A STUDY OF THE ABSORPTION OF ODORS BY MILK Thesis for the Degree of M. 3; MlCHlGAN STATE COLLEGE DONALD YOUNG MCMlLLAN I941 . . . v. .‘ [Jr's ‘5 . \l. ' ‘ l . ‘ ;.J...v lln. ..IVM‘.’1. .Jw'L' . .{ga In ‘1 . .H. . . ..v . .I‘IV.. ,u t . , . _ .thflnvuni . . . . xx. . . I . . raktrlnlvvw 5.. 65.311; $.23“, , ‘ . .. ... .. . ...... A.‘ u . . . _ ..... .‘ ...: . - .‘ ..Anv; \fwbdv... ‘:¢N\ 3. ..vru but." .I . c .Q uh..1.(..\fin.. .tOerh.‘ vu. \,.. . . . . .x A V3.1». .0 C . V O ... ..., d. .. . .. y . .Y $4.... - I . J. . 7 ., f. r I .. . » . . .unifi........-wgthflwnn. m 1%. .{W 1.9.».le4: . 4}..de ”If. PMLW 0|: .1“ ...v‘ ’9 t)...fl.‘r‘ “(3111. t. .- .‘r‘v. 2‘18 . V .vc.‘ «a d §~. ...: Ar ‘ . . u . ‘ g. . - . . , .. . .I . , .. .. . . n .. an. . . . .1 .I' .. ..t ... t x ..x. v . v; t .. ...4. , . 3r . .l‘ . 15.4 .... ‘ ‘OKQKI. . . 1A \ 4 \ . , ‘r. I . . V.. v. ._ ....c .-. .. . I . r .. I . 09)- ," pp . X . .-. r 2 .MV..1 . ,L‘.lv.-14¢.Wv.n.x Pllwfg. 1.0! .‘J’Jul.r.\ oilvn . 3x .1" 4 3.. . . O . n ‘ . V .. ..n.~ a . .. ‘.. .. .. ....a...a)\n. , _.~....~1... wi‘l"‘ A 8ND! OF 'EE ABSGPTION (IF 01133.3 BY MILK BY DONALD YOUNG MOMILLAN 194:1 A S'IUDY OF THE ABSORPTION OF ODGS BY MILK by DONALD YOUNG MCMILLAN A THESIS mbmitted to the Graduate School of Michigan State College of Agriculture and Applied Science in partial fulfilment of the requirements for the degree of “ASTER OF SCIENCE Department of Dairy Husbandry 1941 THESIS ACKN MEN-MM Grateful appreciation and thanke are herewith extended to 11-. G. l. Trout, Professor of Dairy Husbandry. for arrangements, kindly criticism, and advice in connection with the experimental work reported in the thesis and in the preparation of thin manuscript. 136826 TABLE W CONTENTS IN‘IROEICTION REVIEW OF LITERA'IURE Classification of origin of milk flavors The normal flavor of milk External absorption of odors Internal absorption of odors Some fundamentals of gas absorption by liquids EXPERIMENTAL RESJLTS The relative absorption of odors by milk subj ected to various treatments when exposed. to saturated atmospheres 1. Absorption of chlorine-phenol and. phenol odors 2. Absorption of odors of essential oils 3. Absorption of cow manure and urine odors 4. Absorption of formaldehyde and iodoform odors 5. Absorption of silage odors the relative absorption of odors by milk subjected to saturated atmospheres of various foods 1. Absorption 8f odors by milk subjected to various foods at 50 F. 2. Absorption of odors by milk subjected to various foods at 70° 1. Absorption of odors by freshly drawn milk when exposed to various surroundings . Relative absorption of odors by warm milk placed in silo for various periods of time Penetration of odors in bulk pasteurized milk earposed to saturated atmospheres Rate of passage of various substances into milk when fed to the cow 1. Rate of passage of kerosale into milk 2. Rate of passage of ethyl other into milk 3. Rate of passage of onion into milk 4. Rate of passage of aidan III we to milk after ingestion 5. Rate of passage of formaldehyde into milk DISCU SSION EMMARY MEN” 333381869188383 $98} INTRODJCTI 011 here are numerous ways by which flavors w gain entrance into or develop in milk. Ihese generally include feed. absorption of odors from the air. physiological disturbances of the cow. bacterial growth and chemical activity induced.by sunlight. metallic salts or enzymes. Perhaps the most common or best known of the off-flavors of milk are those associated with feed. Many studies have been made and much data collected on this type of flavor. showing largely therrelas tion of time of feeding to the off-flavor in the milk. l'eed flavors are so common that man dairymen and even control officers believe that direct absorption of feed.flavors by milk after it has been drawn plays an important role in clean-flavored milk production. Data on the direct absorption of odors by milk under various conditions are rather limited. The purpose of this study was to ascer- tain under what conditions odoriferous substances enter milk through direct’ absorption and to compare the rate and intensity of directly absorbed off-odors in milk with those which gain entrance to milk through the body of the cow. REVIEW OF LITERA'NRE glassification _of origin of milk flavors Harding. Rogers and Smith (1900) stated that on the basis of origin there were two general classes of flavors, those directly connected with the growth of plant life in the milk and those associated with compounds taken'mp while in the cow or absorbed.after the milk was drawn. In general, Marshall (1902). Ield (1909). and Gamble and Kelly (1922) classified.the origin of flavors and odors of milk as follows! a. The physiological condition of the cow. b. Ihe absorption within the body of the cow of odors from highly odoriferous feeds. c. The direct absorption of odors after the milk was drawn. d. Bacterial development within the milk upon standing. In addition to the above classification of origin of mink flavors Mackintosh (1929), Pien and Herschdoerfer (1935). and Olsen (1988) added those resulting from chemical changes in milk the to sunlight. metallic salts or enzymic action. stat-p (1941). on the other hand, lists six general causes of off- flavor in milk which are as follows! '1. microbial growth and decomposition. to e feed. absorbed. as» chemical composition of the milk. 01 e processing and handling. 03 e enzymatic and catalytic changes.ll - 3 - me normal flavor of milk Ihile many descriptive terms of off-flavors of milk are to be found in the literature. those describing the normal flavor of milk are rather limited. However. several descriptions of normal flavor of milk are given. Pearson (1896). and Ileischnann (1896) stated that normal .111: had a slight pleasant odor and a rich distinctly sweetish taste. linslow (1907) described milk as having. 