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TECHNOLOGY

ume 1 Number 6

SEPTEMBER, 1938

Twenty-seventh Annual Meeting

Cleveland, Ohio, October 19-21, 1938 r ^ Headquarters, The Allerton\: "Λ ,>7 I,

Official Publication ot

INTERNATIONAL ASSOCIATION OF MILK SANITARIANS

(Association Organized 1911) II Advertisements COMPLETELY PROTECT POURING LIPS? ------OF COURSE------The Standard Welded Wire Hood Seal has been doing it for years on billions of milk bottles!

WHY HEALTH OFFICERS WHY DAIRY OWNERS PREFER THE ‘Welded 'Wire C H O O S E THE 'Welded 'Wire SEAL SEAL

1. The dairy-sterilized pouring lip is 1. It's the BEST completely tamper­ completely covered by the "long skirt” proof and sanitary closure they can buy. on the hood. 2. The hood has ample printing surface 2. The hood completely covers the top for name, trade-mark and Health Board of the milk bottle—keeps out germ­ Requirements. laden dust and dirt-—completely pro­ 3. It is easily adapted to any standard tects the milk from the dairy to the bottle. No investment in special bottles. kitchen. 4. Welded Wire Sealing machines are 3. It is strong and waterproof; heavy made in a variety of sizes to synchronize icing will not puncture or weaken it. with any size bottle filler. 4. The Welded Wire Seal is tamper­ 5. Welded Wire Sealers are quickly, proof. The hood is securely locked in easily installed by competent dairy en­ place by the Welded Wire. It cannot be gineers in any bottling room and are de­ pulled off or joggled off in handling. signed to provide economical plant 5. Because the Welded Wire Seal is operation. tamper-proof, the customer is always the 6. It’s the best known closure. Nation­ first to break the seal. wide consumer advertising has made it 6. The Welded Wire Seal is easy to the NATIONAL TRADEMARK OF open. No tools or gadgets are necessary. BETTER MILK AND CREAM.

Milk sanitarians interested in hood-cappiiig are invited to write for free leaflets. Address: Standard Cap and Seal Corporation, 1200 Fullerton Ave., Chicago, Illinois.

When writing to advertisers, say you saw it in this Journal. Advertisements III

VITAMIN D MILK BY VITEX PROCESS 400 USP UNITS PER QT.

• Milk caps and labels for Vitex Vitamin D milks must be approved by state and city food control officials before the milk is distributed within their jurisdiction. Biological assays in laboratories acceptable to the particular food control officials help to maintain the vitamin D potency claimed on the milk cap—400 USP units of vitamin D per quart, extracted from cod liver oil by the Vitex Process. VITEX LABORATORIES, INC. A Nopco Subsidiary HARRISON, NEW JERSEY

■ When writing to advertisers, say you saw it' in this Journal. IV Advertisements

For over 81 years the name B orden ’s has stood for milk that can be depended upon for un­ failing purity and richness.

When writing to advertisers, say you saw if in this Journal. Advertisements V Fr o m 16 To 60 Q uarts-

• A t the left is the No. 5 which fills and caps 60 quarts and up­ ward of cold milk per minute, every minute. It has the stamina, the ability to take punishment for which CP-built machines are noted. Sanitary— good looking. Stainless steel bowl. Variable speed drive which enables you to match your washer capacity exactly and other features you will want to know about before you select your next filler.

R0T0-MATIC BOTTLER For Every Size Dairy

• A t the other end of the capacity scale is the CP Roto-Matic No. 8. See illustra­ tion at the right. It is a real "rotary". Stainless steel bowl with 4 valves and one capper. Has a simple drive that cannot get out of time. Variable speed fills 12 to 24 bottles per minute. The ideal bottler for the large producer-dairy and for specials in the larger plants. The low cost will interest you. In between, there are two other sizes. Put your bottling problems up to CP. THE CREAMERY PACKAGE MFG. COMPANY 1243 WEST WASHINGTON BOULEVARD - Chicago, Illinois

Branches: Atlanta - Boston - Buffalo - Chicago - Dallas - Denver - Kansas City - Los Angeles Minneapolis - New York - Omaha - Philadelphia - Portland, Oregon - Salt Lake City San Francisco - Seattle - Toledo - Waterloo, Iowa CREAMERY PACKAGE MFG. CO. OF CANADA, LTD. THE CREAMERY PACKAGE MFG. COMPANY, LTD. 247 King St. West, Toronto, Ont., Canada Avery House, Clerkenwell Green, London E. C. I., Eng.

When writing to advertisers, say you saw it in this Journal. VI Advertisements

CHERRY - BURRELL SALUTES THE SMALLER MILK PLANT OPERATORS with a NEW BOTTLE FILLER BUILT ESPECIALLY FOR THEIR NEEDS

HE new 6-16 BOTTLE FILLER A N D CAPPER by CHERRY-BURRELL has most of T the features o f the larger fillers and cappers— yet is designed and priced for small milk plant owners having from 200 to 500-gallon capacities per day. Whether hand fed or with Automatic Bottle Conveyor Infeed from a Baltimore Soaker Type Washer the "6-16" efficiently fills and caps all products in any size standard milk bottles at the rate of 16 full quarts to the minute. Successful filling and capping of special products makes the "6-16" a most useful machine in large plants as well. Write us today for Bulletin No. Θ -3Ι9 which illus­ trates the 18 features of the new CHERRY-BURRELL 6-16 BOTTLE FILLER A N D CAPPER or call your nearest CHERRY-BURRELL sales office.

CriERRY- BUrrell Corporation ^ 427 w. Ran do lph st„ Ch icag o

When writing to advertisers, say you saw if in this Journal, JOURNAL OF MILK TECHNOLOGY

Official Publication of The International Association of Milk Sanitarians (Association Organized 1911)

CONTENTS Page No. Editorials ...... 1 A Glass Milk Bottle with Narrow Pouring Lip and Minimum Drip— Lloyd Arnold ...... 5 A Study of a Scarlet Fever Epidemic at Rockford, Illinois-—C. W. Anderson and S. V. Layson ...... 15

Problems Related to Homogenized Milk—F. J. Doan...... 20 Report of Committee on Communicable Diseases Affecting Man—I. A. Merchant, Chairman ...... 26 Note on the Starch-Iodide Test for the Detection of Free Chlorine in Milk— T. H. Butterworth ...... 36 A New Bacteriological Control Unit—Maurice H. Shorago...... 37 Report of Committee on Milk Plant Practice—A. R. Tolland, Chairman...... 38 The Quality Improvement of Creamery Butter—Μ. E. Parker, Chairman...... 44 Fiber from Casein ...... 48 A Special Invitation to Milk Sanitarians to Attend the Dairy Industries Exposi­ tion—Roberts Everett ...... 49 Cleveland—Our Convention City—H. O. Way, Chairman...... 50 Tentative Program of the 1938 Convention ...... 53 New Food Standards Committee ...... 55 Information Concerning Journal of Milk Technology...... 56 Index to Advertisers ...... VIII INTERNATIONAL ASSOCIATION OF MILK SANITARIANS

Secretary’s Office: State Department of Health, State Office Building, Albany, N. Y.

OFFICERS 1937-1931! President, Alexander R. Tolland...... ____ Boston, Mass. First Vice-President, Victor M. Ehlers...... _Austin, Texas Second Vice-President, Paul B. Brooks, M. D...... Albany, N. Y. Third Vice-President, Leslie C. Frank...... Washington, D. C. Auditors: J. R. Jennings...... ______Chicago, 111. F. D. Holford ...... ___Mew York City Secretary-Treasurer, C. Sidney Leete...... ____ Albany, N. Y.

EXECUTIVE BOARD The Executive Board consists of the Association President, the three Vice-Presidents, and the Secretary-Treasurer

COMMITTEES AND COMMITTEE CHAIRMEN COMMUNICABLE DISEASES AFFECTING MAN—Their Relation to Public Milk Supplies I. A. Merchant, Chairman ______Ames, Iowa DAIRY AND MILK PLANT EQUIPMENT Walter D. Tiedeman, Chairman...... Albany, N. Y. SANITARY PROCEDURE Walter D. Tiedeman, Chairman...... :...AIbany, N? Y. DAIRY FARMS METHODS F. D. Holford, Chairman...... New York City SANITARY CONTROL OF ICE CREAM F. W. Fabian, Chairman...... East Lansing, Mich. LABORATORY METHODS - A. H. Robertson, Chairman...... ,______Albany, N. Y. METHODS OF IMPROVING MILK SUPPLIES IN SMALL COMMUNITIES Leslie C. Frank, Chairman______.Washington, D. C. PUBLICITY AND PUBLIC RELATIONS H. A. Ocker, Chairman...... Cleveland, Ohio RESOLUTIONS Ernest Kelly, Chairman...... :.Washington, D. C. LOCAL COMMITTEE ON ARRANGEMENTS FOR THE 1938 MEETING H. O. Way, Chairman...... _...... Cleveland, Ohio JOURNAL o f MILK TECHNOLOGY

Volume 1 September, 1938 Number 6

Editorials The opinions and ideas expressed in papers and editorials are those of the respective authors. The expressions of the Association are completely recorded in its transactions.

Greetings to the Members of the International Association of Milk Sanitarians We always have good conventions. The programs are practical and cover a wide range of subjects of interest to milk sanitarians in official, educational, research, and commercial fields. This year will be noteworthy for several reasons. In the first place, we have a most cordial invitation from the management of the Dairy Industries Exposition to visit the great machinery and supplies exhibit. This will be larger than ever before. No milk sanitarian who wants to keep up on the latest developments can afford to miss it. Moreover, our Association membership has increased greatly in numbers during the past year. We want to meet personally the new members. We anticipate the mu­ tual profit and pleasure of exchanging ideas, and cementing professional ties with friendship. This great increase in membership has brought wider knowledge, new blood, and additional funds into our organization. These will surely make their influence felt in a stronger program and a more attractive meeting. Then again, we have our young and vigorous Journal of Milk Technology. It is one of our major assets. It has largely been responsible for our exceptional growth and strength. It is receiving wider and wider tecognition here and abroad. We must support Bill Palmer and Doc Shrader in making it an increasingly potent factor in im­ proving the quality of dairy products everywhere and rendering a real service to man­ kind. Proposals of state associations to affiliate with our organization will necessitate our voting on several amendments. Come, and help us guide the future develop­ ment of the International. Is there an organization of milk sanitarians in. your state? If not, why not? Come to Cleveland, and talk the matter over with others similarly interested. Have you a perplexing control problem? Tell us about it; maybe some one will have had the same one. Maybe you can help us in ours. So come to Cleveland. Participate in the meetings of your Association; secure more of the newer knowledge of milk technology; renew your personal and profes­ sional friendships, and make new ones. The added inspiration will pay dividends throughout the year to you personally and to those you represent. A. R. T olland, President International Association of Milk Sanitarians. 2 Editorials

The Digestibility of Cheese Cheese is one of the cheapest and most nutritious dairy products, but in the United States its per capita consumption lags far behind that of other dairy products. This rate is one-half that of Italy, Norway, Germany, France, and Sweden, one-third that of Denmark and Holland, and only about one-fourth that of Switzerland. Deep-seated in the public consciousness, there is a belief that cheese is indi­ gestible. An incident is recalled wherein the practice of eating cheese with pie was explained as due to the stimulation of the digestion of the pie by the more indigestible cheese—a doubtful compliment at best. This persistent belief in the difficult digestibility of cheese tends to limit its consumption. People do not eat much of a product they think may cause digestive distress. Is cheese really so indigestible? Experimental studies on the digestibility of cheese were made by Doane back in 1911. Sixty-five young men were supplied with cheese to furnish protein and fat to a basal ration. These investigations showed that old and new American Cheddar cheeses of different degrees of ripeness exhibited no important differences in their comparative digestibility. In no case were there physiological disturbances or constipa­ tion as a result of the cheese diet. Since that somewhat distant date, no researches on the digestibility of cheese seem to have been undertaken (or at least published), except that a study on two young women would "seem to indicate” that the calcium of American Cheddar cheese was as well utilized as that of pasteurized whole milk. In view of the great importance of cheese as a highly nutritious and palatable protein food, it does seem strange that this popular belief in its indigestibility has not been challenged by a wealth of experimental evidence. It is not enough to know that 27 years· ago some experiments showed that cheese was as digestible as meat. That work was performed before the present technic of nutritional research had been developed. Studies should be undertaken with the improved methods of today, including all the controls which present knowledge of metabolism show are necessary. The studies should comprise nutritive value, digestive comfort, ease and completeness of digesti­ bility, and general effect on physical well-being,—all actually determined and not largely inferred from the proximate analysis by analogy to milk. The situation amounts to this: old experiments state that cheese is completely and comfortably digestible, but 27 years later the great bulk of the population are afraid of the physiological effects of eating cheese. New experimental researches should be inaugurated to study this problem. If this work should confirm the earlier reports, the results should not be hid under a bushel (buried in bulletins which are not readily obtainable or out of print) but publicized far and wide. We note research activity on the digestibility and food values of milk, milk powder, and evaporated milk. Cheese needs such investigation more than any of these because it is the dairy product about which we are least informed. J. H. S. Journal of Milk Technology 3

Frontiers of Promising Milk Research Milk will be one of the several farm commodities to be studied in the new research program authorized by the Agricultural Adjustment Act of 1938. By Sec­ tion 202 of the Act, the Secretary of Agriculture is instructed to establish four regional laboratories in which research will center on developing new uses and market outlets for agricultural products. An appropriation of four million dollars must be divided equally among them. Four research areas have been designated by Secretary Wallace, and milk is one of the products assigned to the laboratory of the Eastern area, although the results are intended for use throughout the country. It is planned to consult with research institutions and representatives of producers and of industries as to the work on the commodities named. As a development of farm chemurgy, the component constituents of milk, in­ dividually or combined, must compete in industry with chemicals of controlled speci­ fication, dependable constancy, and known purity. Unless the milk industry knows as much about its products as the competing food and chemical industries know about their products, the marketability of milk or any of its constituents for indus­ trial purposes is at a disadvantage. Although more fundamental research is needed to acquaint us with the compo­ sition and properties of milk, it is probable that the proposed research program will be directed to the more immediate objective of finding profitable uses in new markets. The plan to place the research laboratories in the actual producing areas is well conceived. Academic and other aspects of fundamental research thrive when iso­ lated from the distractions of commerce, but successful industrial research must be catalyzed by intimate contact with industry itself. What are the possibilities for profitable milk research? First, what is the pres­ ent situation ? Nutritionally, milk is recognized as a preeminent food. Its effect on growth, bone structure, and general health have been fully demonstrated. But in none of these qualities is it different from substitute products—and we see soybean milk looming. The nutritional value of milk has been determined almost exclusively by these physical measurements. Has milk any uniqueness that is not equalled by any practically available substitute? Apparently, yes. Its lactose is partly composed of the carbohydrate galactose which is a necessary constituent of nerve and brain tissue. What is the nutritional effect of milk on the nervous system, on brain power, on intelligence of action ? We do not know. This neglected field is as important as that of skeletal structure. Casein is used in large amounts for paper sizing, adhesives, and to a less extent for plastics. Its spectacular use as a substitute for wool fibre is receiving some atten­ tion. However, commercial casein is not sufficiently unique and does not possess a constancy of quality which enables it to protect its markets from the encroachment of substitute products. Lactose is made in commercial amounts for a limited market which will prob­ ably remain limited if the situation is allowed to remain as it is. Surplus milk and milk whey are dried and mostly used in animal feed. Both outlets are about the cheapest available, and force prices down to the level of many other competing agricultural wastes. The sale of evaporated milk is increasing but it utilizes only a relatively small part of the total surplus milk production. The world is struggling for food—not for paper coating, or glue, or billiard balls, or even for clothing. Therefore, the most pressing human need for milk lies in the food field. Casein and lactalbumin are proteins that are the approximate equals of meat protein in human nutritive value. But there have been developed no widely attractive milk protein foods. However, there are soybean protein foods on the market. Lactose would seem to possess value in the structure of nerve and brain 4 Editorials tissue. Milk must have a unique significance, to a «degree not heretofore recognized, in view of its being the one outstanding product made by nature to be a food when the growth demands of the animal are greatest. Until products and markets are developed to take all millk as food, recourse must be had to the denaturation of milk for use in industries. It cannot be expected that the commercial uses of milk casein and albumin will be greatly expanded until we· separate them into their indicated fractions, learn how to prepare them with fairly constant properties, and then explore the industrial field for uses of these speci­ fic products. Uncertain, inconstant mixtures do not find much acceptance in these days of technological constancy and dependability. The industrial possibilities of lactose are indicated by the commercial develop­ ment of calcium lactate, and the influence of the production of lactic acid by fer­ mentation from milk whey on the forced improvement of lactic acid by fermenta­ tion from molasses. An annual market of about fifteen million pounds of organic acids for use in foodstuffs exists in this country ajone, and lactic acid should have its share. Microorganisms are available that can fc»ite, so to speak, into the lactose molecule to produce many different chemical products. So the great milk industry need not consider itself checkmated in the jjreat game of commercial competition. It is probable that milk is capable of being made into a greater number and a wider variety of different products than any other com­ modity in nature. Napoleon is . reported to have ^aid that the best defense against an enemy’s fire is a well directed one of your own, In the same vein, the milk in­ dustry, knowing that it starts with nature’s best product, can be assured markets that are ample in diversity and depth, provided that it fights to retain its present ones, and to develop new ones. It recognizes that it must know more about its own basic product, and then must aggressively seek to place it and its manufactured products where market surveys show that its properties are in demand. Such an economic frontier of potential markets is not static. It changes as conditions change. These conditions are variable as our economic and commercial life progresses from one period to another. Therefore, we can expect that a com­ mitment to an intensive program to develop new markets will require a continuance of such a program. Why? Because the job wjll never be completed—a given objective soon becomes the starting point toward another. Cessation of research aggressiveness means marketing retrogression. J. H. S. Proposed Amendments to the Constitution ·. Several proposed amendments to the Constitution of the International Associa­ tion of Milk Sanitarians have been circularized to the membership by the Secretary- Treasurer. All provide that membership in the Association shall include subscrip­ tion to the Journal of Milk Technology. The proposed amendments that were sent on August fifteenth are intended as alternates for those sent on June twenty-second. They provide for broadening the object of the Association by adding the development of improved milk technology, and disseminating information of value to milk sani­ tarians; they establish a professional status for milk sanitarians; and they provide for adding a new class of members whose qualifications are on the same level as those which have heretofore prevailed. The increased professional qualifications will not be retroactive on the present membership but ate intended only for new applicants. It is hoped that the entire membership will give these proposed amendments their careful consideration so that the discussion of their provisions at the Annual Meeting in Cleveland will throw light on all angles of the questions involved. J. H. S. 5

A Glass Milk Bottle with Narrow Pouring Lip and Minimum Drip* Lloyd Arnold, M. D. University of Illinois College of Medicine, Department of Bacteriology and Public Health, Chicago, III.

