STfiJLL UH CL} TELI'II.) ”£2 X5 OF POW-EU '45 i Oh P0311? J Ciils’s FAEIQM 3? mm mmmu A :J ABSIfiACT StMfith to the School or (Smut: Studies of Ricédgm Stat. University of Agricultzn‘o and A9911“: Scionoa in partial fulfilment of the "quiz-3mm: for the dagme of “Wm OF saw Without of Farm Crap. 1.957 hm Hiya-ate STUDIES 03-! COKE-IT IQIHR‘G (F POTATO-3.5 FOR POTATO Gill-’3 HAKIRG Ventilation Ind modified abacus-primes were ayplied to Run“. Rural potatoao during conditioning, aftur storage at ho or 50°F, and their effect on potato chip color was deteminad. Poor ventilation did not product “ti-factory chipl, Ind was Iccmmied by serious dour 1! very high ”lativu huuddity relultod. Ventilation to give a relative humidity of abnut. 6523 gave for more camaractory (:3de than did ventilation with lit near 100% relative hmaidity. Carbon dioxide in relatively high amount- (10% in air) seemed detrimental to good. conditioning oven in tn nhmp‘nare at ut- isfactory mlativo humidity. A drier Inmaphare, that. produced notable writings, as provided by use of large quantities 01' W12. This was not offactin in oozxditionim; to produce good chipt. fltrogen gas was Mghly dstrizmntal to good cmfiitianingo 511331,.=s on cmmnum 0F 133131.33 Em you?) anus ms. MM 13! mum Emma-mo A Trig: '13 memud in partial f ali‘ illgmfllt of tho mummenta for the dogm- or mstfrm as." “aim. Departmnt of Farm Crepe 195? ACKH‘JIJAZB “Li-HS mo writer with» to cxpreu his airmen appreciation to Professor B.‘ 4. Wheeler mt Profuse: S. '1'. Baxter for their zuidana. IXI‘EJD ’JC TI‘U N . o o o Rafi u’F 1.124.311:sz MAI .3111sz o a o o o imTZiJlS o o o o o .J 11115111313 . o o o o 0 31503351031 . . . . . 531.2111 3 g g o o. o I LITJEEATUL; CITED 0 o v L“ l. 1533’}: 5%. Li: £51“;st Improving tho color of potato chip! 143 I wry Lupox'tant subject for the potato cidpa industry. Potatoes arc stored at. c low tw-ngoratm in order to prevent decay, aprouting and loss or weight. Potatoes taken directly tron In"? mange produce dark colored chip... Such potatoe- must be conditioned at 70° to 80°F until they have recovered sufficiently for use. Such research has boon dam on tho comiitiooing, but. still former studio: m moaned. For mama, Smith (13) remarked that on teem-ot- randy is medal of the following factors as affecting quality of chips. (Ihtoraggo and conditioning ue'zuparnturos (bhtorage and conditioning hmfldity (ch83 of cfndcalc for retarding, sprout growth of potatoes (Mum of modified atmosphere, carbon dioxide, nitromn, ctr... for in- flow-wing zooming cumr content and sprouting (0)1250 of atom, stiglana no other moms which rosult. in incmaaad mopiraticiz cs affecting reducing; sum-r content of potatoos and possibly improving tho color of chips. This thoaia deal: with an inventigation of some of hose problem, capeoially cmmitiomng humidity, modified atmosgihore, etc. 2. REVIEW 0? LITERATURE Sweetman(15) reported that chips made from tubers stored between 32° and 370E were darker than those made from tubers stored between 40° and 550E. The fact that the sugar content of potatoes increases when they are stored at comparatively"ow temperatures was first demonstrated by MuV‘er-Thurgan(11). It was supported by App1eman 0 ). Wright(18) studied extensively the re‘ationship between storage temperatures and potato sugar contents. He put tubers in storage at contro‘”ed temperatures of 32°, 360, 40°, 50°, 600 and 70°F. He found that the Wower the temperature, the higher the sugar content. Barker(5) demonstrated the sugar content gradua“y increased in potatoes when transferred to 1ow temperatures. If, however, potatoes which ware rendered sweet by pro‘onged storage at ‘ow temperatures, or partial‘y sweet by storage for short periods, were transferred to ‘5°C a