuTriTion. ExTension 4-H BulleTin l55K. Michigan STaTe UniversiTy, EasT Lansing, I965. Carroll, RuThalee M. Food Science for Teen Leaders. The Pennsyl- vania STaTe UniversiTy, UnlversiTy Park, I966. Anonymous. Fun wiTh Food Science. The Pennsylvania STaTe UniversiTy, UnlversiTy Park, I970. Camp, Susan and Williams, Izola. AdvenTures in Food Science. UnlversiTy of Florida, Gainesville, i965. Cook, Frances. AdvenTures in Food Science. UnlversiTy of Cali- fornia, Berkley, I965. Hindman, Marie S. AdvenTures in Foods-NuTriTion. Clemson UniversiTy, Clemson, SouTh Carolina, I967. STewarT, May. 4-H Food Science. Colorado STaTe UniversiTy, ForT Collins, I963. NaTional 4-H Service CommiTTee. Exploring Dairy Food Science. Chicago, Illinois, I965. 20. 3| , Telephone conversaTion wiTh Dr. Lowell RoTherT, Program Leader, 4-H YouTh Programs, Michigan STaTe UniversiTy, EasT Lansing. SepTember 20, I972. Morr, Mary L. and IrmiTer, Theodore F. lnTroducTory Foods. New York: McMillan Co., I970. Coleman, Mary C. and Deskins, Barbara 8. lnTroducTory Food Prep- araTion. Michigan STaTe UniversiTy, EasT Lansing, I966. STewarT, May. 4-H Food Science: Record Book. Colorado STaTe Univer- siTy, ForT Collins, I969. APPENDICES ExperimenT Book Record Book Slide NarraTive OuesTionnaire DOGS) APPENDIX A ExperimenT Book 32 4-H BULLETIN 155J MICHIGAN STATE UNIVERSITY FOOD SCIENCE AND YOU rrrr merilyn mock food! nutrition specialist IF YOU'RE INTERESTED IN... 33 ..DO THESE EXPERIMENTS WhaT ingredienTs Do 6 7 8 9 IO ll l2 l3 l4 l5 l6 l7 Measuring I 2 3 4 5 Flour l 6 I3 56 57 Leavening 8 l2 32’ 33 34 35 SaIT 9 I4 59 66 Eggs l0 I6 52 58 59 60 87 89 IOO FaT ll I7 38 44 5| 52 53 54 55 63 80 Building a Muffin l8 I9 20 2| 22 23 24 25 26 27 28 29 30 3| Alkali (Baking Soda) 33 47 83 84 85 CornsTarch 36 37 38 39 40 4| 42 43 Acid 40 45 48 64 69 73 79 8| 82 83 85 Cellulose 47 48 49 50 Egg WhiTe 53 6| 62 63 64 65 66 ProTein 56 57 58 59 60 6| 62 63 64 65 66 67 68 69 70 7| GelaTin 67 68 69 70 7| Enzymes 7l 78 Color 80 BI 82 83 84 85 86 STorage 87 88 89 90 98 99 Freezing 89 9O Microbiology 9i 92 93 94 95 96 97 98 99 IOO TABLE OF CONTENTS Measuring WhaT IngredienTs Do Leavening CarbohydraTes -STarch “Sugar -Cellulose -Emulsions -Frying ProTeins -Flour -Egg -GelaTin -Mi|k I ~MeaT Color in FruiTs & Vegefables Feed STorage Food SaniTaTion References Llne Spread TesT PAGE 20 2| 23 23 24 26 26 27 32 34 35 38 4| 44 50 5| 35 THINGS TO REMEMBER... ...abouT FOOD SCIENCE AND YOU ..This projecT is designed To help you find ouT whaT heppens when you change one of The parTs of a food sysTem. You geT To do all The "don'Ts." ..Some of The experimenTs are easier Than oThers. BuT The easy ones are mixed in wiTh The more difficulT ones. Read Through all The secTions before you decide which experimenTs To do. ..Recipes (or formulas) should come from a sTandard cookbook. Use any basic cookbook you wish. ..A record book is included as parT of This projecT. Records are an imporTanT parT of any scienTific projecT. The record book helps you keep Track of whaT happened in each experimenT. .ln mosT experimenTs a conTrol is used for comparison purposes. The conTrol is The sTandard or yardsTick againsT which you compare The experimenTaI food. ..When doing The experimenTs, keep everyThing The same as The conTrol EXCEPT The one Thing ThaT changes. Use The same size pans, same bowls, mixing speeds. Be sure ThaT jusT one Thing changes each Time. If The experimenT calls for Three cake pans The same size, for In- sTance, and you don'T haVe Three, jusT use one Three Times. The cakes can be wrapped and frozen unTil you evaluaTe Them. ..Be sure To label which food is which when conducTing These experimenTs. Use a piece of Tape, a marking pencil, a crayon, or anyThing ThaT will help you remember which Is which. In some experimenTs you'll have no Trouble Telling The foods aparT. In oThers, The appearances may be The same. ...The experimenTal food is noT meanT To be a perfecT producT. The conTrol is more apT To be perfecT. Since you are deliberaTely doing someThing "wrong" you can'T expecT iT To be perfecT. So lT's OK when someThing Turns ouT "bad." ThaT's whaT is supposed To happen. In mosT cases The experimenTal food will be edible anyway. ..All The experimenTs are seT up in The same way. The principle To be TesTed is given firsT. Then a lisT of The equipmenT needed. NexT, The procedure. And Then The explanaTion of whaT happened and why. ..The experimenTs are wriTTen To help you learn The principles of food preparaTion, food sTorage and food handling, AND To have fun wiTh food! 36 (4) MEASURING Proper and consisTenT measuring of ingredienTs will bring consisTenT resulTs In food preparaTion. STandardIzed recipes call for sTandard- ized measuremenTs. DeviaTion from These sTandard pracTices may produce unaccepTabIe producTs. Dry Measuring Dry ingredienTs are more easily and accuraTely measured in sTandard measuring cups. Leveling off wiTh The sTraighT edge of a spaTula gives accuraTe measuremenT. EXPERIMENT # | Principle: SifTing flour before measuring breaks up lumps and makes The flour more uniform. EquipmenT needed: flour l-cup sTandard dry measuring cup flour sifTer Procedure: Measure I cup of flour wiThouT sifTing. SifT This same cup of flour and measure again. Measure how much flour is lefT over. ExplanaTion: SifTing flour before measuring makes The densiTy more uniform. The measuremenT is more accuraTe when flour is sifTed each Time before measuring. EXPERIMENT # 2 Principle: Firm packing of brown sugar during measuring eliminaTes air spaces and gives consisTenT measuremenT. EquipmenT needed: brown sugar I-cup sTandard dry measuring cup Procedure: Spoon brown sugar inTo measuring cup wiThouT packing. Level off wiTh The sTraighT edge of a spaTula. Pack down The brown sugar. Ob- serve The space lefT aT The Top. Add brown sugar To fill To The Top, noTing how much iT Takes. ExplanaTion: Brown sugar is very moisT and cannoT be sifTed like flour. To insure uniform densiTy, brown sugar is packed info The cup. Brown sugar should hold iTs shape when Tipped ouT of The cup. 37 ‘ (5) Liquid Measuring Liquid ingredienTs are more easily and accuraTely measured in sTandard measuring cups. MeasuremenT of liquid in The glass measuring cup should be checked aT eye level To be sure The liquid is aT The proper line on The cup. EXPERIMENT # 3 Principle: Eye-level measuring produces more accuraTe liquid measure. EquipmenT needed: sTandard liquid measuring cup (glass) waTer Procedure: WiTh measuring cup below eye-level (on counTer or in boTTom of SlnR), pour in waTer To I-cup line. Raise cup To eye-level and remove waTer by Teaspoonfuls unTil waTer reaches The l-CUp mark. NoTe how much waTer musT be removed. ExplanaTion: Vision is disTorTed when looking down on an objecT. One cup of liquid becomes more Than one cup. MeasuringfiUTenslls Measuring cups and measuring spoons have been STandardIzed by The American STandards AssociaTion. OTher cups and Spoons are noT STandardIzed. EXPERIMENT # 4 Principle: STandard measuring cups give accuraTe measure for dry and liquid ingredienTs. EquipmenT needed: l-cup sTandard dry measuring cup I-cup sTandard liquid measuring cup (glass) coffee cup or Tea cup sifTed flour waTer Procedure: Spoon sifTed flour InTo coffee or Tea cup. Level wiTh edge of a spaTula. Transfer To sTandard dry measuring cup. Observe difference in measure. NoTe how much flour musT be added or removed To make one sTandard cup full. Pour waTer InTo coffee or Tea cup, filling To The brim. Transfer To sTandard liquid measuring cup. NoTe how much liquid musT be added or removed To make one sTandard cup full. ExplanaTion: Ordinary coffee and Tea cups are noT sTandardized, and i ofTen cannoT be relied on for accuraTe measure. I -—-4 38 (6) EXPERIMENT # 5 Principle: STandard measuring spoons give accuraTe measure. EquipmenT needed: salT sTandard Teaspoon and Tablespoon measures Teaspoon for Table use Tablespoon for Table use Procedure: Measure a Teaspoon of saIT in Teaspoon for Table use. Level wiTh edge of SpaTula. Transfer To measuring Teaspoon. NoTe how much saIT musT be added or removed To make one sTandard Teaspoon full. Measure a Tablespoon of self in Tablespoon for Table use. Level wiTh edge of spaTula. Transfer To measuring Tablespoon. NoTe how much salT musT be added or re- moved To make one sTandard Tablespoon full. ExplanaTion: Ordinary silverware is noT STandardIzed and ofTen can- noT be relied on for accuraTe measure. WHAT INGREDIENTS DO All of The ingredienTs in a baTTer or dough sysTem work TogeTher To pro- duce The desired producT. Each lngredienT has a parTicular purpose and performs a cerTaln funcTion. The abiliTy of The ingredienTs To perform Their funcTions prOperly depends on The proporTion of The oTher ingredi- enTs in The sysTem. Flour helps To form The framework or The sTrucTure of The finished baked producT. Two proTeins in flour, gluTenin and gliadin, form gluTen sTrands when moisTened wlTh liquid and sTirred. The sTarch in The flour also swells when moisTened wiTh The liquid. In a formula which has IiTTIe liquid In proporTion To The flour (like muffins) IT is very easy To dev- elop The gluTen sTrands by sTirring. If The formula has a high propor- Tion of liquid To flour (as pancake baTTer) IT Is difficulT To form The gluTen sTrands by sTirring. The liquid also makes The Ieavening agenT (baking powder, baking soda or yeasT) give off carbon dioxide gas. When The sysTem is heaTed or baked, The gas rises Through The gluTen sTrands, making The producT rise. If There is Too much flour for The sysTem The liquid cannoT moisTen all of if, and The producT will be heavy and compacT. If There is Too liTTIe flour There will noT be enough gluTen To form The proper framework and The producT will be low in volume. Liguid dissolves The sugar, salT and Ieavening, and moisTens The gluTen. If are is Too much liquid The baTTer will be Thin. The flour and egg proTeins will be diluTed Too much, and The baked iTem will be low in vol- ume. If There Is Too liTTle liquid The gluTen will noT be moisTened enough, and noT enough carbon dioxide will be given off from The Ieavening. The baked iTem will be heavy and compacT. it") I I" ) Baking_powder will give off carbon dioxide in The presence or moisTure and heaT. Bakingiscda gives off carton OIOxide in The pres has of moi ~ Ture, acid and beef. If Thele is Tnc much Ieavening, iCxlhu h carucn dioxide will be produced and The producT will have large Inlcu. IT will be low in volume because The gluTen sTrands are sTreflth T’O rich by The carbon dioxide and Trey cellapse. Too lilTie |ca.enir3 h AFC 3T le enough carbon dioxide is produced, and TI baled producT wiil be heavy, compacT and low in volume. Too much baking Spda can givO he bales iTem r"- \-ie a soapy Tasle and a yellow cc FaT makes a baied producT Tender. If The faT is buffer or war'.nr ETEO conTribuTes flavor and color. if There is Too much faT The L kiT iTem will be Too Tender and crumbly. IT can have The volume will be low. If There is Too liTTle f be dry and Tough. I a GI, TIA) I$-.;|"\'c:tci Light. VII || Suqar adds fluvuf and Tenderness, as well as conTribuTing To The bicenih —__J.__ ‘ . ‘ . _ of The baked prcducl. If There ls Too muc sugar The izww will be Too Tender and Too sweei. The Top crusT will be siicky an: xvly brfhfl. Ii There is Too IilTle su.ar The baked ‘roducT will e TCJQU noT suecl ._f D p . ; enough, and have a pale crusT. E218 add flavor, color and proTein for sTrucTure. If Itere is l,o much egg, The iTem will be rubbery and low in volume. If There is noT enough _ .,., _ - y. 4.. glquJJV Tl_;c'| g1lu| lg} .Io. I egg, The baTTer may curdle because The egg yolk keeps 'he faT from separ- aTing ouT. Too liITle egg also decrease; The volume of The raira :ipm, SalT ConTribulus To flcvc'. If There is Too nuph self, The balzd item wl|| have a decijedly salTy flavor, and The volume may he less Than “Gin: If There Is Ice liTTle salT, he flavcr of The baked ilim will re \qu TIII. ExperimenTs are filvdfl hele To demonsTraTe The fun Tign of Tao liliie cf various Ingredichls In a baiier Sysiem. Use a Slanierd Ive 3 cake T)“ from a basic cookbook. Be sure To use only one variable per cahe. Fe e: To make The slandari coke for comparison puiggs- ables you decide To reel. If you make all The VJTIODIBS, yen r-LI only one sianddrd Coho for comparison. EXPERIMENT A 6 Principle: Too liTTle flour in a cake sysTem gives a c.ie Thai is law F volume. EquipmenT heeled: sTandard l-egg cake belie: frcm Casi; v¢'ii..« Si'dl‘lcidld IT'CJQI {JIM} LJdI’TL-Bl‘, Il‘ediil I'lnii ILL: Ili'n‘li’" 2 cake pans, same Size and Shd;w Procedure: piUpdrd cakes as diregTei. C ndu l liwe .gJ—gj i~uf on b cake baTTels (see Appendix I). Bake calos unlil d 3:. .. ' TexTure and flavor wiTh sTandard cuie. :1,’ {TC} (SUIT-'13:- lied Til...'r'.'