Considerable confusion has existed in tie of milk. It was necessary to define the rules of various public health agencies the area of the bottle to be covered or regarding the methods of enclosing the protected by a- cap. We began our study milk in a glass bottle. A review of this by pouring milk from bottles by hand, subject showed that there had been little and observing the behavior of the milk as scientific work done upon which to base it was pouring out of the bottle and over enforcing regulations to protect milk the lip. We were convinced that this properly. We undertook such a study method was unscientific, uncontrollable, in this laboratory. and variable. It was impossible to dupli­ Dearstyne and Ewing (1920) studied cate the same identical conditions. We the bacterial flora on the lips of milk then designed a pouring machine to al­ bottles. They found that some bottles low us to pour milk from several bottles of pasteurized milk, enclosed with flat of different design at the same time under disc caps, had 100,000 to 200,000 viable identically the same conditions. The ma­ bacteria on the lip. They concluded that chine used for the major part of this work the bacteria deposited on the lip and cap is shown in Figures 1 and 2. were probably more dangerous than the We observed early in our work that the bacteria in the milk inside the bottle. angle to which the bottle was rotated ex­ Jackley (1922) called attention to the ercised considerable influence upon the seriousness of lip contamination, because behavior of the milk as it passed over the the poured , milk contained these bacteria pouring lip. The first glass of milk is as well as the cap which acted as a bac­ delivered from a full quart when the bot­ terial reservoir to contaminate the milk tle is rotated from the upright or 0° to continuously. the 78° angle, and held in this position Rice et al. (1924) studied the bacterial as long as the milk flows out of the flora in and on paper caps. Isaacs and bottle; the next glass of milk is delivered Zeiben (1932) recorded the bacterial when the bottle is rotated from 78° to counts in milk capped with discs and 84°. Table 1 gives in exact form the hoods. They showed the former did not results of one hundred pouring experi­ protect the milk as efficiently as the com­ ments. It was found that when the full plete coverage afforded by the hood. quart of milk was rotated from 0° to 78°, Sansby and Halvorson (1936) described there was more surface area of the glass a new type of bottle neck design to pro­ contacted by the milk than at any other tect the pouring lip with a relatively small angle. There was more drip at the 78° metal cap. angle than at any other. Angles greater than 90° do not present pouring lip prob­ STANDARD POURING MACHINE lems because the milk does not have an We began this study with the objective opportunity of contacting the lip in the of trying to ascertain the most suitable same manner. Hence, we chose the 0° type of cap to use to enclose a glass bot- to 78° angle, or the first glass of milk pouring from a quart bottle as the best *Aided b y a grant from the Associated Milk Dealers Inc. of Chicago. . single pour to define the pouring lip. Lip Contamination of M ilk Bottles

Figure 1. This shows the stand­ ard pouring machine in an upright position ready to be loaded with six bottles for testing.

Figure 2. This shows the stand­ ard pouring machine tilted to '78° angle and held in this po­ sition until one glass of milk is delivered from the bottle. Journal of Milk Technology 7

MEASUREMENT OF LIP CONTAMINATION could not be used. We finally used a Our next problem was to find an in­ twenty-four hour old broth culture and dicator to use to aid us in determining the applied this to the glass without dilution. exact area of the glass of the bottle adja­ The seeding was so heavy and the bac­ cent to the opening contacted by the milk terial population so dense that even if during pouring. It is possible roughly fifty percent or more died, there were to evaluate or classify bottles by observ­ still several thousand (10,000 to 50,000) ing, with the eye, the stream poured and on the lip even after twenty-foijr hours. the drip, but this is not accurate and is Small tightly wound cotton swabs were only useful for orientation purposes. We sterilized and dipped into a twenty-four tried to use dyes and stains, biit so far hour broth culture of B. prodigiosus. The this has not proved successful. We had excess fluid was pressed out by rotating to use living bacteria applied to the glass the swab against the inside wall of the test surface as our indicator of the area of tube which contained the culture. This the glass contacted or covered with milk swab was used to inoculate or mark the during pouring. surface of the upper end of the glass bot­ Some investigators have used quantita­ tle over which the milk was to be poured. tive methods in determining the bacteria The outside of the pouring lip including washed off from the pouring lip of milk the upper part of the neck of the bottle bottles. We were unable to do this. If was divided into horizontal, concentric bacteria are suspended or diluted in water anular zones from the top downwards. or saline, and applied to a clean glass Each anular zone was usually approxi­ surface, the death rate is high because mately 14 inch. If for instance, six of the dessication factor. The number zones were to be studied, six bottles of of living bacteria decreases with time. the same type were washed, rinsed, cov­ Therefore, counting the bacteria in the ered with a paper extending down over milk after it has passed over such a seeded two-thirds of the bottle, and tied with, a surface would be variable unless corre­ strong string. The bottles were then lated with the time of sojourn of the autoclaved at 15 pounds pressure for 35 bacterial population on the glass surface. minutes. These bottles were then put in We used bacterial suspensions 1:100, the dry air sterilizer to dry the paper and 1:250, 1:400, 1:750 and 1:1000, and bottles. The paper wrapping was re­ found none of these satisfactory because moved, and the sterile bottle was handled of the high death rates of the bacteria on by holding it below the upper third. It the glass surface. Bacteria.were suspended was immediately filled with fresh fluid in egg white, gum acacia, milk, and other grade A pasteurized milk’ without touch­ vehicles in order to protect them against ing the lip during the filling. The up­ dessication. The foreign materials al­ per 14 inch zone on one bottle was then tered the smooth glass surface and painted with a twenty-four hour old changed the pouring lip; hence, they broth culture as indicated above, the sec-

TABLE 1 The average angles at which approximately 200 cc. of fresh fluid pasteurized milk are poured from a quart bottle. The pouring machine shown in Figures 1 and 2 was used. Volume of milk Angle of bottle in degrees Γη bottle In glass Approximate Average amount From To 950 cc 204.5 cc. 0 78.07 750 cc. 204.3 cc. 78.07 84.3 550 cc. 207.0 cc. 84.3 89.7 350 cc. 208.5 cc. 89.7 96.9 8 Lip Contamination of Mili^ Bottles

ond zone of another bottle was similarly Severa} examples of bottle finishes and painted, and so on through the several the pouring lips as determined by our zones of the six bottles respectively. Thus, method are illustrated in the accompany­ there were six bottles, each with only one ing drawings. In order to convey to the zone painted with our bacterial indicator. reader thp style of bottle corresponding to In other words, bottle No. 1 had only our type number, a drawing has been the upper *4

LEGEND The behavior of milk poured with use of the Standard Pouring Machine indicated by the number of times the milk contacted the respective zone during the pouring is recorded for each type of bottle tested. The zones indicated on the drawings and the percent figures are based upon one hundred pouring tests. Each type of bottle is indicated by the respective numeral inside the bottle neck.

a

I

5

6 a

d 20% * 20%

\ a 7

10 10 Lip Contamination of Milk Bottles

II

9 12

b — 94·% 1.502 6%

f 14

b

c50% a 40% «70%

f

15

SL

d 25% /— « 25% 18 A

IT B 25 Lip Contamination of Milk Bottles Journal of Milk Technology 13

Bottle type No. 20 is similar in design tests, involving the testing of four hun­ co type No. 14. dred and twenty-six (426) bottles. The Bottles of types No. 22 and No. 23 results are indicated in the diagram. have One protruding angle each located Another glass bottle manufacturer has near the top of the bottle. The diagrams molded this bottle from the blue print showing the results of our experiments sent him. The pouring experiments gave indicate that this principle is not as ef­ identical results as was obtained with the fective in reducing the adhesive forces first design made at my suggestion. of the milk poured as recessed angles. Bottle type 21 A (54 mm. diameter) Bottle type No. 21 (55 mm.) is the does pour as well as the 55 mm. (No. best design we have been able to de­ 21) with the same design. The zone velop so far in our work. The top sur­ below the lowest recessed angle showed face of the bottle is flat, the first re­ contact with the milk one time in ten cessed angle is 1/32 inch. This angle pours. is 3/16 inch below the top of the bottle. Bottle type No. 31 (54 mm. diameter) The second recessed angle is 1/16 inch, differs from the 21 A type in that the and placed 1/16 inch below the first first angle recesses 0.04 inch instead of angle. The third recessed angle is 3/32 0.02 inch. The second recessed angles inch placed 3/16 inch below the second are the same on both bottles. The lower angle. Considerable experimentation was angle on the No. 31 is very shallow. necessary to arrange these angles to the It will be difficult to close this type No. greatest advantage. The first recessed 31 with a seal, because of the absence of angle, reinforced by the second deeper a shoulder of glass of sufficient mass to recessed angle, reduces the pouring lip encase properly. This bottle is the best to % inch below the top of the bottle. we have so far tested. Sixty-five pours The lower angle prevents drip of the have been made using the standard pour­ drop Or two of milk passing the second ing apparatus, and the zone below the angle when the bottle is returned from last angle was not contacted by milk in the 78° angle to the upright position. any instance. The zone between the mid­ The cap should completely cover all three dle and last recess angles was contacted angles, extending down below the last by the milk in one pour in five. In other angle or 7/16 inch from the top of the words, the first and second angles were bottle. effective in eighty percent of our experi­ Bottle types No. 24 and No. 25 repre­ ments ; the next zone was in contact sent our efforts in making slight altera­ with the milk in twenty percent of our tions in the dressing of the type No. 21. tests. The zone below this third re­ The main purpose was to make the hori­ cessed angle was not in contact with the zontal flat top surface less sharp on the milk during or after pourings. margins, and to elevate the outer margin The detail drawings of these two fin­ so as to avoid possible chipping of the ishes (No. 21 A and No. 31) are shown inner margin adjacent to the seat cap. in Figures 3 and 4. The principle of The results given in the diagrams show breaking the adhesive surface of the glass that these finishes were not so satisfactory by recessed angles is well illustrated in as that of No. 21. The flat top (zone A) these two drawings. played a greater role in the behavior of The overall top diameter of the type the milk poured from the bottle than had No. 31 bottle should be reduced to 51 been suspected or considered. mm. or less. The distance of the last We have worked with type No. 21 for recessed angle from the top of the bottle six weeks in our laboratory. We ordi­ should also be reduced. Experienced narily do twenty complete pouring experi­ glass manufacturers state that 54 mm. is ments with each bottle to be tested. Type the narrowest overall size they can make No. 21 has been used for . one hundred at this time. It is believed that such a and forty-two (142) complete pouring bottle will not have the . proper strength 14 Lip Contamination of Milk Bottles if the dressing is reduced to less than Experiments with a new type of finish 7/16 inch from the top in the presence involving recessed angles to interrupt the of a seat cap depression on the bottle. adhesive force of the glass surface have The presence or absence of the cap seat been described. The pouring lip has does not influence the pouring lip of the been reduced to 7/16 of an inch from bottle. It may be possible to reduce the the fop of the bottle so that there is a area occupied by the three anular rings minimum of milk drip during the pour­ or recessed angles if the cap seat is elim­ ing. inated. If would be possible to reduce REFERENCES the size of the cap if the diameter were reduced and the external recessed angles Dearstyne, Roy S. and Ewing, C. LeRoy: Num­ ber of Bacteria on the Lips of Milk Bottles placed closer together. and Their Significance. Am. Journal Pub­ The design described above can, of lic Health 1920, 10:533-535. course, be put on bottles of larger di­ Isaacs, M. L. and Zeiben, I: A Comparative ameter. The 5 6 mm. diameter and larger Study of Milk in Bottle with Single and sizes should be easier to make, because Double Caps. Am Journal Hygiene 16: there is more glass to work with in mold­ 806-822, 1932. ing the dressing. Isaacs, M. L. and Zeiben, I.: Am. Journal The pint and half pint size bottles Hygiene 16:806. should have the same dimensions. The Jackley, J. G.: The Danger of Improperly outside diameter of the neck of a quart Capped Milk Bottles. Journal Dairy Science bottle below the dressing is 1.812 inches. 1922, 5:406. The pints and half pints have an overall neck diameter of 1.750 inches. In order Rice, J. L. Van Saun, Anna I, and Haywood, to utilize the mechanical capping equip­ Katherine E. Advocating Bacterial Counts on Milk Bottle caps with a Comparison of ment, it is' suggested that the area below the Effect of Different Methods of Capping the last recessed angle on the small size on Such Bacterial Counts. The Nation’s bottles be held at 1.812 inches outside Health, 1924, 6:325-327. dimension for at least y4 inch, and then recessed to 1.750 inch diameter. This Rice, J. L. Van Saun, Anna I., and Haywood, Katherine E. Bacterial Counts on Milk would permit the same mechanical equip­ Bottle Caps with a Comparison of the Effect ment to be used on all sizes of glass bot­ of Different Methods of Capping on Such tles. Bacterial Counts. Abs. Bact. 8 (1): 15-20, SUMMARY 1924. (iflec. Expt. Sta. Rec., 1924, 51:778). A standard pouring machine for milk Sansby, J. Martin and Halvorson, H. O. Con­ bottles, and a standard technique for de­ tamination of Pasteurized Milk: Including termining the behavior of milk poured Bacterial Study of the Milk After it is from glass bottles have been described. Poured from Bottles Contaminated with B. colt. Presented in part at a meeting of the The degrees of bacterial contamination Milk Sanitary Advisory Board, United obtained from bottles of different fin­ States Public Health Service, Washington, ishes have been measured, X D. C., May, 1936. 15

A Study of a Scarlet Fever Epidemic at Rockford, Illinois* C. W. Anderson Director of Laboratories, Rockford Department of Public Health and S. V. Layson Milk Sanitarian, Illinois Department of Public Health

The city of Rockford, Illinois, with a plant. It seems significant that all cases population of 90,000 has had a compul­ among the customers of this station were sory pasteurization ordinance since 1932. using its raw milk and none the pas­ However, economic conditions have caus­ teurized milk exclusively. ed the city to become surrounded with A review of the incidence of scarlet cash-and-carry milk stations, located just fever in Rockford during the past ten beyond the city limits, to which customers years compared to 1937 will give a back­ take their own containers to be filled with ground for the present study. Chart No. 1 dipped raw milk. State laws prohibit the gives a ten-year monthly average com­ sale of pasteurized milk by this method pared to the number of cases for 1937. but there are no regulations governing Referring to the chart it can be readily the raw product except in the case of seen that during the months of January, emergency, such as an epidemic. The February, March, May, and June the in­ jurisdiction of city health authorities does cidence of scarlet fever was considerably not extend beyond city boundaries. below the ten-year average while the The stations undersell the pasteurizing large increase in April over the average plants three to four cents a quart. Sales was due to the epidemic in that month. are not limited to homes in the lower The first case using this supply became income brackets. Expensive cars with ill March 13 as shown on Chart No. 2, liveried chauffeurs are not infrequently and a sister of case No. 1 on March 16. seen getting their milk supplies at the No contact or source other than milk stations. The milk has that old familiar could be established for these two cases. (cow manure) flavor to which they were During the week of March 21 to 27, accustomed back on the farm. the attention of health authorities was A sudden increase in the reported focused on Station A when eleven cases, cases of Scarlet fever during the last week all users of Station A dipped raw milk, of March 1937 caused the health officer were reported. of Rockford to give special attention to Investigation of one case reported on all cases. Their localization to a residen­ March 27 revealed a factory worker, who tial section on the north side of the city to augment his income, worked nights (Map 1), and multiple cases in homes and on holidays as clerk in Station A. indicated a common source of infection. Onset of this case had been with a sore Close scrutiny of case histories revealed throat March 23, the last night he was oil that Milk Station A was the source of duty. He was a milk drinker and used milk supply in a large percent of the Station A raw milk in his home. At first, homes involved. This station was selling this case was thought to have been a 220 quarts of dipped raw milk and 340 factor in causing the epidemic but it quarts of bottled pasteurized milk se­ later appeared more probable that he be­ cured from an approved pasteurizing came infected by drinking the raw milk. His nineteen year old sister was reported * Read before International Association of Milk Sanitarians, October 13, 1937, Louisville, Ky. as a case on March 31. SCARLET FEl/ER CASES US/NG R /QWM/LK Journal of Milk T echnology 17

