INVESTIGATION OF SlLICONE APPUCATIONS TO YHE DAIRY fiNDUSTRY Thesis f0? Hm Degree 0‘5 M. 5. MECHIGAN STATE UNIVERSHW Victor A. Jones 1959 33H FJSIS :17 u- M J ' +72. LEIIRAR} I‘llidfil‘f‘l‘l SW“? ; Umvuslty (9...; u“ ..—- «v. « __--._._..._—.'. _ __H INVESTIGATION or sxucom: APPLICATIONS To um um mus'rmr ‘ BY VICTOR A. JONES AN ABSTRACT Submitted to the college or Agriculture Michigan State University of Agriculture and Applied Science in.partia1 fulfillment of the requirements tbr'the degree or MASTER OF SCIEICE Department of Dairy 1959 Approved /92 (1/444 ABSTRACT VICTOR A. JONES The application of various silicone antifoam agents and release agents to .thc dairy industry was investigated in laboratory and dairy plant tests. Foams frequently present problems in the processing of dairy products, especially in fillim operations, vacuum condensing, and reconstitution of dry milks. 'me effectiveness of Antifoans A, B, and AF Emulsion at various concentrations and temperatures in breaking down the foams of reconstituted nonfat milk, skin milk, and homogenized our was studied in two types or labora- tory tests. In the first test foal m produced by mechan- ieally agitating test tubes of silk treated with antifoan agents and observing the foam breakdown tine. Concentrated antifoan agents were sprayed on milk foams in the second test, and the time required for the foam to dissipate was determined. Antifoan AF Eullsion was tested in a comer- eial can fillim operation, and the effect of Antifoans A, B, and AF Emulsion on the whippinz Properties of cream was investigated. Antifoams B, and AP Emulsion were not detected by flavor or appearance when used at concentrations of 500 and 170 ppm respectively. Antifoan A spray left an objec- tionable film on the milk surface but Antifoan A did not impart an off-flavor when used in milk at the rate of 50 ABSTRACT VICTOR An JOKES ppm. Each of the antifoan agents was relatively ineffec- tive in breaking down foals of reconstituted nonfat milk, skin milk, and homogenized milk at 32°F but became increas- ingiy effective at 60, 90, and 120%. At 120°? they were very effective. when used at the sane level of active antifoan concentration, Antifoan AF muss appeared to be more effective than Antifoans A or B. Antifoan AF hil- sion reduced the tine required to fill a ten-gallon can with homogenized milk at 40°!" tron approximately 34 seconds to 32 seconds when used at the rate of 27.5 ppm. 'lhe whip- pim properties of cream did not appear to be significantly ilpeired by 250, 1000 or 340 pp- of Antifoans A, B, or A? Emulsion respectively. Silieom Antifoans A, B, and AF Eamlsion appear to have limited applications in the processing of dairy Prod- ucts. Because of the many factors which influence their effectiveness, these antifoan agents should be tested under the conditions in which they will be employed to determine the practicality of their use. Silicone release agents including Slipieone, 200 Fluids of 100 centistoke and 1000 centistoke viscosity, M141, and silicone resins were tested for their ability to inpmve appearance, to prevent product adhesion, and to reduce the total operating labor required in cleaning oper- ations in a nil): plant. Silicones were applied to glass ABSTRACT VICTOR A. JONES slides which were washed in a mechanical washing apparatus, to alumimm wall panelim, and to stainless steel‘dairy plant equipment including pasteurizim vats, cheesevat, butter chum, spray dryer, and table top. The silicones - did not seem to improve appearance or ease of cleaning of equipment or panelist in these tests. he results of prod- uct adhesion tests indicated that Slipicone did not prevent butter from stickixg in the churn, and inconclusive results concernilg nonfat milk powder mesion were obtained on silicone resin treated plates in a spray dryer. his results of investigations with silicone release agents suggest limited if any practical applications of siipicone, 200 Fluids, silicone resins, and mm in im- provirg cleanability or appearance of stainless steel I equipment or alumim panelim . INVESTIGATION or ssxucom: atrucanoss , To me DAIRY INDUSTRY BY VICTOR Ac JONES A THESIS Submitted to the college of Agriculture Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for'the degree of MASTER OF semen Department of Dairy 1959 < a V \2) (i 3 FK‘ - r: \l imowmmmwrs Although many individuals have contributed to the progress of this study, the author wishes especially to acknowledge with gratitude the assistance and cooperation of the following: Dr. ‘1'. I. Rodrick, Dairy Department, whose interest and guidance in this study and in the preparation of this manuscript were major contributions. Dr. R. R. McGregor, Assistant Director of Research, Dow Corning Corporation, for inspiration and advice. Dr. I. P. Ralston, Bead, Dairy Department, and the entire Dairy Department staff for their cooperation, and to:- making available facilities, equipment and materials. Dow corniig corporation for financial support and materials. laryetta Jones, my wife, for her encouragement throughout the stuw and assistance in preparing the mamscript. TABIB OF COHEN‘I'S MRODUfllou'eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 1 umm WOOOOOOOOO00000.0.0.000...000.000.00.000 Suggested Application of Silicones in the Mry Industry........................... Antifoam agents............................... Release agents and lubricants for processing.. laintenance................................... Miscellaneous uses............................ Types and Properties or Silicones Used in This Research PPOJecteeeeeeeeeeeeeeeeeeeeeeeee Dinethyl 811130110 fluidBeeeeeeeeeeeeeeeeeeeeee Antifoam agents............................... Slipicone..................................... ”1&1000OOOOOOOOOOOOOCOOOOCOOOOOICOQOOOOOOOO. Toxicity and Legal Limitations of Silicones........ Dimethyl silicone fluids...................... Antifoan agents.............................. Slipicone.................................... Mini"..................................... EXPERIMENTAL PROCEDURE................................. Silicone Antifoan Agents.......................... laboratory investigation of antifoan U camels-tow \O\O\O\OG>O\O\ 10 10 10 12 .8th dispersed in nilk........... 13 Effect of antifoan BPMB On milk :OWeeeeee Antifoam AF Mlsion test in a comercial can “111‘! operation.............. 17 18 Influence of antifoan agents on the shipping properties Qt Gnueeeeeeeeeeeeeeee 1 Silicone 3313889 Agents"......................... Laboratory cleanability test usirg a ~ mechanical washing apparatus . . . . . . . Laboratory investigation of milk powder adhesion"......................... Effect of release agents on dairy plant panelilg ma equipment............. BMW“ 13801198................................... 