/ "4 :l.’ ' 40 (8) ExplanaTion: There Is noT enough gluTen presenT To fonn The proper framework. The baTTer is Thin and The finished cake has less volume because The flour proTeins are diluTed Too much To form The sTrucTure. EXPERIMENT # 7 Principle: Too liTTle sugar in a cake sysTem gives a pale crusT, Tough crumb, and IiTTle flavor. EquipmenT needed: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. Compare color, TexTure and flavor wITh sTandard Cake. Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh baTTers (see Appendix I). Bake cakes unTil done. Conpare color, Tex— Ture and flavor wiTh sTandard cake. EéplanaTion: Sugar aTTracTs moisTure in a cake sysTen. When Too liTTIe sugar is presenT, more gluTen sTrands are formed and The cake is Tougher. As sugar caramelizes when heaTed, a cake wiThouT sugar has a pale crusT. - EXPERIMLHT # 8 Principle: Too IiTTIe baking powder in a caie sysimn gi.as a heavy com- pacT producT. EquipmenT needed: sTandard I-egg cake baTTer frag basic crmkbook sTandard l-egg cake baTTer, using no taking powder 2 Cake pans, same size and shape Procedure: Prepare cakes as dIrecTed. CondurT line spread TesT on thin cake baTTers (see Appendlx I). Bake cakes unTil done. C rware COIar, TexTure and flavor wiTh sTandard cake. _.q~.—.- . ——- ~- " —--¢n- H'.--‘“fi*vuu "mm M ExplanaTion: Mosr cake sysTens depend on carbon dluxide Ieavedlng fromgbaklng powder. wiThouT baking powder The Cake does noT rise A small amounT of air ls beaTen lnTo The taTTer buT This is noT sur- flcienT To make The cake rlse. .-.a w.- -.a—« W".""“"'". m EXPERIMENT # 9 H Principle: Too IiTTls saIT in a cake sysTen gives a producT ThaT he- ‘ llTTIe flavcn EquipmenT needed: sTandaid lwegg cake baTTer from hasic Ci Izaak sTandard I~egg cake baTTer, using no salT 2 cake pans, same size and shape 4| (9) Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. Compare color, TexTure and flavor wiTh sTandard cake. ExplanaTion: OniTTing The salT from a cake makes The flavor very flaT. EXPERIMENT # IO Principle: Too liTTle egg in a cake sysTem gives a producT low in volume. EquipmenT needed: sTandard l-egg cake baTTer from basic cookbook sTandard l-egg cake baTTer, using no egg 2 cake pans, same size and shape Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. Compare color, TexTure and flavor wiTh sTandard cake. ExplanaTion: Egg yolk conTains leciThin which acTs as an emul- sifier and keeps The faT from separaTing ouT. The volume of The cake is less Than The sTandard, and The cake is pale in color. EXPERIMENT # ll Principle: Too liTTIe shorTening in a cake sysTem gives a Tough, dry producT. EquipmenT needed: sTandard I-egg cake baTTer from basic cookbook sTandard l-egg cake baTTer, using no shorTening 2 cake pans, same size and shape Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. Compare color, TexTure and flavor wiTh sTandard cake. ExplanaTion: ShorTening coaTs The gluTen sTrands and makes The cake Tender. WiThouT chorTening, The cake is Tough and dry, and ofTen humps up in The middle. ExperimenTs are given here To demonsTraTe The funcTion of Too much of various ingredienTs in a baTTer sysTem. Use yellow cake_mixes, all The same brand. The cake mixes may be small mixes (making one layer) or half of larger mixes. Be sure To use only gne_variable per cake. Be sure To make The sTandard cake for comparison purposes, no maTTer how many variables you decide To TesT. If you make all The variables, you need To make only one sTandard cake for comparison. 42 (IO) EXPERIMENT # I2 Principle: Too much baking powder in a cake sysTem gives a cake wiTh large air holes and a low volume. EguipmenT needed; yellow cake mix for one layer yellow cake mix for one layer, sITTed wiTh 3 TeaspOOns baking powder 2 cake pans, same size and shape Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. Compare TexTure, flavor and color wiTh sTandard cake. ExplanaTion: Too much baking powder creaTes Too much carbon di- oxide gas, sTreTching The gluTen sTrands Too much. The cake has large air bubbles, a coarse TexTure, and may fall in The middle if The gluTen sTrands collapse. EXPERIMENT # l3 Principle: Too much flour in a cake sysTem gives a heavy, compacT producT. EquipmenT needed: yellow cake mix for one layer yellow cake mix for one layer, sifTed wITh l/2 cup flour 2 cake pans, same size and shape Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. COMPETE TexTure, flavor and color wiTh sTandard cake. u—a who-"Huy- “5-- ExplanaTion: ExtTa ilour makes The baTTer sTIff. The liquid cannoT moisTen all The flour so The gluTen does noT develop properly. The cake is heavy and cunpacT, and may have a Tloury TasTe. EXPERIMENT # I4 Principle: Too much salT in a cake sysTem gives a producT wiTh a salTy TasTe and less volume. EquipmenT needed: yellow cake mix for one layer yellow cake mix for one layer, sifTed wiTh 2 Tenapu ; salT 2 cake pans, same size and shape Procedure: Prepare cakes as dlrecTed. ConducT line spread TesT oh p.n cake baTTers (see Appendix I). Bake cakes unTil done. Ckmmare TexTure; flavor and color wiTh sTandard cake. 43 (ll) ExplanaTion: ExTra salT gives The cake a salTy TasTe. The volume may be less Than The sTandard cake, and The cake mighT sink a llTTle in The middle. EXPERIMENT # I5 EEIDEJBLEF Too much sugar in a cake sysTem gives a Too Tender,Too sweeT cake. Eguipmenf needed: yellow cake mix for one layer T yellow cake mix for one layer, sifTed wiTh l/4 cup sugar 2 cake pans, same size and shape Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix I). Bake cakes unTil done. Compare TexTure, color and flavor wiTh sTandard cake. ExplanaTion: A cake wiTh Too much sugar is Too Tender and Too sweeT. The cake may run over during baking. This happens when The sugar Takes up The liquid fasTer Than The flour does. There is noT enough liquid lefT To form gluTen sTrands, so The Ieavening acTion makes The cake run over insTead of rise. EXPERIMENT # I6 EEIDEIBLE} Too much egg in a cake sysTem gives a produce ThaT is rubbery and low in volume. EquipmenT needed: yellow cake mix for one layer yellow cake mix for one layer, wiTh an exTra egg 2 cake pans, same size and shape Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake baTTers (see Appendix l). Bake cakes unTil done. Compare TexTure, color and flavor wiTh sTandard cake. ExplanaTion: ExTra egg adds more proTein To The cake sysTem. The heaT of baking coagulaTes or Toughens This proTein. The cake is rubbery and Tough. And The cake may be more yellow because of The addiTional egg yolk. EXPERIMENT # l7 Principle: Too much faT in a cake sysTem gives a cake ThaT is grease and Too Tender. EquipmenT needed: yellow cake mix for one layer yellow cake mix for one layer, wiTh 2 Tablespoons oil 2 cake pans, same size and shape (I2) Procedure: Prepare cakes as direcTed. ConducT line spread TesT on boTh cake BaTTers (see AppendixJI). Bake cakes unTil done. Compare TexTure, color and flavor wiTh sTandard cake. ExplanaTion: WiTh Too much faT, a cake Is very Tender and crumbly. IT has a greasy feel and TasTe. The volume of The cake may be lower Than sTandard. V The experimenTs given here demonsTraTe whaT ingredienTs do in muffins. Because of formula modificaTlons, some muffins will noT brown well. Do noT use The degree of browning as lndlcaTlon of doneness. If you condUcT all 0? The experimenTs, you wTTT make IJTBaTcEes of muffins. General procedure for each experimenT: l. Combine dry IngredienTs by slleng Them TogeTher info a mixing bowl. 2. Make a well In The dry ingredienTs. 3. Mix liquid IngredienTs TogeTher in a glass measuring cup. 4. Add liquid To dry IngredienTs wiTh JusT enough sTirring To moisTen all The dry ingredienTs. Do noT sTir unTil The baTTer is smooTh; baTTer should be lumpy. DeTermine The number of sTirs for you and use ThaT number In each experimenT you TesT. 5. Porfion The baTTer InTo greased muffin cups, filling Them 2/3 full. 6. Bake in preheaTed 425'F. oven for 20 minuTes. EXPERIMENT I l8 l cup sifTed all-purpose flour l/2 Teaspoon salT I/2 cup waTer EXPERIMENT I 20 I cup sifTed all-purpose flour I/2 Teaspoon self I l/2 Teaspoons baking powder I I/2 Tablespoons oll I/2 cup waTer EXPERIMENT I 22 I Cup sifTed eii‘purpose flour l/2 Teaspoon self I l/2.Teaspoone baking powder I I/2 Tablespoons sugar i I/Z'Tabiespoons oil i/2 oep eeeee * 2 Tablespoons egg, well-blended EXPERIMENT I I9 l cup sifTed all-purpose flour l/2 Teaspoon salT I l/2 Teaspoons baking powder l/2 cup waTer EXPERIMENT I 2i I cup sifTed all-purpose flour I/2 Teaspoon saIT i l/2 Teaspoons baking powder I I/2 Tablespoons sugar l l/2 Tablespoons oil I/2 cup waTer EXPERIMENT I 23 l cup sifTed all-purpose flour I/2 Teaspoon saIT l l/2 Teaspoons baking powder I l/2 Tablespoons sugar l i/2 Tablespoons oil l/2 cup milk 2 Tablespoons egg, well-blended 45 EXPERIMENT I 24 _ l cup sifTed all—purpose flour I/2 Teaspoon self I l/2 Teaspoons baking powder i I/2 Tablespoons sugar l/4 cup oil l/2 cup milk 2 Tablespoons egg, well—blended EXPERIMENT I 26 I cup sifTed all-purpose flour I/2 Teaspoon saIT l I/2 Teaspoons baking powder l/4 cup sugar I I/2 Tablespoons oil I/2 cup milk 2 Tablespoons egg, well-blended EXPERIMENT I 28 I cup sifTed all-purpose flour l/2 Teaspoon salT l I/2 Teaspoons baking powder I I/2 Tablespoons sugar I I/2 Tablespoons oll l/2 cup milk 2 Tablespoons egg, well-blended EXPERIMENT I 30 I cup sifTed cake flour l/2 Teaspoon saIT l l/2 Teaspoons baking powder I l/2 Tablespoons sugar i I/2 Tablespoons oil l/2 cup milk 2 Tablespoons egg, well-blended (I3) EXPERIMENT I 25 l cup sifTed all-purpose flour I/2 Teaspoon self I I/2 Tablespoons baking powder I l/2 Tablespoons sugar I i/2 Tablespoons oll I/2 cup milk 2 Tablespoons egg, well~blended EXPERIMENT I 27 I cup sifTed all-purpose flour l/2 Teaspoon salT l I/2 Teaspoons baking powder I I/2 Tablespoons sugar I I/2 Tablespoons oil l/2 cup milk I egg, well-blended EXPERIMENT I 29 I/2 cup sifTed all-purpose flour I/2 cup cornmeal i/2 Teaspoon saIT I I/2 Teaspoons baking powder I I/2 Tablespoons sugar I l/2 Tablespoons oIl l/2 cup milk 2 Tablespoons egg, well—blended EXPERIMENT I 3| l cup sifTed all-purpose flour l/2 Teaspoon self I I/2 Teaspoons baking powder I/4 cup sugar I l/2 Tablespoons oil I/2 cup milk I egg, well-blended LEAVENING ..‘m p.__'- Leavening means Ir;;c:sing The Surface area of a baTTer or daugh by creaTing gas bubbles. This gas Is mainly carbon dioxide, and lT is produced by baking powder, baking soda or yeasT. also used for Ieavening, and mosT baTTer and dough sysTems use a combinaTlon of carbon dioxide, air and sfeam for a perfecT resul YeasT produces carbon dioxide in The presence of liquid and sucs.. Air and sTeam are 4% I. v. 46 . (I4) EXPERIMENT I 32 Principle: The leavening acTion of baking powder is affecTed by liquid and heaT. EquipmenT needed: 5 pop boTTIes, same size 2 Tablespoons each of vinegar, waTer, orange juice, milk and molassas IO TeaspoOns baking powder 5 small balloons, same size Procedure: Place The five liquids in The five pop boTTIes, one per BoTTIe. Label which is which. "Add 2 Teaspoons baking powder To each. Cap each boTTIe wiTh a balloon To Trap The gas produced. Work fasT. Some of The gas will escape. Shake The boTTles and place in a pan of hoT waTer. Observe The sizes of The balloons. Ex IanaTion: Each of The balloons should show some Trapped gas. The smallesT Is The molasses, because There is noT much waTer presenT To reacT wiTh The baking powder. When heaTed, The gas in The balloons increases. - EXPERIMENT I 33 Principle: The Ieavening acTion of baking soda is affecTed by liquid, acid.and heaT. EquipmenT needed: 5 pop boTTIes, same size 2 Tablespoons each of vinegar, waTer, orange Juice, milk and moISEEEs i0 Teaspoons baking soda 5 small balloons, same size Procedure: Place The five liquids in The five pep boTTIes, one per EoTTIe. Label which is which. Add 2 Teaspoons baking soda To each. Cap each boTTIe wiTh a balloon To Trap The gas produced. Work fasT. Some of The gas will escape. Shake The boTTles and place in a pan of hoT waTer. Obeserve The sizes of The balloons. ExplanaTion: Vinegar, orange juice and molasses have acid presenT To IIberaTe carbon dioxide from baking soda. WaTer and fresh milk have no acid presenT. Sour milk or buTTermilk would reacT like vinegar. Molasses has llTTle waTer presenT because of The high concenTraTion of sugar. The balloons expand even more when heaTed. EXPERIMENT I 34 Principle: The Ieavening acTion of yeasT Is affecTed by The TemperaTure of The liquid. 