The following week, March 28 to April 3, the suspicion of health authorities was strongly confirmed by the occurrence of fifteen additional cases using this raw milk supply. The evidence was believed sufficient to warrant Closing the station which was done on April 3. Twelve more cases developed during the week of April 4 to 10 and only one the fol­ lowing week of April 11 to 17. This single case was evidently a contact from a case reported April 2. Allowing the usual incubation period, it seems prob­ able that the epidemic had been stopped by the closing of Station A. The epidemic period extended from March 23 to April 9 during which time a total of 48 cases occurred, one case resulting in death. The cases were evenly divided between male and female. Those of school age were scattered throughout nine schools,. the highest number in any one school being seven, all of whom were users of Station A raw milk. A total of 41 cases were users of this sup- 1%· It is reasonable to assume that where cases of scarlet fever are due to chance contact, the number of cases occurring among customers of a large dairy would be relatively greater than those occurring among customers of a small dairy. This relationship is brought out in Chart No. 3. The first column shows that 41 percent of all cases occurring in Rockford during March and April were due to Station A dipped raw milk, whereas the volume of this milk distributed was only 0.7 of one percent. No cases occurred with Station A pasteurized milk which amounted to 1.1 percent of the total supply. The larg­ est pasteurizing plant B (see Chart No. 3) which distributed 29.4 percent of all the milk consumed in Rockford had 17.1 percent of the cases during this 60 day period. A comparison of the remaining plants is shown. distributed by the various plants during The next, Chart No. 4, also brings the 60 day period. This chart would out the relationship between number of seem to indicate that the element of cases and volume of distribution. In this chance contact played a very minor role chart, however, the cases have been com­ in the case of Station A dipped raw milk. puted on the basis of number of cases As first step in gracing the epidemic, developing for each 10,000 quarts of milk composite samples of milk were collected 18 Scarlet Fever Epidemic at Rockford

from all stations selling raw milk. Blood which resemble human pathogens in these agar plates were made to determine activities h>ut are of little significance in whether hemolytic streptococci were pres­ disease in man. ent in significant numbers, such as 1,000 Composite herd samples were taken per cubic centimeter1. About 30 percent from the four producing farms supplying showed 100 or more hemolytic streptococci Station A. Samples from Herds No. 1 per cc. Typical colonies picked from these and No. 2 were negative. Those of No. plates were tested for their ability to 3 and No. 4 were positive for hemolytic hydrolyze sodium hippurate. The speci­ streptococci. Individual cow samples men from Station A was the only one were then taken from these two herds. negative to this test. The failure to hy­ Herd No. 3 consisted of 28 cows, 25 of drolyze sodium hippurate was taken as which were Bang’s reactors and had been presumptive evidence that the organism branded as such for more than a year. resembled those of human origin. Eight of these cows had varying numbers As a means of differentiating human of hemolytic streptococci. Although strains of beta hemolytic streptococci from quarter samples were taken of these eight those of bovine origin, Coffey2 states that cows, no strains resembling human patho­ the following biochemical characteristics gens were recovered. Herd No. 4 con­ are of considerable value, namely, final sisted of eleven cows, and it was foufid hydrogen ion concentration of 4.6 or that cows No. 4, 5, 6 and 8 had hemoly­ above in one percent dextrose broth, a tic streptococci in considerable numbers. positive' fermentation of trehalose, nega­ Quarter samples were taken on these four tive fermentation of sorbitol, and failure cows and the differential tests were ap­ to hydrolyze sodium hippurate. The same plied on all strains isolated. The Table author further states that the group-pre­ No. 1 shows that one member of the cipitation procedure is also necessary as herd known as Bessie (No. 6) had a it serves to differentiate not only strains very large number of hemolytic strep­ which may be distinguished by the above tococci in two quarters, 51,000 and 95,- biochemical properties but also those 000 per cc. in the right front and left

Table 1 Results from examination of milk of individual cows in infected herd Number Hydrolysis Hemolytic of pH in Strep. sodium Dextrose per cc. hippurate Broth Trehalose Sorbitol Mannitol Lactose Salicin Cow No. 4 Left Front 3,000 Pos. 4.4 Pos. Neg. Neg. Pos. Pos. Quarter Cow No. 5 Left Rear 18,000 Pos. \ 4.5 Pos. Neg. Neg. Pos. Pos. Quarter Cow No. 6 Right Front 51,000 Neg. 4.7 Pos. Neg. Neg. Pos. Neg. Quarter Cow No. 6 Left Front 95,000 Neg. 4.7 Pos. Neg. Neg. Pos. Neg. Quarter Cow No. 8 Right Front 2,000 Pos. 4.5 Pos. Pos. Neg. Pos. Pos. Quarter Cow, No. 8 Right Rear 2,000 Pos. 4.5 Pos. Pos. Neg. Pos.. Pos. Quarter (Bad) Journal of Milk T echnology 19 front quarters respectively. There was Yearbook 1936-372. The successful iso­ no clinical evidence of infection. The lation of Group A strains from a cow’s strains isolated from both quarters fer­ udder apparently requires that the milk mented trehalose, failed to ferment sor­ specimen be obtained promptly during bitol or to hydrolyze sodium hippurate, the course of the epidemic or immediate­ and gave a pH of 4.7 in 1 percent dex­ ly afterward. trose broth. The biochemical properties The facts presented can not be taken of these organisms indicated human path­ as conclusive evidence that Cow No. 6 ogens. was the source of the epidemic, but Cultures of the strains isolated were circumstances indicate such was the case. submitted to the Referee of the A.P.H.A. How did Cow No. 6 become infected? committee for further identification by Mr. B, a tenant on Farm No. 4 assisted the group-precipitation test. with the milking daily until February 21 The samples of milk, from which the on which date illness of his five year old submitted cultures were obtained, were daughter was diagnosed as scarlet fever. collected more than a month after the epi­ She had been ill two days when seen by demic occurred. The test indicated that the family physician, placing onset Feb­ the beta hemolytic streptococci isolated ruary 19. Mrs. B, the mother, had been from Cow No. 6 were of the C-G group. ill with acute tonsilitis on February 17. The referee stated that in other out­ (Due to impassable roads the family was breaks of streptococcus infection which practically isolated during February and had been studied, the organisms isolated early March). A younger daughter de­ from patients had been in Group A. veloped a sore throat with rash and tem­ Considering this fact alone, it might elim­ perature on March 14 and was ill for inate Cow No. 6 as a source of the epi­ three weeks. Unfortunately, no cultures demic. However, the number of out­ were obtained from these cases at the breaks studied is rather limited, and the time they occurred and there may be no toxigenic activity of some strains in group connection to the epidemic but again cir­ C-G from sources other than man or milk cumstantial evidence indicates a possible has been established. chain of contact. In view of the fact that more than a month had elapsed from the onset of the REFERENCES epidemic and the time the organisms were 1. Williams, Anna W.; "Streptococci in Re­ isolated, it is possible that Group A or­ lation to Man in Health and Disease”, ganisms, which may have been .present Chapter VIII, p. 162. in the udder during the epidemic, were 2. Coffey, Julia M., Referee; “Tentative Meth­ supplanted by strains in Group C-G. ods of ' Isolation and Identification of Hemolytic Streptococci”, American Public This occurred in the case of Cow No. Health Association Year Book, 1936-37, 3007 reported in Table 2 of the A.P.H.A. pp. 135-138. 20

Problems Related to Homogenized Milk* F. J. Doan, Dairy Department, The Pennsylvania State College, State College, Pa.

The homogenizer was first used in the enced recent sanitary changes in the piston dairy industry for preventing fat separ­ machines. ation in evaporated milk. Some years later Sonic homogenization is accomplished it was found almost essential in the pro­ with equipment acting on a different prin­ duction of smooth-textured ice cream. To­ ciple. Milk is conducted between dia­ day it is being used in the processing of phragms oscillating at high frequency, the a great variety of manufactured products effect on the product being very similar to and also fluid market milk. For the that of the pressure homogenizers treatment of fluid milk for retail sales, although no pressure is utilized. Appar­ the homogenizer has not been used ex­ ently the violent vibration produced in the tensively, although there is much interest milk causes a break-up of the fat glob­ among milk dealers in its possibilities, ules. particularly from the viewpoint of pro­ In general, the efficiency of any homo­ ducing a milk of low curd tension and im­ genizer (sonic excepted) depends on the proved digestibility. velocity with which milk is caused to go Homogenizers have undergone several through the constricted aperture which changes since their first development. constitutes the homogenizing valve or jet, Most of these have had to do with three the force which it impinges on the cham­ things: the development of a more effici­ ber wall surrounding the valve, the num­ ent homogenizing valve or aperture, im­ ber of such apertures it goes through, and proved mechanical operation, and better perhaps the degree of staggered flow pro­ sanitary features. At present the com­ ducer Tliis explains the existence of two mon form of homogenizer is a three piston and three stage valves, and the other com­ pump operating against a ground drop plications frequently encountered in hom­ and lift valve. Newer models are con­ ogenizing valves. Several years ago, structed so that every part contacting the studies at Pennsylvania State College with milk can be taken apart and easily cleaned single valves of the drop and lift type Even the pistons are capable of being re­ indicated that maximum efficiency results moved for washing purposes. when the valve construction causes the Rotary machines, operating on the prin­ milk to strike the wall of the chamber ciple of a gear or Bump pump, develop­ as nearly at right angles as possible, and ing lower pressures and utilizing less when the distance from the valve seat to power, have been developed over the past such wall is short. Most modem hom­ five years. Some of these machines have ogenizers are equipped with valves having vety elaborate homogenizing valves or these features. jets, the idea of their designers having THE EFFECTS OF HOMOGENIZATION ON been to compensate the necessarily lower MILK pressure with a more efficient valve. In Homogenization causes certain changes this they have apparently partially suc­ in the physical and chemical properties ceeded. These machines are highly sani­ and characteristics of milk. For the most tary in construction and no doubt influ- part, these changes are proportional to the fat content of & milk, the more fat pres * Presented before foe Metropolitan Dairy Technology S ocietyy. , New York, N. Y„ April 19, 1938. ent the greater the change. That fat plays Authorized for pul,lioib'oti on July IS,, 1938, as a predominent role in the effects of homo­ paper No. 842 in the Journal Series of the ' Penn-* syfrania Agricultural Experiment Station. genization is readily seen when it is con- Journal of Milk Technology 21 sidered that up to the present time no one the first stages in coagulation. The in­ has shown that homogenization of skim- stability of homogenized milk toward co­ milk produces any measurable change in agulation becomes more pronounced with the product. higher fat content. The most evident change in homogen The surface tension of milk is increased ized milk is the greater number and very slightly by homogenization, but the smaller size of the fat globules as shown effect becomes quite definite at fat levels in Table 1. Globules with an average di­ of over 6 percent, when the property is ameter under about 2.75 microns will not measured with the DuNuoy instrument. rise to such an extent as to show evidence The specific gravity of milk is not ap­ of creaming in milk held for 48 hours preciably affected by homogenization, so When the average size is reduced to about long as the machine and the suction line 1 micron, even centrifuging and analyses are air-tight, but, if air is sucked into the of the upper and lower layers reveal only milk in the processing, the specific gravity small differences in the fat content. may be reduced considerably, at least The reduced size of the fat globules in temporarily. homogenized milk makes it practically im­ The curd tension of milk is reduced possible to recover the fat by separation. very greatly by homogenization, as shown Whenever the pressure exceeds 1500 lbs. by many investigators. The effect in­ per sq. in., the fat in separator skimmilk creases with the fat content of the milk will be in the neighborhood of one per and the pressure or efficiency of homogen­ cent. This interferes with the easy dis­ ization. Table 2 contains a set of typical posal of returned goods, and constitutes data obtained in the writer’s laboratory. one reason for dealers hesitating to go in­ The data indicate that pressures over to production. Homogenized milk or about 2000 lbs. per sq. in. accomplish cream will not readily churn. This is an little with average milk, although with advantage in decreasing the possibility of milk of high fat content (standardized), cream plug, grainy texture, and oiling-off, greater reductions are obtained with but again prevents easy recovery of the higher pressures. They also show that the fat in the surplus product. percentage reduction is least with natur­ The viscosity of homogenized milk is ally soft curd milk and greatest with nat­ higher than unhomogenized. This gives urally hard curd milk. Two-stage process­ the product a richer flavor. This effect is ing apparently has no advantage over not great unless the fat content is in single stage in lowering the curd tension creased to 5 or 6 percent. of average fluid milk. The alcohol test indicates that milk is It is well known that temperatures of more easily coagulated after homogenize preheating, pasteurizing, and processing tion, and the same results are obtained influence curd tension. This heat factor, with rennin and acid. The explanation however, is not of great importance until probably lies in the greater amount of ad­ the heat considerably exceeds that of pas­ sorbed casein on the expanded amount of teurization. Nevertheless, the effects of fat globule surface. Such casein is fixed. heating and homogenizing are difficult It has lost its mobility and that is one of to divorce completely.

TABLE 1. Effect of Homogenization on Fat Globule Break-up Diameter of Fat Treatment of Pasteurized Milk Globules (microns) LJnhomogetiized ...... 4.21 Homogenized at 500 lbs...... ,...... 3,34 " 1000 " ...... -..... -...... 2.61 " 1500 " ...... 2.38 " " 2500 " ...... 1.67 *' 3500 " ...... 1.13 22 H omogenized Milk

TABLE 2. Effect of Homogenization on Curd Tension Curd Tension (grams)* Treatment of Pasteurized Milk 5.1% fat 4.2% fat 3.6% fat Unhomogenized .. 12j3 56 34 Homogenized— 500 lbs. at 145° F. .. 72 44 29 1000 .. 58 27 20 2000 - 3;7 18 14 3000 - 3,8 19 12 4000 .. 40 17 12 1000— 500 lbs. at 145° F. .. 60 28 20 2000— 500 ...... 41 17 15 3000—1000 ...... 42 17 11 3000— 500 ...... 39 19 13

^ Curd tension determinations were made using Miller’s technique with several modifications in manner of mixing sample and coagulant (0.3% HCI and 0.45% pepsin). (Editor: See J. Dairy Science 18, 259 (1935)1

While homogenization of cream and preheating temperatures for inhibiting ice cream mix usually results in a clump­ rancidity in homogenized milk have been ing of the fat globules as well as a reduc­ found to be 148° F. flash, 137° F. for 15 tion in their size, the effect is not signifi­ minutes holding, and 132° F. for 30 min­ cant in fluid milk. Fat clumping does utes, applied either before or immediately not occur until the fat content exceeds after homogenizing. In unpreheated milk, about 6 percent. It is the fat clumping rancidity can usually be detected within phenomenon which causes such noticeable 30 minutes following homogenization, changes in the alcohol stability, the vis­ especially when high pressures are used. cosity, the surface tension, and to some de­ The liberation of fatty acids causes a drop gree in the curd tension. It is also this in surface tension and in pH, and an in­ phenomenon which makes the two stage crease in titratable acidity. The reaction can valve of such value in reducing viscosity easily be followed by determining these and increasing stability. When fat clumps values at intervals. Because of lipase ac­ are absent, a second valve produces little tion, it is impossible to produce an homo­ or no effect. genized raw milk. Tallowy or oxidized flavor has been OTHER EFFECTS OF HOMOGENIZATION very troublesome in market milk for some Homogenization produces certain other years, and is still an important problem. changes in milk, some of which consti­ While the reaction causing tallowiness is tute troublesome problems to the manu not absolutely known, it appears to be an facturer, and many of which are not oxidation of the fat or the lecithin or thoroughly understood. probably both. Some consider it an en­ If milk is homogenized without previ­ zyme reaction. Others believe that it is ous heating or immediate subsequent probably a non-biological, physico-chem­ heating to a temperature in the neighbor­ ical catalysis wherein several agents may hood of 140°-150° F., an enzyme, lipase, act as catalyzers such as light, copper, and which is always present in mixed milk, other pro-oxidants; or a lack of normal will attack the fat and cause a character­ anti-oxidants from feed sources may cause istic rancid flavor. The mechanism of this the same result. Whatever the reaction reaction is not understood, but presumably is and whatever it may be due to, or ac­ the adsorbed layer on normal fat globules celerated by, we now know that homo­ acts as a protective membrane against the genization will definitely delay its appear enzyme. Homogenization destroys this ance or even prevent it if the homogen­ coating, and exposes new fat surface. The izing pressure is sufficiently great. This lipase is adsorbed with other substances statement has one exception. If the tal­ to form a new membrane. This brings it lowy flavor is induced Sy sunlight, homo­ into intimate contact with the fat. Critical genization is no protection. On the con Journal of Milk Technology 23 trary, homogenized milk is more sensitive greater susceptibility of homogenized milk to sunlight than unhomogenized milk, so to sunlight. Finally, in the case of that dealers offering homogenized milk to sample 16, it is shown that paper con their trade would do well to keep this tainers are not measurably superior to cleat fact in mind. If homogenized milk can glass in protecting milk from the effects be protected from sunlight, other causes of sunlight. of tallowy or oxidized flavor may be for· Homogenization of milk tends to agglu gotten as far as this product is concerned tinate particles of fine dirt, bacteria, and It has been suggested that homogenized cellular elements in milk, and to cause milk be retailed in green glass bottles or them to settle, forming a grayish sludge protected by green Cellophane wrappers which in a milk bottle is unsightly. This Such treatment will efficiently protect material in normal milk is apparently homogenized milk from the effects of ex swept up with the rising fat globule clus· posure to sunlight. Data dealing with ters, and is unnoticed in the cream layer, homogenization and tallowy flavor are The amount of sedimentation caused by given in Table 3. homogenization depends on the condition In the first portion of the table, the of the milk, i. e., the amount of sediment data show that homogenization of milk at and cells present, and to a lesser degree on pressures of 2000 lbs. or over prevents the pressure used. Filtration of the milk, oxidation in milk treated with copper. In ' either before or after homogenizing, does the second portion of the table the data not reduce the sedimentation since most of indicate the value of green as a protective the material responsible will readily pass color both for unhomogenized and homo- through a filter. Clarification, however, genized milk. They also illustrate the will effectively eliminate any visible sedi-

TABLE 3. Homogenization and Tallowy Flavor Degree of Tallowy Flavor Treatment of Pasteurized Milk 24 Hours 48 Hours Copper Treated 1. Unhomogenized—untreated—check ...... none none 2. Unhomogenized—treated with 3 p.p.m. copper...... + + + + + + 3. Treated 3 p. p. m. copper—Homogenized 500. lbs...... + + + + + 4 . " " ··■ “ “ " " 1000 " ...... - none + 5. ” " " ” " " " 2000 " ...... — none none 6. " " " " " " " 3000 " ...... none none Exposed to Sunlight (30 min.) 1. Unhomogenized—Exposed in opaque glass...... none none 2. " ” " clear glass...... —------+ + + 3. " " " " green cellophane wrapper none none 4. " " " " " blue wrapper ------none ± 5. " ...... yellow wrapper ------+ + + 6. " ...... recoffee to a ious and complicated. For this reason, re­ greater degree than unhomogenized milk sults have been slow in forthcoming, and or cream. insufficient data are available for definite One of the greatest objections on the conclusions as yet. However, the follow­ part of health authorities to homogenized ing statements will give some idea of the milk is the unsanitary construction of the findings. These may have to be modified older homogenizers and careless cleaning or altered after the accumulation of more methods frequently used by plant oper­ data and after the available data are critic ators. Until recently the stuffing boxes ally analyzed. were practically impossible of access in There is reasonably close-agreement be­ washing. Equipment of this type has long tween curd tension results and digestibil­ been outlawed for .market milk purposes, and it is not likely that bottled homogen­ ity in the case Of normal raw or pasteur­ ized milk will become an important type ized untreated milk and in the case of of market milk until the equipment used boiled milk. is as accessible for cleaning and is washed Homogenized milk does not exhibit as and sterilized with equal carefulness to good digestibility characteristics as the that exercised with the usual milk line curd tension would seem to indicate. The equipment. It has been shown that with reason for this appears to be that the co­ the more recent sanitary models of homo­ agulum, although soft compared with un­ genizers, bacterial counts no higher than processed milk, is adhesive and holds to­ those obtained with ordinary pasteurized milk can be had with homogenized milk. gether in a mass instead of breaking up While homogenization tends to break up into a granular or flaky condition. Homo­ bacterial clumps and give higher plate genization undoubtedly improves the di­ counts, clarification following homogen­ gestibility of milk but the curd tension ization is more efficient in throwing out apparently is not an index of the improve­ bacterial cells, and appears to more than ment. Journal of Milk Technology 25