311100310 Antifoal “entfleeeeeeeeeeeeeeeeeeeeeeeeee laboratory investigation of antifoam agents dispersed in nilk........... Effect of “1:0” BPWS on ”in tweeeeee Antifoam AF msion test in a comercial Can filling operation.............. Influence of antifoan agents on the whippim properties of GMeeeeeeeeeeeeeeee Silicon. 391.589 flatten...".................... laboratory cleanability test usim a We“ washing ”Mtueeeeeee laboratory investigation of milk powder 3&08103 eeeeeeeeeeeeeeeeeeeeeeeeee Effect of release agents on dairy plant paneliig and equipment............. DISCUSSIweeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 311100110 “151:0“ Agents.......................... laboratory investigation of antifoan - agents dispersed in nilk........... Effect of antifoan sprays on milk foam...“ Antifoan AF Milsion test in a comereial can fill“ operation.............. Influence of antifoan agents on the whippiig properties or OMeeeeeeeeeeeeeeee 19 19 22 22 27 27 2‘? ti 47 51 51 56 56 56 62 62 62 Silicone 301038. Agents........................... 63 laboratory cleanability test using a mechanical‘washing apparatus....... 63 Effect of release agents on dairy plant paneling and equipment............. 63 SUIIARY Ann CONCLUSIONSeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 65 81113030 A“tithe“:Agentfleeeeeeeeeeeeeeeeeeeeeeeeee 65 Silicone B‘loafle Agentfleeeeeeeeeeeeeeeeeeeeeeeeeee 67 LITER‘IURE cIrKDeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 69 ”mnOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO0.00000000000000 73 MRODUGI‘ ION Silicon and ongen, the basic materials from which sili- cones are formed, constitute threes-fourths of the earth's crust (20) . The comercial development of silicone: was not realized, however, until wartime demnd stimlated their pro- duction in 19113 (26). Since the war, industry has been fast in recognizing the usefulness of silicones in improving effi- ciency of operation or quality of products. Silicones have been used for a variety of purposes includirg antifoamants, lubricants, release agents, water repellents, dielectrics, and numerous other tasks. The silicones are chemical polymers which may be pro- duced as fluids, greases, resins or rubbers by varying their molecular structure (31). The properties of the silicones with which this paper will be primarily concerned include antifoam, water repellent, and anti-stick or release proper- ties. Manufacturing processes in the dairy plant are frequent-3 1y slowed by foams, and increased efficiencies could be real- ized if foams could be eliminated or reduced. Some of the major problems with foams occur in filling operations, in- cluding vats, bottles and cans; vacuum condensing operations; vat pasteurization; reconstitution of dry milks; separation; and clarification. In the Michigan State University Dairy Plant filling of 10-gallon cans could be accomplished in .2; one-third of the time and at colder temperatures if foam could be eliminated on homogenized milk. - In considering the control of foam in dairy products, the definite relationship between the physico-chemical properties which cause foaming and the various activities at the fat globule interface should be kept in mind (12) (15) . Destroying the ability to foam may influence churning of butter, whipping of cream, and overrun attainment in ice cream. Cleaning operations in the milk plant require between 2555 and 30% of the total operating labor (7) . If the water resistant or release agent properties of silicones could be utilized to keep dairy products from sticking or in a bene- ficial way cause the equipment and containers to clean more easily, tremendous savings could be made. This study was designed to determine the effect of var- ious silicones in controlling foam and improving cleanability in dairy plant operations. LITERATURE REVIEU Numerous applications have been suggested for silicones in the dairy industry. Little research data have been pub- lished to verifi or disprove these potential uses, however. This literature review is divided into three sections: (1) Suggested Applications, (2) Types and Properties of Silicones Used in This Research Project, and (3) Toxicity and Legal, Limitations of Silicones. Suggested Applications of Silicones in the Dairy Industry m m. Ross (33) states that silicones are, perhaps, the most versatile of all the antifoaming agents. Todd (#1006) (#6) suggests the use of silicone defoamers in the dairy industry to increase production, decrease process- ing time, upgrade quality of products, and permit the saving ~ of product sometimes lost as foam in the agitation, mixing, and pumping of dairy products. His suggestions included foam control in the production, processing and evaporating of skim milk and cottage cheese whey; in dairy confection mixes which are molded and frozen on stick handles: in deter- gent cleaning solutions; and in recirculating cooling brine systema. One dairy (10) found that a silicone defoamer, Dow coming Antifoam AF Emilsion, promptly eliminated or reduced to a minimum the foamforned in the processing of Fudgsicle mix. Methods of applying the antifoam agents vary with the type of agent used, but include the following (44) (#5) (46) z 1. 5. Coat the sides of processing equipment above the normal liquid level. ' Apply to wire mesh suspended above the foaming system. Coat inside of filling nozzles. Disperse in dry ingredients and add to foaming Bistm. i Add directly or dilute with water and add to foaming system. .423“ email—W" c t seam-Listed below are some of the uses for the silicone release agents which have been suggested by Todd (44) (45) (#6) : 1. Apply to processing equipment to prevent burn-on or build-up of product and to make the surface easier to clean. Treat paper used for wrapping or containers to prevent sticking of product. Apply to hot irons for release in heat sealing plastic film or to prevent build-up on heat sealing bars. lubricate valves used for high temerature operations. Use as a lubricant for installing tubes or hose on metal pipe. ~5- 6. Use silicone rubber on conveyor belts to release hot or cold’products. Schulz, hook and Siegn-ied (39), found that a silicone coat- ed stainless steel surface kept Elnental cheese curd from adhering as tenaciously as to uncoated stainless steel. Sapp and Hedrick (38) concluded that pan glaze applied to novelty molds for ice cream bars did not aid in the release of the frozen bars e We. Rupprecht and Crost (35) state that mo- tors rewound with silicone (Class H) insulation are more re- sistant to heat and water than motors rewound with any other class of insulation. The capacity of a motor may be increas- ed by as much as 50% by rewinding with a silicone insulation, and the life expectancy of the motor is greatly increased when exposed to high ambient temperatures, overloads or mois- ture. The ability of silicone insulation to resist water could be especially helpful in dairies since a large volume of water is used in cleaning and rinsing