rapid desweetening occured. He found that on changing the temperature to 15°C the respiration increased rapid‘y, and after 18 hours reached a peak va‘ue which was rough‘y seven times the previous respiration at ~1°C. Denny and Thornton(7) found that the brown co‘or corre‘ated we“ with the reducing sugar, Iess satisfactori‘y with the tota‘ sugar, and not at a‘t with the sucrose content. In that test tubers of Russet Rura‘ that produced chips very Vight in co‘or were Vow in reducing sugar but not in sucrose. Denny and Thorntcn(9) reported that the va1ue 5.0 mg of reducing sugar per cc of Juice was found to be the dividing iine. Tissue with amounts higher than this furnishing chips too dark brown in color. for awreafiy satisfactory commerciai cc‘or the veins shcu1d probab1y be as 10w as 3.0 mg. their experiment showed the temperature of 9°C was a favorab1e one for storage for potato chip manufacture since many of the varieties were maintained at tow reducing sugar values for periods of 108 to 131 days after start of storage. “ Wright et 11(20) acquired evidence showing that storage be‘ow 40 F for more than a few days was iikely'tc resu‘t in potatoes that were unsatisfactory for processingo-regard‘ess of subsequent attempts to condition them.j According to ArreguinfiLosanc and gonnerial, the decomposition of starch is accomplished by phosphcrstse which attacks starch at ‘ow (air?) temperatures producing g‘ucose-i-phcsphate. But at high temperatures(68° to 86°F) the starch remains unattached by phosphory“ ass. Effects of modified atmospheres on potatoes have been studied for many years.“ Thornton (16)treated tubers with 30% and 60% of carbon dioxide in the presence of 20% oxygen for various periods up to 2‘ days at 21°C. He observed that the rate of respiration and specific conductivity of ‘eaching from the treated potato tissue increased. Also, the cata‘ase activity, PH, reducing sugar content, and sucrose in the extracted Juice were great‘y increased over that .' found in the ccntrc1. 0 Danny and Thornton(8) reported the rapid increase in reducing sugar which occurs in potato tubers stored at 500 was prevented by storing the tubers in an atmosphere containing 5% of carbon dioxide. it the end of two months at 5°C, the reducing sugar content of the carbon dioxide treated ‘ct was approximateiy one—fifth of that of the contrc“1ot in air. ‘ _ However, Denny and fhornton(10) stored potato tubers at 29,5° and 936 in atmospheres containing 0, 5, and 20% of carbon dioxide and 21% offioxygen, and determined themsercaae content of the Juice at intervais of 30, 60 and 90 days. They found the genera‘ effect of carbon dioxide upon the sucrose content was to great‘y increase it, about sizafc‘d at s' and 7°C. At 2°C treatment with carbon dioxide first retarded sucrose increase, as compared with the untreat- ed, and then great‘y increased it. Barker and Saifi(d) studied the effects of nitrogen on potato tubers at 10°C. ‘ Changes in the rate of carbon dioxide production, sucrose and heroes contents, 1actic acid content, aicohc1-soiub1e sc‘ids, PH, and a1cohc1 content were investigated. In nitrogen, the carbon dioxide production showed a compiex form, the initia‘ phase consisting of an increase fciiowed by a.marked decrease to a minima‘ rate after ,6 to 9 days. In air, sucrose and hexose contents changed 1itt1e, but in nitrogen, sucrose content decreased marked‘y and the hexoses were either stands or increased: Under u anaerobic conditions, ‘actic acid accumuflated progressiveiy; a1coho1 content did not increase unti‘ after about 7 days. Subsequent‘y, the rate of acoumm‘ation of ‘actic acid decreased and that of a‘ccho‘ increased. During the period in which 1actic acid content increased, an approximateiy equivalent increase