LOW PRESSURE HOMOGENIZERS trifugation, sediment was obtained in all A number of trials with milk have been of them, the greatest deposits being found made using two low pressure rotary in the samples homogenized by the piston homogenizers, and comparing the results machines at high pressure. with two high pressure piston machines The rotary machines were easier to take The rotary machines were not capable of apart for cleaning than the new sanitary lowering the curd tension as much as the piston machine which was used. Less time piston machines, but at equal pressures was required therefore in cleaning and the rotary machines apparently had a sterilizing. Both rotary machines were measurably greater effect as shown in capable of complete dismantling, and all Table 4. surfaces coming in contact with the milk Data on reduction of fat globule size were readily accessible. are shown in Table 5. It will be noted The standing-up qualities of the rotary that at equivalent pressures, the rotary ma machines appeared to be good but they chines caused greater break-up in the fat were not in use long enough to be rated globules. in this regard. The alcohol stability correlated with the In conclusion, it would seem that homo­ data shown in Tables 4 and 5. None of genized milk and cream will become a the samples processed by any of the more familiar product in all markets. machines exhibited a measurable cream Within 10 or 15 years, the dairies selling layer after standing 24 hours at 40° F. these products will probably be the rule Upon high speed centrifugation the rather than the exception. There are many samples of milk homogenized by the factors which tend to prevent the appear­ piston machines at high pressure gave no ance of homogenized milk and homogen­ cream layers or fat films. At low homo­ ized cream on our markets at the present genizing pressures and with the rotary time. These, however, will be gradually samples, films were frequently noted. Less overcome as the advantages of the pro­ separation was noted on the samples of ducts become better appreciated. Regard­ rotary homogenized milk compared with less of whether homogenized milk is gen­ samples of piston homogenized milk pro­ erally accepted by pediatricians as: a good cessed at similar pressures. This would base for infant formulas, homogenized be expected from the data shown in Table milk will probably be accepted and de­ 5. No sedimentation by gravity was ob­ manded by consumers because of its other served in any of the samples. Upon cen­ obvious merits. TABLE 4. Effect of Type of Homogenizer on Curd Tension Original Piston I Piston I Piston II Piston II Gear Rotary Bump Rotary Curd 650-1000 3000 650-1000 3000 800-1000 650-850 Tension lbs. lbs. lbs. lbs. lbs. lbs. (grams) (grams) (grams) (grams) (grams) (grams) (grams) 47 23 18 — — 22 — 50 29 19 — — 25 — 52 32 23 — — — 26 64 37 — — — 35 — 61 44 — — — — 31 48 25 14 — . — 24 — 29 ■ ------— 14 11 ' 12 12 45 — — 21 15 19 20 TABLE 5. Effect of Type of Homogenizer on Pat Globule Size (Average several runs) Original Piston I Piston I ■ Piston II Piston II Gear Rotary Bump Rotary Milk 650-1000 3000 650-1000 3000 800-1000 650-850 lbs. lbs. lbs. lbs. lbs. lbs. (microns) (microns) (microns) (microns) (microns) (microns) (microns) 5.11 3.0 1.69 3.26 1.67 2.15 2.59 26

Report of Committee on Communicable Diseases Affecting Man* I. A. Merchant, Chairman Iowa State College, Ames, Iowa,

The annual report of this committee The type of milk or milk product which “ has the privilege of extending its scope was involved in the epidemics is also of to almost any phase of milk and dairy interest. The 46 milkborne epidemics sanitation, since epidemics of diseases which were recorded in the United States affecting man may originate any place were all caused by raw, sweet milk. In along the line from the cow to the con­ 13 epidemics, the milk was of Grade A sumer. Past reports have discussed the quality; int 2 epidemics the milk was various epidemics which have occurred in Grade B ; in 4 epidemics the milk was un­ the United States and Canada, and have graded ; no data were available for the re drawn attention to some of the factors mainder. which have inaugurated and perpetuated In the four typhoid fever epidemics in them. While our report desires to call Canada, ope probably originated in a attention to the epidemics of milkborne dairy, whije the other three originated diseases for 1936, it also emphasizes some from Cheddar cheese. Investigation of of the progress which has been made in these three epidemics revealed that they controlling the diseases of man which are all originated from the same lot of Ched carried by milk and milk products. dar cheese which was prepared at a cheese The outbreaks of milkborne diseases as factory at Thorsby, Alberta. The epidem reported to the United States Public Serv­ ics occurred at Thorsby, Springbank, and ice are given-in Table 1. Edmonton, all in the Province of Alberta All occurred simultaneously. One of the most interesting points brought out in Table 1 is the large num­ The case of tuberculosis was reported ber of epidemics of scarlet fever during from the province of Manitoba. The case 1936. Typhoid fever usually holds first was a tubercular adenitis of a fourteen place, yet epidemics of this disease were year old boy. The organism was not re not as numerous as in other years. The covered from the case and typed, there, great number of cases involved in milk­ fore it could not be definitely stated that borne scarlet fever is also shown in the it was of bovine origin. The herd from table. which the milk supply originated proved to be one hundred percent tuberculous, The determination of the origin of the and for that reason the case was presumed organisms which are responsible for epi­ to be of bpvine origin. demics is always imperative. An analysis of the 46 epidemics which appeared The location of the epidemics in the in the United States, showing the origin United States is a matter of interest. of the various epidemics, appears in Table Table 3 shows the states in which the 2. epidemics occurred. The states reporting the greatest number of epidemics have The total number of 21 in scarlet fever very efficient milk control programs, and is due to the presence of more than one case or carrier in some of the epidemics. probably for that reason more milkborne epidemics are detected and reported. It * Presented at 26th Annual Meeting of the Internationa) is noted in Table 3 that only 21 states ^ Association of Milk Sanitarians, Louisville, Ky., Oct. 11-13, 1937. reported epidemics of milkborne disease. Journal of Milk T echnology 27

What can be done to bring about a One of the newer methods, the phospha­ more complete reporting of milkborne tase test, shows great possibilities. disease epidemics? Possibly all the cases are reported which are called to the atten­ THE PHOSPHATASE TEST AS AN EPIDEMI­ tion of health officers. Yet, we all know OLOGICAL AID* that these figures can not represent the The New York State Department of true picture in the United States. We Health, in its weekly Health News of know that numerous cases (family epi­ August 2, 1937, reported its first practi­ demics) of septic sore throat and gastro­ cal application of the phosphatase test enteritis occur in farm areas. While such (for determination of faulty pasteuriza­ cases may be outside the field of organized tion) in connection with the investigation milk control agencies, they are important of a disease outbreak. Early in July, an and necessary to complete the true epi­ outbreak of about 75 cases of gastroenter­ demiologic picture of milkborne diseases. itis occurred in two associated children’s The methods by which faulty pasteuriz­ camps. The onsets occurred a few hours ation of milk may be detected have re­ ceived much study during recent years. * Prepared by Paul B. Brooks, M. D.

TABLE 1 Milkborne Epidemics* 1936 Number of Cases in Cases using Diseases epidemics community suspected supply Deaths UNITED STATES: ’ . Typhoid fever ...... !...... 15 114 103 5 Paratyphoid fever ...... :...... 1 21 21 0 Scarlet fever ...... 16 1222 971 16 Septic sore throat ...... 6 271 268 7 Gastroenteritis ...... 2 63 63 0 Enteritis ...... 1 25 25 0 Food poisoning ...... 1 100 100 0 Undulant fever ...... 4 15 14 0 Totals ...... 46 1831 1565 28 CANADA: Typhoid fever ...... 4 28 4 Undulant fever ...... — 12 0 Tuberculosis ...... — — 1 . 0 Totals ...... :...... 4 41 4 *In this report the term epidemic is applied to cases of disease involving one or more persons.

TABLE 2 Origin of Milkborne Epidemics in United States Gastro- Pata- Septic enteritis Typhoid typhoid Scarlet sore and food Undulant fever fever fever throat poisoning fever Total Cases ...... 3 —; 15 5 — — 23 Carrier ...... 7 1 5 1 — — 13 Cow ...... - - — — 1 — 3 4 8 Water ...... 1 — — — — —■ 1 Undetermined ...... 4 — — 1 1 — 6 28 Communicable D iseases Affecting Man

TABLE 3

Distribution of Milkborne Epidemics by States—1936 Para- Septic Gastro- Total Typhoid typhoid Scarlet sore enteri- Undulant Epi­ Total State fever fever throat tis, etc. fever demics cases New York ____ ..... 1(11)* 6 (686) 2 (58) 1 (36) 10 791 California ...... 5(24) 1(3) 6 27 6(150) ...... 6 150 Massachusetts ...... 1(1) 2 (10) 3 11 Illinois 2(94) ------____ 2 94 Kentucky ...... 1 (21) -...... 1(5) ...... 2 26 New Mexico ...... ,...... 1 (4) 1 (6) ____ 2 10 Washington _____ 1 (10) ------1 ( 1) 2 11 Connecticut ...... 1(24) ...... 1 24 Florida ...... 1 (2) ' ...... _____ 1 2 Georgia ------1 (23) ------... ______1 23 Michigan ...... 1 (25) 1 -2 5 Minnesota ______1 (8) ...... 1 8 Montana ______1 (11) ...... 1 11 Nebraska ------1 (2) ...... 1 2 New Jersey ...... ------1 (175)...... 1 175 Ohio ...... — ...... -...... 1 ( 100) ...... 1 100 Pennsylvania ...... 1(37) 1 37 Rhode Island ...... 1 (27) ...... 1 27 Texas ...... 1 (9) ...... 1 9 Virginia ...... 1 (2) ...... 1 2

‘ Figures in parenthesis represent number of cases. after consumption of milk purchased from above-mentioned cow, had been examined a local producer-dealer as Grade A a few days previously by a local veterin­ Pasteurized. The milk was delivered to arian. the camp in cans. Epidemiological evi­ The investigators were able to secure dence pointed clearly to this milk as the a sample of milk from the same can from cause of the outbreak. which that responsible for the outbreak A department veterinarian, on examin­ was said to have been taken. The phos­ ation of the herd supplying the milk, phatase test proved it to be raw milk. found several cows with bad udders. Hemolytic streptococci, as well as bacilli Among them was one showing extensive of the colon group, were isolated from udder involvement and giving obviously this sample. abnormal milk. This cow was slaughtered On investigation at the plant, it ap and the udder taken to the state labor­ peared that the substitution of raw milk atory. On sectioning, discharging ab­ probably was accidental, due to careless scesses were revealed. Hemolytic strepto­ methods of handling. The dealer ordin­ cocci, not of the type commonly associated arily used separate cooling vats for cans with scarlet fever and septic sore throat, of raw and pasteurized milk. Due to a were found on culturing. At the time of leak in one of the vats, all of the cans the state veterinarian’s visit to the dairy, had been stored in one vat, the raw milk the dealer produced a report apparently supposedly in one end, the pasteurized in indicating that the herd, including the the other. The cans were not adequately Journal of Milk T echnology 29 labeled, and the supposition was that an carefully studied. Epidemiologically, ac­ employee had taken out a can of un­ cording to Dr. Ramsey, there is no dis­ pasteurized milk by mistake. tinction between the two conditions, "the A year or more before this incident, a characteristics being the same, regardless milkborne epidemic of scarlet fever and of the name given the disease”. Milk "sore throat” occurred in two CCC camps should always be suspected, he said, when under similar circumstances. The milk a number of cases occur with onsets al­ was purchased for the camps as having most simultaneous. been pasteurized, but there was consider­ Dr. Stebbins, in collaboration with Dr. able evidence suggesting that the milk Hollis S. Ingraham, had made detailed responsible for the epidemic never had studies of several of the more recent epi­ been in the pasteurizer. Experts who ex­ demics. The studies cited related to thre„ amined the temperature charts at the plant epidemics "classified as scarlet fever”, ag­ believed that some of them had been gregating 801 cases, and three of septic "manufactured" for the occasion. The sore throat, totaling 590 cases. From a case was turned over to the legal author­ comparative study of symptomatology in ities for prosecution but ultimately was groups of over a hundred cases each in dropped, on the ground that the evidence the two types of epidemics, he concluded was not such as to convince a lay jury. that, except for rash and desquamation, The result of the phosphatase test, in the the "signs and symptoms” were practically more recent outbreak, supplied the hither­ the same for the two types of illness. Of to missing link in the chain of evidence. 749 cases associated with scarlet fever epidemics, 14 percent gave a history of MILKBORNE STREPTOCOCCUS INFECTION* having had scarlet fever previously. Of This was the subject of a symposium these, only 30 percent developed typical presented in connection with the· 1927 rash, whereas among those giving no his­ Annual Conference of Health Officers tory of previous scarlet fever, 64 percent and Public Health Nurses in New York developed typical rash. From this and State. The discussion brought out the previously published data, it appears that facts that studies of milkborne epidemics persons who have had scarlet fever are of so-called scarlet fever and septic sore not protected against reinfection, but are throat, made in New York state and else­ much less likely to develop rash when re­ where, have thrown considerable light on infected. Dr. Stebbins showed that cases the subject of streptococcus infection in of erysipelas occurred in connection with general, and furnished evidence strongly each of two epidemics of scarlet fever suggesting that scarlet fever, septic sore and two of septic sore throat studied with throat, and erysipelas, instead of being reference to complications. Usually the separate and distinct clinical entities, in­ erysipelas occurred in persons previously cited by specific strains or types of hemo­ lytic streptococci, simply represent differ­ having throat infections, but, in a few ent individual reactions to the same in­ cases, apparently occurred as a primary in­ fecting agent. fection. New York State, Dr. Ramsey pointed Miss Coffey’s discussion related chiefly out, "according to the published records” to the functions of the laboratory in con­ had had a larger experience with milk­ nection with the investigation of epidem­ borne epidemics of scarlet fever and sep­ ics. She pointed out, however, that "the. tic sore throat than any other state Some streptococci associated with scarlet fever, of the discrepancy, he believed, was due septic sore throat, and other infections to differences in reporting. In the pre­ cannot be differentiated by laboratory pro­ ceding two years, he said, nearly all such cedures”. "Streptococci with the charac­ epidemics occurring in the state had been ters attributed to Streptococcus epidemi­ cus, the reported incitant of septic sore ^Prepared by PauPB. Brooks, M. D. throat”, she said, "are encountered in scar­ 30 Communicable Diseases Affecting Man let fever, erysipelas, puerperal sepsis, and known to react positively to skin tests other streptococcus infections. Moreover, with both "scarlet fever” toxin and "ery­ not all strains associated with septic sore sipelas” toxin. One group was inoculated throat have the properties of the so-called with "erysipelas” toxin and later skin- Streptococcus epidemicus. Similarly, stud­ tested with "scarlet fever” toxin; the ies, of the toxigenic properties of strains other group inoculated with "scarlet from different sources have failed to dem­ fever” toxin and later tested with "ery­ onstrate a specific relationship between a sipelas” toxin. The results of nearly all particular toxin and the disease manifesta­ of the tests, in both groups, were nega tion.” tive, shoeing that "erysipelas” toxin pro­ Dr. Brooks, in general discussion, duced immunity to "scarlet fever” toxin brought out the following facts relating and vice versa. to epidemics: gastroenteritis a n d f o o d p o i s o n i n g Epidemics of septic sore throat usually Since the 1935 report of this Commit­ are milkborne. tee, which discussed in a brief way the In most extensive milkborne epidemics, subject of food poisoning, numerous re­ either of septic sore throat or scar­ ports of epidemics of gastroenteritis have let fever, cows with mastitis are in­ been made. Many of these epidemics volved. have beep traced to milk and to an in­ The cow, probably invariably, has been fected dipry cow. infected with an organism from a In considering food poisoning as being human source, i. e., a person with a an acute gastroenteritis, a number of dif­ throat or other infection. ferent etiologic agents must be kept in Dr. Brooks referred to Dr. Anna Wil­ mind. First: the staphylococcus toxin, liams’ book on Streptococci, published in or rather that particular part of the toxin 1932, in which she cited several epidem­ complex of the organism known as gas­ ics in which it was reported that septic troenteric toxin which causes an acute sore throat and scarlet fever cases occur­ condition apparent within two to four red. In one of these, in England in 1892, hours, manifested by nausea, abdominal the report stated "Definitely both condi­ pain, and diarrhea. Second: infection due tions. Those who had had scarlet fever to Salmonella organisms, more particular­ had only sore throat.” Dr. Williams ly Salmonella enteritidis and other mem­ quoted Dr. W. G. Smillie as saying, in bers of the colon-typhoid group which is 1917, that in many so-called septic sore a conditipn appearing not less than six throat outbreaks, scarlet fever cases also and frequently as high as seventy-two were observed. Erysipelas cases, Dr. hours after consuming the infected food; Brooks pointed out, had occurred in prac­ symptoms, similar to the above. Third: tically all of the New York state epidem­ an alkalqid poisoning due to drinking ics recently studied. Thus, he said it ap­ milk from cows which have eaten white peared that, in an individual epidemic, a snake roof: or rayless goldenrod. Although single strain of hemolytic streptococci rare, these weeds are found in certain sec­ from one human carrier and coming tions of the United States. The alkaloid, through the medium of a cow’s udder, trematol, which is found in both plants was responsible for all three conditions. causes a condition known as trembles in This suggests, he said that all were merely cattle and other animals, and in man pro­ different individual reactions to the same duces symptoms similar to those caused infecting agent, and "scarlet fever is sim­ by staphylococcus toxin. Fourth: the.strep­ ply septic sore throat plus rash.” As an­ tococci apparently, may produce toxic other evidence of nonspecificity of strains, products which can cause acute intestinal he referred to the results of an experiment disturbances. The report just given of cited by Dr. Williams. Two large groups the cases in New York is evidence of of children were used, all of whom were that fact. Just what species of strepto­ Journal of Milk T echnology 31 coccus was incriminated and what the tox­ undoubtedly been formed after the in­ ic substance may have been was not de­ vestigation of herds with acute mastitis termined. which involved a large number of animals. The great majority of the acute cases of One wonders if the situation is the same, food poisoning are due to the staphylo­ however, when large number of herds cocci. Those which arise from milk are have been examined and when the organ­ for the most part due to a staphylococcic isms present in one or two infected cows mastitis in one or more cows in the herd. are identified. Many of the cases of Shaughnessy and Grubb have recently staphylococcus milk-poisoning have been made some valuable suggestions for the traced to only one cow in the herd. It investigation of such outbreaks. They would seem evident, therefore, from the stated:, public health point of view, that individ­ "In each outbreak of staphylococcus food ual cases of bovine mastitis present a poisoning that we have investigated, cows with problem of importance and that staphy­ staphylococcus mastitis have been detected in lococcic mastitis must be revalued in the the herd supplying the milk. This suggests light of present-day knowledge. that parasitic staphylococci may be more capa­ Gwatkin and his associates in Canada ble of producing enterotoxin than saprophytic have contributed valuable information staphylococci. concerning staphylococcic mastitis. In a In investigating outbreaks of staphylococcus recently published report, they made the milk-poisoning, some persons who appear to following summary: be naturally insusceptible and others who seem "Nineteen cases (7.3 per cent) of mastitis to have become immunized to the staphylococ­ in which staphylococci appeared to be the cus enterotoxin have been encountered. These etiological factor were detected during the findings may mislead the· investigator in trac­ examination of 260 cows. ing the offending food. In localities where One hundred and ninety of 275 strains of milk sickness, caused by white snake-root, Staphylococcus pyogenes fermented mannitol occurs, the investigator must be careful to dis­ and 85 were negative. Twenty-four positive tinguish this type of poisoning from staphy­ (12.5 percent) and 60 percent of the nega­ lococcus milk poisoning. tive strains were recovered from apparently The most reliable method at the present time normal udders. for detecting food-poisoning strains of staphy­ Forty of 65 strains of staphylococci showed lococci is to culture suspected strains under some degree of zone production on Stone’s conditions favorable for the production of the beef extract-gelatin-agar plates and 11 of these enterotoxin, and feed the sterile filtrate of the liquefied Stone’s beef extract-gelatin. Seventeen cultures to human volunteers— with due pre­ kittens were given intraperitoneal injections of cautions. ' When such a procedure is not prac­ 3 cc. of boiled filtrates of some of these ticable and the presence of large numbers of strains and seven of them showed some gastro­ staphylococci in the milk from cows which intestinal symptoms, in one case severe. Two, chemical and microscopic tests indicate have a however, had worms in their vomitus and mastitis infection and clinical findings point to should probably be excluded. All the kittens a staphylococcus poisoning, it is considered injected with filtrates showed lassitude. Two that these findings constitute presumptive evi­ of the kittens that vomited had received fil­ dence for the diagnosis of staphylococcus milk­ trates of strains that were negative by both poisoning and warrant the elimination of the gelatin tests. (These were not the two that infected animals from the herd.” had worms in the vomitus.) One of the four kittens injected with unseeded, boiled medium STAPHYLOCOCCIC MASTITIS OF COWS manifested some pain and uneasiness for about Numerous surveys which have been five minutes but no lassitude. The other three been made of the bacterial flora of the showed no symptoms. infected bovine udder have concluded Agglutination and complement-fixation tests that streptococci played the most domi­ on blood serum and whey from streptococcic nant role. Most of these conclusions have and staphylococcic cases were negative. 32 Communicable D iseases Affecting Man