'a peculiar. pleasant odor and taste which cannot be described." Hastings' (1926) description of milk flavors follows: "ihe fresh clean pro dict of a healthy well fed cow is alm0st devoid of taste and smell. so completely so that it can be used daily with con- stant satisfication. me more nearly the milk retains its original properties. the greater will it attract the consumer and the more it will be used to the ultimate good of all.” Van Slyke (1927) explained that. “Perfect flavor in market milk is indicated by freedom from all traces of abnormal odor and taste. There should be no marked odor and no trace of any offensive smell. The taste should be palatable. slightly saline. and rich without any unpalatable aftertaste. It should not be flat or insipid." front (1982) believed that, “Hormel whole milk is pleasantly sweet. possessing neither a foretaste nor an aftertaste other than that imparted by the natural richness of the milk." Bckles. Combos and Macy (1936) concluded that milk had no pro- nounced taste but was slightly sweet to most persons. Milk freshly s. -4- drawn had a characteristic flavor which was quite volatile and soon disappeared when the milk was exposed to the air. Thus. it would seem that the tendency exists to describe the flavor of normal milk in negative terms. that is. what flavors should not be present. rather than in positive terms. External absorption of odors Harley (1829) noted that when milk came into contact with foreign substances or impure air the taste and smell was impaired and stated that milk was even tainted simply by drawing it from the cow to a pitcher in foul air. l'hus he believed that barns should be well ventilated to avoid odors in the milk. sateen (1897) stated. Wen: liquids have a great affinity for matter in a gaseous form and will absorb varying amounts of such sub- stances. l‘hese can be readily recognised if the absorbed substances contains an odoriferous principle. A fluid milk possesses this property to an unusual degree for not only does liquid serum absorb volatile odors. but the fat also has a great affinity for many of these sub- stances.“ rho opinion was current that milk warmer than the surrounding atmosphere gave off odors and only milk cooler than the surrounding air took on odors. Russell (1897) disproved this theory. l‘urthermore, he (1898) found that the odor was greater in the warm milk as shown by the following data. Relative absorption of odors in warm and cold milk. L 8 8 8 Kind of odor 8 Time of exposure 8 No. of tests 8 No. of tests with 8 8 made 8__rstronger odors in _ 8 8 8 aim-ilk 8 Cold milk r 8 8 fi‘ 1 T corn silage 8 1 hour 8 5 8 5 8 8 3 hours 8 3 8 2 8 l 8 5 hours 8 2 8 2 8 8 8 8 8 8 8 8 8 Horse manure 8 § hour 8 3 8 l 8 8 1 hour 8 3 8 2 8 8 1% hours 8 2 8 2 8 8 2 hours 8 2 8 2 8 8 8 8 8 8 8 8 8 Oil cinnamon 8 1 hour 8 6 8 5 8 8 2%- hours 8 2 8 2 8 8 3 hours 8 3 8 3 8 8 8 8 8 O. D. D. O. 0. Relative absorption of odors in warm and cold milk. r eie mmun Ato a; 1m at m... m u. rms.reooe numomm Mia m r dk la 11 um. mm eon abri t 0000 .188 o u k mmm mu Nwo _Wm a rm 08 ...v e8 oe Nt f9 on 8 mm m... Kind of odor h 1.211 8 hours 011 cas s in Cinnamon 0...:‘0. 34.5 111 16 16 16 00:00.... hour hour 8 1 1%)» 8.0.0.... Oil of winter- green 65 72 8 498 12 12 Oil of pepper- winter 70 83 3:00.... Horse manure 69 % hour 8 1 hour 8 11 hour 8 Urine of cow e. s. m- o. so so me to 0. CI . at t. as ew as ea In to .- to .e . . .0 e. ‘\ as s: «a es O. is 9' I. e. vs II 0. De I. I. D. e. we as as 0- to s so to so vs . . em as to no so so so to to It , V to in Ge o Co Co I. a. O. a. V. -7- King and Iarrington (1897) demonstrated that odors were more readily absorbed in warm than in cold.milk. They pointed out that al- though silage odors were absorbed by the milk the odors in the milk were less intense than those in the milk obtained.by feeding silage Just before milking. Bitland (1399) working with the turnipy taste of .111: conducted the following experiment. I'Two cows which were on.pasturage were fed turnips out of doors and.mkaed in the stable. and later they were fed hay and turnips in the stable and milked mut.of doors. the object being to test the absorption of the turnipy odor. Ho grain was fed at any time. !he amount of turnips fed was as high as 1 hectoliter (2.84'hu.) per cow daily. Tests of the milk at different times by a number of persons failed to reveal any turnipy taste in the milk. lbs conclusion is reached that the characteristic taste often observed when turnips are fed is due entirely to the absorption by the milk of the volatile in- gredients of the turnips.” Ibmbrowslq (1904). working with absorption of odors by goats' milk. found.thar odors of iodoform and anise were taken up readily and held for some time while those of carbolic acid. turpentine and formalin were taken up and lost quickly. be odor of chloride of lime was only feebly absorbed. Bordas and Touplain (1906) erposed milk for several minutes in an atmosphere of l to 100.000 parts of formaldehyde. They found that the fresher the milk the more rapid was the absorption. Iazis (1917) demonstrated the absorption of odors in cream by placing the odoriferous substances onto a cheese cloth directly over the cream. -3- and corn silage were all readily absorbed. 'hen higher temperatures He found that the odor of onions. garlic. cabbage. turnips and longer periods of exposure were used. the off odors of the cream were stronger. distinct odors in the cream. hposure to gasoline, kerosene and creolin resulted in Oils of peppermint and wintergreen pro- duced stronger odors in cream than did oil of cinnamon. Gamble and Kelly (1922) allowed warm milk to flow through a closed chamber saturated with silage odor. silage odor. fhe milk took on a decided later dancnstrated and concluded that direct absorption of silage odors during milking were of minor importance. However. under controlled and adequate experiments. they Alt (1926) exposed milk at different temperatures to air which had been passed through bovine urine. He found that the fat of milk was largely responsible for the absorption of the foreign odor. \ Lea (1933) cited work of Gene's as follows8 'Gane has carried out some investigations on the absorption by butterfat of d-limonene (610 316) which is the chief constituent of the oil of orange-ring. The avidity with which this strongly odorous substance is taken up from the air by a free surface of fat is as follows8 --- " 8 8 8 8 8 8 Leyerature 8 20 8 10 8 5 8 0 8 -lO 8 --20 8 8 8 8 8 8 Vapour-pressure of limonene 8 8 8 8 8 8 mm. .) 