occured in a non-sugar, non.1actic, a1coh01asolubie fraction. ‘ a‘thcugh early researchers considered that the reducing sugar in tuber tissue caused the dark brown color of chips, the idea has been modified to some extent. According to batada and hunka1(17), amdno_acids combine with reducing sugar to form the undesirab‘e coicr which often occurs in the process of making potato chips and french fries. In order to store potato tubers without decay other factors than the low temperatures and modified atmospheres have been studied by many workers. Burton(5) suggested that the tubers shoufid be kept in the dark in a venti‘ated storage. a‘though there shou‘d not be rapid air movement over them; the atmosphere shcufld be neither so moist that fungai growth is encouraged, nor so dry that water floss is excessive. Bright and hhitaman(2‘) recommended that the re‘ative humidity of a potato-storage house aheu‘d be 85 to 90%, to prevent undue shrinkage through toes of water. Insu‘ation was aisc“ suggested to prevent the condensation of moisture on the sails and ceilings and the consequent undesirab‘e wetting of stored stock, which favors the development of decay. achii’atter and Eichey1i2) noticed that when the potato tubers are stored in open-mesh seeks the ‘ceer tier of snake shou1d rest upon a s‘atted or fa‘se ficor of wood, because bur‘ap next to a concrete or earthen f‘oor wi‘i rot. _ imith(1d) reported that contra? or temperature and venti~ totion is particulcr1y important for potatoes to be made into chips. “ It was ciao found the greatest amount of decay occured in the Vote which had been moot eovcrc‘y bruised during harvest- ing operationa. I mince most of tho paporc concerning storage were concerned with profi‘cne of decay, aprouting or shrinkage rothor than - with potato chip quc‘ity'ee such. it seemed worthwhi‘o to investi- gate the matter further. . 3. *1" humat ii: a}. pot. twa B's-3m mad 1:: hot}: £§4>-;¢1.;-~.:1t I u»; 11. The potent-yea 1‘ .;:.r nape-41.4mm 1 Mrs. pa wacwi at. Law bit; Maya: i....:arst Ewtim 6:11 kept in n 1144842? babe-«ant it weak 53°F f-Jr' 75) (3338. Tm tuba}? 3.18mi f9!“ flickgliflrjuvblstp :1 I m h- x‘mamc‘. M Lila Citj mad . ”no“. u - A ' ‘ 1 . flare—:1 at hu r for 72) £15.; a. 0132', new. tubers mm max: 191‘ tag mam. u. :5 I 3312!; Experbwnt I riot-1 Gan: acre prepared as shown in Figure 1, the covers bang made air-ugfiat with macaw-sensitive tape. he v-ulmaa of a mm was 15.70 liters. Forty tubers wi'aici’: Deemzied about 6.53 litez'u were put into tin: can on WWIIbm 2h. Fourteen can: w..m um and tubszzrs in each on: fire wanted in dixi'emnt ways. 1b replication was made because Media-tent I m aonfiucbed u a prelimLInry test. All the cans were kept. in the laboratory of 3am Cups Depart-mat. under the roam temperutum of 65° to 75°F. 1h. treatments were u fungus: I) Ventilated with 1% 003. A» mixture of 99% of I1? and 11 o! 002 was passed tiwough 12:8 can at C "to of 120cc per minute. Appmtul for this is (195011de in Figaro 2. L knonm «Inactivation 0f sulfuric acid was dropped. into 1 concentrated taxation of locum amount. at a «1mm rate so as to get the constaz'zt mum of air and C02. b) sztilated with 5% 002. A mixture of 9553 of air and 5,1 of 002 m aiadhrly plugaared and plum twang": the can. 0) Ventilated with 10;: 002 u wow. :1) Ventilltsd with air alone, n show. 0) Roistomd with water and 0115;}'.t1y ventilated. Tho when were moistened with water, bafore placing in the can. Both of the ventilation pipea attachvd 1n the cm were closed by screw cramps, no no air passed through those pipes. Scotch was was not used an the boundary 01' container and cover, :0 sums air could pass throng-3h that boundary. Thu cover was removed. once a week when the eagle was taken