Sixty-two samples of blood serum were ex­ In a survey of the incidence of mastitis amined for their content of staphylococcus in the coys supplying milk to the city of antitoxin in terms of International Standard Ames, Iowa, Venzke has obtained some Units. In a group of 42 abattoir samples from interesting results. The survey is not com­ heifers and young steers, only about 12 percent plete so this material has not been pub­ had four or more units per cc. In a group of lished. Jfn detecting mastitis, the strip 14 staphylococcic mastitis cases, 79 percent cup, the chloride test and palpation were had 4 units and over, and <54 percent had 10 used. Samples of milk from chloride pos­ units and over as compared with 2.4 percent itive quarters were taken to the laboratory, of the abattoir group. Two cases of Strepto­ incubated 12 hours and 0.2 cc. plated in coccus mastiditis infection had 2.5 units per 5 percent horse-serum beef-infusion agar. cc. each. The predominating types of organisms One cow was found from which staphy­ were isolated and classified by the fer- lococci were isolated but which did not have mentaion of sucrose, lactose, mannite and mastitis at the time of examination. The blood raffinose, by pigmentation, and by the serum had a titre of 38 units per cc. This zone produced in Stone’s gelatin-agar cow was from a herd in which there were The cows were for the most part ordin­ three definite cases of staphylococcic mastitis. ary farm animals in which no concerted In the examination of 32 samples of whey for effort had been made to eliminate mas­ the presence of antitoxin, the milk of one titis. cow showed the same titre of antitoxin as was Results which have been obtained thus present in the serum, namely 20 units per cc, far in thip study are presented in Table 4. from one quarter of the udder. The content While there are many things of inter­ of antitoxin in the milk of the other three est in this table, the most significant for quarters was low. In a second cow with a our purpose are the 107 cows with para­ serum titre of 20 units, the whey had five units sitic staphylococci in their udders, and per cc in one quarter and from 1.5 to 2.5 in the rather small number, 15 cows, with the others. Samples from other cows suffer­ streptococcic mastitis. It is of interest, ing from mastitis were in the last named also, to note that of the 231 cultures of range.” staphylocpcci, 135 fermented mannite and It is evident, from this summary, that the 26 showed positive reactions on Stone’s complete study of staphylococci found in gelatin-agar. bovine mastitis should be subjected to It would seem that in this number of careful laboratory studies involving car­ cows, there were numerous potential bohydrate fermentation, toxin formation, sources of milk-poisoning epidemics. The and toxin antitoxin neutralization. dilution and pasteurization of the milk

TABLE 4 Mastitis Incidence in Farm Dairy Herds 40 individual herds tested 574 cows, 2296 quarters tested 38 cows (6.6 percent), 51 quarters (2.2 percent) positive by strip cup 235 cows (41.1 percent), 535 quarters (23.3 percent) positive by chloride test 366 cows (63.7 percent), 996 quarters (43.3 percent) positive by palpation 45 cows with 67 quarters yielded Staphylococcus aureus 62 cows with 92 quarters yielded Staphylococcus alhus[ 46 cows with 65 quarters yielded Staphylococcus epidermidis 6 cows with 7 quarters yielded Staphylococcus citreus 25 cows with 31 quarters yielded Micrococci sp 3 cows with 6 quarters yielded Streptococcus lactis 15 cows with 28 quarters yielded Streptococcus apalactiae. Journal of Milk Technology 33 from these animals were probably the con­ suffering from pulmonary tuberculosis. During trolling factors. It would be of value to approximately the same period, the bovine type know if any of the families on the farms was found in 39 specimens of pus from the harboring infected animals suffer peri­ cervical glands, in the cerebral spinal fluid, odically with intestinal disturbances. This and urine taken from the residents of Copen­ we hope to determine in the continuation hagen. All of these patients were under thir­ of our work. However, one must keep ty-two years of age and 10 under five years. in mind the immunity which may have In only one case was open tuberculosis found been produced throughout the years when in another occupant of the patient’s home. such milk has been consumed. The writers of the report state that, so far from pulmonary tuberculosis due to the bovine TUBERCULOSIS type being rare, it is, as a matter of fact, ex­ Tuberculosis is not extinct in the tremely common. United States or in Canada. The case of "In Amsterdam, in an examination of 115 tuberculous adenitis reported from Can­ adults suffering from pulmonary tuberculosis, ada is good evidence that scattered cases three gave the bovine organism, and in the must appear from time to time. Tubercu­ province of North Holland, 10 out of 89 such losis of bovine origin, in the past, has cases also gave the bovine organism. Gastric been generally believed to be of the non- lavage of 110 children yielded the bovine or­ pulmonary type. Our attention, however, ganism in nine. Examination of material from is called to the fact that pulmonary other forms of tuberculosis gave 55 human tuberculosis may also be caused by the type and eleven bovine, but this latter finding bovine organism by the following edi­ is not pertinent to the present discussion. torial in the American Journal of Public Griffith and Smith, on the basis of extensive Health: investigation in the northeast and southern "From time to time we have published ed­ counties of Scotland, make the statement that itorials on the transmission of bovine tuber­ pulmonary tuberculosis is frequently caused by culosis to human beings. That such infection the bovine type of organism. From April, takes place was definitely proved at the Uni­ 1934, to December, 1935, these authors in­ versity of Pennsylvania in 1902. The reports vestigated 103 cases of pulmonary tubercu­ of the British Royal Commission and of the losis, in 13 of which the bovine type of or­ German Imperial Commission amply confirmed ganism was cultivated from the sputum. In the findings, and since that time no one has five of these, there was a history of previous seriously questioned the danger to human be­ glandular tuberculosis so that the channel of ings, especially children, of tuberculosis in entry was almost certainly the alimentary canal. cattle. The vehicle of transmission is, in the "America appears to have fallen behind in vast majority of cases, milk. We have more this investigation. As far as we are aware, or less complacently accepted the fact that the there is no laboratory in the United States bovine type of organism is transmissible to hu­ doing systematic typing of cases of pulmonary man beings, and that it is prone to produce tuberculosis. It is a tedious and expensive lesions of the glands and bones; but not the piece of work which can be undertaken only pulmonary disease · known generally as con­ by well financed organizations, but that should sumption. There have been many articles ar­ be no bar to the investigation. It is not too guing for the relative unimportance of bovine much to say that we have no idea at the infection, and the National Tuberculosis As­ present time how many cases of pulmonary sociation decided not to engage in that phase tuberculosis are occuring from infection with of the tuberculosis problem. the bovine type of bacillus. We believe that "Our complacency in this regard has been we are in a better position as regards bovine considerably ruffled by the reports of pul­ tuberculosis than other countries, due to the monary tuberculosis due to the bovine or­ activities of our Bureau of Animal Industry, ganism. From February, 1931, to July, 1933, but this does not excuse our lack of interest the State Serum Institute of Copenhagen found and activity in regard to the particular ques­ the bovine type of organism in 26 patients tion under discussion. 34 Communicable Diseases Affecting Man

"Very recently the editor has been repeatedly TABLE 5 urged to take the matter up and do all within Progress of Tuberculin Testing, United States, his power to bring about such studies as are 1917-36 being made in England and some of the Scan­ Year ended Number Number Percent dinavian countries. This is due to a situa­ June 30— tested reacted reacted tion in some of our states so serious as to ex­ 1917...... 20,101 645 3.2 cite apprehension. 1918...... 134,143 6,544 4.9 "As an actual fact, we do not know what is 1919...... 329,878 13,528 4.1 1920...... 700,670 28,709 4.1 going on, and this of itself is sufficient rea­ 1921...... - 1,366,358 53,768 3.9 son for undertaking the study.” 1922...... 2,384,236 82,569 3.5 Statements have been made from time 1923...... 3,460,849 113,844 3.3 to time that the decrease in the number 1924...... 5,312,364 171,559 3.2 1925...... 7,000,028 214,491 3.1 of tuberculin reactors in dairy cattle in 1926...... 8,650,780 323,084 3.7 the United States is a factor which ac­ 1927...... 9,700,176 285,361 2.9 counts for the decreased rate in nonpul- 1928...... 11,281,490 262,113 2.3 1929...... 11,683,720 206,764 1.8 monary tuberculosis in humans. While 1930...... ,... 12,845,871 216,932 1.7 this may be true, no one has subjected the 1931...... 13,782,273 203,778 1.5 figures to a careful statistical analysis. If 1932...... 13,443,557 254,785 1.9 such a fine index as the cases of tubercu­ 1933...... 13,073,894 255,096 2.0 1934...... 15,119,763 232,368 1.5 lous adenitis in children under 16 years 1935...... ,,... 25,237,532 376,623 1.5 of age would be correlated to the decrease 1936...... 22,918,038 165,496 .7 in the percentage of bovine tuberculin re­ actors, we may have a significant result. Total...... 178,445,721 3,468,057 1.9 It may be of value to record here the re­ sults of tuberculin testing in the cattle states than in others. The Chief of the herds of the United States since the tuber­ United States Bureau of Animal Industry culosis eradication program was initiated reported: "During the fiscal year 1936, in 1917. This is shown in Table 5. agglutination blood tests for Bang’s dis­ ease were applied to approximately brucellosis ( u n d u l a n t f e v e r ) 6,600,00C| cattle· A considerable num- Brucellosis (undulant fever) continues to hold a prominent place in the minds of the milk producers and consumers on TABLE 6 the American continent. It is an undis­ Brucellosis Cases in the United States, 1936 puted fact that numerous cases of this Alabama ------43 Nebraska------1 disease result from drinking milk from Arizona _____ 35 New Hampshire 50 Arkansas -. ---- 35 New Jersey__ 58 infected cows, but contact with the in­ California — 172 New Mexico — 21 fection which may be present in other Colorado ____ 1 New York __ 214 farm animals, hogs and horses, probably Connecticut __ 99 North Carolina.. 23 affords just as great an avenue of infec­ Delaware____ 2 North Dakota .. 1 16 79 tion especially in midwestern states. It Georgia _____ 20 Oklahoma ...... 96 will be seen in Table 6 that 2044 cases 84 21 of Brucellosis were reported in the United Indiana __ ___ 55 Pennsylvania _ 101 States during 1936. In Table 1 there Iowa______113 Rhode Island .. 12 Kansas ______96 South Carolina.. 9 are only 14 cases reported as having Kentucky ____ 51 South Dakota .. 4 originated definitely from milk. This Louisiana —__ 37 Tennessee ----- 26 emphasizes the fact that numerous cases Maine ______13 Texas ______36 of disease are not traced to their origin, Maryland 41 TTtah 10 Massachusetts .. 55 Vermont ____ 18 thereby leaving the impression that many Michigan ____ 27 Virginia...... 33 are caused by drinking infected, raw milk. Minnesota ...... 76 Washington .... 33 Bang’s disease eradication is continuing Mississippi ..... 9 W. Virginia .... 1 Missouri ...... 9 Wisconsin ...... 107 to make progress in the United States. Montana ...... 4 More progress has been made in some TOTAL .2,044 Journal of Milk T echnology 35 ber of the tests were retests. Of this references number of cattle tested, approximately United Public Health Service. Outbreaks of 445,000 or 7 percent, were declared to be Disease Caused by Milk and Milk Products reactors to the test.” as Reported by Health Authorities as In view of the fact that indemnity is Having Occurred in the United States in paid to cattle owners for reacting cattle, 1936. all communities should avail themselves of this opportunity to establish Bang’s Gwatkin, Ronald. Further Observations on disease free herds for their milk supply, Staphylococcic Infections of the Bovine thereby eliminating that source of Brucel­ Udder. Canadian Public Health Journal, losis. 28, 185, April (1937). POLIOMYELITIS Shaughnessy, H. J. and Grubb, T. C. The The large number of poliomyelitis cases Incrimination of Milk and Milk Products during the past summer has made those in Staphylococcus Poisoning. Canadian interested in milk-control rather uneasy. Public Health Journal 28, 229, May Very little definite knowledge is available (1937). concerning the spread of this disease, but Rosenau cites a few instances where milk Rosenau, M. J. Preventive Medicine and Hy­ supplies have been incriminated.* All giene. D. Appleton-Century Company, cases of poliomyelitis should be thorough­ New York, 1935. ly investigated to determine their contact Editorial. Pulmonary Tuberculosis Due to Bo­ with milk supplies. vine Tubercle Bacilli. American Journal I. A. Merchant, Chairman Public Health, 26, 1128, November Paul B. Brooks (1936). L. C. Bulmer Mohler, J. R. Report of the Chief of the Leslie C. Frank Bureau of Animal Industry. U. S. D. A., F. L. Mickle Washington, D. C, 1936. H oratio N. Parker A. R. B. Richmond *Editor: See also Rosenosv. J. Infect. Dis. SO, 377 W. W. Scofield (1932) ; J. Pediat, 2, 568 (1933).

Methods of Analysis for the Butter milk, skim milk and cream for acidity, Industry .— Laboratory Manual pre­ sediment, and fat content are also covered, pared by the Research Committee, with chapters on keeping quality deter­ American Butter Institute, 1937. 48 pp. mination and the checking of acidity and Price $1.00. salt test solutions. The Institute’s laboratory manual fills The user’s comfort has been consid­ every need of the butter industry, food ered in other directions, also, in the prep­ and dairy inspectors, laboratory workers, aration of the manual. It is well printed, health officials, and consumers for a com­ in a readable type face on restful India pendium of accurate, reasonably simple, tinted paper. Another important feature and relatively inexpensive procedures. is the binding which permits the book to The methods outlined are those used in lie flat on the desk when in use and the laboratory of the American Butter In­ facilitates insertion of replacement sheets stitute. as issued. The ten sections of the manual cover Interested health officials desirous of sampling, microbiological examination, obtaining the manual should communicate chemical analysis, and the determination with the American Butter Institute, 110 of flavor factors in butter. The testing of North Franklin Street, Chicago. 36

Note on the Starch-Iodide Test for the Detection of Free Chlorine in Mflk T. H. Butterworth, Ph. D. Formerly Milk Analyst, San Antonio Department of Health.