equipment. Silicone paints are suggested for boilers, exhaust stacks and steam lines (11) (18) . Silicone paints withstand high temperatures (up to lOOO°F) and moisture and require a minim of maintenance. Other maintenance uses mentioned for the silicones in- clude gasket or seal material which is heat stable, odor- less, and resistant to oil; lubrication for bearings opera- ting at high temperatures or in the presence of moisture; 6- and finishes for the exterior of masonry buildings to prevent efflorescence, stain, and water penetration, but allowsthe material to breathe (5) (ll) (26) (M) (as) (46) . W 2333. Silicone coating of glass bottles reduces scratching and breakage and gives the bottle a brighter and glossier appearance (1) (9) (44) (45) (46) . The silicone is sprayed on the outside of the bottle between the washer and filler. Moisture, even from normal air, adsorbed by surface abrasion weakens the glass (1) . The strength of glass is partially rejuvenated by the adsorption of silicone in the abrasion. The silicone is hydrophobic and so repells the water. Todd (44) (45) (46) suggests water repellent fabrics and shoes treated with silicones for dairy plant employees, but he does not consider the treated shoes a substitute for boots . . He also mentions silicone hand creams for protection from water borne irritants to help combat problems of skin irrita- tion in the food industry. Types and Properties of Silicones Used in This Research Project m Siucgge Fluids. Dimethyl silicone fluids, known in chemical literature as dimethyl siloxane polymers or dimethyl polysiloxanes, have the chemical rormla (6) (26): an on 033-36113- 0-813 -o-Siicu3 ca c113 n ma 3 nearegor (22) states that these products are available from .7... the General Electric Company as 'G. E. Silicone Oils" in a wide range of viscosisties. They are water white fluids which are very stable to heat and oxidation and have a more nearly constant viscosity over a wide temperature range than any other liquid (6) . The dimethyl silicones are useful in the following tasks where the properties mentioned are particularly important for accuracy, constant performance , minimm maintenance or long life (6) : 1. 3. 50 As damping fluids - heat, oxidation and mechanical shear resistant, and constant viscosity over wide temperature ranges. As instrument fluids '- low freezing and high flash points, constant viscosity, and low vapor pressure. As hydraulic fluids - constant viscosity over a wide temperature span, low freezing, high flash points, high autoignition temperature, and resis- tant to heat and shear breakdown. As liquid dielectrics f" superior dielectric to most other liquids, heat and oxidation resistant, con- ' stant viscosity and dielectric properties with temp- erature changes, and water repellent. As lubricants - heat and oxidation stability, con- stant viscosity over wide temperature ranges, high flash and low freezing points. As release agents - heat stable, oxidation resist- ant, non volatile, readily wet mold surfaces, foisns~ .8. no carbonaceous deposit. 7. As water repellent ., heat stable, high surface resistivity. 8. As polishim agent .. readily wet surfaces, lu- bricant for hard surfaces, water repellent, stable at high and low temperatures, nonVolatile, and resistant to oxidation and weathering. ' 9. As coating and impregnant in pump packings - wa- ter repellent, resistant to a variety of chu- icals, and stable to heat. . 10. As an additive - antifoamant in many non-aqueous systems, increased temperature stability and re- sistance to abrasion and weathering when added to synthetic rubbers . mm m. Silicone antifoal agents are com- pounds made by addim a few percent of a finely divided . silica to a high poy'lmer dimethyl silicone (26). The compounds retain the heat resistance, low freezing point, low volatility, and dielectric properties of the dimeth- yl silicones, and they gain antifoam properties in some aqueous systems. The silicone antifoamers accomplish their mission by breaking down the foam bubbles after they are formed. The 100$ silicone compound used in this reuarch project was Dow Gowns Antifoan A. A .1... ilar product, Antifoam 81066, is available from the Gen- eral Electric Cm (33) . , I Antifoam cullsions are also available which are .9. combinations of 100% silicone compound with an mlsify- ing agent (41) . now coming Antii'oam a1? Emulsion is a stable dispersion of 30% Dow Cornirg Antifoam A and unlu- sifyim agents connonly used in the food industry (2) . me AF Mlsion has the consistency of thick cream and is white in color. Dow Corning Antifoam s is 10% Dow Corn- ing Antifoam a with food grade emulsifiers (8). It is free flowing, readily dispersible in aqueous solutions and exceptionally stable on dilution. W. Slipieone is a release agent silicone compound available from the Dow Corning Comoration (4). It is heat stable, resistant to oxidation, and does not break down to leave a carbonaceous residue. It is not irritating to the skin and is safe to use in sealing. packages containing food. _ £441. This product is a glass protectant pro- duced by the Dow Corning colporation. It is water re- pellent when applied in a thin film to glass (3) . It also protects the glass from scratches and reduces breakage. Similar material is available from General Electric company as 314-70 Emnsion (9). Syl-aard 17 is glass protectant mamfactured by Dow Cornim espe- cially for use by dairies (3) . Toxicity and Legal Limitations of Silicones W M Ma- 30“: £3. 3.]. (34), found .10- that no discernible ill effects resulted when test ani- mals were fed up to 2% of their bow weight of the di- methyl silicone fluids. lleGregor (26) states that there are no cases on record of am‘ permanent physiologial disturbances of persons handling methyl, mixed methyl, and phexwl polysiloxanes in research, production, or “See mm m. Toxicological studies on rats and guinea pigs by Rowe, Spencer and Bass (34) gave the first indication that the defoamers were non-toxic. In a two year feediig test with rats, they found that concentra- tions or 3,000 ppm had no adverse effect on rats (35). In reference to Dow Cornim Antifou A, Lehman (24) rep- resenting the U. 8. Food and Drug Administration report- ed in 1950 that! “The toxicological data which have been submitted appear to show that the material is relatively non-toxic by oral athlnistration. We have seen no reason to object to its use to suppress feeling when the quantity uployed does not exceed 10 ppm.” At present up to 10 ppm of Antifoam A are permitted in processing or food with- out standards or identity (2) (5). Food grade emulsifying agents are used in manufacturing Antifoam AF Emulsion and its use is penitted up to 34 ppm in nonstandard food products. Antifoam B is a newer product containim food' grade emulsifiers which has not yet been approved by the rssd and Drug ministration. .11.. W. If slipicone