out, Figure 1. Container of Potatoes 10 then put on again. t) mot. moistemd with stator and slightly matilatoci. The tubcm not must-arsed with want were put into the can. Conditions of the can v-ro preparad the sum as (9). Perfect vmtilation was also only once a week. 3) Poorly wr'xtilatcd with tit. Th: cover was sealed by scotch tag-o and ventilation pipes were closed by Icrev mp0. Air 3mm was made once I week when the ample was taken out. n) Poorly watilnted With 2.5;; 002 ind 97.513 air. The can for that tmatment was prepared in the nae way as (5;). In order to mica the mixture of 57,38 the pipes of potato fines. can was Opened, than otdtablo luv-“aunt of carbon dioxide was introducod from the upper pipe. After the substitution or air by 2.5% of anchor: dioxide was tuliillad, the pipes were closed by urea era-4m. The can was owned and tubezs wore moaned to air once a we}: while the samba was tax-an. After that the inside abscoaphesre was made the mac as its previous state. 1) Poorly ventilated with onvl‘jen. moors mm kept in Oxygen using can prepared u in (5;). Chang-go of go. W 02100 0 mask. 3) Poorly ventilated with 2.535 602 and 97.553 oxygen. mt lot was grep—mod 111:0 (21). First the cm: was filled with oxygc-m. Carbon dioxid. was than ad.;ed to the can so as to mun a mixture of 2.51% 002 am 97.52%; mast). Change of gas was once a weak. k) Poorly ventilated with nitrogen. Fiathod was win: to (1). 1‘, 1) Poorly ventilated with 2.525 (:02 and 97.5.2 nitrogen. Imthod use like (3)., m) Pom-L7 mutilabod with air an: drlod with 03012. The can was pro-pared 112cc (g). A dish containing 253g of Cafila'flao was put 1:181:10 of the can in onler to take out wcfietare. Air and 0: 101m fluoride were changed one. I week. a) Poorly ventilated with air and (/32 was removed by “(0292. Ethel. tubacr mfaceo were mated with 1} of Ca(3€~5)2 then stored in the can. Air was flanged one. Omsk. o) Shocicad the tap part or tubers. mistemd blotter was Md «1 a flat cement block and tubers were dropped from o height of 7 feet. Shocked part was moistened and marked. The top part refer-:- ad to the dominant part of polarity. ‘I'ubers shocked the top part were 3619ch and marked, then put into a heap tack and l'tomd 1n the ram. p) filmcked the and part of tubers. Tmatad arms as: (a). The and part refm'rcd to the: campsite of the top part. q) Shocked th- eme part of tubaz-a. Treated an. as (o) and (p). The side part referred to neither top part not and part. 1*) Framed by 17 pantie on aides of tubsra. Three tubers were laid on a «want block an: another cow-om block as laid on the tube”. mo block weighed 5?) Wu. 3) Pmsscxl by 33 pounds on aides of Where. Treated mm as (r), and two blocks mm put on the tubers. t) Pressed by 50 poms}: or: the sides of tuber» Treated same no (r)'and (a). Three blocks were put on the tubers. me next Mmrimenu were conduct-ed to dam—arcing the 13st from dacay in difi‘arant condition aftcr five weeks of ccmitioning. u) Sprinkled with water once a weeks. meaty tubew were put into a 7.633 1. acct-ml can 81' Wt sprinkling with watch “my cover was scaled by scotch tape. The can was opwmd and tubers Iter- aprinizlad once 8 mic. v) Sprinklod. with Inter once a day. Treated Mac as (u). The cm was owned and tubers were acfinalad with water once I day. t) Moved 1mm miatm with calcium chloride. A dish containing; the chemical 8t 8 rate of 5/31 of the weight of'tho tuber. was ran-389d once I week. I) Just sealed. iio chemical was applied. The can we opened and the air dang-.11 one. a weeks. A littlo cam:- was condenscd on the surfaces of twat-a and «at. y) Kapt in Open 81!“. inc war I” not put em. Experiment II The same can: mm used no in Experiment. I. Fifty tubers ware put into each can. As the potatoco occugiad 7.30 liters, the unoccupied syaco U88 calculated to be 6.