47 (IS) EquipmenT needed: 3 pop boTTIes, same size 3 envelopes dry yeasT l cup Ice waTer l cup warm waTer I cup boiling waTer 3 small balloons, same size. Procedure: Label each pop boTTle wlTh The TemperaTure of waTer used.' PTace The conTenTs of one envelope of yeasT In each pop boTTle. Add The A designaTed waTer. Cap each boTTle wiTh a balloon To Trap The gas produced. Shake The boTTIes and place The ice waTer sample in The refrigeraTor. LeT The oTher samples sTand aT room TemperaTure. Observe The sizes of The balloons afTer 5 minuTes, l5 minuTes, 3O mlnuTes and l hour. ExplanaTion: YeasT is a living planT. Freezing TemperaTures slow down The producTIon of carbon dioxide by yeasT. Warm TemperaTures are preferred for yeasT To grow and produce carbon dioxide. TemperaTures ThaT are Too hoT will kill The yeasT, and no dioxide will be produced. EXPERIMENT I 35 Principle: The leavenlng acTion of yeasT Is affecTed by The presence of sugar. EgulpmenT needed: pop boTTIes, same size 3 3 envelopes dry yeasT 3 l l I Tablespoons sugar cup Ice waTer cup warm waTer cup boiling waTer 3 small balloons, same size Procedure: Label each pop boTTle wiTh The TemperaTure of waTer used. Place The conTenTs of one envelope of yeasT In each pop boTTle. Add I Tablespoon of sugar To each. Shake The boTTles To mix The yeasT and sugar. Add The designaTed waTer. Cap each boTTle wiTh a balloon To Trap The gas produced. Shake The boTTles and place The ice waTer sample In The refrigeraTor. LeT The oTher samples sTand aT room TemperaTure. Observe sizes of The balloons afTer 5 minuTes, l5 minuTes, 3O mlnuTes and I hour. ExplanaTion: YeasT needs sugar in order To grow and produce carbon dioxide. YeasT and sugar ln ice waTer will produce llTTle carbon dioxide unTil The waTer warms up. Warm TemperaTures allow The yeasT and sugar To produce The mosT carbon dioxide. Too hoT Tappern aTure kills The yeasT, and even wiTh sugar presenT, IlTTle or no carbon dioxide will be produced. 48 (l6) CARBOHYDRATES CarbohydraTes are sTarches, sugars and cellulose. STarches are used in food preparaTion primarily for Thickening as in soups and sauces; for molding or forming gels as in cornsTarch puddings; and for bind- ing as in The sauce base for croqueTTes. Some sTarchy subsTances such as flour also conTribuTe proTeins ThaT form gluTen, The framework of baked goods. Sugar is used for Tenderness and browning as in baked iTems; for pre- servaTion as in jellies and jam; and for forming highly saTuraTed soluTions as In candles. Cellulose forms The sTrucTure of fruiTs and vegeTables. Food prepara- Tion procedures can affecT The soaness of vegeTable cellulose. STarch The sTarch molecule is a polymer, a long chain. When a sTarch mixTure Thickens, The molecule absorbs wafer. This molecule holds The liquid raTher like a balloon holds waTer. The Thickness and firmness of This sTarch pasTe depend on The proporTion and kind of sTarch, The raTe of heaTing, agiTaTion, The proporTion of sugar, and The presence of acid and faT. ‘ Too liTTle sTarch makes The mixTure runny; Too much makes iT Too Thick. A high raTe of heaTing gives a Thicker mixTure; a lower heaTing raTe gives a Thinner mixTure. Excessive sTirring makes The mixTure Thinner. Too llTTle sugar makes a very Thick mixTure, while Too much sugar makes a Thin, almosT syrupy pudding. Acid makes The pudding Thinner; faT also makes The mixTure Thinner. In conducTing These experimenTs, use a sTandard cornsTarch (or vanilla) pudding formula from a basic cookbook. SelecT a formula which con- Tains cornsTarch, sugar, milk, saIT and vanilla, and no eggs. Pre- pare half-baTches of pudding for comparison in each experimenT. Cook This pudding in a heavy saucepan over direcT heaT (medium) no maTTer whaT The direcTions say. NoTe carefully The Time iT Took To cook This pudding. Cook all The puddings This IengTh of Time. Cook all The puddings over direcT heaT unless The experimenT says oTherwise. If you decide To compleTe all The experimenTs on cornsTarch puddings, you need To make only one baTch for comparison purposes. Prepare half- baTches of puddings for all experimenTs. EXPER [BENT I '36 Principle: Firmness of a cornsTarch gel is affecTed by The concen— TraTion of cornsTarch. 49 (I7) EquipmenT needed: sTandard formula (half— baTch) cornsTarch pudding, for comparison purposes sTandard formula (half— -bafch) cornsTarch pudding, double The amounT of cornsTarch E19cedure: Crok boTh puddings unTil done. Observe Thickness of each sample. Observe flavor and mouTh feel. ConducT line spread TesT for each sample {see Appendix I). .-_._—-- ...- .—.-—w... r.— ExplanaTicn: ExTia cornsTarch makes a ver ry Thlc.k pudding which TasTes sTarchy and gooey. The addiTional cornsTarch Takes up The liquid and makes a pudding Thicker Than usual. EXPERIMENT I 37 Principle: Firmness of a cornsTarch gel is affecTed by The concen- TraTion of cornsTarch. Equ pnenT ne ed d: sTandard fonmula (half-baTch) cornsTarch pudding, for comparison purposes sTandard formula (half-baTch) cornsTarch pudding, wiTh half The amounT of cornsTarch Efccrfure: Prepare boTh puddings and cook unTil done. Observe Thick- ness of boTh samples. Observe flavor and mouTh feel. ConducT line spread TesT for each sample (see Appendix I). _—-—vv—— _E iIinaTIJQ.T‘hXD liTTIe cornsTarch makes a very Thin, milky pudding. Ti neie is flui (naugh sTarch presenT To Take up The liquid and give The proper TUE isTency. EXPERIMENT I 38 Princj lg; Firmress of a cornsTarch gel is affecTed by The presence of buffer or faT. EquipmenT neede sTandard formula (half-baTch) cornsTarch pudding, W for comparison purposes sTandard formula (half- -baTch) cornsTarch pudding, ' wiTh I Tablespoon buTTer added (.1 Procedure: Cook baTn puddings unTil done, sTirring in buTTer afTer removing one sample from The heaT. Observe Thickness of each sample. Observe flavor and ”cuTh feel. ConducT line spread Tes T for each san)le (see Appendix I). ExplanaTion: BuTTer makes The pudding a liTTle Thinner because The buTTer InTerferes wiTh The formaTion of The gel. The mouTh feel of The pudding is silky (l8) \T‘. C), EXPERIMENT # 39 Principle: Firmness cf a cornsTarch gel is affecTed by The raTe of TIGUTTEIS . EgyjpmenT needed: slanjard formula (half-baTch) cornsTarch pudding, for comparison purposes sTandard formula (half-baTch) cornsTarch pudding Procedure: Cook one baTch of pudding over direcT heaT unTil done. Cook second baTch of pudding The same lengTh of Time buT over hoT waTer. Observe ThICkness of each sample. Observe flavor and mouTh feel. Con— ducT line spread TesT for each sample (see Appendix I). ExplanaTion: The pudding cooked over hoT wafer is Thinner Than The one cooked over direcT heaT. The raTe of heaTing is slower over hoT: waTer. AT a slower raTe of heaTing, The sTarch granules swell more evenly. During rapid heaTing, some sTarch granules swell much more rapidly Than oThers. EXPERIMENT # 4O Principle: Firmness of a cornsTarch gel is affecTed by The presence of acid. EquipmenT needed: sTandard formula (halfebaTch) cornsTarch pudding, for comparison purposes sTandard formula (half-baTch) cornsTarch pudding, 2 Tablespoons lemon juice added Procedure: Cook boTh puddings unTil done. Observe Thickness of each sample. Observe flavor and mouTh feel. ConducT line spread TesT for each sample (see Appendix l). ExplanaTion: Acid, in The form of lemon juice, makes The pudding Thinner. Acid breaks The polymer chain of The sTarch molecule. The sTarch is unable To Take up as much liquid. in lemon pudding and pie filling, egg yolk adds The needed Thickening as well as color. EXPERIMENT # 4| Principle: Firmness of a cornsTarch gel is affecTed by agiTaTion. EquipmenT needed: sTandard formula (half-baTch) cornstarch pudding, for comparison purposes sTandard formula (half—baTch) cornsTarch pudding Procedure: Prepare boTh baTches of pudding. As pudding cools, beaT one sample wiTh elecTric mixer for one minuTe. Observe Thickness of : 5| (l9) each sample. Observe flavor and mouTh feel. ConducT line spread TesT for each sample (see Appendix I). ' ExplanaTion: AgiTaTion, or beaTing, breaks The sTarch cells and re- leases liquid. Thls makes The pudding Thinner. EXPERIMENT # 42 Principle: Firmness of a cornsTarch gel is affecTed by The concenTra- Tion of sugar. Eggipmenf needed: sTandard formula (half-baTch) cornsTarch pudding, for comparison purposes sTandard formula (half-baTch) cornsTarch pudding, wiTh half The amounT of sugar (Procedure: Cook boTh puddings unTil done. Observe Thickness of each sample. Observe flavor and mouTh feel. ConducT line spread TesT for each sample (see Appendix l). ExplanaTion: TOO IiTTle sugar makes a very Thick pudding, wiTh a pasTy mouTh fee|.. More liquid is available for The cornsTarch To Take up, making The pudding Thick. r— EXPERIMENT I 43 Principle: Firvmess of a cornsTarch gel is affecTed by The concenTraTion of sugar. EgpipmenT needed: sTandard formula (half-baTch) cornsTarch pudding, , for comparison purposes sTandard formula (half-baTch) cornsTarch pudding, double The amounT of sugar Procedure: Cook boTh puddings unTil done. Observe Thickness of each sample. Observe flavor and mouTh feel. ConducT line spread TesT on each sample (see Appendix I). ExplanaTion: Too much sugar makes The pudding very Thin and very sweeT. The sugar Takes up The liquid and The cornsTarch does noT have enough liquid available To swell The sTarch granules and Thicken The pudding. 52 (20) Sugac Sugar is used for sweerening many of our foods, and for keeping The color and TexTure of fruiTs when canned or frozen. ConcenTraTed sugar soluTions are especially TasTy when colored and flavored and allowed To harden: This is candy. Many Things affecT The sugariness of candy. Corn syrup and acid can make The candy mixTure sofT. STirring keeps The candy from geTTing grainy. BuTTer also makes The mixTure sofT. NoTe: In conducTing These experimenTs, use a sTandard fonnuia for choco- IaTe fudge from a basic cookbook. Make half-baTches for each experimenT. A conTrol sample should be prepared for comparison. if you choose To compleTe all The experimenTs on fudge, you need To make only one conTrol sample. EXPERIMENT # 44 Principle: BuTTer keeps fudge sofT and creamy. EquipmenT needed: l/2 baTch sTandard chocolaTe fudge formula from basic cookbook, for comparison l/2 baTch sTandard chocolaTe fudge formula from basic cookbook, double The buffer I/2 baTch sTandard chocolaTe fudge formula from basic cookbook, omiT The buffer 3 heavy saucepans 3 pans, same size, for cooling The fudge; EEEEEQEEE} Prepare fudge as direcTed. Pour inTo pans To cool. Label which is which. When fudge is cool, observe soaness by cuTTing wiTh a knife. Observe grainlness by TasTing. -ur ~- " ExplanaTion: FaT inTerferes wiTh The crysTaliizaTion of The sugar in fudge. The fudge made wiThouT buTTer is grainy and briTTle. WiTh buTTer The fudge is sofT and creamy, and buTTery in flavor. __f EXPERIMENT # 45 fflipglple: Acid delays sugar crysTalllzaTlon and makes fudge sofT. EgpipmenT needed: i/2 baTch sTandard chocolaTe fudge formula from basic cookbook, for comparison l/2 baTch sTandard chocolaTe fudge formula from basic cookbook, add l/8 Teaspoon cream of TarTar 2 heavy saucepans 2 pans, same size, for cooling fudge Efocedure: Prepare fudge as direcTed. Pour info pans To cool. Label which is which. When fudge is cool, observe soaness by cuTTing wiTh a knife. Observe grainlness by TasTing. 53 (2|) ExplanaTion: Fudge made wlTh cream of TarTar is sofTer and creamler. The acid forms lnverT sugar from-some of The sugar in The formula. lnverT sugar delays crysTaIlIzaTion, making The fudge sofT. EXPERIMENT # 46 Principle: Corn syrup delays sugar crysTalllzaTlon and makes fudge sofT. figulpmenf needed: l/2 baTch sTandard chocolaTe fudge formula from basic cookbook l/Z baTch sTandard chocolaTe fudge formula from basic cookbook, add I/4 cup corn syrUp. 2 heavy saucepans 2 pans, same size, for cooling fudge Procedure: Prepare fudge as direcTed. Pour lnTo pans To cool. Label which is which. When fudge Is cool, observe soffness by cuTTing wlTh a knife. Observe gralnlness by TasTing. ' . Explanaflon: Fudge wiTh corn syrup ls sofTer and creamler. Corn syrup conTains lnverT sugar, which delays crysTallizaTion, mak- ing The fudge sofT. Cellulose Cellulose gives shape and flrmness To fruiTs and vegeTables. Pecfic subsTances are lso found In fruiTs and vegeTables. They acT as glue, To hold The cells TogeTher. Lignln and hemlcellulose are Two componenTs found along wiTh cellulose In The sTrucTural wall. Lignln ls raTher like wood; IT doesn'T change much when The vegeTable is cooked. The amounT of hemlcellulose changes by cooking, and wiTh acids and alkalis. MeThods of preparaTion and sTorage affecT The cellulose sTrucTure, and make The food iTem sofT or firm. Alkali added To The cooking waTer of vegeTables makes Them sofT, almosT mushy. Acid in The cooking waTer has The opposlTe effecT: The vegeTable Is firmer and Takes longer To cook. lce waTer can revive wIlTed fresh vegeTables, and self waTer will cause vegeTables To become limp. EXPERIMENT # 47 Principle: Alkali and heaT sofTen vegeTables. ~ m: w ...c ,1 .