is to- be used in contact with food, it should be applied in a film sufficiently thin that the food will not pick up over 10 ppm of slipicone (4). w. This material should not be used in con- tact with food products (3) . Only the exterior or con- tainers should be treated. A downdraft over a sprayixg operation is recomended to ensure no spray drifts into the containers. The, 2-4141 container label warns a- gainst prolonged breathing of vapor or repeated skin contact . EXPERIHENI'AL PROCEDURE Silicone Antifoam Agents The antifoam properties of Dow Corning Antifoam A, Anti- foam AF finnlsion, and Antifoam B were tested with skim milk, homogenized milk with approximately 3.5% butterfat, and re- constituted 9$ nonfat milk from the Michigan State University Dairy Plant at 32, 60, 90, and 1200?. Preliminary investigations were made to determine a sat- isfactory method of producing foam in these products and methods for measuring the quantity and stability of the foam. The preliminary investigations included the four methods des- cribed below. Test tubes, 2 x 20 cm, containing 25 ml of reconstituted nonfat milk and 300 ml kJeldahl flasks, containing 300 ml of reconstituted nonfat milk, were hand shaken. The height of foam was measured imediately, and l, 2, and 5 minutes follow- ing agitation of the milk. The time for foam to breakdown completely was also determined. Hand aha-king was unsatisfac- tory because of the difficulty of duplicating results. Foam production with a Waring Blendor and with an A1111 Solubility Index Mixer were attempted with 100, 200, 300, and 400 ml of reconstituted nonfat milk with agitation per- iods of lo, 30, and 60 seconds. The Waring Blendor was op- erated at both slow and fast speeds. The foam volume was -13.. measured imediately and l and 5 minutes following agitation. Foam produced by this means was very stable and did not seem to respond similarly to foams produced in conmercial process- ing operations. Fifty milliliters of milk was allowed to drain from a burette into a 100 ml graduate. Investigations were conduct- ed with reconstituted nonfat milk, skim milk, and homogenized milk. The foam formed by this method was measured immediately and at l, 2, and 5 minutes. Although results could be dupli- cated, this method was slow, required cleaning of the burette between different types of milk, and required a large number of graduates. Foam was also produced by bubblim air through 50 ml of milk in a 100 ml graduate. The air was introduced into the milk by a glass tube with a small opening in the end inserted into the milk. The volume of foam and milk at 15, 30, 45, and 60 seconds or the time for the foam to reach the 100 ml level or the top of the graduate was determined. Whether volume or time measurements were used depended upon the vol- ume and speed of foam production. Transfer of antifoam a- . gent by the glass rod was possible by this method unless the tube was thoroughly cleaned after each test. Control of the air taperature was another obstacle to this method. W Was a: W Assam 21:22:19.1 _1_n 21m. Hechanical agitation of test tubes was the most suitable method for producing foam in the laboratory. -1u- Twenty five m1 of milk was placed in 2 x 20 cm test tubes and the tubes were stoppered. .The test tubes were mechanically agitated for 30 seconds in a horizontal position with the length of the test tube parallel to the direction of agita- tion. The agitator’moved the tubes through a distance of 1% inches at the rate of 275 times per minute. Temperature of the milk was controlled by placing the test tubes in a water bath for the 60, 90, and 120°? tests. The 32°F test was con- ducted in a refrigerated cooler. The effectiveness of the antifoam agent was determined by measuring the time for’the foam to break down to the point where any part of the sure face of the milk was visible. In cases where the foam.did not break down within a given time, the height or the foam at the specified.time was recorded. Antifoams A, B, and AF Emulsion were selected for this experiment because they represented the commercially avail- able silicone antifoam.agents. As was indicated in the lit- erature review Antifoam.A was the active antifoam.component of each of the three types of antifoamhagents used in this investigation. The Food and Drug Administration permit the use of 10 ppm Antifoam.A in foods without standards of iden- tity. The, Antifoam A content of Antifoam AF Emlsion was used by the Fbod and Drug Administration in setting the lev- el at which Antifoam AF Emulsion may be used in food without standards of identity. Therefore, the Antifoam A concentra- tion was used as the basis for comparing the types of anti- foamhagents. To avoid confusion in discussing the antifoam -15- agents, Antifoam A concentration is frequently expressed as ppm of ”active antifoam'. The terms "Antifoam A" and ”active antifoam' are used synonymously for purposes of clarity with- in this paper. Dow Corning Antifoam A was diluted in toluene to give 0.1, 0.2, 0.4, and 1.0% solutions. Toluene was the most readily available of the solvents suggested by the manufac- turer. Test tubes were filled with the solution; the solu- tion was poured off; and the test tubes were permitted to dry. In preliminary investigations test tubes and stoppers were weighed imediately before the solution was added and imediately after it was poured off. These weights indica- ted that the test tubes contained about 0.125 mg of Anti- foam A when the 0.l$ solution was used; 0.250 as for 0.2%, 0.50 mg for 0.u%iand 1.25 mg for 1.0% solutions. These quantities of Antifoam A were equivalent to 5, 10, 20, and 50 ppm of active antifoam respectively in 25 m1 of milk. , Dow Corning Antifoam AF Emlsion was diluted to 8.5% by dispersing in distilled water for the tests at 32°F. This diluted Antifoam AF mlsion was then added to the milk as follows: . 1 drop in 125 m1 of milk to give approximately a 31! ppm concentration; 2 drops in 125 ml to give 68 ppm, it drops in 125 ml to give 136 ppm; and 1 drop in 25 ml to give 170 ppm. For the tests at 60, 90, and 120°F the Anti- foam AP Emlsion was diluted to 0.85:6 by dispersing in dis- tilled water. One drop of this dispersion in 25 ml of milk was approximately. 