Occasionally one finds it expedient to effect on the color in faint reactions. Such test milk for the presence of residual or tests are frequently called negative or free chlorine. This test is indicated doubtful, and in either case are unsatis­ when patrons having an established factory. reputation for high count milk suddenly The following extremely simple modi­ begin delivering milk of one or two thou­ fication of the test has been found to ob­ sand organisms per cubic centimeter, or viate this difficulty and is recommended when low bacteria counts are associated for all samples suspected of containing with filthy sediment tests or similar signs but small amounts of free chlorine. that the bacterial content of a milk has To 50 <:c. of the milk in question there been reduced by other means than care, is added 3 cc. of a 25 percent acetic acid cleanliness, and cooling. solution. The milk is then warmed in a The customary test is the starch-iodide water bath just sufficiently to cause the reaction in which the iodine in potas­ curd to mass up and give a clear whey. sium-iodide is replaced in an acid medium Five cc. of the whey is then pipetted to by any free chlorine which is present, a test tube, and the test is carried out as the liberated iodine then being detected usual by adding li/2 cc. of a 9 percent by a starch indicator solution. The usual potassium-iodide solution, except that procedure is to add the chemicals directly only 2 cc. pf a 50 percent hydrochloric acid to the milk, noting the blue coloration solution is added instead of the custom­ formed from the starch-iodine combina­ ary 4 cc. The tube is heated at 180° F. tion in the serum below the curd after for ten minutes, and cooled. Then 2 cc. heating. In practice, however, the curd of a 2 percent starch solution is added. frequently forms a plug in the tube, hold­ In the case of faintly positive reactions, ing back the indicator solution when the blue of the starch-iodine reaction added; if the tube is then shaken, the shows more distinctly in the clear milk particles of curd cause a decided masking serum than when the curd is present.

Description of Milk Sanitation Ratings In order to inform communities con­ milk handled. Details concerning the cerning the relative quality and safety of methods pf calculating the score, together their milk supplies, the U. S.. Public with illustrations of the procedure, are Health Service has been using a system described in an article on "Sanitation of rating whereby a numerical score indi­ Ratings of Milk Sheds,” by Frank, Fuchs, cates the degree of compliance with local regulatory measures. This score is cal­ and Dashiell, published in Public Health culated on the ratings of the producing Reports, Vol. 53, No. 32, pages 1386- farms, the processing plants, and the 1399, August 12, 1938. Copies can be product itself, and is finally weighted on obtained by writing to the National In­ the basis of the respective amounts of stitute of Health, Washington, D. C. 37

A New Bacteriological Control Unit By Maurice H. Shorago Boston, Massachusetts

The education of the consuming public these needs of the industry. This unit is to the thought that all manufactured prod­ illustrated in Figure 1. The apparatus is ucts in general and food products in par­ made up of a large, dry air, sterilizing ticular must be handled under strict lab­ oven; a self-contained, electrically heated oratory control has presented the dairy autoclave; an electrical incubator of large manufacturing industry with the problem capacity equipped with constant, forced of the necessity of having adequate inex­ circulation of air; two electrical hot pensive control apparatus. One of the plates; and a self-contained transformer. prime factors in the relatively slow re­ All of this equipment is housed in a stain­ sponse to this demand has been the plaint less steel cabinet, with the top portion "our plant has no spare room that can be utilized as a work bench. The equipment devoted to the housing of a laboratory.” is thoroughly insulated throughout. The During the past ten years a great many only installation required is simply insert­ of the smaller New England milk com­ ing the plug into a suitable receptacle. panies felt the urge to install laboratory The unit is designed to handle plates equipment, and have called on the author and cultures, and is admirably adapted to for advice. Through the experience thus the use of the resazurin test for country gained, a compact, efficient bacteriological plants. This equipment is not to be con­ control unit was devised that satisfies fused with the ordinary lightly con­ structed room-consuming laboratory equipment but offers for the first time a complete bacteriological laboratory that can be placed in a space of approximately 6 x 4 feet.

Figure 1. Laboratory Unit 38

Report of Committee on Milk plant Practice

A. R. Tolland, Chairman Health Department, Boston, j^Aass.

In 1856 the Legislature of Massachu­ ner that the pouring lip is protected from setts, in response to an appeal by physi­ contamination by anyone handling it. cians, health officers, and citizens inter­ ested in the furthering of public health SOAKER RASHERS, OR WASHING MILK enacted a law providing for the control BOTTLES of the milk supply of the City of Boston. Considerable work has been done on this subject by Professor Levine of Ames, When pasteurization was first practiced Iowa, for the American Bottlers of Car­ there it was done not so much as a health safeguard as to make possible the sale bonated Bpverages.1 Also, some of the largest manufacturers of soaker washers of partly decomposed milk which other­ in this country are doing extensive re­ wise would not be salable. After a series search work on bottle washers. of milkborne epidemics, costly in their By using higher temperatures, there toll of lives, health authorities as well is a lowering in the percentage of caus­ as dealers began to realize that raw milk ticity as ψείΐ as the time of exposure was not a safe supply, due not only to to the caustic. These investigators have the conditione under which it was pro­ proved th^t different plants need differ­ duced but also to the human element in its handling. ent tempefatures and time, as well as lower caustic strength. One hundred Pasteurization by the holding method seventy degrees F. for 3 minutes’ in a was first set up in Boston in 1907. In 2% percent caustic will give a sterile this year there were 760 deaths of chil­ bottle. It should be necessary to provide dren less than two years old due to diar­ recording thermometers on the various rhea and gastroenteritis. Contrast this tanks, located at the front end of the with our 1935 report of 49 such deaths washer, so that the operator can watch his with our milk supply 99.8 percent temperatures. Some small washers are pasteurized. using 180°i F. for five minutes in a 2y2 It has been axiomatic that following percent caqstic; larger, 60 per minute, are any milkborne epidemic, the faith of the using 180° F. in a 2l/2 percent caustic consumer is inevitably shaken, with a re­ from 3V2 to close to 5 minutes. It ap­ sultant decline in consumption and loss pears that some of these authorities are to both dealer and farmer. not too kepn on brush washers, claiming It therefore follows that pasteurization that if you get ropy milk from the country is the most readily adopted safeguard for into the plant, as sometimes happens, the any milk supply. Every care should be organism may get onto the brush of the taken to have the milk produced from washer and be carried from one bottle to clean healthy stock, under sanitary con­ another. Some attention has been paid ditions, and processed by modern meth­ to covers over conveyors. ods available to all, and delivered in a Heat penetrates much quicker than package which is capped in such a man- caustic; hence the reason for increasing temperatures. Presented at 26th Annual Meeting of the International The dirtiest bottles returned to plants Association of 'Milk Sanitarians, Louisville, Ky., Oct. 11-13, 1937. come from bottle exchanges, and it would Journal of Milk T echnology 39 appear that bottle exchanges should em­ over a tubular cooler instead of the vat, ploy a soaker washer and send these cool slowly to about 55° F., and gradu­ bottles back clean. ally drop to 50°. These same authorities also state, “Do The reasons given by Sommers (Theory not use re-circulated water.” In some sec­ and Practice of Ice Cream Making,Olsen tions of Philadelphia, all water going in­ Publishing Co., 1934) for the causes of to washers must be chlorinated. cream plug and which incidentally cause oiling off, are: PAPER BOTTLES 1. Agitation of the milk at the farm and in The use of paper bottles has not been transit. too successful in this territory because of 2. Severe agitation and heating during pro­ competitive conditions. The housewife cessing. 3. Agitation of cream in separating. is milk-conscious, and looks for the cream 4. Freezing of milk and cream. line. There are many angles to this prob­ lem for the milk dealer. He must operate The extensive use of cream for house­ a milk bottle factory, as these bottles will hold purposes is a development of recent come to his plant in pressed form, and it years. This was made possible by the de­ velopment of suitable means for securing is his problem to put them in shape for a final package. the cream in a fresh condition, and main­ taining this condition by cooling until I have been informed by some dealers consumed. In this day of milk market that factories manufacturing single serv­ instability, it is extremely necessary that ice containers cannot fill their orders. we pay particular attention to the quality As milk control officials, we should in­ of our cream.2 sist that all paper bottles be sterilized im­ First of all, let us consider the various mediately before using; Preparing these factors on which cream is scored. The bottles in a central plant for delivery to housewife is interested in the flavor, vis­ distant plants would be extremely diffi­ cosity, color, whipping ability, appearance cult. It may be possible to make bottles in coffee, serum separation, and freedom in a central plant and sterilize them in a from a plug. The restaurant and hotel plant where they are to be filled. proprietor is interested in its coffee-color­ (Editor: See discussion on this subject in ing ability and keeping quality. The dairy the July issue of this Journal.) chemist is interested in all of the above PROPER PROCEDURE FOR MAINTAINING factors, plus its condition as revealed by THE NORMAL VISCOSITY OF CREAM bacteriological examination, microscopic appearance, and acidity determination. All We find there is a very good set-up for of these factors influence and direct the cream now operating in Connecticut. methods with which we handle bottled They use a small stainless steel spray vat, cream. pasteurize their cream at 145° F. for thirty minutes, and cool with ice water From the outset, the quality of cream right in the vat down to 40° F. The water is naturally dependent on the quality of would be about 38° F. They use an air­ the milk from which it is derived. All tight separator which gives, as they claim, factors contributory to poorly flavored or the best body. Of course the first essen­ poor quality milk will affect the cream tial is good milk. Separate the milk at separated therefrom, with the possible ex­ 85° F. and run into the vat. Keep the ception of lipase milk. The enzyme water temperature at about 100° F. Keep causing this off flavor in milk can be ar­ this temperature differential of 15° all rested by heating to 110° F. momentar­ the way up to 160° F., and then cool ily. slowly. The same applies to heat. Heat SEPARATION. The temperature at which slowly. It is claimed there is no cream cream is separated is dependent on the plug, no feathering, no oiling, and a very use to which it is to be put and the treat­ good body for the cream. If you cool ment it will be accorded subsequently. It 40 Milk Plant Practice has been the experience of others, as well VISCOSITY. Factors contributory to the as. ourselves, that separation at pasteuriz­ oiling off of cream are agitation and ing temperature gives the cleanest differen­ pumping. These are likewise destructive tiation. Separation at this temperature of the body or viscosity of the cream. It does, however, reduce the tenacity with is a well known fact that the body of pas­ which the fat globule is held and oiling teurized and cooled cream is thinner than off ensues. If the cream is homogenized that of the original raw cream. Since vis­ in a later step, prior to bottling, then this cosity is orie of the characteristics on which factor is of little importance. bottled cream is judged by the consumer, various practices have been tried in an at­ PASTEURIZATION. In the pasteuriza­ tempt to regain the viscosity lost through tion process too much heat and agitation processing, These methods are based on will likewise contribute to oiling off. It is cream tempering, addition of total solids, therefore desirable that a slow paddle be prolonged storage at cold temperatures, used for agitation, that the vat will not be and homogenization. The cream temper­ filled too quickly, and that the heating ing process was first described by Dr. time will be restricted to no longer than Dahlberg; and more recently Dr. Ellen- 30 minutes. berger of Vermont has enlarged consider­ ably on the original research. The heat COOLING. If the cream is cooled in the treatment or heat tempering process in­ same vat in which it is heated, then it is volves heating the cold pasteurized cream desirable that the cooling be done as to a temperature of about 80° F., hold­ •quickly as possible and with the least pos­ ing for 10 to 20 minutes, and then slowly sible amount of agitation. If the cream is cooling. The entire procedure of heat­ run over a cooler, care should be exer­ ing, holding, and cooling occupies a cised that freezing on the cooler does not period of about fifty minutes, Through take place, for this fault causes the cream this method, the original raw cream vis­ to oil off six times worse than similar cosity is attained and even surpassed. It cream agitated for 30 minutes at pasteur­ must be considered, however, that every ization temperature. housewife heat-tempers her own cream on In conducting these procedures of sep­ the back porch of her home, particularly aration, pasteurization, and cooling, the in the summer time. Moreover, it has greater the length of sanitary line and the been our own experience that the viscos­ larger the number of pumps necessary for ity of all cream approaches a constant fulfilling these functions, the greater is when brought to a temperature of 52° F. the possibility of causing fat globule sep­ Thus, when one considers the expense of aration. the heating and cooling processes, the Laboratory tests for oiling off of cream temperature of the environment, and that may be conducted by using coffee, hot of the household icebox, the validity of water, or the more quantitative method of this process is questioned. using hot water, a definite amount of Homogenization of cream has demon­ cream, and centrifugal force. With the strated its beneficial effect on viscosity, latter method, a skim milk test bottle is and its ability to maintain at a minimum used and the amount of fat separation ex­ the oiling off of cream. Research con­ pressed in percent. Because of the dif­ ducted at the University of Illinois has ference between water and coffee, and for shown that homogenization at 300 lbs, to direct correlation with results obtained by 400 lbs. pressure will increase the viscos­ the housewife, it is more desirable to use ity, Frozen cream should pass through coffee as a testing media wherever facil­ the homogenizer to prevent oiling off in ities permit. These tests should be con­ coffee. Homogenizing pressures above ducted daily and, preferably, tests should 400 lbs. will cause feathering in coffee. be made at each station of the cream oper­ Storage of cream at cold temperatures ation. for 12 to 15 hours after bottling is con­ Journal of Milk Technology 41

ducive to increasing in viscosity. This a minimum fat separation or oiling off, plug procedure is desirable if there is ample formation, and increasing viscosity. storage facilities. 4. Cream is like raw milk, the less it is Laboratory methods for determination handled the better. of cream viscosity involve the use of vis­ cosity pipettes or viscosimeters. The ne­ MILK PLANT DESIGN AND FLY CONTROL cessity of making line-run viscosity tests The committee is in agreement that we on cream is paramount. should insist on separate rooms for re­ Factors just discussed as being con­ ceiving, pasteurizing, processing, cooling, ducive to oiling off and to loss in viscos­ bottling, and bottle washing. Smaller ity of cream also induce serum separation. plants use one room for pasteurizing, cool­ This separation in cream is aided by the ing, and filling, but they should have a amount of agitation and pumping pres­ separate receiving room. In country re­ sure to which the cream is subjected. It ceiving plants where the milk is taken in from producers, cooled, and shipped to is. therefore apparent that the less the large city plants for processing and cream is handled, the better is the vis­ cosity and the less is the oiling off and bottling, there is no necessity for a sep­ arate receiving room when conveyors carry serum separation. milk in cans direct to the weigh can, and PLUG FORMATION. If homogeniza­ when emptied cans are washed and de­ tion of the cream is practiced for the livered to truckman via another convey­ purpose of increasing the viscosity and or. Many plants wash cans in this room. reducing the fat separation, the possibil­ The milk is carried to the pasteurizing ity of plug formation under the cream cap room by a pipe line through wall. Some is materially reduced. . plants unload milk from trucks onto a conveyor. Cans pass on the conveyor WHIPPING ABILITY. The whipping through a flap door into the receiving ability of cream does hot appear to be a room. Raw milk should not be hauled function of viscosity, but rather that of into pasteurizing room. Every time a door proper conditions surrounding the whip­ is opened, flies enter the room. All win­ ping process. It has been our experience dows must be screened. All doors must however, that the less the cream is be screened, and provided with proper handled, the easier it is to whip. The in­ spring to make them self-closing. Doors troduction and sale of equipment for should open outward. whipping cream which involves the use A one story plant or a one story plant of nitrous oxide or some other gas has with a balcony reduces the labor cost, not met with the success forecast by the which is a factor in the price of the fin­ distributors. The main criticism against ished product. the procedure is the inability of such Conveyors for the raw milk should whipped cream to hold up. not be in the way of conveyors loading SUMMARY. Therefore, tp control the milk to the wagons or trucks for delivery, quality of bottled cream it is essential nor should they interfere with the un­ that: loading of returned milk from wagons or 1. All factors on which cream is scored by trucks. the consumer should be considered when set­ Some plants use fans at opening flap ting up a procedure for handling bottled from filler to chest to keep out flies. The same is true on flap from receiving room cream. to pasteurizing room. 2. All. uses and abuses which the consumer Quite a number of milk plants are exacts of, the cream should be duplicated by using a spray preferably a spray without hie dairy control laboratory daily. odor. A Mason jar of spray is inserted 3. The homogenization of cream at reduced into steam line; the top of the jar carries pressures is recommended for maintaining at an atomizer. When the plant is cleaned 42 Milk Plant Practice up after the day’s run, close all windows This orange drink is flash pasteurized, and doors and open steam or air valve. cooled, ancl bottled with a metal tamper­ Next morning, sweep up the flies. proof cap. We have encouraged dealers Various authorities state that the win­ to patronize this plant. dow space in each room should not be Some cqmmittee members believe that less than ten percent of the floor space we are paying too much attention to this in order to get proper light and ventila­ subject, and if we should just apply com­ tion and to prevent condensation. mon sense sanitation to this problem we Many plants use a suction blower in should not have any trouble. the wash room. It is inserted in the wall of this room for the purpose of carrying INSTALLATION OF MILK PLANT FLOORS off steam out of plant. WITHOUT SHUTDOWNS The ventilation of plants in Canada is In some sections of the country we described by D. K. Douglass: Single use metal grids, particularly where cement story building, ventilate by half top of floor would be worn out by unloading window sash for fresh air, and an out­ and rolling jugs. With metal grids un­ let vent for foul air fitted with a control derneath portions of the floors, the latter valve through roof to cupola; when pipe can be repaired overnight. projects through roof, better drawing Some committee members thought that power is obtained and less draught and plant should be shut down when a floor condensation if pipe is well insulated. is installed, but this would not be neces­ In larger plants, two or three stories, sary when a portion of a floor is to be the outlet duct is fitted with an electrical laid. fan where the pipe leaves the room to go outside, and extends up to outer walls, WET SURFACE PAINTS FOR COLD ROOMS The inlet is the top sash of one or more Red lead andrinks, a large company has in­ use on surfaces that are reeking with stalled a plant in Boston, and now pro­ water, but it will take care of jobs nicely cesses ana bottles this product for many where there is the natural condensation of our small dealers. of a day’s work to be contended with. Journal of Milk T echnology 43