84.01 8 0.54 8 0.39 8 0.33 8 0.17 8 0.08 8 8 8 8 8 8 Lomonene absorbed 8 8 8 8 8 8 (mg. per 100 am. cm. per ming: 3.60 8 1.76 8 0.96 8 0.59 8 0.18 8 0.08 8 8 8 8 8 8 Ratio of rate of absorption 8 8 8 8 8 8 ifvapour-pressure 8 3.57 8 3.26 8 2.46 8 1.78 8 1.08 8 0.96 -9- Ihen solid butterfat was exposed to limonene for a period of 14 days in a saturated atmosphere only the outmost one mm. of fat absorbed we odor. Roadhouse and Henderson (1935) noted that milk readily absorbed odors from paint. coal-tar disinfectants. gasoline. kerosene. some fly sprays. and tobacco smoke. The amount absorbed depended on the efficiency of vaitilation. Hammer (1938) stated. ”he practice of pouring bottled milk into a shallow pan and allowing it to stand so that it can be skimmed easily is especially objectionable. not only from the standpoint of contamination but also because it permits the rapid absorption of odors of other food products placed near the milk." Babcock (l939) well summarised the importance of direct absorption of odors by milk in the following statement: "he absorption of odors as a source of abnormal flavors in milk has been over-emphasized. Experimental work has shown that even under extreme conditions milk produced in a silage permeated atmosphere was seldom sufficiently tainted so that a silage flavor could be detected in the milk. If under extreme conditions sufficient silage is not absorbed so that it can be identified in the milk it appears as though we should encounter but little trouble from this source lien milk is produced under normal condi tions.‘ Internal absorption of odors Marv data are available concerning the effect of various feeds and feeding practices on the taste and smell of milk. The few citations presented here show that the internal absorption of odors have a profound -10- effect on the flavor of milk unless precautions in dairy herd management are taken to prevent flavor impairment. King and l'arrington (1897) believed that when a cow ate any substance which contained a volatile principle this substance would be removed from the blood by the various channds of excretion. than these substances were circulated in the blood in a cow's body and she was being milked. then some of the volatile substances would be removed in the milk which would cause an abnormal flavor and odor. If sufficient time had passed between feeding volatile substances and milking such products would have been removed from the blood by the skin.lungs. and kidneys and the milk drawn would be normal. neischmann (1896) recommended that putrifying food of any kind should not be fed to dairy cows. He found that beans. peas. pea-straw and barley-straw should not be fed to milk cows while good grass. hay. grains. especially oats and wheat bran, produced milk without taints. Marchal (1925) treated grain with p-dichlorobenzene and fed it to cattle. resulting in a slight modification of the flavor of the milk. Procter (1926) found that when cattle ate Hammad a taint was produced in the milk. An extract was prepared by mixing two pounds of Mayweed in water and given to the cow in the evening. The milk next morning showed a faint Mayweed taint. The California Agricultural Elmeriment Station (1931) conducted the following experiment with alfalfa Juice. “Four cows were drenched with the Juice expressed.from 25 pounds of green alfalfa. This quantity of alfalfa yielded 5 to, 6 quarts of Juice. It required from 3% to 5 minutes for two peeple to administer this quantity of liquid. The cows 10 -11- were partially milked in some cases every 5 minutes for the first 30 minutes. and in other cases at the end of 45 minutes. 1 hour and 2 hours after drenching. It was found that feed flavor could be definitely detected in the milk 20 minutes after drenching. file most prominent flavor was present in the milk drawn between 45 and 60 minutes after drenching. i‘he 2-hour samples were less prominent in feed flavors than were the samples drawn l-hour after drenching.“ Babcock's numerous experiments (1923-a). (1923-b). (1924). (1924-b) and (1927) show conclusively that feed and time of feeding with respect to milking have a marked effect on the flavor of the resulting milk. Even when the cows were permitted to breathe odoriferous substances without ingesting them \1925-a). the characteristic odor was present in the milk within two minutes after cows inhaled garlic for ten minutes. For a substance to pass througi' the digestive system before entering the milk requires considerable time. Moore 81939) showed ex- perimentally that when a rich carotene feed such as freshly cut alfalfa was fed to cattle. 