17 mm; 2 drops, 3‘4 ppm; it drops, 68 ppm; and 10 drops, 170 ppm. In all tests the diluted Antifoam AF Emulsion was used within three hours of its preparation. Dow Corning Antifoam B was diluted to 2.5% by dispers- ing in distilled water for all tests. One drop of the dis- persion in 25 m1 of milk was approximately 50 ppm; 2 drops, 100 ppm; ’4 drops, 200 ppm and 10 drops, 500 ppm. The diluted Antifoam B was used within three hours of its preparation. Reconstituted nonfat milk, skim milk, and homogenized milk samples were treated with 0, 5, 10, 20, and 50 ppm ac- tive antifoam in the form of Antifoams A, B, and AF Emulsion for tests at 60, 90, and 120°F. At 32°F samples of recon- stituted nonfat milk, skim milk, and homogenized milk were treated with 0, 5, 10, 20,. and 50 ppm active antifoam in Antifoams A and B and with 0, 10, 20, 110, and 50 ppm active antifoam in Antifoam AF Emulsion. Five replicate samples of reconstituted milk and skim milk were tested at 32, 60,- 9), and 1200?, and five replicate samples of homogenized milk were tested at 32 and 1200?. Only duplicate samples of homogenized milk were tested at 6035‘, and only duplicate samples of untreated homogenized milk were tested at 9009 because the foam breakdown times for untreated homogenized milk at these temperatures were 10 seconds or less. The signs (and ) were used in recording the foam break. down time or height of foam to show that the value was less than or greater than the value indicated. The reasons for the use of these symbols fall into three categories. First, no attempt was made to accurately measure foam breakdown -17- times of less than 5 seconds. Times of less than 5 seconds were recorded as (0:05. Second, when the foam did not breakdown within 1 hour, the foam height was measured at a specified time following agitation of the test tubes. This time was not the same for all trials, and so an exact aver- age could not be calculated. In cases of this nature the signs ( or ) were used to give the best indication of the foam height or breakdown time. Third, in a few tests the exact time of foam breakdown had passed before the observation was made. This occurred in less than 2% of the trials. When this happened, the foam breakdown time was recorded as less than the time when the observation was made ( ( ) . Samples with each type of silicone antifoam agent and each concentration of antifoam agent were checked immediate- ly and at 1, 3, 7, and 15 days for flavor and other detri- mental characteristics . Effect of, m m 9;; Milk m. The effective- ness of Antifoams A, B, and AF Emlsion in dissipating foams of reconstituted nonfat milk, skim milk, and homogenized milk was investigated. Milk, foam, and air temperature were main- tained at 32°F by conducting the experiment in a refrigerated cooler. Foam was produced by beating 300 to 500 ml of milk With a Dormeyer Electric Mixer. The foam produced in this manner was not always of uniform bubble size and density, however. The milk foam was transferred into four 250 m1 glass beakers with a tablespoon to give as uniform samples -18- as possible. Antist B and AF Emulsion were diluted with one and two parts of water respective1y. The dilutions were spray- ed onto the milk foam with a perfume atomizer. Antifoam A was dispensed from a commercial pressurized spray container. Two trials were made with homogenized milk and skim milk with each type of antifoam agent. Two reconstituted nonfat milk trials were conducted with Antifoama B and AF Emulsion and one trial was conducted with Antifoam A. The effective- ness of the antifoam agents was determined by measuring the cm of foam and milk at time intervals of 1,12, and 5 minutes depending upon the stability of the foam. mm a: W Teas is a W 9211 Zillias megtign. Antifoam AP Mlsion was tested for its effec- tiveness in reducing foam in the Barrett air operated can filler in the Michigan State University Dairy. The foam produced in filling a ten—gallon can was collected from the foam vent . This foam normally would have returned to the surge tank of the can filler. Observations were made on the time required for the first foam to come through the vent, time required to fill the can with milk, and the volume of foam. Foam volume was measured as the height of foam in a stainless steel container 8 inches in diameter and 10 inches high. Approximately 600 gallons of homogenized milk was col- lected in a cold storage tamc. About 250 gallons of this milk at 1:101" flowed by gravity through the can filler as a control. The surge tank of the can filler was enmtied. To -19- the remaining 280 gallons of milk, was added 30 g of Anti- foam AF Eimlsion which was thoroughly “dispersed in ‘2 gal- lons of control milk and then added to the storage tank. The storage tank agitator was allowed to operate for 5 min- utes before the experiment was continued. The Antifoam- AF Euulsion concentration in milk was calculated to be about 27.5 ppm. The treated milk was run through the can filler. Twanty gallons or control milk and treated milk were allow- ed to flow through the can filler before data was collected, and the data collected-when the surge tank was not hall was omitted. laziness: 9!. imam Assam on ma W W 9,; 9mm. The effect of silicones on the whipping time, vol- ume, body, stability, and flavor of whipped cream was checked by adding Antifoams A, B, and AF Mlsion to 200 m1 of whipp- ing cream at the rates of 250, 1000, and 3150 ppm respectively. The cream tested 34 .ll% butterfat and was whipped with an elec- tric beater for. 2 minutes at 50°F. Immediately after whipping the treated samples were compared with two control samples for volume, body, and flavor. A second comparison was made after holding the samples for 2 hours. Body and stability of the whipped cream were checked by visual observation. Silicone Release Agents W W Esra Him a ‘ksbsmsal lash: 195 W0 The mechanical washing apparatus described .20- by Jensen (21) was used to wash glass slides coated with various silicones. Dow Corning products, Slipicone, 2-4141, . 100 centistoke 200 Fluid, and 1000 centistolce 200 Fluid, were coated on 1 11/16 x 2 3/8' inch, double strength, B type glass slides. Slipicone was wiped on the glass slides, and the excess was removed with a clean cheese cloth. Slides were innersed in a 1:500 dilution of 2-4141 in distilled wa- ter, removed and allowed to drain, dry and cure for 24 hours. The 100 centistoke and 1000 centistoke 200 Fluids were diluted to 5% by dissolving in toluene. The glass slides were immersed in this solution, removed and permitted to drain and dry. Duplicate slides with each type of silicone release ag- ent treatment and control slides with no treatment were im- mersed in homogenized milk at room temperature. The slides were removed from the milk and placed in a metal rack at a- bout a 1‘5 degree angle and permitted to drain and dry for 15 minutes. I A 0.l$ detergent solution was prepared ”by using All Fur- pose Cleaner No. 7 manufactured by E. F. Drew and Company, Inc. and tap water. The temperature of this solution was maintained at 1200?. The slides were soaked in this solution and then propelled in Jensen's washing apparatus at the rate .of 52 oscillations per minute. The length of soaking and washing periods is given hereafter. Following the wash per- iod the slides were immersed in distilled water to rinse, immediately removed and allowed to dry in the draining rack ~21- mentioned above. A light transmission reading was determined for each slide by 'placing it in a Genoa-Sheard-Sanford