“) liters. Summoning tests were corflucted in cm laboratory of Farm Grap- Deparuwnt unis:- the temperatun of 65° and 75°F. me cane were treated in the different ways which warn described a fallout _-m r ‘13 Figure 2. Ventilation apparatus for dry air. Air intake ¢ ' x mgcs; ) (l) 002 generator Gas mixer Tube container Pressure Pressure wate: equalizer reducer pump + regulator Figure 3. Ventilation apparatus for wet air. A/ boo Moisture Air MOistened donner catcher blotter container /Z'—“"1T° suction pumj Tuber container 1 4_ a) Kimmie“: vita dry air. Four t'ez.;-Tl.icrmio-na. _ 3m mama an inpatient I was applied. air flow was 12:33“ put minute. b) Ventilatd with wet air. Four ugliest-ism. During; two first bio min-m of coniiuoning, “they dry air was used in the can: way as (a). after that 329cc par minute of air, which was Cw;osw to be 1:132 minim: misfits, was ventilated. I?» apparatus 15 3 mm in Figm 3. c) mutilated with 1:233 502 in dry air. time sustiwci u Engin'flmflnt I (c) was mum. d) Poorly ventilated with dry sir. Commuter was tooled with scotch tape. 0') Paul: ventilated with not air. Potatoes mm monitored with mm: then put. into can. —' The can val Iuflad with £03143?! tag”. f) Poorly ”3%th with 13.5 C932. a} fin gram of 641513 was put into can. 33:: ventilatim. 31) fax: pans: of £3612 was put into can. :fio ventilation. 18 a) Grade of chips. ' fires tubers were taken tron each lot. three weeks after starting test, and five there at. h and 5 weeks. The manila portion of the tuber was sliced by the chip slicer. Three pieces ware picsed up frma each tibi‘, then soaked in cold water fur 10 minutes. Mire? that they were fried in cotton med oil at starting taqmratum of 365°? until they were sufficiently cooked. When bubbling ceased, indicating. the cmzpletion of moral of Katy, the slices new well fried. Tmaa chip! 1mm iraji‘a‘idually scored according to the steward 01‘ Coughlin and on event} was calculated. True lower the grade, tho better w quality. Grad-as of l o 3 or. desirable and below 5 is acceptable for calling. Results are shown in Table I. ‘16 TAfiLfi 1. Tho chips produced after the storage cozxfltions in Experiment I mm given the follouirng; chip grades. treatment fitart 1 week 2 week.- 3 weeks I; mks 5 weeks a) Vent. 156 002 5.66 5.00 5.66 5.20 5.25 h.0o b) Vent. 5:! 002 5.66 6.00 5.00 6.“ 5.60 6.60 4:) Vent. 103 002 5.66 6.66 h.33 5.60 5.1.0 6.00 <1) mm. an- 5.66 5.16 5.33 5.20 5m 3.00 a) new. 320 5.66 6.00 5.33 5.60 6.00 6.20 t) Not mint. 5.66 6.00 5.66 5.00 5.60 5.60 a) Poor'vunt. air 5.66 5.00 b.66 6.00 6.50 6.60 )1) Poor mt. 002 . _ and air 5.06 6.00 5.00 6.00 5.60 6.20 1) Poor vent. 02 5.66 5.00 5.00 5.60 5.20 5.00 3) Poor vent. I C‘12 ’ 02 5-66 6.00 5.33 5.60 7.00 6.20 k) Poor vent. 02 5.60 5.33 6.66 6.20 6.2.0 «- 1) Poor vent. 002 o 02 5.66 6.00 5.60 6.2;: 7.00 .- 3) Pour. vont, air and 63012 5.66 5.66 5.00 5.20 7.00 6.1.0 :0) Poor wont. 111' . and 0.0.03, 5.66 6.66 5.00 5.1.0 5.00 5.00 o) 8000): top 5.66 - 5.00 6.00 -- - p) Shock and 5.66 5.33 5.00 6.33 -- - q) Shock aide 5.56 5.33 5.66 ‘ 5.33 - n 1-) Press 17 lbs. 5.66 5.33 h.66 5.66 - ”06 0) Pros: 33 lbs. 5.66 6.00 1666 5.00 - 5.33 1.) Press 50 lbs. 5.66 5.00 5.th 6.00 - 6.33 .1- n.--» M m"-.. c an am 6.15:} €415 .. .- 17 b) Decay met 1. Strain: of tubers decayed during each period was éivic'icd by the nmnbor of tubers at the baginning of each period to give the! fiegxw of storage. The results were shown in table 2 as percentages. 36:31.; 2 Decay test 1 Percentage arid-w after interval: of utorago. 0-2 week- 2-3 .660. 