15 hours were required before the blood plasma of the cow showed a sligit increase in its carotene content. Some fundamentals oLgas absorption by liquids Laws relating to absorption of gases by liquids would seem to be applicable in sane respects to absorption of odors in milk. According to Henry's law the concentration of the dissolved gas in solution is directly proportional to the concentration in the free space above the liqiid or g = K. where I is called the solubiliv co- efficient and is defined as the ratio of concentration of dissolved gas -12- C to the pressure of the gas P. The extent which a gas would dissolve would depend on the pressure. the temperature. the nature of’the gas. and the nature of the solvent. Whitman (1923) held that diffusion occurred through a gas film and was caused.by the partial pressure differences of the solute in the gas and.that it was in equilibrium with the liquid of the film. Becker (1924) found that when a liquid and a moderately soluble gas were allowed to come in contact. and the liquid.kept uniform in composition. the rate of solution of the gas would vary directly as the degree of unsaturation of the liquid. Becker has shown experimentally the absorption of oxygen and nitrogen in air-free water by'allowing the gas to bubble up through a tube filled with air-free water and measuring the reduction in pressure of the bubble due to the absorption of a por- tion of the gas. Many factors affected the absorption of a gas by stationary water depending upon. the gas. its density. surface tension. viscosity. and temperature. It was found that carbon dioxide. hydrogen. and hydrogen sulfide saturate the surface layers of the water while nitrous oxide. nitric oxide. and chlorine do not form saturated surface layers and are therefore absorbed at a greater rate. Ellie effect of dissolved gas on the density of the water is to increase it while the surface tension and the viscosity tend to maintain the surface in its original condition. It was found that sometimes the rate of solution was greatly affected.by slight disturbances of the liquid. lhitman and mvis (1924) studying the absorption rates of fair gases found that the absorption rates for sulfur dioxide. oxygen. ammonia. and hydrochloric acid could be predicted with an accuracy of 15 per cent or better. Eatta (1938) found that the velocity of absorption was increased by about so per cent per 10° 0. rise in temperature and when the :11. of liquid was thin. the velocity was inversely prOportional to the thickness and almost independent of change in composition of the liquid. Higbie (1934) showed experimentally that as the time of exposure was decreased. the rate of absorption or the coefficient did not increase indefinitely as predicted by the penetration theory. He found there was a maximu- or initial rate of absorption which was approached by shortening the time of exposure. and agitating beyond a certain degree was useless in the absorption of carbon dioxide in water. has it would appear that the solubility of gases in liquids is limited. ‘me extent to which a gas dissolves in a substance such as milk apparently depends upon the pressure. the surface tension. the temperature. and the nature of the gas. As previously stated Lea (1935) citing Gene's work stated that when there was a decrease in vapour-pressure and temperature. the rate of absorption would also decrease. ~14... MERIMENTLL The different types of milk were obtained from the Creamery. of the Department of Dairy Husbandry. Michigan State College. The raw milk was secured from a vat full of’milk ready to be pasturized. the homo- genized and pasteurized milks were obtained.from the same milk after processing. The heated.nka was processed by heating to 1700 F. for five minutes and cooling immediately to the desired temperature in order to inhibit creaming. After the milk was tempered.fior exposure. 50 ml. samples of milk were placed in small ground glass. low wide form. weighing bottles with covers ground to match. Six of these bottles were placed in a desiccator. Four desiccators were used in each trial with a different type of milk placed in each. the desiccators were placed in the ants-room of an ice cream storage room at a temperature of 50° F. and in an incubator at 1000 I. file desiccators and milk were at the desired tanperatare before the odoriferous substance was placed.in them. The odoriferous substance was placed in a small beaker and.the glass bottles placed.around.the beaker. Enough of the odoriferous substance was used so that the milk would be exr posed to a saturated atmosphere. lhen identical amounts of the same odoriferous substance were placed in each desiccator the covers were removed from the weighing bottles. lhs different types of milk were then exposed for 15 minute periods ranging from 15 to 90 minutes. Each different odor under study was run at 50° F. and at 1009 I. to compare the absorptive power of different types of milk when the fat was in a liquid and in a solid state. After exposure the bottles were examined.and then placed in the ante-room at 500 F. for 246hours. Before final grading of the samples for odor intensity the milk was tempered to room temperature. Inch glass weighing bottle had an identification number. These bottles were shuffled.and.graded.into groups by smell according to intensity of odor by two Judges. All Judging was done I'blind". ihe room in which Judging was done was free from all odors. The intensity of odors were deisgnated as follows! 7 : doubtful + Z slight odor + + = pronounced odor + e e I very pronounced odor which for practical purposes in making up the tables and graphs were calledrl. 2. 3. and 4. respectively. The chlorineaphenol solutions were made'up as follows: Solution A - three grams of’B-K and three grams of phenol crystals were dissolved in 94 ml. of water: Solution B - four grams of 3-! and two grams of phenol crystals in the same amount of water. ihe five per cent phenol solution was made up by dissolving five grams of phenol in 95 m1. of water. The phenol crystals were obtained from«J. T. Baker's Chemical Company. Phillipsburg. New Jersey. The different.types of milk were exposed to different essential oils. namely. those of cinnamon. dillweed. lemon. orange. peppermint. turpentine. and wintergreen. Ihese oils were obtained from lill Corporation. Rochester. New York. Magnus. Mable do Reynard. Importers. low York City imported certain of the above oils for the 'ill Corporation. -15- Corn silage was taken from the silo and placed in an air-tight container. As the silo from which the grass silage was obtained did not have a roof. the silage was taken fran a considerable depth below the surface in order to secure a representative sample having