Photolometer with approximately a 0.115 In slit and a 450 millimicron filter which was 0A5 mm thick. The slit opening had to be adjusted slightly durim the test to maintain a reading of 100 for a clean, untreated glass slide. Four readings were obtained for each slide, and these were averaged. . Selling the glass slides, soaking, washing, rinsing, and photolometer readings as described above were repeated 15 times. The first set of five slides, including a con- trol and one slide with each type of silicone treatment, was soaked in the detergent solution for 1 minute and wash- ed for 1 minute for the first through the fourth trials; in the fifth and sixth trials the slides were soaked for 30 seconds and washed for 30 seconds 3 and for the seventh through the fifteenth trials the slides were soaked for 15 seconds and washed for 10 oscillations of the washing appar- atus. The second set of slides were soaked for 1 minute and washed for 1 minute for the first and second trials; soaked for 30 seconds and washed 30 seconds, for trials three and four; and soaked 15 seconds and oscillated 10 times in the washing solution for the fifth through the fifteenth trials. The soak period and washing time were shortened during the test to permit the photolometer read- ing to be reduced below 100. -22- W Wise a: an: 4a.? v er macs- Slipicone was coated on the outside surfaces of 500 ml stainless steel beakers and 300 ml glass beakers. The beakers were buffed to remove as much silicone as possible. The beakers were placed in a plastic bag containing a small quantity of. nonfat'dry milk and the sack was manipulated to produce a' dust. Upon removal from the seek the beakers were observed for thickness of dry milk film, and ease of removing the dry milk with an air blast or brush. m . t rimmiammmmmm m. Silicones were coated on eight areas of alumi- num wall paneling and nine pieces of equipment in the HSU Dairy Plant as outlined below. The treated areas were checked for adhesion of soiling product, ease of cleaning, and general appearance including the ability to flush clean, and dry to a bright appearance. Before the sili- cone was applied, the area was cleaned with trichloroeth- ane. Slipicone was sprayed on the area, and the excess was removed with a cloth. The 200 Fluids of 100 and 1000 centistokes viscosity were dissolved in toluene to give concentrations of 0.2, l, 2.5, and 10%. The solution was wiped on the area with a cloth and allowed to dry. It is routine procedure to apply mineral oil to the exterior of stainless steel equipment in the Michigan State University Dairy after each cleaning to inprove the appearance. 0b- servations were made to determine if Slipicone or the 200 -23- Fluids applied to equipment was a semi-permanent coating which would not require application after each cleaning. Aluminum Wall Paneling. The 100 and 1000 centistokes 200 Fluids in l, 2, 5, and 10% concentrations were applied to aluminum wall and overhead paneling. Twelve areas were included in the investigation including two untreated con- trol areas, two mineral oil coated control areas, and one area with each concentration of 100 or 1000 centistoke 200 Fluid. Each treated area was approximately 2 x 9 feet. About 5 feet of the length was vertical wall paneling and the remining 4 feet was horizontal overhead paneling. The appearance of the silicone treated areas was compared with control areas at 1 week intervals for 10 weeks by visual observation. The ease of cleanim was checked about 3 months after the silicone treatment by manually cleaning the areas and observing the ease 'of soil removal. Stainless Steel Table Top. A 3 x 5 foot stainless steel table top was divided into ten 12 x 18 inch areas. Duplicate areas were coated with 0.2, l, and 5% solutions of 1000 centistoke 200 Fluid and four areas were left as controls. After the table was used in the normal routine work of the pilot laboratory, observations were made on the ease of cleaning and the appearance of each area each day for 1 week following the silicone treatment. ‘ The third day after the silicone treatment, about 1 pint of reconsti- tuted nonfat milk was poured onto the table and allowed to .21;- dry. Observations were made on the ease of mamaal cleanixg and resulting appearance. Cheese Vat. Slipicone and a 10% solution of 100 and 1000 centistoke 200 Fluid were applied to three 2 x 3 foot areas on the inside walls of a Meyer-Blanke 400 gallon Nu- Vat. Cheddar cheese was made in the vat. Visual observa- tions were made on the ease of cleaning the vat by a manual washing procedure. Stainless Steel Pasteurizing Vats. Slipicone and 5% solutions of 100 and 1000 centistoke 200 Fluid were applied to six areas on the exterior surfaces of three stainless steel circular vats of various sizes in the dairy plant. Each area was approximately 3 square feet. The surfaces were checked for appearance each day for 3 days following the silicone treatment . Roller Dryer. Approximately one-half of each of the drums of a Buflovak laboratory Vacuum Double Drum Dryer was coated with a 5i solution of 1000 centistoke 200.Fluid. Observations were made on the ease of removal of a film of nonfat dry milk immediately after the silicone application. Spray Dryer. The Dow Corning Corporation coated 6 x 8 inch stainless steel plates with silicone resins, contain- ing both methyl and phenyl groups, and designated in this experiment as 12-1, 12-2, 12-3, 3.2-1}, 12-5, and 12-6. These plates were suspended from the baffle plate in the ~25- exhaust end of the Rogers Dryer in the ISU Dairy Plant. The plates were in a vertical position perpendicular to the air flow. The nonfat dry milk build-up, ease of brush- ing powder from the plates, and appearance were compared to a control plate which received the same treatment ex- ' cept that it was not coated with silicone. The plates were placed in the dryer for four trial periods. In trials No. l and No. 2 the dryer was operated for about 9 hours. Trials No. 3 and it covered 2 and 3 nine-hour days of dryer operation respectively. The plates were washed manually _ with a general purpose cleaner between each test. Butter Churn. A standard (No. a) finish stainless steel plate 8 x 21: inches was coated with Slipicone. The plate was attached to one of the shelves in a GOO-pound stainless steel Gosselin butter churn. Observations were made on the adhesion of butter to the coated plate during and following the churning process. Slipicone was also applied to two portions of the sandblasted interior sur- face of the churn. Approximately 2 square feet of the drum and 1 square foot of a shelf was coated with the Slipicone. Visual observations were made on the adhesion of butter and ease of cleaning . Sanitary Valves. Slipicone and a 10% solution of 1000 centistoke 200 Fluid were applied to three-way stainless steel valve plugs and valve seats. The Slipicone was spray- ed on to, the