~ V" CE.” l‘Cl’s waTer baring sLT» rZ“~"."‘. ‘ " ‘1 ' ‘ 3 I“. v‘ - -~ - F; —' T ' " "" 4, -‘ . 237“" I " . ‘ "‘f ' . " .‘ " ‘ i P- I . "e v ' ' '. - ‘-\.t;>‘ .-;;. '..lftr'ul. col -'..'? i :Tzlu .-.JT lzliQ uili Tl-” m “bit-sob.— ile idb evenly DET‘UE” The saucepans. Add wafer To cover. Afd 1/? Teaspoon baking " *3 a”"" ' which is which. Cook o'er medium heaT unTii boTh samples are TEHLGV. Cbserye Tenderness by cuTTing wiTh a fork. A IanaTion: Alkali in The form of bakirg soda sofTens The hemi- v —___..._.—-— -.fl- LL.iulose of The carroTs and makes Them mushy. Alkali also desTroys The Thiamine in vegeTables when baking soda is added To The cooking 1 we er. -. s 419m '1‘ A-.~_ fl—“-'- ‘.. ’..-‘..-.--_ ,—. .-.x .1— ’ ‘ P 'T # 41 E i pie: li j T ho.f make a. eTahles firm. E :“””§T needed: 2 saucepans raw carroTs vinegar waTer frufiuiif;i Clean carrvfs and cuT lnTo uniform pie es, Divide evenly ttrlv-i The saucepans. Add waTer To cover. To one sample, add l-Z Table» “* .ihegar. Label which is which. Cook over medium heaT unTil Tender. F3??“f Times for boTh samples. Observe by cuTTing wiTh a fork. i Liplanafion: When an acid such as vinegar is added To The cooking fi aTer, The vegeTables Take longer To cook. The TexTure is firmer 3rd more solid because The acid firms up The pectic subsTances in ‘ Frs vegeTables. l -¢~ an. v< ~— —-~.§*‘ -_ won. -—r~« - ~ "7 _. w.w.gu-~.- : ——w_ v ...— ..— LET; =1:f='iENi ff 455‘ Erirolglef hilfef greens may be freshehed in ice wafer qu§cgenT needed: 2 wiiTed ieTTuce leaves ice waTer bowl £i§f433_3} Place are ieTTuce leaf in bowl and add ifld wfl.gh ficfrigerafa' Piece s? and leaf in refrigeraTor wiThouT i;e waTer, is? sTssw overnighf. Oascrxec crispness of boTh IeTTuce leaves. I” ——w— _ ‘.....— -...,',,_,,. - . .... . “an“..- ..,_. .- -~-". 1 ___M_daTion The leTTuce leaf in ice wa Ter regains , ;.:spness. WaTer again enTers The ceil T l : king iT firm. — ‘— r- [I ' . ___v.—.——--- - i )TIB )T ii} i rucTure of The leTTuce, i i ,. h. ‘J EXPERIMENT # 50 Principle: SalT waTer makes vegeTables sofT. EguipmenT needed: 2 bowls waTer salT sliced cucumbers, celery sTicks or ieTTuce leaves Procedure: Place I cup waTer in each bowl. Add 2 Tablespoons salT To one and sTir unTil if is dissolved. Divide vegeTables evenly beTween bowls. Label which is which, and refrigeraTe aT leasT one hour. Observe The firmness of The vegeTables. ExplanaTion: The vegeTables in salT waTer are sofTer, perhaps even limp. The cell membranes are "semi-permeable" and allow waTer To pass In and ouT. The concenTraTion of salT is higher on one side of The membrane Then on The oTher, so The wafer will go ouT of The cell. ‘ FATS FaTs perform several funcTions in foods. They add flavor; They form one phase of many food emulsions. FaTs are also used To fry or cook foods, and for making baked producTs Tender and flavorful. Emulsions . An emulsion is a mixTure of oll and waTer, wiTh someThing added To keep The oil and wafer from separaTing. French dressings and mayonnaise are Two Typical food emulsions. In French dressing, The spices help keep The mixTure TogeTher. In mayonnaise, egg yolk keeps The oil from sepa- raTlng ouT. ‘ EXPERIMENT # 5i Prlnci le: Finely ground powders help form Temporary emulsions. EquipmenT needed: l/2 cup oil 2 Tablespoons vinegar 2 Tablespoons lemon juice l/2 Teaspoon sugar l/4 Teaspoon salT l/4 Teaspoon dry musTard l/4 Teaspoon paprika dash of cayenne 2 jars wiTh TlghT lids Procedure: In one jar, place l/4 cup oil, l Tablespoon lemon juice and I Tablespoon vinegar. In second jar, mix spices TogeTher. Add remain— ing oil, lemon Juice and vinegar. Cap boTh jars and shake for 30 seconds. Observe The speed aT which The salad dressings separafe. Record This Time. 56 ‘ (24) ExplanaTion: Finely divided powders such as spices help keep French dressings from separaTing for shorT peridds of Time. Spices also add flavor and color To The dressing. EXPERIMENT # 52 Principle: FormaTion of a mayonnaise emulsion is dependenT on The con- cenTraTion of egg yolk. EquipmenT needed: l/Z baTch sTandard mayonnaise formula from basic cook- book, for comparison l/2 baTch sTandard mayonnaise formula from basic cook- book, wiTh whole egg insTead of egg yolk Procedure: Prepare mayonnaise as direcTed. Label which is which. .Con- ducT line spread TesT on boTh samples (see Appendix I). Observe which mayonnaise is Thinner. ExplanaTion: The mayonnaise made wiTh whole egg is Thinner Than ThaT made wiTh egg yolk. Egg yolk conTains leciThin, which em- ulsifies The mixTure and makes iT Thick. WiTh whole egg, The whiTe diluTes The yolk so less leciThin is presenT and The mixTure is Thinner. ' . ' EXPERIMENT # 53 Principle: FormaTion of a mayonnaise emulsion is dependenT on egg yolk. EquipmenT needed: l/2 baTch sTandard mayonnaise formula from basic cook- book, for comparison l/2 baTch sTandard mayonnaise formula from basic cook— book, wlTh whole egg insTead of egg yolk Procedure: Prepare mayonnaise as direcTed. Label which is which. Con- ducT line spread TesT on boTh samples (see Appendix I). Observe which mayonnaise is Thinner. - ExplanaTion: The mayonnaise made wiTh egg whiTe is very Thin, and really isnTT mayonnaise. Since egg yolk conTains The emulsifier leciThin, if is necessary To form The emulsion and make mayonnaise. Frying When faTs are used for frying, They prevenT food from sTicklng, Transfer heaT, and produce a characTerisTic flavor and color. When The faTs and oils used for frying sTarT To break down, They begin To smoke. This smoke poinT is a TemperaTure which is higher for some faTs Then for oThers. 57 (25) Solid shorTenings (excepT lard) conTain an enulsifier which lowers The smoke poinT. VegeTable oils do noT have an emulsifier. The presence of waTer in buffer and margarine also lowers The smoke poinT. The TemperaTure of The faT in which The food ls cooked gives food TexTure, flavor and color. If The faT is noT hoT enough, The food will be greasy and sofT. If The faT is Too hoT, The food will be burned. MosT foods are fried aT 350 - 375°F. EXPERIMENT # 54 Principle: DifferenT faTs have.dlfferenT smoke poinTs. EquipmenT needed: small saucepan faT ThermomeTer 3/4 - l cup vegeTable oil 3/4 - l cup solid shorTening (noT lard) 3/4 - l cup buTTer or margarine Procedure: cPoszion;ThermomeTer uprighT in saucepan. Add enough faT so ThaT The bulb of The ThermomeTer is covered during The enTire experimenT. Cook over high heaT unTil The faT gives off a bluish smoke. Record The TemperaTure. RepeaT wiTh The 2 remaining faTs. ExplanaTion: The smoke pojnT.of a faT'TsThe TemperaTure aT which The faT begins To decompose. BuTTeh.or margarine has-The lowesT smoke poinT because boTh conTain wafer. Solid shorTening smokes aT The nexT highesT TemperaTure, because The emulsifiers which are added lower The smoke poinT: The oil smokes aT The highesT Temp- eraTure. Oil is probably The besT faT for deep-frying. EXPERIMENT # 55 Princl le: Frying TemperaTure affecTs color and TexTure of food. EquipmenT needed: l box or bag frozen french fried poTaToes oil for deep frying heavy saucepan or french fryer wire baskeT or sloTTed spoon faT ThermomeTer Procedure: Divide poTaToes lnTo 4 equal porTions. HeaT oll To 275°F. Cook one porTion of poTaToes for The Time indicaTed on The package. Drain and label. HeaT The same oil To 325°F. Cook second porTion of poTaToes for The Time given on The package. Drain and label. Again heaT oll To 375°F. Cook Third porTion of poTaToes for The indicaTed Time. Drain and label. HeaT The oil again To 425°F. Cook renalning poTaToes for The indicaTed Time. Drain and label. Observe crispness, color and flavor of all The samples. 58 - (26) :5iigflaiion: The poTaToes cooked aT The lowesT TemperaTure are pale, ”off and greasy. Those cooked aT The highesT TemperaTure are Too w drawn and crisp. The ideal poTaToes are probably Those cooked aT .—o—c;- :) I .41 r e _"‘- PRCJTEHTS Many flccs are sources of proTeins. The MeaT and MeaT SubsTiTuTes Food Grmuw .rcbably comes To mind firsT when you Think of proTeins. BuT The f:ik Group and The Breads and Cereals Group also conTain proTeins. The .roTcins give These foods cerTain characTerisTics when These foods are p- pared for us To eaT. 5133" P oTelhs The g~rTeins in flour are "gluTenin" and "gliadin." When These proTeins inix with liquid and are sTirred, gluTen sTrands form. The amounT of qu‘.l formed depends on The Type of grain from which The flour is milled. WTa;T flour proTeins form a loT of gluTen; whole wheaT flour proTeins form iiTTle gluTen because of The bran presenT; rye flour proTeins do noT form gluTen. Refined wheaT flour from hard wheaT forms The mosT gluTen, so This flour is used for The framework of baked prodicTs. Refined wheaT flour is used wiTh whole wheaT flour and rye flour so ThaT The paied iTem has a good framework as well as The flavor and color of The(;Hum‘grains. Prihpigic: Flours vary in qualiTy and quanTiTy of gluTen. EcuipmenT needed: l/2 cup each of whole wheaT flour, rye flour, sifTed ”5"““5 all-purpose flour, sifTed cake flour, sifTed bread flour cold waTer mixing bowl Thin clean handkerchief cookie sheeT Prorfiwre: To make gluTen balls, add jusT enough cold wafer To each of Ti... +0 form a sTIff dough. LeT dough sTand for ID minuTes in a bowl cf cold waTer. Place dough in handkerchief. Wash The dough in cold wafer by kneading and squeezing The dough In The cloTh. ConTinue washing unTil The wafer is clear. This Takes a long Time. When all The sTarch is w;;n d ouT, The dough ball Is very sTrlngy. Shape The dough InTo a round hall and place on a llgthy greased baking sheeT. Label which is whicw. Sake In ‘ preheaTed 400°F. oven abouT 20 minuTes. Reduce heaT To 37?”E. and bake anOTher lO mlnuTes. Compare The sizes of The gluTen balls. 59 (27) ExplanaTion: Flour from hard wheaT will have more gluTen Than flour from sofT wheaT. Cake flour is milled from sofT wheaT, so This gluTen ball is The smallesT. Bread flour is milled from hard wheaT so This ball is The largesT. All-purpose flour is a mixTure of hard and sofT wheaTs. In Michigan, all—purpose flour has a high percenTage of hard wheaT because Michigan raises a loT of hard wheaT. Rye and whole wheaT have liTTle gluTen, and probably no gluTen ball can be formed. EXPERIMENT # 57 Epipgipig: GluTen is developed by liquid and sTirring EquipmenT needed: muffin baTTer made from a sTandard formula from a basic cookbook (selecT a formula which has 2 cups flour, l cup milk, 2 Tablespoons sugar) greased muffin pans Procedure: When preparing muffin baTTer, sifT dry ingredienTs TogeTher lnTo mixing bowl. Mix liquid IngredienTs TogeTher. Make a well in dry IngredienTs and add llquld. l. STlr l5 sTrokes wITh spoon. Remove 2 muffins To greased muffin cups. 2. STlr anoTher l0 sTrokes. Remove 2 muffins. 3. STlr anoTher 3O sTrokes. Remove 2 muffins. 4. STIr anoTher 3O sTrokes. Remove 2 muffins. 5. STlr anoTher 3O sTrokes. Remove remaining muffins. Label muffin cups according To The number of sTlrs. Bake in preheaTed 425°F. oven, abouT 20 mlnuTes. Observe changes In TexTure of baTTer while mixing. Observe differences in shape and volume of The baked muffins. ExplanaTion: STirring a flour-liquid mixTure develops The gluTen sTrands. UndersTlrrlng does noT develop The gluTen and The baked lTem may be low In volume and have flour sTreaks showing. Over- sTlrrlng sTreTches The gluTen sTrands and Tunnels form. Excessive oversflrrlng breaks The gluTen sTrands and They collapse, so The baked lTem ls small and compacT. Egg ProTeln Egg proTein coagulaTes or Toughens during heaTing. The proTeins In eggs form elasTlc films and lncorporaTe air, used for Ieavening in producTs such as angel cakes. 60 (28) EXPERIMENT # 5% Principle; Excessive heaT TreaTmenT of egg proTein resulTs in curdling, WFEQIDQ, and Toughenlng of The proTein. A. Curdling _EquipmenT needed: sTandard cusTard formula from basic cookbook 2 bowls same size Procedure: Cook cusTard mixTure over hoT buT noT boiling waTer, sTirring occasionally unTil mixTure coaTs a meTal spoon. AT This sTage, The cus- Tard clings To The spoon in a coaTing abouT half The Thickness of The chocolaTe coaTing in a candy bar. Record The Time This Took. Pour half The cusTard info a bowl and refrigeraTe. Confinue cooking and sTirring The remaining cusTard unTil iT curdles or separaTes. lT won'T Take long. Record how long. Pour info second bowl and refrigeraTe. When boTh cus- Tards are cold, compare appearance, TexTure and flavor. ExplanaTion: HeaTing Too fasT or for Too long cooks The egg proTein, Toughenlng and shrinking iT. 