a full odor. l'ifty ml. of the different types of milk were placed in the glass weighing bottles and exposed to each of the following seven sub- stances! bacon. banana. cabbage. onion. orange. potatoes. and turnips. These foods were cut up so that the odoriferous substance contained therein could more easily saturate the atmosphere in the desitcator. The cabbage was emosed to the milk in both the raw and cooked form. he potatoes were left unwashed in one case and were washed in another. The turnips were exposed only in the cooked form. The desiccators and milks were placed in the ante-room of an ice cream storage room at a teweramre of 50° F. and anchor trial set was run at room temperature. The samples were exposed to the above substances for a period of l and 24-hours. Immediately after the one-hour emosure the samples were ex- amined for identification of the odoriferous substance and for odor intensity. The one-hour trial sainples were placed in the ante-room at 50° 3'. until the 24-hour exposure samples were to be graded. All the samples were tempered to room temperature and then were examined for identification of the odoriferous substance and for odor intensity. Iresh warm milk having no abnormal odor was obtained from Jersey cow no. 88, at the Dhiry Barn, was divided into lots, and.was exposed to different surroundings for one and one-half hours. One-half -17.. pint samples were placed in six inch culture dishes at the following locations: Calf pen Milk room Inside corn silo Gutter which contained manure Feed room reed alley Barn ventilator exit Corn silo alleyway Bull pen Shavings bin Stall adjacent to a rumen fistula cow Inside grass silo without roof. After the exposure period 50 ml. of the milk was strained througi cheese- cloth. to remove particles of dirt which had fallen into certain of these ' dishes. into glass weighing bottles and coveredqimmediately. file weighing bottles were taken to the laboratory and examined for odor intensity. One—half pint samples of fresh warm milk also from cow Ho. 88 were placed in the six-inch culture dishes and eiqiosed to the atmosphere in the corn and grass silos for 15 minute periods ranging fran 15 to 90 minutes. The corn silo was nearly empty and contained quite a pronounced odor while the grass silage was exposed to the weather and was quite dried out. After the exposure period the samples were strained througi cheese- cloth into the weighing bottles. covered immediately. and examined in the laboratory for intensity of odor. -13.. Eighty pounds of pasteurized milk in a specially fitted ten- gallon milk can was exposed for one hour to grass silage and turpentine wrapped or soaked in a cheesecloth on the underside of the can cover. In both cases the amount of grass silage used was 150 grams. Milk was drawn from the bottom of the can in ten eight-pound lots. Care was taken not to Jar or shake the can so that the different layers of milk would not be mixed. Trials were run with the milk fat in a liquid and in a solid state. The samples were then graded according to the in- tensity of the contaminating odor. Different odoriferous substances were placed in gelatin capsules and given to Holstein cows No. 274 and 287. The capsules were made air-tight by sealing them with parafilm manufactured by the Menasha Products Company. Menasha. Wisconsin. The gelatin capsules with the odoriferous substance were placed in warm water of 102° 1'. to find out approximately the time necessary to dissolve the gelatin capsule and thus release the odoriferous substance. The gelatin capsules were forced down the cow's throat by a capsule gun. Samples of milk were obtained before giving the cow the odoriferous substance and at one-fourth. one-half. l. 8. 16. 24. 32. 40. and 48 hours after the capsules were administered. At certain of these intervals her breath was noted. lhen the cow urinated the smell was noted to find out whether the odoriferous substance had been passed off in the urine. -19.. RESULTS Q3 relative absorption of odors by milk suflected to various treat- mgnts when exposed to saturated atmospheres. Samples of heated. homogenised. pasteurized. and raw milk were exposed at 50° 1'. and at 100° 1'. to saturated atmospheres of various odoriferous substances from 15 to 90 minutes and examined for odor immediately after the experiment and after 24 hours. he data are summarized in table 1. The results secured indicate that the different milks vary in their absorptive capacity to take up the odoriferous substances. The milk with the fat in a liquid state absorbed the odoriferous substances faster as well as in greater quantities than when the fat was in a solid state. However. some discrepancies and inconsistencies of ab- sorption of the different substances were noted. In general. exposures of milk to saturated atmospheres of odoriferous substances required 30 minutes or longer before pronounced odors were detectable in the milk. . and at 100° 1. :: 0 : 15 : so : 45 : 60 : 75 : 90 . and at 100° F. :75:90:: :45:60 Treatment : Relative absorption of odors bLmilk when exposed at 50° F ofmilk 30:15:30 The relative absorption of odors in milk subJected to different processes when exposed to saturated atmospheres for various periods of time at 50° 1' Odoriferous substance Table 1. : 2.5: 2.0: 3.5: 3. : 2.0: 1.0: 1.0: 2. :0 :: 0 :: 0 :0 :: O :0 :: 0 : 3.0: 4.0: 4.0: 3.5: 4. :0 : 1.0:1.5: 2.0: 2.5: 3.0: 3.5:: 30 : 0.0: 1.5: 2.0: 2.0: 2.5: 3.0:: : 0 : 1.0: 2.0: 2.0: 2.5: 3.0: 4.0:: :0 : 2.0: 2.0: 2.0: 3.5: 4.0: 4.0:: : Past. : Raw solution.A O. Chlorineephenol (avg. 2 trials) .0: 2.0: 3.0:,3.0 :: 0 :0.5: 1.5: 2.0: 2.0: 3.0: 3.5 :: 0 : 0.5: 0.0: 2.0: 2.0: 2.0: 3.0 :: 0 : 2.0: 2.5: 2.5: 3.0: 4.0: 4.0 :: 0 80.0: 1.5: : 1.0: 2.0: 2.0: 2.5: 3.0:: : 0 : 0.5: 1.5: 2.0: 2.0: 2.0: 3.0:: :0 : 1.0: 2.0: 2.0: 2.5: 3.0: 3.5:: : 0 : 2.0: 2.0: 2.0: 2.5: 3.0: 4.0:: :0 :0 : Heated Homo. : Past. Raw solution B (an. 2 trials) Chlorineephenol : 2.0: 2.0: 2.0: :: 0 :2.0: 2.0: 3.0: 3.0: 3.0: 4. :: 0 : 2.0: 2.6: 3.0: 3.0: 3. :: 0 :0 :: 0 : 2.0: 3.0: 3.0: 3.0: 8 2.0: 2.3: 2.6: 3.0: 3.6:: 81.6: 2.0: 2.0: 2.0: 2.0:: :0 : 1.3: 2.0: 2.0: 2.0: 3.0: 3.0:: :0 :0.3: 2.03 2.0: 2.03 3.0: 3.33: :0:0 :0:0 Homo. : Past. :Raw Heated (avg. 3 trials) Cinnamon. oil of Cow manure (fresh) (avg. 2-4 trials) 4 4 4 0 0 O 4.0: 4.0: 4.0: 4.0: 4.0: 4. 