valve and then spread with a cloth to a thin -26- coating. Observations were made on the lubricating value and permanence of the silicone coating hiring use and the influence of the usual manual washing procedure. EXPERIMAL RESORTS Silicone Antifoam Agents W W at; Aniline: meals $2.23..» e .a 3,; any. The foam breakdown times for reconstituted 9% non- fat milk, skil milk, and homogenized milk treated with sili- cone Antifoams A, B, and AF Builsion, are presented in Ta- bles l to 3. Theresults regarding the stability of milk foam on reconstituted nonfat dry milk at 32 , 60, 90 and 120°F are given in Table l. The same information is given for skim milk and homogenized milk in Tables 2 and 3 res- pectively. The values in these tables represent the aver- age of five replicate samples except for homogenized milk at 60 and 90°F. Because the foam breakdown time for un- treated homogenized milk at the 60 and 90°F temperatures was 10 seconds or less, only duplicate samples were tested. The original data from which the foam breakdown times were calculated are recorded in Tables 10 to 20 of the Appendix. In most cases the reason for the use of the symbols _( and) in Tables 1, 2, and 3 can be determined by referrilg .to the original data in Appendix Tables 10 to 20. The use of the symbols in the Appendix is explained in the Experi- mental Procedure. A foam breakdown time of 601minutes was detemined for one of the reconstituted milk samples at 60°F with 20 ppm of active antifoam in the form of Antifoam AF Emlsion. -28- The other four samples had foam breakdown times of 26, 39, 43 and 60 seconds. Since the 60 minute foam breakdown time was completely out of line with the other results, and far in excess of the foam breakdown time for one-fourth this concentration of Antifoam AF Emulsion, this value was not included in Table 11 of the appendix nor in the calculation of the average value shown in Table 1, Figure l or Figure 4. The average foam breakdown times are presented in graphical fem in Figures 1 to 6. Figures 1 to 3 show the relative effectiveness of the three antifoam agents used in this experiment. Figures 4 to 6 depict the same data to ' show the affect of temperature on the effectiveness of the antifoam agents. The data was plotted as 1: the < and > signs did not exist. The results presented in the tables and graphs con-s tain four variables: type of milk, type of silicone, con- centration of silicone, and temperature. The effect of each of these variables will be reported. Types of hilk. The foam of untreated reconstituted nonfat milk was more stable at 32, 60, and 90°F than un- treated skim milk or homogenized milk foams. Homogenized milk foam was more persistent at 32°F than skim milk roan, but the reverse was true at 60 and 90°F. At 120°F the foam lasted for more than 1 hour on all three types of milk. Type of Silicone Mtifoam Agents. Figures 1 to 3 show the relative effectiveness of Antifoams A, B, and AF , .29. milsion in reducing foam breakdown time. In general when the silicone antifoam agents were used at a rate to provide the same concentration of active antifoam in the milk, Anti- foam AF Mlsion was equally or more effective than Antifoam B, and Antifoam B was equally or more effective than Anti- foam A. Reconstituted nonfat milk and skim milk at 32 and .6001? were exceptions to this general trend. In these cases Antifoam A was equally or more effective than Antifoam B. Concentration of Silicone Antifoam Agents. Increasing the concentration of antifoam agents reduced the foam break- down tine in lost cases. weptions were in skim milk with Antifoams B and A at 32 and 90°? respectively, and in homog- enized‘milk-with Antifell A at 32, 60, 90, all! 1200?, Anti- foam B at 32. and.60°F, and Antifoam AF Emllsion at 60°F. In each easethe increase in foam breakdown time was small. Influence of Temperature on Silicone Antifoam Agent “Effectiveness. Antifoams A, B, and AF Emlsion were most effective in preventing or dissipating foams on reconsti- tuted nonfat milk, skim milk, and homogenized milk at 120°? and least effective at 32°F. The antifoam agents appeared to be slightly more effective at 90 than at 60°F. At 120°p§ all of the milk salples which were not treated with a sili- cone antifoam agent had foam lasting for more than 1 hour. Five ppm of active antifoam in the foul of either Antifoans B or AF Mlsion destroyed the foam within 25 seconds at 120°F. Antifoam A coated on the test tube walls greatly .30- decreased the foam breakdown time when used at the rate of 5 ppm of active antifoam. At 90°F untreated skim milk foam dissipated within 7 minutes, but untreated reconstituted nonfat milk foam per- sisted for more than 60 minutes. Reconstituted nonfat milk foam required 10, 20, and 50 ppm of active antifoam in Anti- foams AF Emilsion, B, and A respectively to reduce the foam breakdown time to less than 1 minute. Five, 10, and 20 ppm of active antifoam in the form of Antifoams AF hulsion, B, and A respectively were required to reduce the foam break- down tine of skim milk to less than 1 minute. Homogenized milk foam dissipated in less than 10 seconds at 90°F and so- no attempt was made to determine the effect of silicone antifoam agents. At 60°F the foam breakdown time for reconstituted non- fat milk was reduced from more than 60 minutes to less than it minutes by using 5 ppm active antifoam in the fem of Antifoam AF Mlsion, but 50 ppm in the form of Mtifoam A or B‘were required. Each antifoam agent was more effective at 60°F than at, 32°F when tested with the reconstituted non.- fat milk. Untreated skim milk at 60°F had a foam breakdown time of 2 minutes. The antifoam agents reduced this time, but even 50 ppm active antifoam in Antifoams A, B or AF ' Emlsion did not dissipate the foam in less than 30 sec- onds. Untreated homogenized milk foam remained for only 10 seconds at 60°F. The antifoam treatment at this tempera- ture did not appear to be significant. The data seems to suggest a trend toward slightly increased foam breakdown times when silicone antifoam agents are used on homogen- ized milk at 60°F. The foam of reconstituted nonfat milk at 32°F persis- ted fcr more than 60 minutes when the milk was treated with 10 ppm of active antifoam in Antifoams A, B, or AF Mlsion. The foam breakdown times for untreated skim milk and homo- genized milk were approximately 5 and 18 minutes respective- ly. Treatment with 10 ppm of active antifoam in Antifoamg A, B or AF hillsion did not appreciably reduce the foam breakdown time. Even 50 ppm of active antifoam in Anti- foams A or B or 40 ppm in Antifoam AF Enlilsion did not have any appreciable effect on the foam breakdown time. Fifty ppm of active antifoam in Antifoam AF Emlsion gave ‘ a substantial reduction in the foam breakdown time, however. Effect of silicone Antifoam Agents on Flavor. Anti- foams A, B, and AF Emlsion could not be detected in recon- stituted nonfat milk, skim milk or homogenized milk by flavor, odor or appearance during the 15 days following their addition. When Antifoam A was applied to test tubes in a toluene solution, the toluene was detected as causing an off-flavor of the milk. Reduced Ability of Antifoall Agents to Destroy Foam Upon Repeated Agitation. A number of observations were made concerning the loss of ability of Antist A, B, and AF Emilsion to breakdown the foam of reconstituted nonfat .