3-1. mks 6-5 ml:- int. 1% 002 A 03 0;:- oih 0% Vent. 5:3 032 0 O 0 h.2 Vent. 10% 002 o 0 o o Vent. air 0 o o 0 flout 320 o 0 o 16.7 riot. mist. o o o 0 Poor vent. .1:- o o 10.3 1.7.6 Poor vent. €02 4- air 0 O 0 29.2 Poor vent. 02 O O O 3.16 Poor vent. co: 0 02 0 0 O 16.7 Poor vent. N2 0 32.3 85.7 100 Bar vent. 002 . “H2 0 29.1. 100 .. Poor vontuir 0 0.012 0 0 0 0 Poor "at. air 0 7 8 o) Decq test 2 . Same kind of traament as (‘0) was «inducted using; twenty tubers per lot. The data were amen at five team after altar-ting, test. Ha- aultc are mm in Tabla 3. 353.535.” 3 new test 2 mmt ' Douay Prawns. 83112161661 once I rock. Wot 10035 Spri nkled one. a 63;: . Hot 65 Dried by 6-81; Dry 0 Ventilated one. a week. Dry 35 Control, put in Open air. Dry 0 Expertwnt II ‘) Grade 0‘ 031133.- 917. tuber! were man for uerple from each or the four replicated cam. and” or chips vero m in the can» u Ewart-neat I. Results are shown in Table 1.. - 2032.2; 1. Results of scoring chips in Elxgmriuent II 19 .Start 3 weeks 5 weeks 7 mks 9 weeks Vent. dry .1: 1 9.50 6.60 5.60 3.20 (2.60)» 2.60 2 9.50 0.61. 6.1.0 3.16 (6.00) 6.00 3 9.50 7.60 5.00 2.69 (3.25) 3.1.0 I. 9.5-0 6.6- 5.60 3.20 (3.1.0) 3.60 Ava-ego 9.50 7.1.0 5.65 3.12 (3.31) 3.1.0 Vent. vet air 1 9.50 7.60 6.20 5.60 (5.60) - 2 9.50 7.25 5.60 6.1.0 (5.1.0) - 3 9.50 1.20 6.20 6.00 (6.00) .. h 9.50 7.60 6.60 6.20 (5,60) .. Average 9.50 7.36 6.25 6.10 (5.70) - 00)... 10% 002 9.50 6.00 6.60 6.60 (7.00) - Pom' vent. dry .11- 9.50 7.75 - -- - Poor vent. not .1:- 9.50 7.1.0 .. .. .. Poor vent. 10.: 002 9.5.0 .— .. .- .. Poor vent. 50 0.01.2 9.50 7.00 .- .. .. Poor vent. 103 0.012 9.50 8.1.0 - on no wowed at waning tannerntuxv of 370°l". Figure h. Improvement of chips color after seven weeks of conditioning in moist air and dry air in comparison to check made at.start of eXperiment. check: start. wet : wet air ventilated. dry : dry air ventilated. Figure 5. Improvement in chip color after 3, S and 7 weeks of condition- ing in ventilated dry air. ; 0.7 ’ u! 3 : chips were made at 3 weeks after start. 5 : " " " at 5 weeks after start. 7 : " " " at 7 weeks after start. .28 Figure 6. Results of chip color at 3, 5 and 7 weeks of continuous exposure to moist air. 5 NET 3 : At 3 weeks after start. \J'l At 5 weeks after start. 7 : At 7 weeks after start. 33' Figure 7. Comparison of chip color at 7 weeks from 10% 002, wet and dry vent- ilation treatments. f b) Percentage height 1050. The percentage weight 1050 0101.3; 0 period was dividrad by the tub-era weighed at the beginning of the period. izeesults 9. re shmn in Table 5. T100033 5 Percentage weight loss of potatoes at 3; 5 w 7 week! after start of Myexfiwnt _ . f A4. Start-3 week. 3-5 week: 5-7 weeks from a. ._.._ A m “r.— ‘fl‘.‘y*."-.w Vent. dry uir 1 0.013 _0.365 0.33% 1.35% 2 0.52, _0.17 0.02 , 1.11 g 3 0.57 0.31 0.37 1.25 h 0.59 0.07 0.52 1.58 Average ' 0.57 '0.33 0.02 1.32 Vont.‘iat air 1 ‘0.50 .o.lh 0.26 0.90 2 0.L2 0.10 0.10 0.76 3 0.05 0.11 0.30 0.70 h 0.39 ' 0.10 0.22 0.71 Anerago' 0.hh ' 0.13 10.20 0.70 that. 10% 002 0.50 . 0.30 0.33 1.17 Poor vent. any air 0.00 0.11 0.13 0.32 Poor vent. wet air 0.10 - -- - I’oor ant. 10% 002 0.21 - - -- the. vent. 50 0.012 0.73 - .., - Fbor vent. 103 03012 1.1}. .- .- .. c) Percentage 1:50 fram decay. Decay 1200 was tested in the saga way as in Experimsnt I. The ‘\ results are sheen in Table 6. 10.305 6 Percentageloss from decay of tubers at 3, 5, .7 Ind 9 weeks intervals .- .* 336. .0qu fit? 2"!" ‘ _ V C ‘ . . In” Start-3 week: 3-5 week. 5-7 week: 7-9 weeks mu. airy .1: 1 ‘ 0:0 ' 0% 7 5.0% 0.: 0. 2 0.0 0.5 27.0 0.5 3 ' 0 ' ' 0 0 5.7 h ' " 0 0 0 2.0 Average 0.5 1.1 8.0 3.2 Wait. at air 1 2.0 ' 0 66.6 100 2 11.0 11.6 69.11 100 3 0 2.3 15.3 100 I. ' 2.0 ‘ 0.5 50.7 100 Average 2.0 2.8 62.0 1.00 Vent. 10% 002 0.0 0 13.1 53.5 Poor vent. dry air 3h.o 90.1.. 100 .. Poor vent. wt air 100 .. .. - Poor vent. 10$ 002 76.0 100 .. .. Poor vent. 5g 0.012 10.0 97.5 100 .