2.0: 3.0: 4.0: 4.0: 4. £0:£0:a0:a0 : : 3 : : 1.0: 2.0: 2.5: 2.5:: :2.0: 2.03 3.0: 8.0: 4.0:: O 0 :0 :0 :0 0 :0 :0 : Heated : Homo. : Past. : Raw 4. 4. 4.0: 4.0: 4.0: 4.0 0000 4. 4. 4. O...” 0 0 0 : 0 3 2.0: 3.0: 4.0: 4.0: 4.0: 4. :: 0 : 1.5: 2.0: 8.0: 4.0: 4. :: 0 : 3.0: 3.5: 4.0: 4.0: 4. :: 0 : 4.0: 4.0: 4.0: 4.0: 4. 323.33 . JeeJ seas méow saoo mJJJ ......” 0000 O... mn¢n 5583 0.. HNNN 0000 O... HNNN 0000 v Gee no» 3 8 3 ‘ mmmg A c 0H 50‘ HQ 333 on g“ gm 3:5 as V O. 2.0: 2.0: 3.0: 3.0: 4.0: 4.0 :: 0 :2.0: 3.0: 3.0: 2.6: 3.6: 4.0 :: 0 : 2.0: 2.0: 2.0: 3.0: 3.3: 4.0 ::O 0 : 2.0: 3.0: 3.3: 4.0: 4.0: 4.0:: :: 0 : 2.0: 3.0: 3.0: 3.0: 4.0: 4.0 0 : 1.6: 2.0: 2.0: 3.0: 3.0: 4.0:: : 0 : 2.0: 2.0: 2.0: 2.0: 2.0: 2.6:: : 0 : 2.0: 2.0: 3.0: 3.0: 3.0: 3.3:: : Heated : Homo. :hu. :Raw Dillweed, oil of (avg. 3 trials) .l i. l. i O 0 e D. -. O. o a m 0. d. -- v 5 Q a. a. .0 e e e C. O. at I O ¢ 0 . Q- ‘Q Q. I. D. O. on d. D. I. I. O. .a .. .. I . J. O O . l o. O. C. I l O i . O. .- 0' C I I J O. O. I. O I 6 . . .- I. 0' e 0 0 I. i. I. e m C II .0 I. . a. .. .. I. I -. O. D. U I .. . a- .- ' I Q. .- e I t. A. I D .. a. w e O. O. m e O. l- 5. .- e- c. .C .- -- em . 0 e . o- .. e O .. ea- 9 e I‘ l- e l C. v- ' e I. U. 0 D . .1 O. In I. n m m- ,. C I an -— Q I .. .- l U o- O. I C so u. i 6 .. me- . O 0. v. a. so no .5 m- u- -e ma . a -.. o. J O 1 em a. n . C .m .- I O . II I. O C u- a. O C .n a. .e .0 0 so so ‘ . 5- m4 ' v a- .- 0 1 1. me O O n. as C O m- .- . a II we .0 I. u- o. an. n. .. .- O I m. o. . O .- O. C D -- e- . . .0 om . C a- no 0 n. I. et so .- .ms - I . I. l- .. v. C a . O. I- I. m- e e a. I. D. .- q o . O- .A O. m. ' A . g- .e 0. mm C. 0‘ .0 DO U. IO 0. I. a. a. I. n. I. l. e- .e .0 Oh I. 0 o O. ‘0 O. 0‘ 0 o I- C. n. O. o m . I. Q. ~- I. O O O 0:. II I. t. I 0 O ‘ u i. u. m. e. n A. e e A. on a. I. u. .- .. .. u. . - n . .. ‘ e I- .o O. o. : 45 : 60 : 75 : 90 : 1.0: 2.0: 2.0: 2.5: 3.0 0 8 1.0: 2.08 2.0: 3.0: 3.0: 3.0 :8 0 : 1.0: 2.0: 2.0: 3.0: 3.0: 3.0 : 15 : 30 :: O : 1,0: 2.0: 2.0: 2.5: 3.0: 3.0 : 0 :: 0 :: 0 : 45 : : 1.0: 2.0: 2.0: 2.5: 3.0:: : 1.0: 1.5: 2.0: 3.0: 3.0:: : 0 : 1.0: 2.0: 2.0: 2.5: 3.0: 3.5:: : 0 : 1.0: 2.0: 2.0: 2.5: 3.0: 3.0:: : 0 : 0 : 0 : 0 : 15 : 30 : Treatment : Relative absorption of odors by milk when exposed at 50° F. and at 1000 I. : 0 : of milk : Heated : Homo. : Past. : Raw ) Table 1 continued (avg. 2 trials formaldehyde odoriferous substance O. : 0 : 0 : 0.6: 0.6 :: 0 : 0 : 0 : 0.3: 2.0:: : 1.0: 2.0:: : 0 : 0 : 0 : 0 Heated Iodoform (powdered) ( avg. 3 trials) : 0 :: 0 :: 0 : 0 : 0 8 0 : 0 : 0.3: 1.3: 2.0 : 1.0: 0.6: 2.0: 2.0: 2.3 : 0 : 0.3: 0.6: 2.0: 2.68 3.0 :8 0 : 0.3: 0 : 1.0: 2.033 3 2.0:: : 0 : 0 : 0 : 0 : 0 : 0 : 0 Homo. : Past. : Raw :: 0 32.0: 2.0: 3.3: 4.0: 4.03 4.0 :: 0 : 2.0: 2.0: 3.03 3.0: 3.0: 3.3 : 0 : 1.5: 3.0: 3.0: 3.0: 3.3: 4.0 :: 0 : 1.03 2.0: 3.0: 3.6: 4.0: 4.0 : 0.3: 1.0: 0.3: 1.6: 2.0:: : 0 : 2.0: 2.3: 2.6: 3.0: 3.6: 4.08: 8 0 3 2.0: 3.0: 3.03 3.6: 4.0: 450‘: : 0 : 0 eated omo. : Past. : Raw (avg. 3 trials) Lemon. 0 11 of 8 1.6: 2.0: 2.0 - 31 - O O 0 O O O O 3 4 4 : 1.6: 2.0: 2.03 3.0: 3. 1.0: 2.0: 2.3: 2.6: 3.3: :: 0 : 1.0: 2.0: 2.0: 2.0: 3.0: :: 0 : 0 :: O : 0.6: 1.3: 2.0: 2.0: 3.0: :: 0 8 2.0: 2.0: 2.0: 2.0: 3.0:: : 2.0: 2.5: 3.0: 3.0: 3.0:: : 2.0: 2.0: 2.0: 3.0: 3.0:: : 0 : 0.5: 2.0: 2.0: 2.0: 2.0: 3.0:: 0 : 0 : o : 0 : 0 : 0 sated omo. H H : Past. : Raw 0. (avg. 2-3 trials) Orange. oil of .03 3.03 4.0 :: 0 : 2.0: 2.0: 2.0: 2.0: 2.08 3.0 : 0 : 2.0: 3.0: 3.0: 3.5: 450: 4.0 0 : 2.0: 2.5: 3.0: 3.0: 4.0: 4.0 :: 0 : 2.0: 2.0: 3.0: L : 0 : 2.0: 2.0: 2.0: 2.0: 2.5: 3.0:: :0 : 2.0: 3.0: 3.0: 3,0: 3.0: 4.0:: :0 : 2.0: 3.0: 3.58 4.0: 4.0: 4.0:: : 0 : 2.0: 2.0: 2.5: 2.6 : Heated : Homo.’ : Past. : Raw Peppermint. oil of (avg. 2 trials) : 0 : 0 : 0 : 0 : 0 : 0 : 0.5:: :: 0 : 0 : 0 : Heated Phenol solution (5%) (avg. 2 trials) 020 H0 00 .... CO CO OO OO O.” OO ”.9 04 a O. O. :60:75:90 :15:30:45 0 : 75 : 90 :: :30845860 :15 Treatment : Relative absorption of odors bx milk then exposed at 50° F. and at 1000 F. : of milk : O substance Odori ferous flable 1 continued 0. : 2.0: 3.0: 4.0: 4.0: 4.0 00 3.0: 4.0: 4,0: 4.0: 4.0 :: O : 2.6: 3.6: 4.0: 4.0: 4.0: 4.0 :: 0 : 2.0: 3.0: 4.0: 4.0: 4.0: 4.0 .0: 2.6: 3.3- 3.3: 4. 0 0 .3: 2.3: 3.0: 3.3: 4. NW O.” : 0 : 2.6: 3.0: 4.0: 4.0: :x 0 : 3.0: 4.0: :30 .3” : 1.3: 2.0: 2.3: 3.0: 3.3: 4.0:: : O : 1.0: 2.0: 2.0: 3.0: 3.0: : 1.3: 2.0: 2.6: 3.0: 3.3: 4.0:: :0 81.3: 2.0: 2.6: 3.0: 3.3: 4.0:: : Heated : Homo. : Past. : Raw 3 trials) Silage (grass) (avg. 22- C. 5: 1.0: 2.0: 1.53 3.5 5: 3.0: 3.5: 3.5: 3.5 2.0: 3.0: 3.3: 3.3: 3.3: 4.0 0 2 :: 0 : 1.6:1.6: 2.6: 2.6: 3.0: 3.0 : 0 : 1.0: 1.3: 1.0: 2.6: 2.6:: 3 0.6: 1.3: 1.3: 2.0: 3.0: 3.6:: : 1.0: 1.6: 3.0: 3.3: 3.6: 3.6:: :0 :1.0:1.0: 2.3: 2.53 3.3: 3.3:: 0 0 :0:0 : Heated : Homo. : Paste :Raw Turpentine. oil of 3-4trials ) (avg. :: 0 : 2.5: 3.0: 3.0: 4.0: :: 0 : 2.0: 2.0: 2.5: 3 :80 2.0: 3.0: 3.5: 4.0: 4.0:: 0 : 1.5: 2.0: 2L0: 2.5: 3.0: 3.0:: 1 :0 :1.0: 2.0: 2.0: 2.0: 2.5: 3.0:: 0 : 2.0: 2.0: 3.0: 3.0: 3.0: 4.0:: : 0 : 2.0: : Heated : Homo. (avg. 2 trials) Urine (fresh) 00:00 1 2 5 : 1.5: 1.5: 2.0: :0 0 0 : 2.0: 2.0: : 3.0: 3.0: 2.5: 3. : o : :0 :0 0 :0 :: 0 : 0 :: 0 : O :: 0 : O :: 0 : 0 : 1.0: 2.0: 2.5: 2.5:: : 2.0: 2.0: 2.5: 3.5:: : 1.0: 2.5: 3.0:: :0 :0 0 :0 :0 : 2.0: 2.0: 3.0: 3.0: 4.0: 4.0:: : 0 : 0 : O :0 O 0 : Homo . 3 Past. : Raw Wintergreen, oil of : Heated (avg. 2 trials) .. a- s. ,. .. .- r C D o C .- -. .u c. .. .- o C o v r .I u. .0 o. .I 0‘ v c o o v OI - I. II I. .4 I F C D O .. -. .o co -. .4 o I D C O .- .. .- A. .- o. .. -. -. -. .. -. .