'An overcooked cusTard is curdled, waTery, and has a curdy or lumpy mouTh feel. The flavor is The same. EXPERIMENT # 59 B. Weeping EquipmenT heeled: sTandard cusTard formula from basic cookbook cusTard cups baking pan wiTh rack cooling rack Procedure: Pour cusTard mixTure evenly inTo cusTard cups. Place half The cupsgin shallow pan wiTh rack and pour hoT waTer around The cups To a depTh of abouT one inch. Place in preheaTed 350°F. oven. Place re— maining cups in oven wiThouT hoT waTer. Bake abouT 45 minuTes. Remove onTo a plaTe. CuT each in half To observe The inTerior. NoTe The firm- ness, and The presence of bubbles. TasTe each and observe any difference in flavor, appearance and TexTure. ExplanaTion: Overcooked cusTards (Those cooked wiThouT hoT waTer) are waTery, Tough, and have more bubbles. The Tops are browncr and Tougher. There is no difference in flavor. EXPERIMENT # CO C. Toughenihg EquipmenT needed: 2 eggs, room TenperaTure 2 saucepans wiTh lids 6| (29) Procedure: Place one egg in each saucepan. Add waTer To cover. HeaT one To The simmering sTage. -Cover; remove from heaT. LeT sTand 20 minuTes. Place egg in cold waTer To sTop The cooking process. Bring second saucepan To a boil. -Boil 20 minuTes. Place egg in cold waTer To sTop The cooking process. Observe The condiTion of The shells. Peel each egg. CuT ln half wiTh a Table knife. Look for a greenish ring around The yolk. TasTe each and observe The Tenderness of The whiTe. ExplanaTion: The shells of eggs TreaTed wiTh excessive heaT are ofTen cracked. Boiling makes The whiTe Tougher, and a greenish ring may appear around The yolk. This ring is caused by a reacTion beTween heaT, The iron in The yolk and The sulfur in The whiTe. The ring is iron sulfide. EXPERIMENT # 6i Princl ie: STablliTy of an egg whiTe foam is affecTed by The degree of beaTing. EgylpmenT needed: 2 egg whiTes from fresh eggs of The same size 2 mixing bowls, same size beaTer or mixer Procedure: Beaf one egg whiTe To foamy sTage. ConTinue beaTing unTil maximum volume is reached. Record The Time iT Took. Keep This egg whiTe for comparison. Beef second egg whiTe aT same speed, for Twice The Time of The firsT one. Pour The foams lnTo Two clear drinking glasses of The same size. Label which is which. LeT sTand one hour. Pour off The accumuiafed liquid and measure iT. EXpianaTion: -The amounT of liquid ThaT leaks ouT of The egg whiTe foam indicaTes The sTabiliTy of The foam. The more liquid, The less sTable The foam. Excessive beaTing increases The volume of The foam buT decreases The sTabiliTy because The proTein becomes Too Thin and less elasTlc. EXPERIMENT # 62 Princl ie: STablllTy of an egg whiTe foam is affecTed by sugar. EquipmenT needed: 2 egg whiTes from fresh eggs of The same size I Tablespoon sugar 2 mixing bowls, same size mixer or beafer 62 ' (30) Procedure: BeaT one egg whiTe To foamy sTage. ConTinue beaTing unTil maximum volume is reached. Record The Time This Took. Keep This egg whiTe for comparion. BeaT second egg whiTe, aT The same speed, adding sugar gradually. BeaT To maximum volume, recording The Time lT Took. Pour The foams inTo Two clear drinking glasses. Label which is which. LeT sTand one hour. Pour off The accumulaTed liquid and measure iT. ExplanaTion: The amounT of liquid ThaT leaks ouT of The egg whiTe foam is an indicaTion of The sTabiliTy of The foam. The more liquid, The less sTable The foam. The addiTion of sugar increases The Time required for maximum volume, buT The foam is more sTable. EXPERIMENT # 63 Principle: STabiliTy of an egg whiTe foam is affecTed by faT. EguipmenT needed: 3 egg whiTes from fresh eggs of The same size oil 3 mixing bowls, same size beaTer or mixer Procedure: BeaT one egg whiTe To foamy sTage. ConTinue beaTing unTil maximum volume is reached. Record The Time This Took. Keep This egg whiTe for comparison. BeaT second egg whiTe To foamy sTage. Add I drop of oil. ConTinue beaTing unTil maximum volume is reached. Record The Time. Beef Third egg whiTe To foamy sTage. Add 2 Teaspoons of oil. ConTinue beaTing unTil maximum volume is reached. Pour The foams inTo 3 clear drinking glasses. Label which is which. LeT sTand for one hour. Pour off The accumulaTed liquid and measure iT. ExplanaTion: The amounT of liquid ThaT leaks ouT of The egg whiTe foam is an indicaTion of The sTabiliTy of The foam. The more liquid The less sTable The foam. A drop of oil increases The sTabiliTy of an egg whiTe foam. Larger amounTs of oil decreases volume and sTa- biliTy. EXPERIMENT # 64 Principle: STabiliTy of an egg whiTe foam is affecTed by acid. EquipmenT needed: 3 egg whiTes from fresh eggs of The same size 3 mixing bowls, same size cream of TarTar lemon juice o£_vinegar 63 ’ (3|) Procedure: BeaT one egg whiTe To foamy sTage. ConTinue beaTing unTil maximum volume is reached. Record The Time This Took. Keep This egg whiTe for comparison. BeaT second egg whiTe To foamy sTage. Add l/8 Teaspoon cream of TarTar. ConTinue beaTing aT same speed unTil maximum volume is reached. Record Time. BeaT Third egg whiTe To foamy sTage. Add I Tablespoon lenon Juice or vinegar. ConTinue beaTing aT same speed unTil maximum volume is reached. Record The Time. Pour The foams inTo clear drinking glasses, same size. Label which is which. LeT sTand one hour. Pour off The accumulaTed liquid and measure iT. ExplanaTion: The amounT of liquid ThaT leaks ouT of The egg whiTe foam is an indicaTion of The sTabiliTy of The foam. The more liquid The less sTable The foam. Acid, as cream of TarTar, increases The beaTing Time for maximum volume, buT makes The foam more sTable. Vinegar or lemon juice increases The beaTing Time and decreases The sTabiliTy. EXPERIMENT # 65 Principle: STabIliTy of an egg whiTe foam is affecTed by liquid. Egulpmenf needed: 2 egg whiTes from fresh eggs of The same size cold waTer 2 mixing bowls, same size mixer or beaTer Procedure: BeaT one egg whiTe To foamy sTage. ConTinue beaTing unTil maximum volume is reached. Record The Time This Took. Keep This egg whiTe for comparison. BeaT second egg whiTe To foamy sTage. Add I Table— spoon cold waTer. ConTinue beaTing aT same speed unTil maximum volume is reached. Pour boTh foams info Two clear drinking glasses, same size. Label which is which. LeT sTand one hour. Pour off accumulaTed liquid and measure iT. ExplanaTion: The amounT of liquid ThaT leaks ouT of an egg whiTe foam is an indicaTion of The sTabiliTy of The foam. The more liquid, The less sTable The foam. The presence of ice waTer increases The volume of The foam buT lessens The sTabiliTy because The proTeins are diluTed Too much. EXPERIMENT # 66 Principle: STabiliTy of an egg whiTe foam is affecTed by salT. EquipmenT needed: 2 egg whiTes from fresh eggs of The same size salT 2 mixing bowls, same size mixer or beaTer 64 (12) Procedure: BeaT one egg whiTe To foamy sTage. LonTinue beaTing unTil maximum volume is reached. Record The Time This Took. Keep This egg whiTe for comparison. BeaT second egg whiTe To foamy sTage. Add l/2 Teaspoon salT. ConTinue beaTing aT same speed unTil maximum volume is reached. Record The Time. Pour boTh foams inTo Two clear drinking glasses, same size. Label which is which. LeT sTand one hour. Pour off The acoumulaTed liquid and measure iT. ExplanaTion: The amounT of liquid ThaT leaks ouT of The egg whiTe foam is anflindicaTion cf The sTabiliTy of The foam. The more liquid, The less sTable The foam. SalT decreases The sTabiliTy of The egg whiTe fcenu -*.—-.—_--~- _-._,_-.—"___ -v‘--.- -m"~‘_.—' —. - -‘- GeIaTin ProTein GelaTin is obTained by heaTing connecTive Tissues, Tendons and carTilage of animals in waTer. AfTer many processing sTeps The gelaTin (proTein) is lefT. IT is pulverized and sold as unflavored gelaTin. GelaTin des- serT powders are a mixTure of unflavored gelaTin, sugar, and coloring and flavoring. A gelaTin gel is formed when gelaTin is dissolved in waTer. NoTe: We suggesT ThaT a conTrol sample, for comparison, be used in each seT of experimenTs. However, if you plan To compleTe all The experimenTs on gelaTin, only one conTrol sample needs To be prepared. if you do all The experimenTs on gelaTin, you will need l2 envelopes oi urflavored gelaTin. Formula for conTrol sample: Dissolve conTenTs of l envelope of gelaTin in l/2 cup cold waTerAdd l l/2 cups boiling waTer; sTir unTil geTaTin is dissolved. Pour inTo dish or pan and refrigeraTe unTil firm. EXPERIMENT # 67 Principle: Firmness of a gelaTin g:l is affecTed by The concenTraTion of gelaTin. EguipmenT needed: 3 envelopes unflavored gelaTin waTer Procedure: Prepare conTrol sample, using formula. Prepare SECQHd sample using 2 envelopes of gelaTin. Observe boTh samples afTer l5 minuTes, 30 minuTes, l hour, 6 hours and l day. Observe firmness and Tenderness by cuTTing wiTh 3 Table knife. 4 ExplanaTion: A higher concenTraTion of gelaTin makes The gel seT fasTer because There is more gelaTin To Take up The waTer. The gel is very firm, almosT rubbery. un—mn— 65 (35) EXPERIMENT # 68 Principle: Firmness of a gelaTin gel is affecTed by TemperaTure. EquipmenT needed: 2 envelopes unflavored gelaTin waTer Proceduie: Prepare conTrol sample, using formula. Prepare second sample according To conTrol formula, buT leT gel form aT room TemperaTure. .Ob— serve samples afTer l5 minuTes, 30 minuTes, l hour, 6 hours and l day. Observe firmness and Tenderness by cuTTing wiTh a Table knife. ExplanaTion: A gelaTin gel forms more slowly aT higher TemperaTures. Once formed, however, The gel does noT melT as rapidly as one formed aT a low TemperaTure. EXPERIMENT # 69 Principle: Firmness of a gelaTin gel is affecTed by acid. EquipmenT needed: 3 envelopes unflavored gelaTin waTer vinegar or lemon juice I Procedule: Prepare conTrol sample, using formula. Prepare second sample, using conTrol formula, buT using l/2 cup cold waTer, l/2 cup vinegar or lemon Juice, and I cup hoT waTer. Prepare Third sample using conTrol formula, buT using l/2 cup cold waTer, i cup vinegar or lemon juice, and l/2 cup hoT waTer. Label which is which. Observe samples afTer l5 minuTes, 30 minuTes, l hour, 6 hours and l day. Observe firmness and Tenderness by cuTTing wiTh a Table knife. ExplanaTiog; Acid breaks down or digesTs proTein. Increasing amounTs of acid will make a gelaTin gel very sofT and runny. Acid can prevenT a gel from forming. EXPERIMENT # 7O Principle: Firmness of a gelaTin gel is affecTed by sugar. EquipmenT needed: 3 envelopes unflavored gelaTin i sugar waTer Procedure: Prepare conTrol sample, using formula. Prepare second sample according To formula, buT mix 2 Tablespoons sugar wiTh gelaTin. Prepare Third sample according To conTrol formula, buT mix l/2 cup sugar wiTh gelaTin. Label which is which. Observe samples afTer l5 minuTes, SO minuTes, l hour, 6 hours and l day. Observe firmness and Tenderness by cuTTing wiTh a Table knife. 66 (34) ExplanaTion: Sugar makes a gelaTin gel sofT. Too much sugar can make a gelaTin so sofT ThaT iT cannoT unmold. The sugar Takes up The wafer and leaves Too liTTle for The gelaTin. EXPERIMENT # 7| Principle: Firmness of a gelaTin gel is affecTed by enzymes. EquipmenT needed: 5 envelopes unflavored gelaTin l/Z cup well drained canned pineapple l/2 cup chopped fresh pineapple l/2 cup frozen pineapple, Thawed and drained I/2 Teaspoon powdered meaT Tenderizer Procedure: Prepare conTrol sample, using formula. Prepare second sample, using conTrol formula and adding canned pineapple. Prepare Third sample, using conTrol formula and adding fresh pineapple. Prepare fourTh sample, using conTrol formula, and adding frozen pineapple. Prepare iasT sample, using conTrol formula, and sTirring in meaT Tenderizer. Observe samples afTer l5 minuTes, SO minuTes, l hour, 6 hours and I day. Observe Tender- ness and firmness by cuTTing wiTh a Table knife. ExplanaTion: Enzymes digesT proTein. Pineapple conTains an enzyme, bromelin, which digesTs proTein and prevenTs a gel from forming. Canned pineapple has been heaTed during canning and This enzyme has been desTroyed. Fresh and frozen pineapple have noT been heaT TreaTed. MeaT Tenderizer is an enzyme which comes from a planT. Milk ProTeins Milk conTains Three proTeins, casein, lacToglobulin and lasTalbumin. Fluid milk iTself does noT coagulaTe (become firm) wiTh heaT. Two of The proTeins, lacTalbumin and lacToglobulin, are coagulaTed by heaT. Casein, The main proTein in milk, is coagulaTed by rennin and acid, buT noT by heaT. EXPERIMENT # 72 Principle: LacToglobulin and lacTalbumin are coagulaTed by heaT. EquipmenT needed: small saucepans l cup each of fluid whole milk, fluid skim milk, reconsTiTuTed nonfaT dry milk, and undiluTed evaporaTed milk Procedure: Keep l/2 cup of each milk for comparison. Place l/2 cup of milk in each saucepan. Label which is which. Cook over medium heaT unTil scalding (small bubbles