-32- TABLE 1 Effect of temperature and antifoam agent concentration on the foam breakdown time of reconstituted nonfat milka Antifoam' AF Maggi “181 on Antifoam B Antifoam A at: foam b b b ‘1’") {3:70.1323.) ‘33 (.133...) 1533' c.1332.) 32 0 2.2 180:00 2.2 l :00 2.2 180:00 32 5 ... ...... 1.4 :00 1.1 1 0:00 32 10 0.0 73:36 1.8 l :00 0.9 5:00 32 20 .0 23:56 1.4 1 :00 .6 60:00 32 no . O 2 3 8 16 no- ”a--. .9- B-- 32 50 .0 1:16 1.1: 180:000 .0 ><19§2 60 0 > 1.7 60 :00 > 1.7 60:00 )1.7 60:00 60 5 .0 2 :3 > 1.2 60:00 .0 >39 :00 60 10 .0 1: >1.0 60:00 .0 21:11 60 20 .0 0: 2 >0.3 60:00 ..0 (6:19 60 50 .0 :32 .0 3:25 - .0 1:06 90 0 1.0 60:00 1.0 60:00 1.0 60:00 90 5 .0 l: .0 >60:00 .0 )25:oo 90 10 .0 : g .0 15:5 .0 )37:00 90 20 .0 :2 .0 0:3 .0 1:29 90 50 .0 :14 .0 < :05 .0 0:29 120 0 1.4 60:00 1.4 60:00 1A 68:00 120 10 .0 :33 .0 :09 .0 :50 120 20 .0 : .0 < :05 .0 :2 120 50 .0 < 805 .O < 805 .0 81 C —_ -: a Each value represents the average of five trials. b It the foam did not breakdown within one hour, the foam height was measured in cm at the time specified. ”53?? .33- TABLE 2 Effect of temperature and antifoam agent concentration on the foam breakdown time of skim milka’ AntifoamlB Ant ifoam A F b T F b T ($ (magic) (3 (main 120 120 120 120 120 t L Antifoam.AF Active in“, hilsion can b ' ‘ on T (99') (cm) (minzsec) 0 0.0 5:16 ' 5 C.- a... 10 .0 4:§§ 20 .0 3: 40 .0 2: .0 0:5h 0 .0 1:58 5 .0 < :56 10 .0 852 20 .0 :23 50 .0 :27 0 .0 ' 7:00 13 '3 :35 20 :0 :03 50 .0 ( :05 0 1.5 60:00 5 .0 :25 10 .0 :09 20 .0 < :05 5O .0 < :05 0.0 .0 .0 .0 .0 5:16 <§E§§ 4:26 .322 1: 1 0: 2 :25 7:00 (1:3 : :07 .(805 60: < : < :06 < 805 < 305 0.0 5:16 .0 :10 .0 :21: .0 3:38 .0 3:16 .0 1: .0 (1:39 .0 1:11: .0 O8 .0 :32 .0 7: .0 2: .0 21:26 .0 1:01 .0 :11 1.5 ' 60:00 .0 5:11 .0 :15 .0 :1 .0 : a Each value represents the average of five trials. b If the foam did not breakdown within one hour, the foam height was measured in cm at the time specified. TABLE 3 Effect of temperature and antifoam agent concentra; tion on the foam breakdown time of homogenized milk Antifoam AF Active Antifoam B Antifoam A . “(3% ant 1- Enilsion b k :00! F b b 0am T Foam Time Foam Time (ppm) (cm) (min:sec) (cm) (min:sec) (cm) (min:sec) 32 0 0.0 17:38 0.0 l : 0.0 17: 32 10 .0 15:28 .0 13:56 .0 1 :08 32 20 .0 15:06 .0 :56 .0 12:52 32 #0 .0 11:02 - -.- .... u... 32 50 .0 1:1:2 .0 18:30 .0 10:16 60 0 .0 0:10 .0 0:10 .0 0:10 60 5 .0 :12 .0 ( :10 .0 :1 60 10 .0 :10 .0 :15 .0 :1 60 20 .0 :10 .0 :33 .0 :13 60 50 .0 :07 .0 : .0 :10 9O 0 .0 ( :10 .O ( :10 .0 ( :10 120 0 .7 60:00 .7 60:00 .7 60:00 120 5 .0 :23 .0 < :21 .0 1:32 120 10 .0 :12 .0 :06 .0 : 120 20 .0 ( :05 .0 < :05 .0 :37 120 50 .0 < :05 .0 < :05 .0 < :05 a Values for 32 and 120°F represent the average of five trials. Values for 60 and 90°F represent the average of duplicate trials. b 1: the foam did not breakdown within one hour, the foam height was measured in cm at the time specified. ' Min. Temperature " 32°F. Min. Temperature - 60° F ‘ >60 " 1“” ”“1 > 1 l n i ANTIFOAM a i 20 __ i _:i. _ -._ .1220 _--___.. " 15 c i g I6~-— "w . d. ‘3 i x o I i 0 . 5 l2r- q ”"1"" t «t *— Tm *3 I0 I , E : ANTIFOAM AF E 8 _____fiL_ if... EMpLsnou : ; I i 5 1 4 —-i—— ——-~~—~~~~i—---- Minimum-.- ; } I ANTIFOAM AF , 1 . t W15“. 0 IO 20 30 40 50 0 IO 20 30 4O 50 Active Antifoom (ppm) Active Antifoom (ppm) Min. Temperature - 90°F Min. Temperature - l20°E >50 ’” “T“”T“ “"1”” ““1 >60 ' """ 1 " ’ g " “ “’ " v‘fl > i ,, i I ( l ANTIFOAM A \ i . ' i6 2 3 ANTIFOAM a I j i 0 ANTIFOAM B 5 l i ' g '4 —~—»T>——--- 7 L—~ —--J) — :- -__+-._...___L .__-— -( c '2 5 _ANTIFOAM B AND ? 3 ANTIFOAM AF EMULSIon 3 to «My 5 w: ~~+e——— ~ o E g 8 K 3 4 \ i ' ...... i -n m-.- .-__. -.-_.. J E 6 1, 3 A 8 ANTIFOAM AF l “- 4 EMULSiON 2 4 i >——— .— .—4»- —..__.-—.,_.._._--- -4? 2 l i i A 0 o-.. _ 1,3 0 IO 20 30 40 50 ‘ 0 IO 20 30 40 50 Active Antifoom (ppm) Active Antitoom (ppm) Figure I. Effect of silicone antifoam agents on reconstituted nonfat milk foam break- down time. Min. 6 f" 1' ‘T " _l _ —i 5 l... -_L.___.__.' .5 - _.J D I -.-4 3 ‘ - i P . l “‘l’ §4r~~ ' -.4------.---_._4 , , 4 8 I AtlTIFOAM Ag .1: . l ' 8 ‘ l 5 3;——~~-- i - E l ' l 8 i 1 i 3 LL '._____.- _. _._ ._-_ -_--.__.. _ =__-__-_- - . - 21 l T A‘lTlFOAM AF t i . EHULSION . ; Ir..- .1)..- --_.-_L.-_ - ”_-_-i“. _ _ “-4--- ._ ,- i l ’ c l | l l l l O ,-__- - _L 1 i _.-__- ..__.‘- __._._._J 0 IO 20 30 4O 50 Active Antifoam (ppm) Min Temperature - 90° F. l 1 7 ""“‘"T"‘””li”‘ " ”‘T""‘”“ _' ‘i k I I ; 6. j. _._4- ._.,A _.' l 3:35 4 ‘“ ’ “' c l ANTIFOAM A ‘ 34?- f i “' 9 i /\ i . 3. . O : l I . 9 a l . LS3?— - t. _. F 8 LL i w? _ . .. X/VANTIFOAM e l I 2; t -r--- ~. I %/ ANTIFOAM AF 1; / EMULSION \- l OL_--..,. _ -_ _ - 0 IO 20 so “”40 50 Active Antifoam (ppm) Temperature - 60° F Sec. I20 l 1 r . i . l i loo: l . ' I VYMTIFOA'A Bf soL fl ‘ ) 4 . I f l 60? ARTIFOAM A 40: ' i ‘ l 203,- 4 M4- “-4 N... __}--.-- _ - T , ANTIFJAM AF 1 : q EMULSIONé ol-___-, 1 1' l..,-_.--l-- 0 IO 20 30 4O 50 Active Antifoam (ppm) )Min. Temperature - IZO°F . 60f T 1 6, i : . 1 i g ' a 51X L 4' i (ANTIFOAM A l l l : l J 41 1‘ 1 l \ l s i . i ' 5: 4 l 1 l l l 2}.“ . “_-_.nHJ..- _._-_- A ‘ ANTIFOAM AF EMULSION lL—H “—4- «my 9 ~ ANTIFOAM a 0L - :{L 0 IO 20 30 4O 50 Active Antifoam (ppm) Figure 2. Effect of silicone antifoam agents on skim milk foam breakdown time. Temperature - 32°F. .37- Temperature - 60°F. Min. Sec. 20V f f I 20f l l ‘ ‘II 9 . I 2 I ‘ A TIF'AM e j. g l6r N 9 g: 3 ANTIFOAM A c i 3 ~ . l2:' I l : W * I O I I l 9 I ' ‘ * , i l D 8: ‘ , 8% * f E g . IANTlFOAM AL ; ' ‘4»— (l g ‘ , l EMULS'ON ' IANTIFOAM AF u. 4'- . ‘ . \ 4‘ i- i EMULSION O; L i 0 Cl (L I i 0 IO 20 30 4O 50 0 IO 20 30 4O 50 Active Antifoam (ppm) Active Antifoam (ppm) >Min. Temperature - l20°F. 60 \ 0 GOI ANTIFOA A .§ ' 503 c . ; l O s a . ‘3 40: \ 2 n . \ a 250i - E l \ 20: ANTIFOAM AF \ , EMULSION \ IOE K | \ l \P OI ANTIFOLAM a 0 IO 20 30 4O ‘50 Active Antifoam (ppm) Figure 3. Effect of silicone antifoam agents on homogenized milk foam breakdown time. 65: 5.3335 Eco. 5:: .83: 3323.302 :o 3500 63on 2.8:? 3 333:3»? 2: co 23.2352 *o 3.32:: of. .v 2:3... 253 63qu 0384 2.2: 63:24 0384 .62: 63:24 3:04 On Go on ON 0. 0 on oe On ON 0. 0 00 cc on ON 0. o I J 0 (j. o .o 5% meow. / A H “.08- ¢ c v .h_oo/m../A a mooQ\ .3 w w m WI m m _ w _ - a 8. , m N. r r o N. I N. m doom . M N NOON .x .. M w. m. M m. u 4/ doom w. ON ON Iii A - ON a / y J A / / EONM r( VII- mowm/ A N om om . . .w w I