- Poor vent. 102 0361.2 0 100 - a... 26 Figure 8. Tubers that wewe ventilated with dry air, nine weeks from dormant potatoes at beginning of eXperiment. 2'7 5, 1719:3'0‘7‘752 "q No treatments in Experiment I mar-e rimlicated. Eowever, some pi't-enomeeu mig‘rt be mvoeled. Tubers ventilated with 12-000 per minute of room air age-eve the best chips score. Generally speaking, csrbon dioxide inhibit the L:nprove.:zent of chips color, but 10:5 032 VBJtiIR'LiOB resulted in the best at two weeks after start which is worth fur ther- testing. Poor- ly vazitilatsd conditions awued in var: on: atraosph-eres were umgsim'ole. P: 1:5 - mint?“ and nit-r9393 "‘ CO; lots were the poorest. Black spots were noticed g in the center portion of chip. which were made from the tube” kept in that. 7 £083.. ‘ é Results shown in Table 1 reveals the necessity of aerobic respiration of tubers 601-1 :13 conditioning; in order to improve Quips quality. Shock must be avoided, because often bnmish spots simmered in the chips rm shocked tutors, cozreoponding to the position to which shock was given. This would indicate sow-xi Mnjuried pototuea should be used in quality ©1111) Mx.mactm. Pressing must also be avoided because of slaw 1...};rovozaent of color. ”fable 2 show that it is necessary to apply ventilation or chemicals (1.0. 03101101 amends or calcium hydroxide) to prevent the decay. Table 3 shows wet and poorly vsotilatod tubers tend to decay easily. Experiment 11 was attempted to get information about the effects of m- lative 7100;101:0100 of vmtilation air. Tm tubers which had been kept at 1.00? for any. were considered 7651"] (111310011. to cm'tdtion to satisfactory chip color, but they were sufficiently recovered by applying dry air ventilation for seven weeks. The relative hmidity of the air ILOVG the pot toes that were ventilated with dry air was £0000 to ‘00 a;proxi.ately 853 51.51. Dry air ventilation lot He. 2 should be considered to be a failure boos-.100 the ventilation pip-0 was choked by coademod water from second to fourth weeks after starting test. 23 In the cam of wntllation viii-'2 130.3; rolatlvo h‘mldity air, the chip color did not r-:--cov;-r sufficiently. This fact might w emphasiaod because saline of {5.3 camercial cozxditlonizm “’3me are. not. Improviszg of chi,» color was; f::.ct...:-st at three weeks aft-m atarfi‘lu; men 1053 13°32 HM woulated. “float fact was mxalogouu to the or so of Exawor'iuaegzt I. Tale 5 and 6 show that itsigffii‘icamt sportage daring corral no. im; occumd when dry air was used in ventilation, out. agortaga was axiom in other woos. Application oz" 53 or log calciua chloride put c. :1 did not provmt the decay of town. In how-Locus I utilizing large snow“ of calcium chloride did act. holy Lngrovomat of chip color though it promoted decay perfecm’. At. the pmsont time, the write-r camwt reconnand the applicaiion of calcium chlorido during cmditloning. Imide relative hmddity was hoot US to 90 percent when (try air Ufifi ventilatod. Too dry atxoosyhoro seam undwsimhlfi as well as too wet fits.i)2ph;il‘eo Both shrinkage of pots-toss and Lowdlnation of oat-or on the surface of tu‘oozs must. be avoided. Ventilation and modified,at«¢3pherua ware apglicd to potato tubers daring coxfiitiozzir.g, after storage of L0 or 560?", am“: their eflact on potato chip colqr uaa deturmined. Poor vaatilatidn did not prufluce sat- isfactory claps, am we acumpanied by s-.:ri.ous decay if wry high relative Ventilatiun to giva a rolativa hunidity of bout 85$ gavw far mole aat;éfact9ny ch19; than did ventilaticn with air agar 136; relative humidity. carbon diuxida in r&latively high am043ts 53 mod dairiaontal to good can- ditioning even in an atm_59hqre at satisfactory relativa humidity. A drier atmoaghure, that procuced notable shrinkaga, was pruvided by use of large quantit;as of 63612. This was not effectivs in canditioning to prouuco guud chipa. Jitrogea 343 was highly datreuintal to gaod conditioning. 