around The edge). Renove from heaT and leT sTand unTil cool. Observe The skin on The surface of The milk, and The scum on The sides and boTTom of The pan. 67 (35) ExplanaTion: The skin on The Top of The milk is lacToglobulin. The scum on The sides and boTTom of The pan is lacTalbumin. The milk sTays fluid. EXPERIMENT # 73 Principle: Casein is coagulaTed by acid buT noT heaT. EquipmenT needed: vinegar or lemon Juice cold TomaTo Juice | cup each of fluid whole milk, fluid skim milk, reconsTiTuTed nonfaT dry milk, undiluTed evaporaTed milk Procedure: Keep l/3 cup of each of The milks for comparison. To l/3 cup of each milk, add 2 Teaspoons vinegar or lemon Juice. To remaining milk samples add I Tablespoon cold TomaTo Juice. Label which is which. Observe The Thickness and curdling of The milks. ExplanaTion: Acid coagulaTes or Thickens The casein (proTein) in The milk. TomaTo Juice conTains less acid Than lemon Juice or vine- gar. The milks wiTh TomaTo Juice show less Thickening Than Those wiTh The vinegar or lemon Juice. The coagulaTion of casein is de- sirable in producTs such as buTTermilk and yogurT. MeaT ProTeins When meaT is heaTed, The faT and connecTive Tissues sofTen and The fibers ("meaT" parT) Toughen. WiTh prolonged heaT, The fibers conTinue To Toughen and shrink, and The meaT Juices are squeezed ouT. Fish and shellfish have very liTTle faT and connecTive Tissue, so They require liTTIe heaT To Toughen The fibers. Less Tender cuTs of meaT have more connecTive Tissue, so moisT heaT and a longer cooking Time is required. Enzymes and acids break down or digesT proTein To make if sofTer and more Tender. EXPERIMENT # 74 Etjflgiplgf MeaT proTein becomes Tough wiTh exTended heaT. EguipmenT needed: 2 ground beef paTTies, same size and Thickness broiler pan and rack Procedure: PreheaT broiler. AdJusT rack so ThaT The Tops of The beef paTTies are 3 inches from The heaT. ,Broil one paTTy 6 minuTes per side, Turning once. Broil second paTTy l2 minuTes per side, Turning once. Remove To plaTe. Measure diameTer and Thickness of paTTies wiTh a ruler. TasTe boTh when warm buT noT hoT. Observe color, Tenderness, flavor and mouTh feel. 68 (36) ExplanaTion: Longer cooking makes The beef paTTies dry, Tough and less TasTy. The diameTer is less Than The raw paTTies, and The cen- Ter is Thicker because The proTein has shrunk. There is less flavor because The drippings are IosT. EXPERIMENT # 75 Principle: Fish and shellfish become Tough and rubbery wiTh exTended heaTing. A. Fish EquipmenT needed: 4 filleTs of fish (perch, sole, eTc.) of The same size g£|l box frozen fish cuT inTo 4 equal size blocks baking pan \ Procedure: Place fish on ligthy greased baking pan. Bake in reheaTed 3505F. oven abouT 25 minuTes. Remove one piece of fish. ConTifiue baking anoTher IO minuTes; remove anoTher piece of fish. Bake an addiTional lO minuTes; remove Third piece of fish. ConTinue baking anoTher l0 min- uTes; remove remaining fish. Flake each piece of fish wiTh a fork. I TasTe The fish while warm buT noT hoT. Observe dryness, Tenderness and mouTh feel. .. - ‘ ExplanaTion: Prolonged heaTing Toughens proTein. The longer The fish is baked The Tougher and drier lT becomes. No much flavor is.lefT. EXPERIMENT # 76 B. Shellfish EquipmenT needed: l box or bag of shrimp, fresh or frozen (noT breaded) large saucepan or keTTle Procedure: Bring salTed waTer To a boil in saucepan and cook shrimp according To package direcTions. Remove l/4 of The shrimp. ConTinue simmering anoTher lO minuTes; remove anoTher l/4 of The shrimp. Simmer an addiTional iO minuTes; remove anoTher l/4 of The shrimp. Cook on- oTher IO minuTes; remove remaining shrimp. Observe Tenderness by break- ing wiTh The fingers and cuTTing wiTh a fork. Observe flavor and mouTh feel. ExplgpaTlon: Prolonged heaTing Toughens proTein. The longer The shrimp is cooked, The Tougher and more rubbery The pieces become. The ouTside layer of The shrimp is especially Tough. The flavor does noT change much. 69 (37) EXPERIMENT # 77 Principle: MeaT cooking losses increase wiTh TemperaTure and Time. Eggipmenf needed: 4 ground beef paTTies, same size and Thickness heavy frypan or skilleT Procedure: Cook one beef aTT aT a Time ' according To The followingpschzdule: , USIHg Clean frypan for eaCh’ I. Use medium heaT, cook 5 minuTes per side. 2. Use medium heaT, cook IO minuTes per side. 3. Use high heaT, cook 5 minuTes per side. 4. Use high heaT, cook IO minuTes per side. Measure drippings from each. Observe The color and odor of The drippings. Measure Thickness and diameTer of each paTTy wiTh a ruler. TasTe each when warm buT noT hoT. NoTe flavor and mouTh feel. ExplanaTion: The drippings from meaT cooked over low heaT are clearer and have a "meaTy" aroma. Drippings from meaT cooked over high heaT are darker and more solid, and ofTen burned onTo The pan. The longer meaT is cooked, The darker The drippings will be. ExTend~ ed heaT and Time cause more drippings To be cooked ouT, and The meaT paTTies are smaller and drier, wiTh a Tough, dry crusT. EXPERIMENT # 78 ,Egigglple: Enzymes and acids break down or digesT proTein. A. Enzymes EquipmenT needed: 2 pieces of meaT, same size and Thickness, from same cuT, such as round commercial meaT Tenderizer, pg: insTanT Type broiler pan and rack Procedure: Sprinkle one piece of meaT wiTh meaT Tenderizer according To package direcTions. Leave second piece plain. PreheaT broiler. AdJusT rack so ThaT Top of meaT is 3 inches from heaT. Broil boTh pieces of meaT To desired doneness, Turning once. TasTe each when warm buT noT hoT. Observe mouTh feel, ease of chewing and ease of cuTTing wiTh a fork. ExplanaTion: Commercial meaT Tenderizer is an enzyme exTracTed from a planT. MeaT TreaTed wiTh This enzyme is sofTer and more Tender Then unTreaTed meaT. The ouTside of The TreaTed meaT is especially sofT. If used on»a Tender cuT of meaT, meaT Tenderizer can make iT mushy. 7O (38) EXPERIMENT # 79 8. Acid quipmenf needed: 2 pieces of meaT, same size and Thickness, from same cuT, such as round marinade made of l/4 cup salad oil, 2 Tablespoons ' vinegar, l/2 Teaspoon salT, l Teaspoon Worcesfershire sauce ‘ broiler pan and rack Procedure: Soak one piece of meaT in marinade. Refrigerafe in marinade overnighT. Refrigerafe second piece of meaT also, buT wiThouT marinade. PreheaT broiler. AdJusT rack so ThaT Top of meaT is 3 inches from source of heaT. Broil unTil meaT is of desired doneness, Turning once. TasTe each when warm buT noT hoT. Observe mouTh feel, ease of chewing, and ease of cuTTing wiTh a fork. ExplanaTion: The acid in The vinegar of The marinade sofTens The meaT and makes a IiTTle more Tender and easier To cuT and chew. The ouTside of The meaT is sofTer Than The inside. The oil in The marinade also keeps The meaT from drying ouT during cooking. Mari- neTIng a less Tender cuT of meaT is a good way To make iT more TasTy COLOR IN FRUITS AND VEGETABLES The color in fruiTs and vegeTables is due To several color pigmenTs. MosT fruiTs and vegeTables have more Then one color pigmenT, buT one is dominanT over The oThers. Some have Two pigmenTs in fairly equal dis- TrIbuTion. Red cabbage, for insTance, has boTh red and whiTe pigmenTs. Much of The appeal of fruiTs and vegeTables is Their varied colors. Changes ThaT Take place during cooking and sTorage can make These colors unaTTracTive. The color pigmenTs in fruiTs and vegeTables are: Chlorophyll (KLOR-or-fill)..........green CaraTinoids (CARE-a-Tin-oids) ....... yellow and orange AnThycyanins (an-Tho-SY-a-nins) ..... red, blue and purple AnThoxanThins (an-Tho-ZAN-Thins)....whiTe Acid changes chlorophyll To a dull olive green color. CaraTinoids dis- solve In faT or oil. Alkali Turns anThocyanins dark; acid Turns anTho- cyanins redder. AnThocyanins also dissolve in waTer. Acid keeps anThoxanThins whiTe; alkali Turns Them yellow or brown. 7l (39) EXPERIMENT # BO Principle: CaraTinoids dissolve in faT or oil. EquipmenT needed: raw carroTs graTer Procedure: Wash carroTs and graTe on largesT holes of graTer." Observe The color of your hands afTer graTing The carroTs. g ExplanaTion: The oil in your skin dissolves some of The caraTin— oids, so your hands Turn orange. CaraTinoids conTain The sub— sTance ThaT forms ViTamin A. EXPERIMENT # 8| EClflEiELEF Acid Turns chlorophyll a dark olive green color. A. Cooked spinach EquipmenT needed: fresh or frozen spinach 2 saucepans, one wiTh lid Procedure: Divide spinach equally lnTo The saucepans: Add a small amounT of waTer To each. Cover one saucepan. Cook boTh-samplesrovermmedium heaT unTil spinach is very Tender. Observe The color of boTh'samples. ExplanaTion: Acid Turns chlorophyll a dark olive green color. When green vegeTables are cooked uncovered, The planT acids evap~ oraTe lnTo The air. When The pen is covered, The planT acids cannoT escape. These acids Turn The green spinach To brownish spinach. EXPERIMENT # 82 B. Uncooked beans EquipmenT needed: l box frozen green beans 3 small bowls vinegar vinegar and oil salad dressing Procedure: Thaw green beans and divide info The 3 bowls. Keep one bowl for comparison. Add vinegar To one sample; sTir so ThaT all beans are coaTed. Add salad dressing To remaining sample; sTir so ThaT all beans are coaTed. Observe The color changes. w ExplanaTion: Vinegar, an acid, will Turn The chlorophyll of green vegeTables To an olive green color. Salad dressing also conTains acid, such as vinegar or lemon Juice or boTh. ...— 72 (40) EXPERIMENT # 83 Epipglple: AnThocyanins Turn blue in alkali and red in acid; The reacTion is reversible. EquipmenT needed: red fruiT Juice, such as cranberry, grape, red raspberry (red sofT drinks won'T work) vinegar or lemon Juice baking soda 3 cusTard cups or glasses Procedure: Pour abouT I/4 cup fruiT Juice in each cusTard cup or glass. Leave one plain for comparison. To one sample add I Teaspoon vinegar or lemon Juice. To remaining sample add l/4 Teaspoon baking soda dtssolved in I Teaspoon waTer. Label which is which. Observe color changes. Add I - 2 TeaSpoons lemon Juice or vinegar To The baking soda sample. Again observe color change. .L‘ ExplanaTion: Alkali in The form of baking soda Turns The red pig- menTs bluer or darker. Acid in The form of lemon Juice or vinegar keeps red pigmenTs red. Adding acid To The alkali sample brings The red color back. Lemon Juice added To a red fruiT Juice punch will keep The nice red color. fir T EXPERIMENT # 84 Eplpgipie; Alkali Turns anThocyanins blue and anThoxanThins yellow. EquipmenT needed: red cabbage saucepan baking soda Procedure: Shred red cabbage. PuT inTo saucepan and add waTer To cover. Add I Teaspoon baking soda. Cook over medium heaT and observe all color changes. #4 ExplanaTion: Red cabbage conTains anThocyanins (red) and anTho- xanThins (whiTe). Alkali in The form of baking soda Turns The red pigmenT blue and The whiTe pigmenT yellow. Blue and yellow make green, so The red cabbage Turns greenish. EXPERIMENT # 85 Principle: Alkali Turns anThoxanThins yellow or brown. EquipmenT needed: cauliflower or whiTe poTaToes baking soda cream of TarTar or vinegar 2 saucepans - 73 (4|) Procedure: CuT poTaToes or cauliflower inTo uniform pieces. Divide evenly inTo The 2 saucepans. Add waTer To cover. To one sample add I Teaspoon baking soda. To The oTher add I/4 Teaspoon cream of TarTar or I Tablespoon vinegar. Label which is which. Cook samples over medium heaT unTil Tender. Observe The color of boTh samples. ExplanaTion: The vegeTable cooked wITh baking soda is more yellow and mushier Than The sample cooked wiTh acid. The acid sample is whiTer and firmer in TexTure. A biT of cream of TarTar (acid) whipped inTo mashed poTaToes will help keep Them whiTe. EXPERIMENT # 86 Principle: LighT colored fresh fruiTs and vegeTables darken when exposed To The air. EquipmenT needed: sliced raw banana, apple, poTaTo or thTe Turnip E 5 cusTard cups sugar salT lemon Juice waTer Procedure: Divide pieces of fruiT or vegeTable evenly among The 5 cus- Tard cups. Sprinkle one wiTh sugar, one wiTh salT, one wiTh lemon Juice, one wiTh waTer, and leave one plain. Label which is which. LeT sTand aT room TemperaTure. Observe The color afTer I5 minuTes, 3O minuTes and l hour. ExplanaTion: Acid keeps lighT colored fruiTs and vegeTables lighT. Sugar and wafer have IiTTle effecT on sTopping The browning. SalT sTops The browning for only a shorT Time. FOOD STORAG E Proper sTorage of foods aT each sTage of The disTribuTion process helps mainTain Top qualiTy, besT flavor and color, and besT nuTriTive value. Home sTorage condiTions can mean The difference beTween food ThaT is high qualify and food ThaT is low qualiTy. Egg STorage To mainTain The qualiTy of eggs, They should be kepT covered in The refri— geraTor. This keeps moisTure loss aT a minimum. Frozen eggs mainTain Their besT qualiTy if mixed wiTh a liTTle sugar or self before freezing. Egg yolks may be frozen successfully wiTh The addiTion of eiTher sugar or salT. WhiTes may be frozen wiThouT any addiTions. 