This material is furnished in three to the field. Small plants may haul forms: a Primer, an Undercoat, and a wastes to land in more isolated districts Wet Wall Enamel. It is recommended by using a tank or trailer. that on new work, these materials be Filtration by gravel or crushed stone: used throughout the entire finishing The five day biochemical oxygen demand schedule. On old work, it may only be of the applied waste should not exceed necessary to use the Undercoat and the 1,000 P.P.M., and an average of 700- Finishing Enamel, while on a surface 800 P.P.M. is desirable. where the paint is still in good condi­ Milk wastes have been the serious op­ tion, it is entirely probable that one and erating difficulties at sewage treatment not more than two coats of the Finish­ works. When discharged untreated into ing Enamel would give the results de­ municipal sewer systems, they must be sired. diluted.5 The quantities and pollutional Another paint manufactured in New strengths of wastes produced by the York has gained favor here. It is acid same type as well as different types of and water proof. milk plants vary considerably. Properly designed and operated trick­ WASTE DISPOSAL AT COUNTRY PLANTS ling filters built of crushed rock one to This problem is usually cared for by two inches in size, six to eight feet in town or city sewers, septic tanks. Where depth and having a capacity of 80 cubic location is near a body of water, par­ feet per pound of five day B.O.D. ap­ ticularly rivers, a waste line is carried plied per 24 hours will normally reduce from the plant and well down the river the pollutional strength of the wastes (as so that wastes are properly diluted. Some measured by the five day oxygen demand states require that whey solids be taken test) 80 percent or more. out of milk when wastes are carried to rivers or lakes. REFERENCES Plant wastes can be treated by four (1) A. B. C. B. Educational Bulletin No. 1. methods—mechanical, chemical, biolog­ Revised Edition. ical, and a combination of the three. (2) Controlling the Quality of Retail Cream. Keenan, John A., Amherst Conference, Each plant is a separate problem.? July 1937. Every pound of milk containing about (3) Warrick, L. F. Food Conference Μ. I. T. 12.5 percent solids requires about 3,000 September 1937. gallons of the average stream water for (4) Disposal of Wastes from Milk Plants. dilution to maintain satisfactory stream Eldridge, E. F. Special Bulletin 272— conditions.4 Michigan State College. (5) Milk Waste Treatments in Wisconsin. Much milk solids come from can Ruff, H. and Warrick, L. F. Reprint from washers. This condition can be helped Sewage Works Journal, Vol. 4, No. 3, by collecting the drip. The equipment May 19, 1934. should be rinsed with water and effort A. R. Tolland, Chairman should be made to recover the solids. D . K. D ouglas Irrigation: Spreading wastes on sev­ H. C. Ericksen eral acres of land that are kept under H. A. H arding cultivation. Sandy soil is best adapted Ralph E. Irwin for this practice. Should odors become J. R. Jennings offensive, chloride of lime, sodium hypo­ C. B. Matthews chlorite, or liquid chlorine may be ap­ W. B. Palmer plied to the waste before it is pumped J. E. Thomson. 44

The Quality Improvement of Creamery Butter Μ. E. Parker. Chairman Research Committee, American Butter Institute, Chicago, III.

SEDIMENT TEST vey was conducted in a number of selected The development a few years ago in laboratories of commercial organizations the laboratories of the United States Food and agricultural colleges wherein seasonal & Drug Administration of a practical and sectiopal influences were studied. method for determining the sediment in After one year’s extensive study, involv­ butter provided the basis for realizing and ing over seven hundred samples of cream unifying a national desire to improve the and more than two thousand samples of quality of the cream supplies used in the butter, it was ascertained that methods per­ manufacture of creamery butter. The re­ mitting the use of standard equipment sults of a sediment test are definite, used in the sediment testing of milk can readily understood, and subject to no be applied to cream and butter. Further­ equivocation. Therefore, when the sedi­ more, it vyas established that the milk ment test for butter was applied, the urg­ sediment standards can be applied equally ent need for immediate attention to the as satisfactorily to cream and butter. The quality of the cream supplies used in its complete report of this investigation was manufacture was generally recognized. published in the August 1937 issue of The industry was prompt to organize a the Journal of Dairy Science. The Amer­ nation-wide campaign, having as its ob­ ican Butter Institute has adopted the Con­ jective the quality improvement of its raw necticut Official Milk Sediment Stand­ cream supplies. ards of 1931 for interpreting the results The government test for the determina­ of sediment tests applied to cream and tion of sediment in butter played a most butter analyzed by its laboratory, and it important role in providing the corner­ is probable that the American Dairy stone upon which the structure of the na­ Science Association will recommend sim­ tional quality improvement endeavor rests. ilar methods for the sediment testing of The moment that the industry started to cream and butter. apply the sediment test to cream and but­ ter, it embarked on a permanent effort. DEVELOPMENT OF THE INDUSTRY The market milk industry has used the In considering the problein of quality sediment test for at least twenty years, improvement, factors other than sediment and while other methods of analysis have are obviously involved. Before we con­ since been developed which are more sider them in detail, it might be well to specific and comprehensive, the sediment discuss briefly something of the complex­ test is still being applied to their raw milk ities and thg extent of the creamery butter supplies. We have been told by leaders industry itself. in that industry that when the vigilance In thq early nineties of the 19th of sediment testing is relaxed, the sedi­ century the development of the centrifu­ ment condition of their raw milk supplies gal separator, first successfully manufac­ declines even in these days of scientific tured by Dr. DeLaval in 1886, provided enlightenment. the basis qf the factory system in this The Research Committee of the Amer­ country as his machine had reached the ican Butter Institute conducted a national stage where it would be used on the farm. survey of methods for determining the The introduction of these hand separators sediment1 in cream and butter. This sur- on the farm was slow at first, but it Journal of Milk T echnology 45 gained considerable impetus in the course It is generally known that the milk of a decade, particularly in the Middle dealer has his regular patrons whose milk Western states. The creamery butter in­ is produced under sanitary conditions, dustry was thus born with the advent of supervised either by local or state depart­ the farm separator, and the art was gradu­ ments of health or both. Most' consumers, ally revolutionized. The large centralized however, do not realize that the quality creameries secured their cream almost en­ problems of market milk supplies have tirely from milk separated on the farms been solved for that industry largely whereas the small local creameries had through the cooperative efforts of official been receiving whole milk and separating health departments in educating and re­ the cream themselves. quiring the producing farmer to observe These large centralizers, as they were practical sanitary precautions. It is obvi called, gathered their supplies by a var­ ously possible to achieve the desired re­ iety of procurement systems. Today, of sults more rapidly in a localized area the more than 4,000,000 farms in the where supervision is relatively simple. In­ United States, it is conservatively esti­ cidentally, the cost for such improvement mated that at least 2,000,000 are produc­ has been contributed in local taxes largely ing cream for buttermaking. Butter is by the consumer. The creamery butter being churned in approximately 4,500 industry does not enjoy these advantages creameries, most of which are located in of such inexpensive means or ready con­ the Middle West, where the distance of trol of quality improvement or mainte­ the producing farmer from his market nance. The major burden of such expense varies from a few to many miles (e.g., 4 must be borne by the industry itself. In miles in Minnesota to 40-50 miles in that connection, a price differential for Texas). Some creameries obtain their quality has proven of benefit in improv­ cream from a few while others draw ing raw cream supplies. The only effec­ from thousands of farms. · As the indus­ tive means the creamery has of controlling try has grown, competition has become quality is by appealing to the producer’s increasingly intense because volume is es­ pocketbook. It should be stated, how­ sential to economic operation. These are ever, that the U. S. Food & Drug Admin­ all important facts to keep in mind in istration as well as state regulatory agen­ order to obtain a comprehensive picture cies have given the industry valuable as­ of the creamery butter industry of the sistance in quality improvement. United States. The problem of quality control is a huge undertaking inasmuch as the bulk of CONTROL PROBLEM OF MILK VERSUS the cream used for buttermaking is pro­ CREAM duced in the more truly agricultural sec­ In recent years considerable attention tions, where the rural population is less has been directed toward the quality of concentrated and the farms are not only the cream used in the manufacture of more widely separated, but do not special­ creamery butter. In the urban centers of ize in dairying. It is doubtful under such our country, where the great bulk of circumstances that supervision, either by creamery butter is consumed, the tendency the industry or regulatory agencies, can has been to compare the production and ever be as intensive or effective as in the handling of raw milk for market milk sup­ case of market milk supplies. The eco­ plies with that of cream produced for but­ nomic burden alone will preclude any ter-making. By so doing, not only have the elaborate inspection service. historical and economical precepts upon which the butter industry is founded been MANUFACTURING FACTORS disregarded but the fallacy of attempting We have referred to "the art of but­ to compare a local type of business with termaking.” This is an ancient art which one operated on a substantially national has been revolutionized by the factory scale has been overlooked. system. The artisan’s skill is still of para­ 46 Q uality Improvement of Creamery Butter mount importance, and in that respect, price and the appeal of its appearance. buttermaking differs significantly from the In merchandising its product, the butter handling and processing of market milk industry is confronted with consumer which is largely subject to technological physiological and psychological prefer­ control. Today, the common experience ences which, it can ill afford to ignore in is that nothing will reveal the differences passing judgment upon the results of its of opinion among buttermakers more own labor. r readily than a discussion of the produc­ Butter produced in Kansas will have tion practices involved in preparing cream different characteristics from that churned for churning. These differences are not in Minnesota, although both will be based entirely upon the whims or caprices equally nutritious and wholesome. Sim­ of individual buttermakers, for seasonal ilarly, consumer preferences in New York and sectional influences make it necessary will differ from consumer preferences in in processing different cream supplies to New Orleans. This explains why butter vary and adjust the degree and type of scoring 90 points (or standard quality) production practices. The skill of the in one market may be accorded 92 points artisan is still a vital factor. (or extra quality) in another. It is for The areas in which climatic conditions these reasons that commercial judges in­ and density of dairy development contrib­ stinctively cpnsider the source of produc­ ute most to relative ease in the produc­ tion and the market when they grade but­ tion of the highest grades of butter are ter. They also attempt to predict keep­ comparatively small. Their output com­ ing quality in order to retain consumer prises not the largest proportion but prob­ acceptance. ably twenty-five percent of all creamery butter made in the United States. The ECONOMIC FACTORS remaining seventy-five, or possibly, eighty Economic precepts and trade customs percent is produced in areas with widely., are recognised as not being your major divergent climatic conditions and degrees concern. They are herewith presented to of dairy development. reveal the fprces with which the industry has to cope. These forces cannot be dis­ m a r k e t in g f a c t o r s regarded without bringing disaster to the Not only in the manufacture of butter industry and . to the agricultural interests is it evident that empirical methods play upon which it is based. This is no plea an important part, but in its marketing for laxity in sanitation but rather a cau­ also, they assume a paramount role. This tion that we cannot contribute to a profit­ is the common trade practice of scoring or able and stable agricultural development grading butter. Butter has been graded if we deprive the farmer of an opportun­ for years by the skilled taste senses of ity to market his cream, providing it is commercial and official judges on the ar­ clean and wholesome. In that connec­ bitrary and numerical basis of 45 points tion, the prpcurement of raw supplies in for flavor, 25 for body, 15 for salt, 10 the creamery butter industry involves sys­ for color and 5 for appearance of pack­ tems where the distance from market age. This method has now been super­ bears a direct relation to quality. In­ seded by a new official rating procedure, cidentally, this reference to "the distance described in the May issue of this Journal. from market” is used broadly and in­ Such procedure of rating merits and de­ volves not only the actual physical meas­ fects might be criticized because it does urement in miles but includes also the not take the judgment of butter quality influence of age. out of the field of human error. On the The solution of cream quality lies in other hand, in judging the quality of any the direction of cleanliness, proper cool­ food product, the consumer is guided by ing, and frequent delivery. Cleanliness the character Of its taste and aroma as applies both to milk and also to cream. well as by the attractiveness of its sales Proper cooling in a milk shed might mean Journal of M ilk T echnology 47 mechanical refrigerating equipment, but and butter by determining its amino nitro in a cream producing area it cannot mean gen content. Until we develop more ex­ much more than cooling with well water act means, we shall have to continue to plus inexpensive protection enroute to use the senses of taste and smell. market. Proper delivery in a milk shed During the past two years, the Research means daily pick-up, whereas in a cream Committee of the American Butter Insti­ producing area it means less frequent de­ tute has studied various methods of livery. Therefore, when these relative analyzing butter and related products. terms are analyzed, they are seen to have After thorough investigation, it was de­ quite a different meaning. Cream pre­ cided to prepare a manual of laboratory pared on the farm is bound to reach a methods to be available to all interested creamery with a varying development of parties. This manual contains the acidity, dependant upon seasonal and sec­ methods used by the laboratory of the tional influences as well as its "distance American Butter Institute. (Editor: This from market.” manual can be purchased from the Amer­ ican Butter Institute, Chicago, 111. Price n e e d f o r n e w t e s t $1.00.) What the industry needs now is some test as relatively simple as the acidity test CHARACTER OF CONTROL PROBLEM or the Babcock test that will detect cream The quality improvement of creamery of inferior quality. Many investigators butter is a permanent responsibility which have attempted to correlate- amino nitro­ the industry and health officials both must gen content with the quality of cream and recognize and share. The ultimate goal its resulting butter, but without significant of clean, cool cream delivered frequently success. Possibly one of the reasons for has not yet been fully realized, although failure is found in the results of recent appreciable progress has been made dur­ studies of the ammonia production in ing recent years. Changing the habits of milk conducted by Perkins of the Ohio at least 2,000,000 farmers is quite a task. State University. While the amount Possibly some may feel that while prog­ of ammonia in fresh milk is usually quite ress has been gradual, it has still been small, bacterial growth probably accounts far too slow. Yet any health official largely for its development. What is who has been engaged in the quality im­ more important, the bacterial species cap­ provement of market milk supplies for able of producing the greater amounts of the past twenty years will recognize that ammonia is Streptococcus lactis. This or­ history is repeating itself. The creamery ganism is always present in overwhelming butter industry is now at the stage of de­ numbers in sour cream, and generally is velopment that the market milk industry considered to be a retarding influence to held in the early days of its quality im­ contaminants which might possess pro­ provement. Furthermore, there is the con­ teolytic properties. In fact, contrary to the trast between a purely local type of busi­ generally accepted idea, the liquefying ness and one that is national in scope type of bacteria do not begin to produce and operation. This will require differ­ ammonia as effectively as Streptococcus ences in the methods for the effective and lactis. Consequently we cannot expect lasting quality improvement of creamery much aid in detecting quality in cream butter. 48

Fiber That Looks Like W ool Can Be M ade From Skim Milk

A synthetic fiber having the appear­ however, the synthetic fiber does not ance of wool can be manufactured from shrink as much as wool. By varying the casein, a milk byproduct, by a process acid bath in manufacture, the fiber may devised by Stephen P. Gould and Earl be made eifher soft or harsh to the touch. O. Whittier of the Bureau of Dairy In­ The softer grades, while not as strong, dustry, U. S. Department of Agriculture. make up into knitted garments which The process is similar to that used in may be worn next to a sensitive skin making viscose rayon from cellulose, and which cannot tolerate knitted wool. public service patents, applied for by the Both the fineness and the length of the Bureau, are pending. synthetic fiber may be regulated in the In Italy, where a somewhat different manufacturing process, the bureau scien­ process for making casein fiber was an­ tists point out, giving it an advantage nounced three years ago, production is over wool in this respect. already on a commercial scale. Most of Because pasein fiber has been produced the fabrics, however, are half synthetic in this country only on an experimental fiberΦ and half wool. basis, commercial costs have not been To make the fiber, casein is softened definitely determined. Gould and Whit­ in water and dissolved in a solution of tier believe^ however, that it can be manu­ caustic alkali. It becomes a thick, sticky factured to be sold at a price on par mass and is carefully worked into the with that of rayon, which is about 50 proper consistency by aging, addition of cents a pound. Although casein usually modifying agents, and dilution. The sells for 10 to 15 cents a pound, com­ mass is then forced through multiple pared with| about 5 cents a pound for spinnerets of the kind used in making cellulose, agents used in treating casein rayon. The fibers are separated and fibers are cheaper than those used in hardened in an acid bath containing for­ making rayon. In addition, the chemical maldehyde and modifiers. used in the casein process may be used Synthetic fiber ■ produced in this man­ over and over again, while that used for ner has a chemical composition almost rayon manufacture cannot. The processes identical with wool except for a lower of manufacture are so similar that rayon sulphur content. The fiber is faintly plants can easily manufacture synthetic yellow in color and closely resembles wool merely by using casein instead of best grade thoroughly washed and carded cellulose and changing the modifying Merino wool, the finest size marketed. agents. The casein fiber has the characteristic Casein is made from skim milk and fine kink of natural wool and may be the United States already produces about blended with it to make a product that 35 million pounds annually. It is used has the resilience of pure wool. Syn­ thetic fibers with this kinky structure have principally as a paper coating and in the been .made from plant materials recently, manufacture of plastics, such as billiard but since they do not take wool dyes, balls. Because of the almost unlimited they are not as desirable as fibers from supply of skim milk available in this animal products for blending with wool. country it is possible to produce as much Because the fibers are smooth, rather as one billion pounds of casein annually. than scaly like natural wool fibers, they This is approximately equivalent to one cannot be felted. For the same reason, billion pounds of casein fiber. 49

A Special Invitation To Milk Sanitarians To Attend the Dairy Industries Exposition

Roberts Everett,

Executive Vice-President, Dairy & Ice Cream Machinery & Supplies Association, New York, N. Y.