- -. .. .. . . I. -C III .I " C- A. .o a. .o .. .- . I v 0 O D I. p. a- I. n- C. v o O C a. a. .. a. Q. .. '0 0 v o o o in a. do us a. .- o 1 O O 0 II .0 D. 0. to .- v o O o D . D. d! O. C- I. U I C O O u. C. .. .- 7- '- .. .. .. .. .- .. . ‘ C .0 O. .- o. a. O. .0 d. c O. 0 v I. oe o C. .- o .. .. c D. " O .0 ’0 .— .. .. .. u- -. .u a. o I. .0 a . on -- O D. A. o C. I. u. .— I e- .0 .o .. I. do u 23 e- 1. Absomtion of chlorine-phenol and phenol odors In comparing the absorptive quality of the different milks to the chlorine-phenol solutions. it was found that the odor of the solution A which was relatively richer in phenol than solution B was absorbed to a greater extent than that of solution 3. Especially was this pronounced in the heated .111: at 50° 1'. It will be noted that in homogenised. pasteurized. and. raw milks there was very little difference in intensity of odor absorbed. At the 100° 1. exposure heated. pasteurized. and especially raw milk absorbed the odor of solution A in greater intensity than solution B while homogenised milk absorbed slightly less of the odor of solution A. when milk was exposed at 50° 1. to the five per cent phenol solution the odor as absorbed only after an emosure of 90 minutes. Heated and homogenized milk contained this odor in only one trial after being exposed for 90 minutes whilejpasteurized.milk absorbed this odor slightly in both trials. Raw milk failed to pick up this delicate odor. Heated.milk at the 1000 1. exposure failed to pick up this odor. Homo- genised and pasteurized milks first picked up this odor after an exposure of 45 minutes while raw milk absorbed the odor only after an exposure of 90 minutes. From these trials it would indicate that the different milks did not absorb the phenol .odor readily unless in chemical combination or mixture with chlorine. 2. Absorption of odors of essential oils The intensity of absorbed odors in milks from the different essential oils when exposed from 15 to 90 mimtes is shown in table 2. -24— The relative absorption of odors in milk when exposed to essential mable 2. Fe and. at 1000 Fe 0 oils for various periods of time at 50 Exposure (min.) of heated milk at Odoriferou substance OF. 100 50° 1. : 15 : 30 : 45 : 60 : 75 : 90 : avg.:: 15 : 3O : 45 3 60 : 75 : 90 : avg. 3 246 l 8W291M9 e 0 e o O O 0 2331221 3000000 . ..... £43333 0000005 . ..... 3% 3232 .....0......'. 0000060 .. .... 33%2223 0......030 0030060 ....... 3332223 00000000000000 6006060 ....... 2221210 0:00:00... 0000060 ....... 2220210 ll&h563 1189223 ....... 2201221 3600035 ....00. 3223332 0.0.0000... 0060535 ....... 3212232 0.0.0.800... 0030060 ....... 2202222 0000030 0 s O o o o 0 2212221 00.000.00.00 0030000 ....... 2202210 00.00.0000... 3005000 e 0000 .0 0200210 mum a ...; an ewa 1.MPmm Mm @mi G La? I Exposure (min.) of homogenized milk at Odoriferous : substance 100° F. 2 3 2 3 2 0 0. 0. 0. .. 0. 00 000000 00.... 332310 0000000000.. 003050 000000 321200 0000000000 006050 00. .0. 220200 mwwmaw e e e e e e 221311 0000000000 300.065 0 3$&£&& 000000000000 060065 000000 332322 000000000... 000000 .0000. 332312 060030 e e e e e e 322312 0000000000 030000 e e e e e e 222310 000000 e e e e e e 220200 : 0.0: 1.6: 2.0: 2.0: 2.0: 2.0: 1.61:: 0.0: 2.0: 2.0: 2.0: 2.0: 3.0: 1.83 Pwmmmt an Iflllweed lurpentine Hinter Cinnamon Lemon mug 4.23331 97.8834. 000.00 221210 0000000000 030050 0.0000 4.33422 0000000000 000 55 0.00.. 332310 0.000.000... 600000 Odoriferous : substance Exposure (min.) of pasteurized milk at 1000 F. 50° F. : 0.0: 2.0: 2.3: 2.6: 3.0: 3.6: 2.26:: 2.0: 3.0: 3.0: 3.0: 4.0: 4.0: 3.16 Cinnamon 1.6: 2.0: 3.0: 3.0: 3.3: 4.0: 2.83 1.0: 2.0: 2.3: 2.6: 3.3: 4.0: 2.55 .0: 3.3: 4.0: 4.0: 4.0: 3.33:: 2.0: 3.0: 3.0: 3.0: 4.0: 4.0: 3.16 : 3.0: 3.0: 3.5: 4.0: 4.0: 3.25 : 2.5: 3.0: 3.5: 3.5: 3.5: 2.73 0.0: 0.0: 1.5: 1.5: 2.0: 1.5: 1.08 05 . 0 20 7 O 2% 0 . . . . 3232 0. 0. .. 0. 0006 . . . 43%3 0. .. .0 0. 000 . . . . 4343 .. 0. 0. .. 6000 . . . . 3342 .. 0. 0. 0. 0553 . . . . 3231 .. .0 0. 0. 0003 . . . . 33231 00006 : 2 : 2 :0 :2 : 0 d e a "D 10 1.. mm may Peppermint Turpentine Wintergreen : odoriferous : substance Exposure (min.) of raw milk at 1000 F. 50° F. L : 1.3: 2.0: 2.0: 2.0: 3.0: 3.0: 2.22:: 2.0: 2.0: 3.0: 3.0: 3.0: 4.0: 2.83 Cinnamon 2.72 2.94 O: 0: .0: 2.0: 3.0: 4.0: 2.33 4. 4. .0: 3.0: 4.0: 4.0: 3.08 .3: 3.33 3.3: 4.0: 3.15 0.0: 2.0: 2.0: 2.0: 1.00 2 3 2 3 3 14 029 69 570 eeeooe 202221 000065 ...... 322339. 0&0530 ...... 312231 000...... 000500 ...... 2065230 0.00:0... 000060 ...... 202210 600000 ...... 100210 tom 6 a mme e a nr Ingaee 10“ ppt 1% ”MD 1 mLQP W : it -25- The odor absorbed in greated intensity by the different milks at 500 F. and.at 1000 I. when exposed.to the seven different essential oils is shown in table 3. Table 3. Predominating odor absorbed by the different milks in greatest intensity when exposed.at 500 F. and at 100° F. L I _: u _—‘—‘ ‘r— Type of milk : Predominating odor in milk when exposed at : 50° F. : 100° F. 'r r Heated : Turpentine : Lemon Homogenzied : Peppermint : Dillweed Pasteurized 8 Peppermint : Peppermint Raw : Turpentine : Turpentine : : The order of intensity of odor when the different types of milk were exposed at 50° F. and at 1000 F. to the essential oils follows in table 4. Table 4. The relative absorptive capacities of the different milks when exposed to essential oils at 50° F. and at 1000 P. peppermint, cinnamon, orange, wintergreen and lemon cinnamon, dillweed, orange and Wintergreen an . T Types of milk : Relative absorptive capacities of milk when exposed at : 5001. : 100°F r 1: m3. Heated : Turpentine, peppermint, : Lemon, dillweed, cinnamon, : cinnamon, dillweed, orange, : turpentine, peppermint, : wintergreen and lemon : orapge and wintergreen Homogenized : Peppermint, lemon, dillweed.: Dillweed, peppermint, lemon, : orange, wintergreen, cinna— : orange, cinnamon, turpentine, : mon and turpentine : and.wintergreen. Pasteurized : Peppermint, dillweed, lemon,: Peppermint, cinnamon, dillweed, : wintergreen, cinnamon, : lemon, turpentine, orange and : orange and turpentine : wintergreen : : Ram~ : Turpentine. dillweed, : Turpentine. peppermint, lemon, - 25 - Yaxis (1917) found oils of peppermint and.wintergreen produced stronger flavors and odors in cream than oil of cinnamon. In the above experiment with milk at 500 F. oils of peppermint and cinnamon produced stronger odors than oil of wintergreen in heated, homogenized and raw milk while in pasteurized.milk wintergreen was slightly stronger than oil of cinnamon. With the different milks at 100° F. exposure oil of wintergreen was much less in intensity. Although the oils of cinnamon and wintergreen contained quite an odoriferous odor, the milks did not pick up the odor of these two substances as readily as some of the other essential oils. Taking the average of the four milks at 50° F. the order of intensity of absorbed odors was found.to be oil of peppermint. dillweed. turpentine, cinnamon, lemon, orange and.wintergreen. At the 1000 F. exposure the order of intensity was essentially the same, being oil of dillweed, lemon, pepper- mint, cinnamon, turpentine, orange and wintergreen. 3. Absorption of cow manure and urine odors When the different types of milk were exposed to fresh and liquid cow manure at 50° F. it was shown definitely that the odor of liquid manure was absorbed in greater intensity than that of the fresh manure. In this experiment the odor in certain cases was intensely absorbed. At the 1000 F. exposure the odor of the fresh cow manure was absorbed in considerably greater quantities by heated, pasteurized and.raw milk than that of the liquid manure while homogenized milk under 45 minutes exposure absorbed more of the liquid cow manure. When fresh urine was exposed to the different milks, pasteurized milk absorbed the greater odor at both 500 F. and 100° F. followed by the ‘un - 27 - homogenized milk. naw milk absorbed more intense odors at 50° F. and less odors at 100° 1:. than heated milk. 4. Absorption of formaldehyde and iodoform odors Formaldehyde was not absorbed as intensely as certain of the essential oils or the odor from liquid cow manure. At exposures of 50° F. the formaldehyde odor was found to be greater in pasteurized followed by raw, heated and homogenized milk. At 1000 F. the pasteurized and raw milks showed the same intensity of odor and heated and homogenized.milk had slightly less odor. At both 50° F. and 1000 I. exposures the pasteurized milk absorbed the more intense odor while homogenized.milk absorbed the least of all the types of milk tested. Three trials were run exposing powdered iodoform to the different milks. The odor of this substance was not readily absorbed at 50° 1'. but at 100° F. the intensity of the odor increased somewhat. At the 50° 3. exposure no odor was detected in any of the milks until exposed for 75 minutes. At 90 minutes the intensity of the odor absorbed was equal in all types. lhen the different milks were exposed at 1000 I. the homo- genized and.pasteurized milk showed an odor of iodoform after 30 minutes exposure. The results with raw milk were somewhat irregular. In one trial the odor was detected at 15 minutes. In the other trial with this type of milk the odor was not detected until 60 minutes and in all cases a lurked odor was only detected at 75 minutes. Heated milk did not absorb this odor until exposed for 75 minutes. Pasteurized milk absorbed the more intense odor followed in order of intensity by homogenized, raw and heated milk. .. 23 .. 5. Absorption of silge odors The different milks were placed in desiccators containing corn and grass silage to determine which type of silage odor could be absorbed faster and also to find out which type of milk absorbed the more intense odor. In comparing the odor intensity at the 50° 1. exposure, heated. homogenized and raw milks absorbed slightly more grass silage odor than that of corn silage while the intensity in the pasteurized milk was the same in both cases. At the 100° 1'. exposure pasteurized and raw milk absorbed more grass silage odor than corn silage odor. This was especially pronounced in the heated milk. In both cases homogenized milk absorbed the same odor intensity. lhen the milks were exposed to corn silage at 50° 1., pasteurized milk absorbed the greater odor intmsity followed by raw. heated and homogenized milk. At the 1000 r. emosure pasteurized milk still absorbed the greater odor intensity followed by homogenized. raw and heated milk. 'ith the 50° 1'. exposure to grass silage, pasteurized and raw milks ab- sorbed the some amount of odor followed closely by heated and homogenized milk. At 100° 1'. pasteurized and raw milk absorbed the same odor intensity followed very closely by heated and homogenized milk. Whom the different intensities of the several odors were averaged, it was found, as shown in figures 1 and 2, that at 50° 1'. exposure, . pasteurized milk absorbed the more intense odor followed in order by raw, homagenized, and heated milk. At 100° 1'. pasteurized milk still absorbed the most odor up to the 75 minute exposure. At the 90 minute exposure raw milk showed a greater absorption of odor that did pasteurized milk. At this temperature also, homogenized milk absorbed more intense odors than the heated milk. - 39 - The data.presented in figure 3 indicated that the various milks absorbed.more odor when the fat was in a liquid state than when in a solid state. 000R INTENSITY +++ PAS TEUR/ZED l 1 0 .30 60 90 0 30 60 90 TIME (Ml/V.) Figure l. Intensity of absorbed odors when heated, homo- genized, pasteurized and raw milk were eXpOSed to odori— ferous substances at 50° F. and at 100° F. -31... .m ooofl go mad .m 000 as moozmumpsm m:oaomfiaoco ou comomko one: xHfla any one wouaasoumma .Uomfizemoaoz .coummx some maoco awakened mo hudmcoucH .m madmah $33: MEIR so so 9.. 0 em on on e n a . 00000000000000 EYQ .l..l QWKQQDWK .0an ...-II. QMNQ