74 (42) EXPERIMENT # 87 Principle: OuaiiTy of shell eggs deTerioraTes wiTh aging and is de- pendenT on sTorage condiTions. NoTe: This experimenT may be conducTed wiTh raw or hard-cooked eggs. A. Raw eggs EquipmenT needed: 9 eggs, same size and age Procedure: STore 3 eggs aT room TemperaTure, 3 eggs uncovered in refri- geraTor, and 3 eggs covered in refrigeraTor (in egg carTon). AfTer l day, carefully break one of each of The eggs onTo a flaT surface. Measure how far The egg spreads. Observe The air cell aT The large end of The egg. AfTer 3 days, break anoTher of each of The eggs and observe as before. AfTer 7 days, break remaining eggs and again observe. ExplanaTion: During sTorage The amounT of Thin whiTe increases, so The older eggs spread ouT more. The yolk increases in size and flaTTens. Eggs also lose moisTure during sTorage and The air cell aT The large end of The egg increases in size. These changes go fasTer aT higher TemperaTures and go slower when eggs are sTored aT lower TemperaTures and are covered. The besT way To mainTain qualiTy of eggs is To keep Them in The refrigeraTor in The carTon They come in. EXPERIMENT # 88 B. Hard cooked eggs EquipmenT needed: 9 eggs, same size and age Procedure: STore 3 eggs aT room TemperaTure, 3 eggs uncovered in refri- geraTor, and 3 eggs covered in refrigeraTor (in egg carTon). AfTer l day hard cook one of each. Plunge eggs inTo cold waTer To sTop cooking. Carefully remove shell of each egg. Observe evidence of The air cell by noTing The flaTness aT The large end of The egg. AfTer 3 days, hard cook one of each of The eggs and observe as before. AfTer 7 days hard cook remaining eggs and again observe evidence of air cell. ExplanaTion: During sTorage, eggs lose moisTure. The air cell increases and The size of The egg decreases. These changes go fasTer wiTh Time and higher TemperaTures, and wiTh The absence of covering of eggs. The besT way To mainTain qualiTy of eggs is To keep Them In The refrigeraTor in The carTon They come in. EXPERIMENT # 89 Principle: The addiTion of sugar or salT To whole egg and egg yolk main- Tains qualiTy during freezing. 75 (43) EquipmenT needed: 5 fresh eggs 5 small Jars wiTh lids sugar or self Procedure: lnTo 2 of The small Jars, break Two of The eggs. STir To blend whiTes and yolks. STir l/4 Teaspoon sugar or salT inTo one. Cover boTh Jars, label, and place in The freezer. SeparaTe one egg, puTTing The yolk in one Jar and The whiTe in anoTher. SeparaTe anoTher egg, puTTing The yolk in The lasT Jar and The whiTe in wiTh The oTher one. STir The yolks; sTir The whiTes. To one yolk, sTir in l/4 Teaspoon sugar or salT. Label all The Jars, cover and place in The freezer. Place remaining egg in The freezer in The shell. Freeze for aT leasT l monTh. Remove from freezer and defrosT in The refrigeraTor. Observe The Thickness and gumminess of all samples. Break open The whole egg and compare wiTh a freshly broken egg. ExplanaTion: SalT and sugar prevenT frozen whole eggs and frozen yoTks from becoming Thick and gummy. Yolks frozen wiThouT sugar or self are much more gummy Than The frozen whole eggs. Egg whiTe mainTains qualiTy during freezing wiThouT sugar or self. Eggs in The shell cannoT be frozen successfully. Freezer Wraps Freezer air is very cold, very dry air. The wrapping around food in freezer sTorage musT prevenT The food from drying ouT in The cold dry air. Improperly wrapped foods in The freezer lose moisTure, flavor and qualiTy. EXPERIMENT # 90 Principle: MoisTure-vapor-proof wrapping mainTains qualiTy of frozen foods. EquipmenT needed: 4 ground beef paTTies, same size and Thickness freezer foil saran wrap waxed paper buTcher paper Procedure: Wrap one beef paTTy in each of The wraps, using drugsTore wrap as described in a basic cookbook or in U.S.D.A. Home and Garden BulleTin Number 70 (Freezing PoulTry in The Home). Freeze for aT leasT 2 monThs. DefrosT in The refrigeraTor wiThouT unwrapping. When defrosTed, observe color changes and general appearance of The meaT. Broil meaT paTTies in preheaTed broiler abouT 3 inches from The heaT, abouT 5 minuTes per side. TasTe each while warm buT noT hoT. Observe flavor, Juiciness and mouTh feel. E“ ExplanaTion: Freezer foIl and saran are good freezer wraps because They prevenT moisTure loss from The food. Waxed paper and buTcher paper are noT good for freezing because They are noT moisTure-proof and They cannoT be sealed air TlghT. The food dries ouT and loses ' flavor. The beef paTTies frozen in waxed paper and buTcher paper are dry, TasTeless, and may be discolored. 76 (44) FOOD SANITATION SaniTaTion is imporTanT In every parT of The food disTribuTion process. SaniTaTion means more Than keeping food clean. Proper handling, wrap- ping, sTorage, preparaTion and cleanup are all involved in food saniTa- Tion. Good food saniTaTion pracTices can mean The difference beTween wholesome and spoiled food. Food spoilage is caused by bacTeria, yeasTs and molds... microorganisms which are presenT everywhere. All microorganisms do noT cause food spoilage, however. For insTance, we rely on molds To make blue cheese and soy sauce; we use bacTeria To make sauerkrauT and cheese; we depend on yeasTs To make wine and To make bread rise. Food spoilage, along wiTh off-colors, off-odors and off—flavors, resulTs when some of The obJecTionable microorganisms mulTiply fasTer Than oThers. This happens when food is noT properly wrapped, sTored, cleaned or prepared. The following,experimenTs TesT some of The principles of food saniTaTion, using Techniques of microbiology. The experimenTs require The use of pre- poured agar (AH-gr) plaTes. The plaTes are sTerile when you geT Them. Microorganisms Transferred To The agar surface will muITiply and produce "spoTS" or colonies. Each colony sTarTs wiTh one or more microorganisms. The molds are fuzzy, and yeasTs and bacTeria are moisT spoTs, ofTen creamy whiTe buT someTimes colored. Prepoured agar plaTes are available in boxes of 20. You may wish To use all The plaTes yourself, or divide Them wiTh someone else. WriTe To: G. A. Ingram Company Noble Blackmer, Inc. 4444 Woodward Avenue pg; BOI SouTh Brown STreeT DeTroiT, Michigan 4820i Jackson, Michigan 49203 Ask for prices and informaTion on: BBL 2Il85 TrypTicase Soy Agar The cosT for 20 plaTes is approximaTely $7.50. When working wiTh agar plaTes, keep The plaTes covered unTil conTaminaTed wiTh microorganisms, Then cover The plaTe immediaTely. Label The lids wiTh a felT pen or Tape so you know which is which. Do noT Touch The agar sur- face wiTh your fingers unless The experimenT says so. Keep unused plaTes in The refrigeraTor so They won'T dry ouT. The agar may noT be used a second Time. The plaTes may be used again if you can find some plaTe counT agar, perhaps in a hospiTal bacTeriology lab. STerllize The plasTic plaTes by boiling Them in waTer for aT leasT IO minuTes. Follow The Iab's suggesTions on meITing and pouring The agar. 77 (45) Prachcally all foods have microorganisms presenT. These experimenTs are designed To show The conTrasT beTween proper and improper saniTaTion. WiTh These plaTes, There is no way of disTinguishing beTween paThogenic (disease) and non-paThogenic microorganisms. The "good guys" and The "bad guys" are There TogeTher. ' Do noT keep conTaminaTed plaTes longer Than 5 days because They begin To smell. You may dispose of Them as you would any wasTe maTerial...in The inclneraTor or The garbage can. EXPERIMENT # 9| Principle: Microorganisms are presenT in The air. EquipmenT needed: I prepoured agar plaTe Procedure: Open plaTe and leT sTand aT room TemperaTure for 2 hours. Do noT Touch The agar surface. Cover plaTe and label iT. lnverT The plaTe and leT iT sTand aT room TemperaTure for 3 days. Observe plaTe for evidence of microbial growTh. ExplanaTion: Microorganisms presenT in The air drop onTo The agar surface. These microorganisms grow on The agar and form colonies. Each spoT on The agar surface means ThaT one or more microorganisms - landed There. This shows how imporTanT iT is To keep food covered. EXPERIMENT # 92 Principle: Used dish cloThs and dish Towels are sources of conTaminaTion. EquipmenT needed: 2 prepoured agar plaTes used dish cloTh used dish Towels Procedure: Use dish cloTh and Towel To wash and dry dishes. Open one agar plaTe. Ligthy Touch cenTer of dish cloTh on surface of agar. Cover plaTe immediaTely and label iT. Open second plaTe. Ligthy Touch cenTer of dish Towel To agar surface. Cover plaTe immediaTely and label iT. lnverT boTh plaTes and leT sTand aT room TemperaTure for 3 days. Observe microbial growTh on boTh plaTes. ExplanaTion: More microorganisms may be presenT on The dish cloTh because if is used on dirTy dishes and pans. There are some micro— organisms on The Towel because The same Towel is used To dry many dishes. Microorganisms can be Transferred from The dish cloTh To oTher surfaces. 78 (46) EXPERIMENT # 93 Principle: Proper care of uTensils decreases The possibiliTy of microbial conTaminaTion. Egpipmenf needed: 3 prepoured agar plaTes 2 clean spoons Procedure: Open one agar plaTe. Holding one spoon by The handle, ligthy move The bowl of The spoon across The agar surface. Cover plaTe immediaTely and label iT. Drop The spoon on The floor. Open The second agar plaTe. Pick up The dropped spoon by The handle and lighTIy move The spoon across The agar surface. Make sure ThaT The parT ThaT hiT The floor makes conTacT wiTh The agar. Lick The second spoon. Open The Third plaTe. Move The spoon ligthy across The agar surface. Make sure ThaT The parT you licked makes conTacT wiTh The agar. Cover plaTe immediaTely and label iT. lnverT all Three plaTes and leT sTand aT room TemperaTure for 3 days. Observe microbial growTh on all plaTes. ExplanaTion: Some microorganisms ofTen remain on clean uTensils. The floor probably has a high microbial counT, and some of These microorganisms may be picked up by uTensils dropped on The floor. Some microorganisms live in your mouTh, and are Transferred To uTensils when They are licked. This shows how imporTanT if is To use only clean uTensils around food. EXPERIMENT # 94 Principle: Low TemperaTures reTard microbial growTh in cooked foods. EquipmenT needed: I piece of cooked meaT (noT ground) cuT in half 2 prepoured agar plaTes Procedure: Cover one piece of meaT afTer cooking and refrigeraTe immedi- aTely. Cover second porTion of meaT and leT iT sTand aT room TemperaTure abouT 8 hours. Open one agar plaTe. LighTIy Touch The agar surface wiTh The surface of one porTion of meaT. Cover plaTe immediaTely and label iT. Open second plaTe. Ligthy Touch The agar surface wiTh The second piece of meaT. Cover plaTe immediaTely and label iT. lnverT boTh plaTes and leT sTand aT room TemperaTure for 3 days. Observe The microbial growTh on boTh plaTes. ExplanaTion: Cooked foods held of room TemperaTure should show evidence of greaTer microbial growTh Than foods chilled immediaTely afTer cooking and held aT refrigeraTor TemperaTure. This shows how imporTanT iT is To refrigeraTe foods as soon as possible afTer cook- ing. 79 (47) EXPERIMENT # 95 Principle: High TemperaTures desTroy many microorganisms. EquipmenT needed: 3 spoons...one washed in auTomaTic dishwasher, one washed by hand and air dried, one washed by hand and dried wiTh dish Towel 3 prepoured agar plaTes Procedure: AfTer dishwasher has compleTed The washing cycle and dishes are cool, remove one spoon, Touching only The handle. Open one agar plaTe. Ligthy move The bowl of The spoon across The agar surface. Cover plaTe immediaTely. Pick up The air-dried spoon, Touching only The handle. Open second plaTe. Ligthy move The bowl of The spoon across The agar surface. Cover plaTe immediaTely and label iT. Pick up The Towel-dried spoon, Touching only The handle. Open The Third plaTe. _ Ligthy move The bowl of The spoon across The agar surface. Cover plaTe immediaTely and label iT. lnverT all Three plaTes and leT sTand aT room TemperaTure for 3 days. observe evidence of microbial growTh on all plaTes. ExplanaTion: The high waTer TemperaTures of auTomaTic dishwashers desTroy many of The microorganisms presenT. Handwashing desTroys some buT noT all of The microorganisms. Microorganisms can be Transferred To uTensils from The dish Towel. EXPERIMENT # 96 Principle: Washing removes some of The microorganisms presenT on skin. qujpmenf needed: 2 prepoured agar plaTes Procedure: Open one agar plaTe. Run your finger across The agar surface. Cover plaTe immediaTely and label iT. Wash your hands wiTh soap and wafer and dry well. Open second plaTe. Run