No registrant is more welcome at the ler and more rapid development of the Dairy Industries Exposition than the dairy industries, and a more economical health officer interested in milk, or the provision of milk and its products to the commercial milk sanitarian. consumer result from an honest effort by In some form as old as human enter­ those .who hold these different viewpoints prise, the dairy industries have always to explain them thoroughly, each to the been inevitably subject to sanitation’s other, and by rational procedures to reach natural laws. a common ground. Today dairy products manufacturers, At the Dairy Industries Exposition, and the manufacturers and distributors of owners and executives of milk and milk machinery and equipment and supplies products companies ·— designers and for the dairy products industries, know manufacturers and distributors of machin­ that these natural laws of sanitation have ery, equipment, supplies, materials, and become known more and more scientific­ services—regulatory sanitarians, and com­ ally. h{ilk research has revealed and still mercial sanitarians—all can meet in a reveals them. Milk sanitarians convey common interest The Dairy Industries the knowledge of them to the industries Exposition this year, in Cleveland, Octo­ and to the public. ber 17th to 22nd, is concurrent with the Men in the milk industries are as eager twenty-seventh annual convention of the to have their operations unimpeachable International Association of Milk Sani­ in terms of sanitation as are the most tarians; and it will afford all milk sani­ conscientious health authorities. General tarians who attend the most comprehen­ executives and operating executives are sive examination of milk industrial prompt to take advantage of the infor­ "tools” that will ever have been brought mation which the commercial milk sani­ together. tarians possess. The Dairy Industries Exposition and Often there are different viewpoints. the Dairy and Ice Cream Machinery and There are those which the operating ex­ Supplies Association, which makes the Ex­ ecutives in the milk industries refer to as position possible, especially and cordially "purely regulatory’’ or "too technical.” There are also , those which the regulatory invite to the Show this year all members sanitarians often refer to as "purely prac­ of the International Association of Milk tical” or "too commercial.” Often, ad­ Sanitarians and all other milk sanitarians vanced public health objectives, the simp­ regardless of their affiliations. 50

Cleveland—Our Convention City H. O. Way, Chairman

When we gather for the 1938 session Case School neighbors with Western Re­ of the International Association of Milk serve University with its many schools Sanitarians in Cleveland, Ohio, October and University Hospital group, Medical 19 to 21, it will be in one of the most Library, Institute of Pathology, and Sever­ beautiful settings in America. October ance Hall, the home of the Cleveland on the south shore of Lake Erie presents Symphony Orchestra. Co-operating closely a picture of serenity and grandeur. Lake with these institutions are the Western Re­ breezes temper the climate from the ex­ serve Historical Society, the Art Museum, tremes of summer and winter. the Museum of Natural History, and the From a little frontier trading post in great Cleveland Public Library. the Western Reserve, laid out by General Euclid Avenue, once the famous "most Moses Cleaveland in 1796, it has grown beautiful street in the world’’, has given to be not only the metropolis of the great way to business; but in its stead have state of Ohio, but the home of more than come thousands of beautiful homes in a million people, the capital of a great the suburbs which properly replace the trade empire within 150 miles of which mansions on "the Avenue.” In this, live 10,245,000 people. Half the popula­ Cleveland Heights, Shaker Heights, Lake- tion of the United States and Canada live wood, and Rocky River are noteworthy. within an over-night ride from Cleveland. Early in its history, Cleveland won the nickname "Forest City.” It has aimed Here Pennsylvania coal, Ohio lime­ to maintain this throughout a substantial stone, and Lake Superior iron ore meet in the great iron and steel industry which together with paint manufacture, oil, men’s clothing, women’s apparel, knit goods, electrical machinery and appli­ ances, brick, rayon, chemicals, and a great variety of miscellaneous items make up an annual industrial output approaching well toward a billion dollars in value. These products are shipped to all parts of the world; blast furnace equipment to China and Russia, wire screen to South Africa and South America, trucks to Australia and China, paint to Italy, locomotives to India, and telescopes to some of the most famed astronomical observatories in the world. Cleveland’s educational facilities are of the best. In addition to over 300 pub­ lic, parochial, preparatory, and high schools, it is the seat of Western Reserve and John Carrol Universities, Case School of Applied Science, and Fenn College, with Baldwin Wallace College located 15 miles southwest at Berea. At the Uni­ versity center, on eastern Euclid Avenue, Art Museum Journa l of M ilk T echnology 51

industrial growth. Its many beautiful and 150 stops. The echo organ is lo­ parks are a testimony to its success, promi­ cated 300 feet from the console. nent among which is the great Metropol­ Cleveland’s transportation facilities, by itan Park system forming a U about the highway, rail, air, and water are among city and its suburbs. The Public Square, the best. U. S. Route 20, the main in the heart of the city, purchased by the thoroughfare between Boston, Chicago Connecticut Land Co. in 1795 for $1.76 and the West passes through Cleveland. is now reputed to have a cash value of The Lakes-to-Sea Highway U. S. Route $20,000,000. From this square, serving 322, also U. S. Route 422, enter from as a hub, streets and street car lines radi­ the east and southeast, U. S. Route 21 ate like spokes of a wheel to all parts of extends south to Florida, while State the city. In the southwestern corner of Route 3 and Route 42 lead from the the Public Square is the Terminal Tower southwest. With the exception of the and its affiliated buildings. On top of Erie and Pennsylvania, which have their this building, 52 stories in height (750 own depots, all passenger trains enter the feet), an observation porch enables one Union Terminal at the southwest corner to see for many miles about the city and of the Public Square. The Cleveland Air lake. Port, embracing 1040 acres on Rocky During the week of our convention, River Drive in the western section of the the Dairy show will be held in the Public city is said to be one of the largest and Auditorium. This was built at a cost of finest in the world. $15,000,000, to accommodate 16 events Lake Erie affords excellent facilities for at the same time, without interference. travel and transportation. Two thirds of The main auditorium, seating 12,500 all the American vessels on the Great people, can be joined with the music Lakes are owned or operated by Cleve hall to hold 16,000 persons. The pipe land interests. Cleveland has over 14 organ costing $100,000, has 10,010 pipes miles of lake frontage. Its harbor is pro-

Terminal Tower Group 52 Our Convention City tected by a breakwater nearly 6 miles in length. The passenger boat landing oc­ cupies a portion of the lake front develop­ ment which it shares with the new Stadi­ um, an out-of-door arena where many events, from ball games to grand opera, are held in suitable weather; and the park area on which the Great Lakes Exposition was held in 1936 and 1937. This will also be the site of the World Poultry Con­ gress in 1939. A new Lake Front Drive has been opened recently. This extends eastward and forms a convenient entrance to the city from U. S. Routes 6 and 20. The week of October 17 to 22, in Cleveland, will be a period of unusual opportunity for those interested in the milk industry. The Dairy Industries Ex­ position will be held throughout the week ter acquaintance of members and es­ in the Public Auditorium. The Interna­ pecially for entertainment of the ladies tional Association of Milk Dealers, The are in progress. Remember all roads International Association of Ice Cream lead to Cleveland. Come to Cleveland Manufacturers and the Independent Ice October 19 to 21. Cream Manufacturers all meet during the H. O. W ay, week. In addition to this, plans for bet­ Chairman, Local Committee.

Allerton Hotel Rates Rates:— Type Single Double Running water ...... $1.75 $2.75 Running water and lavatory...... 2.00 3-25 Private bath (double beds)...... 2.50 4.00 Private bath (twin beds)...... 3.00 4.50 Suite—living, bedroom, and bath...... 7.00 4 persons in a 2 room suite with bath, $2.00 each person. 4 persons in a 2 room suite without bath, $1.35 each person. Send your reservations immediately to the Hotel Allerton, Cleveland, Ohio.

Severance Hall Journal of Milk T echnology 53

Tentative Program of the 1938 Convention

INTERNATIONAL ASSOCIATION OF MILK SANITARIANS

October 19-21, 1938

October 19 Short Time Pasteurization.

WEDNESDAY MORNING (a) Milk Company’s View W. D. Dotterrer, Resazurin Tests. Bowman Dairy Co., M. A. Collins, Chicago, III. United Farmers Cooperative Creamery Boston, Mass. (b) Sanitarian’s View. Paul F. Krueger, Phosphatase Test for By-Products. City Health Department, Harry Scharer, Chicago, III. Bureau of Laboratories, New York City Health Department State Sanitary Control—Maximum and Minimum Requirements. Tests and1 Testing. Charles McDonald, H . C. Goslee, Health Department, Akron, Ohio. Dairy and Food Commission, Hartford, Conn. Homogenized Milk. WEDNESDAY EVENING C. J. Babcock, New Zealand-Dairying (with colored U. S. Department of Agriculture, movies). Washington, D. C. G. J. Hucker, New York State Agricultural Experi­ ment Station, WEDNESDAY AFTERNOON Geneva, N. Y. Joint session w ith laboratory and Report of the Committee on Communica­ plant directors of the International ble Diseases Affecting Man. Association of Milk Dealers. I. A. Merchant, Chairman An Evaluation of the Various Procedures Iowa State College, for Making Phosphatase Tests. Ames, Iowa. L. H. Burgwald, Milkborne Outbreaks. Ohio Agricultural Experiment Station, Paul B. Brooks, Wooster, Ohio. State Department of Health, Practical Applications of the Phosphatase Albany, N. Y. Test. D. M. Roger, Trends of Milk Control in Texas. The Borden Company, T. H. Butterworth, New York City. Lubbock, Texas. 54 Convention Program

October 20 Testing of Bottle Washing Solutions.

THURSDAY MORNING C. M. Moore, Measuring the Bacteriological Quality of The Diversey Corporation, Milk. Chicago, III. C. K. Johns, Department of Agriculture, Mastitis. Ottawa, Canada. Speaker not selected. Nutritional Properties of Milk. C. P. Segard, Effectiveness of Milk Control. Wisconsin Alumni Research Founda­ tion, New York City. R. W. Tyler, Ohio State University, BUSINESS SESSION. Columbus, Ohio.

THURSDAY AFTERNOON Seeing the Dairy Show. ADJOURNMENT THURSDAY EVENING Report of the Committees on Dairy and Milk Plant Equipment and Sanitary Procedure. ponventjon Notes W. D. Tiedeman, Chairman Hotel accommodations should be made State Department of Health, immediately. During the period of the Albany, N. Y. dairy show, hotel rooms are at a premium. Milk Bottle Design with reference to The Hotel Allerton, headquarters of this "Pouring Lip”. association, has postponed reserving all Lloyd Arnold, their rooms! until now in order to give University of Illinois, our members an opportunity to stay Urbana, III. there. Paper Milk Containers. Our program allows half a day for, F. W. Tanner, visiting the, Dairy Industries Exposition. This is really not sufficient time to see an University of Illinois, Urbana, III. exhibit of this magnitude. It is suggested that members go a day early so as to see the dairy show without taking time from October 21 our meetings. FRIDAY MORNING If there is any information wanted Report of Committee on Methods of Im­ concerning hotel reservations, entertain­ proving Milk Supplies in Small ment, or any other questions of local Communities. concern, the members may communicate Leslie C. Frank, Chairman with Mr. H- O. Way, 308 Western Re­ U. S. Public Health Service, serve Building, Chairman of the Local Washington, D. C. Committee on Arrangements. Journal of Milk T echnology

New Food Standards Com­ mittee The new Food, Drug, and Cosmetic Act of June 25, 1938, authorizes the ap­ pointment of a food standards committee to formulate definitions and standards both of identity and of quality, including ( T W t i fill of container, after consideration of all the data—analytical and inspectional— deemed essential to support them. This committee will meet in the Food and Drug Administration in Washington at Advertising intervals to review the data which have been assembled, draft tentative standards, in this Journal hold public hearings, and then make their recommendations to the Secretary of Agri­ presents culture. Under the new act, these defi­ nitions and standards when promulgated by the Secretary, will have the full force Y O U R STO RY and effect of law. The food standards committee, which to the has heretofore functioned in formulating standards for only administrative guid­ ance, will be perpetuated. Its tri-partite LEADING MILK form will be maintained. The members are as follows: SANITARIANS For the Association of Official Agricul- . tural Chemists: C. D. Howard, Di­ in both Official rector and Chief, Division of Chem- - istry and Sanitation, State Board of and Health, Concord, N. H .; Guy G. Frary, State Chemist, Vermilion, South Dakota. Industrial For the Association of Dairy, Food, and Drug Officials of the.United States: organizations J. J. Taylor, State Chemist, Depart­ ment of Agriculture, Tallahassee, Florida; Mrs. F. C. Dugan*, Director Bureau of Foods, Drugs, and Hotels, State Board of Health, Louisville, Ken­ tucky. For the Food and Drug Administration: W. B. White, Chief, Food Division; W. S. Frisbie, Chief, Division of State Cooperation.

■ * Member of the International Association of Milk Sanitarians. 5 6

JOURNAL OF MILK TECHNOLOGY

Official Publication of the

International Association of Milk Sanitarians

(Association Organized 1^11)

Editors

W. B. P a l m e r , Managing Editor J. H. Sh r a d e r , Editor Orange, N. J. East Orange, N. J. .

Associate Editors

C. A. A b e l e E r n e s t K e l l y Montgomery, Ala. Washington, D . C.

Sa r a h V a n c e D u g a n P. F. K r u e g e r Louisville, Ky. Chicago, 111.

J. G. H a r d e n b e r g h Η . N. P a r k e r ' Plainsboro, N. J. Jacksonville, Fla.

M. A. H e i n z m a n Μ. E. P a r k e r Ventura, Cal. Chicago, 111.

J . A. K e e n a n G . W . P u t n a m Boston, Mass. Chicago, 111.

C . K. J o h n s H . R . T h o r n t o n Ottawa, Canada. Edmonton, Alberta, Canada

The JOURNAL OF MILK TECHNOLOGY is issued bimonthly beginning with the Janu­ ary number. Each volume comprises six numbers. It is published by the International Association of Milk Sanitarians, and is printed by The Chronicle Press, Inc., Orange, N. J., U. S. A. Subscriptions: The subscription rate is $5.00 per volume. Advertising: All correspondence concerning advertising, reprints, subscriptions, and all other business matters should be addressed to the Managing Editor, W. B. Palmer, 29 North Day Street, Orange, N. J. Manuscripts: All correspondence regarding manuscript^, editorials, news items, announce­ ments, and other reading material should be addressed to the Editor,· J, H. Shrader, 339 Spring- dale Avenue, East Orange, N. J. Membership and Dues: Active and Associate Memberships in the Association are $5.00 per year. This includes all issues of the Journal. All correspondence concerning membership in the INTERNATIONAL ASSOCIATION OF MILK SANITARIANS, including applications for membership, remittances for dues, failure to receive copies of the JOURNAL OF MILK TECH­ NOLOGY, and other such matters should be addressed to the Secretary of the Association, C. Sidney Leefe, State Department of Health, Albany, N. Y. Advertisements VII Why Take Chances? . . . on cleaning when the protection of Wyan­ dotte Quality costs so little? Wyandotte Cleaner and Cleanser is fast, non-caus­ tic, safe. Gives surfaces properly cleaned for effect tive sterilization. Sterilizing after Cleaning Wyandotte Steri-Chlor kills bacteria without harm to metals, rubber, brushes or fabrics. Powder makes clear solution in hard water or soft, ready instantly for use. Safe— sure. 5 and 10 lb. Cans—25-50-350 lb. Drums

Wyandotte, There is a Wyandotte Michigan Dealer— and a Service The J. B. Ford Co. Representative in your vicinity. Always at ^peciaLhed ^LeaneH your Service. & -QUaiilei

Milk Sanitarians Industrial Quality Control Officers Medical Milk Commissions Milk Plant Operators Milk Control Officials Dairy Technologists Laboratorians Veterinarians KEEP ABREAST of the new developments in milk technology through the Journal of M ilk Technology

Join the International Association of Milk Sanitarians See page 56 for particulars

When writing to advertisers, say you saw it in this Journal. VIII Advertisements

Index to Advertisers

PAGE NO.

Aluminum Seal Company ...... IV

Borden ...... —...... IV

Cherry-Burrell Corporation ...... —. VI

Creamery Package Company...... V

Difco Laboratories...... Back Cover

Diversey Corporation ...... VIII

The constant throbbing of live steam in a Ford Co., The J. B...... :..... VII vat of water eventually opens up seams, loosens fittings and causes costly repairs. Doubly expensive . . . uncertain in results Standard Cap and Seal Corp...... II . . . heat sterilization is today being replaced in most dairy plants by dependable, eco­ Sealtest, Inc...... IX nomical Diversol. Diversol kills bacteria quickly, quietly . . . without injury to equipment . . . and at a Vitex ...... Ill fraction of the fuel cost for steam or hot water. Unlike ordinary sterilizers Diversol never corrodes or damages equipment. £asy to use. Keeps its strength. Order a trial drum of Diversol, today . . . it’s the safe way to save on sterilizing costs. THE DIVERSEY CORPORATION 53 W . Jackson Blvd., Chicago, 111.

KILLS BACTERIA IN COLD WATER

When writing to advertisers, say you saw it in this Journal. Advertisements IX

THE SEALTEST SYMBOL

The Sealtest Symbol has grown to mean much to many families throughout the nation. Careful house­ wives, today, are demanding a high degree of scien­ tific supervision over the dairy and ice cream products they buy— and are insisting that their children take the same care in their daily purchases at school or from the stores. Through a high type of advertising cam­ paign in publications and on the radio, Mrs. America has gained a new knowledge of what Sealtest means. Her use of Sealtest-approved products has verified this knowledge. That is why the Sealtest Symbol, today, signifies to her a scientific assurance of quality and wholesomeness, in the dairy and ice cream products she uses.

The Sealtest System of Laboratory Protection was formed by a group of leading affiliated dairy and ice cream companies— both the System and the companies being under one com­ mon ownership.

SEALTEST, INC., 120 Broadway, New York

When writing to advertisers, say you saw it in this Journal. CENTER FOR RESEARCH LIBRARIES

BACTO-MALT AGAR

FOR DETECTION AND ENUMERATION OF MOLDS

Bacto-Malt Agar is recommended for determining the mold and yeast count of butter and other dairy products. It is also widely used for detecting sources of contamina­ tion by these organisms and for controlling the sanitary conditions of manufacture at different stages of manu­ facture. The dehydrated medium is readily prepared for use by suspending the powder in water, boiling for a few minutes to dissolve the agar and then sterilizing the solu­ tion. No filtration of the medium is required. After the usual autoclave sterilization the medium will have a re­ action of pH 5.5. A more acid reaction, capable of sup­ pressing bacterial growth, may be obtained by adding Lactic Acid as specified on the label of each bottle. Results obtained upon plates of medium prepared from Bacto-Malt Agar are reliable, accurate and comparable because the medium is always uniform in its composition. It is exceptionally stable in its dehydrated form and may be used over a long period of time or in various laborator­ ies w ith excellent satisfaction.

Specify “DIFCO” THE TRADE NAME OF THE PIONEERS In the Research and Development of Bacto«Peptone and Dehydrated Culture Media

D IFCO LABORATORIES INCORPORATED DETROIT, MICHIGAN

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