1. J. h. 5. 6. 7. 8. 9. 10. 11. 12. 30 LIE£¢E3E£ C "1'1: 3 Applause, G. 0. ”Physiological behavior of enzyme and carbohydrate tramfommtion in gttor ripening of potato tuber“. Bot. Gal. 93! W315: 1911. ”regain-Mama, B. mad .1; Bow-mt, "Expewaents on sucrose formation by potato tuber! u influsnced by wi.4>eratura.' Plant Physiolog 2ht720-736. 1919. Barker, Jr. 'Amlytic “nude: in plant reapimtiam N." 'Tho r0- htian of the respiration of potatoes to the concentration of sugars and to tho accuaulatiun of a depressant. at 1m: tagzparaturacfl Part. 1 m0. Roy. 5000 won 3 112.316.335, 1933. .l’ E Baker Jr. and A. 3‘. $8111, “Studies in the rewimtory and carbo- hydrato metabolism of plant tissues. 1 Experimental ltudiea of the for Jauon or carbon dioxide, lactic acid and other productl in potato tubers under anaerobic comiiuunm" Proc. Roy. Soc. London B “00362-305. 19520 Burton, w. a. '1)» Potato' ”Jun, 191.3. g ”m1_fliu._£&7iw III; 7.1a m ‘j I \ .. . l Gaughlin. F. J. 'h‘Baeab-‘ad It thé Production and Technical 1518181031 men. '3" Nathan Potato 029.1,? lasting“. 1951;. Benny, F. E. and H. C. Thornton, ”Factors far calor in the production or potato Clap“... COL-Mb. bcyca TEQJWQI‘. Institute 11'231-31}3' 1,7h0. Denny, E". E. and H. C. Thornton, 'cmbon dioxide prevents the rapid ncmuse 1n the reducing; sugar at low tag-permuted Contrib. Boyce Thampaon Institute 120944., 19m. Donny, F. 3S. and “N. C. Thornton, 'Potato varieties Inga-fuming characteristics of tut-wear in cold strange, and mitehility for produuticm of potato shim.“ Contrib. Boyce Thawson Institute 121217-252, 191:1. now, P. E. and H. C. Thornton, "Intemlationahip of storage tem- perature, concentration, and time in thc effect of carbon dioxido upon tho sugar ember-1t of potato tubers.“ Contrib. imyca mo.upaoa Inautuza 12 .3513} 73' 19:32. Billet-flurgon, 8. ”fiber suckeramiufwg 1n Pflw;w.;t=:ailen in F0150 nimiamr Tarps-rattan. Kin Benn; nut Kenntniss dea Stoffwechaela der Pflmzze:’;.' Land". Jaimb. 11'751-0'20. 1002. Scmletter, J. C. and B. h. Richay, "Textbook of genaral tiorticulture" PE}. 350. 19%. Ewing 0. “bi-oomh mean of the potato chip industry.“ Asterican Potato Joana]. 273113.120, 195:}. 1h. 15‘. 16; 17'. 18. 19. 202. 31 Smith, 0. ”How to grow and atom potatoes for the chip industry." American Potato Journal 32:255-271., 1955. 33369121133, £4. D. "Color of potato chips as influenced by storage te.sz;)en‘at‘umo of the tubers- md other factors.“ Journal Agronomy 38383113?! m'h79'1490. 1930. flxornton, 3. C. “harbor: 021103138 storago VIII.“ “Grieguical champ. in potato tubers resultinf: from upoauro to carbon dioxido.‘ Contrib. Boyce lhwxplon Imtituta 73113-118, 1935. Honda, 1.. S. and R. Enamel. “Tho variation in reducing omar content in different varieties of potatoes.“ hon-loan Potato Journal 32:132- M, 1955. Wright, Dy 6. 'Somo physiological “was of potatoes in “wage." Journal, Wow Research h5t5h3~55§, 1932- wright, R. 6. “Th. cooking quality, palatability, and cubomrdratc communion of potatoes as influwood by storm Wanton." u. s. n. A. Toc‘smcal mm 507. 1936. 'A- 1;)4 Bright, a; cg, r. u. mum-n, J. a. woven, c. w. Culpapper and M. C. Hutchinl. ”But how good will they be after sternum." Food Indus. 21:1229a231, 19:49. Fir-1 sht, R. C. and 1'. H. ihitman. “Tho corona-rein storage of fmita, vegetables and florist and nursery utensil." U. 3. D. A. Agricultural flanobook sinus-1.6, 1951.. Miyamoto, Takao Studies on Conditioning of Potatoes for Potato Chips Making 7 “iii {fixfisfiiflflfiu i’flflixixjflimfl @111le