your washed finger across The agar. Cover plaTe immediaTely and label iT. lnverT boTh plaTes and leT sTand aT room TemperaTure for 3 days. Observe microbial growTh on boTh plaTes. ExplanaTion: The plaTe sTreaked by your unwashed finger will probab- ly show a definiTe paTTern of microbial growTh. The oTher plaTe should show less growTh. This shows The imporTance of washing your hands before handling food. EXPERIMENT # 97 Principle: Washing removes some of The microorganisms presenT in food. EquipmenT needed: I unwashed apple, peach or pear 2 prepoured agar plaTes 80 (48) Procedure: Open one agar plaTe. Roll fruiT over The agar surface, being careful noT To Tear The agar. Cover plaTe immediaTely and label IT. Wash fruiT carefully in running waTer. Dry on a clean Towel. Open second plaTe. Again roll fruiT over The agar surface. Cover plaTe lmmediaTely and label IT. lnverT boTh plaTes and leT sTand aT room TemperaTure for 3 days. Observe microbial growTh on boTh plaTes. ExplanaTion: Washing removes some buT noT all of The microorganisms presenT on food. This shows The lmporTance of washing fruiT before eaTing iT. EXPERIMENT # 98 Principle: Low TemperaTures reTard microbial growTh on meaT. EgpipmenT needed: I piece of raw meaT, cuT In half 2 prepoured agar plaTes Procedure: Cover boTh pieces of meaT loosely wiTh waxed paper. Refriger- aTe one piece. LeT The oTher sTand of room TemperaTure. AfTer 8 hours, uncover boTh pieces of meaT. Open one agar plaTe. Ligthy Touch The agar wiTh The surface of The unrefrlgeraTed meaT. Cover plaTe ImmediaTely and label IT. Open second agar plaTe. LighTIy Touch The agar wiTh The surface of The chilled meaT. Cover plaTe ImmedlaTely and label iT. InverT boTh plaTes and leT sTand aT room TemperaTure for 3 days. Observe microbial growTh on boTh plaTes. ExplanaTion: Microorganisms mulTiply rapidly on meaT held of room TemperaTure. This shows The lmporTance of keeping meaT chilled unTil you are ready To use IT. EXPERIMENT I 99 Epinciple: Defrosflng frozen food of low Tenperafures reTards microbial growTh. EquipmenT needed: I place of meaT (noT ground) cuT in half, wrapped and frozen separaTely 2 prepoured agar plaTes Procedure: DefrosT one piece of meaT aT room TemperaTure and one piece In The refrigeraTor. MeaT should sTand aT room TemperaTure aT leasT 6—8 hours. When boTh pieces are compleTely defrosTed, remove wrapping. Open one agar plaTe. nghTIy Touch The agar surface wiTh The room Temp— eraTure meaT. Cover plaTe ImmediaTely and label IT. Open The second plaTe. Ligthy Touch The agar surface wiTh The refrigerafed meaT. Cover . plaTe lmmediaTely and label iT. lnverT boTh plaTes and leT sTand aT room TemperaTure for 3 days. Observe microbial growTh on boTh plaTes. 8| (49.) ExplanaTion: Microorganisms are presenT on boTh pieces of meaT. However, The microorganisms do noT muITiply as fasT on The meaT defrosTed in The refrigeraTor as on The meaT defrosTed aT room TemperaTure. This shows The imporTance of defrosTIng frozen foods in The refrigeraTor. EXPERIMENT # IOO -Prlnclple: Raw eggs can be conTaminaTed by Their shells. EquipmenT needed: clean Table knife clean cusTard cup clean fork raw egg 2 prepoured agar plaTes clean spoon Procedure: Crack raw egg wiTh Table knife and drop egg InTo cusTard cup. Do noT allow any of The shell To fall info The egg. BeaT egg wiTh a fork. Open one agar plaTe. WiTh clean spoon place a few drops of egg on The agar. Use The back of The spoon To spread ouT The egg. Cover plaTe immediaTely and label iT. Drop half The egg shell inTo The egg. Care- fully pick up The shell. Open second plaTe. Transfer egg To The agar surface by moving The shell around on The agar. Cover plaTe ImmediaTely and label IT. 00 noT inverT plaTes. LeT plaTes sTand aT room TemperaTure for 3 days. Observe microbial growTh by holding plaTes up To The lighT. The opaque spoTs are colonies of bacTeria. A ExplanaTion: Raw egg has few If anyfmlcroorganisms presenT. The shell can be a source of conTaminaTion. iT is safer To noT leT pieces of shall fall InTo The egg. 82 (50) REFERENCES These references may help you in compleTing your experimenTs. They are available in your counTy exTension office. Ask The Home EconomisT To loan you a copy. I. Griswold, RuTh. The ExperimenTal STudy of Foods. HoughTon, Mifflin Company, BosTon. I962 2. How To Prepare and Serve VegeTables. ExTension PublicaTion No. 350. 3. MeaT...LeT's Cook IT RighT. ExTension PublicaTion No. 520. 4. Home Freezing of Prepared Foods. ExTension PublicaTion No. F 270. 5. PrevenT Food Poisoning. ExTension PublicaTion No. 4il. 6. SToring Perishable Foods in The Home. Home and Garden BulleTin No. 78.‘ 7. Home Canning of FruiTs and VegeTables. Home and Garden BulleTin No. 8. 8. Home Freezing of FruiTs and VegeTables. Home and Garden BulleTin No.lO. 9. Freezing MeaT and Fish in The Home. Home and Garden BulleTin No. 93. Available from Michigan STaTe UniversiTy: l. "A Cake Is A SysTem", slide seT and narraTive. 2. "Food Science For Teen Leaders", slide seT and narraTive. 83 ' (5|) APPENDIX | Line Spread TesT The line spread TesT is for The Thickness or Thinness of foods. The Thinner a food is, The farTher iT will spread on a flaT surface. The following page has a diagram for The line spread TesT. To conducT The TesT: 2. Place a sheeT of glass over The diagram. PicTure frame glass is fine. Place a hollow cylinder over The cenTer ring. A TomaTo pasTe can or frozen juice can wiTh boTh ends removed is JusT abouT righT. PuT 2 level Tablespoons of The food To be TesTed inTo The cylinder. LifT up The cylinder and leT The food spread on The glass for 2 minuTes. Take readings aT four widely separaTed poinTs on The rings aT The limiT of The spread of The food. Add The numbers on The rings aT These poinTs. The ToTal gives The line spread value for ThaT par- Ticular food. The higher The number, The Thinner The food. Read The rings carefully. They are numbered in blocks of lO's. The second block is The 'Teens. 84 (52) \ \ x . \. 3‘». ‘- \ K \ “ \ \ \\\\\ l2\31}/6/7890i234587890 APPENDIX 8 Record Book 85 4+! BULLETIN 255J MICHIGAN. SIATE. UNIVE BSIIY FOOD SCIENCE AND YOU RECORD BOOK mariiyn mock food/ nutrition Specialist 86 This record book is To help you evaluaTe and record The food science experimenTs you have conducTed In The Food Science and You learning experience. The experimenTs you conducT may come from The BulleTin, FOOD SCIENCE AND YOU, or you may wish To seT up some addiTional experimenTs on your own. Your 4- H leader, 4- -H YouTh AgenT, ExTension Home EconomisT, home economics Teacher, or science Teacher can give you suggesTions for resource maTerial for your food science experimenTs. in This learning experience you may wish To... ...compleTe experimenTs cencerned wiTh a parTicular nuTrIenT such as proTein 9£_ ..compleTe experimenTs involving a parTicular food group such as breads, or ..compleTe experimenTs dealing wiTh food preparaTion, or food sTorage, or: food saniTaTion. Some of The experimenTs are designed for The novice, and some of The more difficulT ones are for The advenTurer. Keep This in mind when you make The decision abouT which experimenTs you choose. WhaTever your area of InTeresT, selecT noT less Than four experimenTs To compleTe, and you may do more If you wish. Share your new-found knowledge wiTh your family, oTher club members, and oTher members of your communITy. You may do This by demonsTraTions, acTion exhibiTs, posTers, displays, skITs, or any oTher creaTive way which presenTs The informaTion In a way ThaT ls inTeresTIng and Timely To your audience. This learning experience in Food Science Is planned so ThaT you will. ...TesT The principles of food preparaTion, food sTorage, and food sani- TaTion. ...apply whaT you have learned To your own work wiTh food. ...share your knowledge wiTh oThers. ...and mosT of all, have fun wiTh food! 87 NAME Bill SmiTh DATE 6-2I TIME TO COMPLETE | week NAME OF EXPERIMENT? QualiTy of shell eggsdeTerioraTe wiTh aging, and is dependenT on sTorage condiTions. HOW DID YOU SET UP YOUR EXPERIMENT? STore 3 eggs covered in refrigeraTor, 3 eggs uncovered in refrigeraTor, and 3 eggs on counTerTop in kiTchen. Break one of each afTer l day, 3 days, and 7 days. Observe air cell and heighT of Thick whiTe. WHAT RESULTS DID YOU GET? Eggs sTored covered in refrigeraTor showed small air cells and loTs of Thick whiTe even afTer 7 days. Uncovered refrigeraTed eggs showed large air cells. Eggs sTored aT room TemperaTure showed much larger air cells and smaller amounTs of Thick whiTe as Time Increased. HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? Be sure shell eggs sTored covered in The refrigeraTor, and avoid leTTing Them siT ouT for long periods of Time. HOW HAVE YOU SHARED THIS KNOWLEDGE? Told my moTher and sisTers; did display for CounTy 4-H AcTion Day; did demonsTraTion for my club; made posTer and displayed iT in supermarkeT by egg case. 88 NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? 89 NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? 90 NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? 9| NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? 92 NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? 93 NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? 94 NAME DATE TIME TO COMPLETE NAME OF EXPERIMENT? HOW DID YOU SET UP YOUR EXPERIMENT? WHAT RESULTS DID YOU GET? HOW CAN YOU USE AND APPLY WHAT YOU HAVE LEARNED? HOW HAVE YOU SHARED THIS KNOWLEDGE? APPENDIX C Slide NarraTive 95 A CAKE IS A SYSTEM Slide seT prepared for 4-H leaders and oThers working wiTh youTh and food. SLIDE NUMBER 2 NARRATIVE A cake Is a sysTem, Prepared by Marilyn Mook, Food and NuTriTion SpecialisT, Michigan STaTe UniversiTy. No endorsemenT of producTs is InTended or implied. WhaT are The parTs of a cake sysTem? Flour Sugar ShorTening Baking powder Egg Liquid SalT Afld a recipe for The righT proporTions. Why flour? Flour forms The framework of The cake. The proTein in The flour is called GLUETEN. When This proTein is moisTened wiTh liquid, The gas given off by The baking powder rises Through The gluTen sTrands. And The cake rises. Too much flour? A heavy compacT cake, because There is Too much flour for The liquid To moisTen. NoT enough flour? A IITTIe cake, because There is noT enough gluTen To form The proper framework. Why sugar? Sugar adds flavor and Tenderness, and helps The cake To brown. Too much sugar? A Too Tender, Too sweeT cake, wiTh a sTicky crusT. NoT enough sugar? A Tough cake, pale crusT, and noT sweeT. Why shorTening? For Tenderness. And flavor and color if you use buTTer or margarine. SLIDE NUMBER 20 2| 22 23 24 25 26 27 28 29 30 3| 32 33 34 35 36 37 Marilyn Mook 96 NARRATIVE T00 much shorTening? A greasy, crumbly cake. NoT enough shorTening? A dry Tough cake. Why baking powder? To make The cake rise; To make iT lighT and airy. Too much baking powder? A holey cake, and perhaps low in volume because The gluTen sTrands sTreTch so much They collaspe. . NoT enough baking powder? A flaT cake. Why egg? Egg adds flavor, color and some proTein for sTrucTure. Too muCh egg? A rubbery cake, maybe chewy, maybe low in volume. NoT enough egg? The baTTer may curdle because The egg yolk keeps The faT from separaTing ouT. And The cake may be dry and low in volume. Why liquid? To dissolve The sugar and salT. To moisTen The flour proTeins. To dissolve The baking powder so gas can be formed. Too much liquid? The proTeins are moisTened Too much and can'T sTreTch. And The cake is dry and heavy. NoT enough liquid? NoT enough moisTure for The gluTen so iT doesn'T sTreTch. And The cake is dry and heavy. Why salT? For flavor. To bring ouT The characTerisTic flavor of The cake. T00 much salT? A salTy TasTe, and maybe low in volume. NoT enough salT? No flavor. IT looks preTTy good, buT TasTes preTTy flaT. All These parTs work TogeTher In The cake sysTem. When one parT is aITered, The whole sysTem is ouT of whack. And ThaT's why a cake is a sysTem. Food and NuTriTion SpecialisT YouTh Emphasis Michigan STaTe UniversiTy APPENDIX D OuesTIonnaire 97 FOOD SCIENCE AND YOU ReTurn To Marilyn Mook, M.S.U. *3. *4. *5. *8. *IO. in The envelope provided. How old are you? Where do you live? ciTy counTry WhaT experimenTs did you do? LisT The numbers: Did you enjoy doing These experimenTs? yes no so-so WhaT did you learn? How did you share your new knowledge? Are you a Teen leader? Can you use your new knowledge wiTh oTher members? Would you like To do more of These experimenTs? Were any parTs noT clear To you? AnyThing you would change To make This projecT beTTer for oTher young people? *These quesTions were used on The quesTionnaire for The adulTs. “I MICHIGAN STATE UNIV. LIBRARIES llllllllllllllllllllllllIllIlllll|||||lllllllllllllllll 31293105390573