ICE CREAM.

By HARVEY W. WILEY, M. D., Ph. D.

Chief of Bureau of Chemistry, Department of Agriculture.

The use of artificially frozen dishes as an article of diet is not of very ancient origin. It is not the purpose of this paper to discuss the physiological and dietetic effects of introducing ice-cold foods into the stomach. There are grave objections to the practice which will occur to every physiologist and hygienist. Briefly I may state that the process of digestion in the stomach depends upon the free excretion of the peptic ferments by the glands of the inner coats of the stomach. The introduction of large quantities of ice-cold material can not fail to contract the orifices of these glands and check their excretory activity.

Aside from this, however, the question of ice cream is one of grave importance in connection with the dairy supplies of the country, and particularly so because under the name of ice cream are found upon the markets products of the widest variation in composition, varying from the true ice cream to the true frozen pudding.

It is necessary, therefore, in the discussion of the matter, if possible, to ascertain first, what ice cream is or should be, and second, to study the materials from which it is made with a view to determining their sanitary character, and finally to determine the composition of the article itself as it is offered to the market. Incidentally therefore the dairy which furnishes the milk and the milk which furnishes the cream are subjects of inquiry. These two subjects, however, have been carefully gone over in other papers of this series and hence any reference to them will be merely of an incidental character as illustrating some point in connection with the particular subject at hand.

The term "ice cream" is used in this country to cover a large variety of products, which in Europe are known under the general term of "ices." The Neapolitan ices are said to be a type of the European dishes. This type of ices is found in most of the cities of Europe, served often in very attractive packages with various adornments or used directly without molding upon the table. The art of representing different kinds of fruits and flowers, animals, and other

objects is also said to be of distinct European origin, although copied very largely in this country. For this reason there may be seen in both countries frozen products representing fruits of every description and usually colored and flavored to imitate the fruits which they represent. Strawberries, apples, pears, lemons, oranges, pineapples, peaches, apricots, bananas, grapes, and nearly all other fruits are thus represented. Various figures of statuary, or public buildings, or objects of art are also imitated in the form of frozen packages of this description. Even when milk or cream is used in the composition of these frozen dainties in Europe it is not the custom to call them ice The Italian general name for these dishes is "sorbetto," the German is "Gefrorenes," the French " glacé," and the English "ice." With the exception of the frozen dish called "sherbet," practically all the forms known in Europe under the names given are called, or have been called until recently in this country, “ ice cream."

cream.

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In the discussion of this problem I shall first offer the investigations made under the auspices of the committee appointed by the District Commissioners to advise them in regard to the dairy products on sale in the District, including a study of the raw material from which ice cream is made and of the ice creams themselves. These studies have been conducted both from the chemical and bacteriological points of view.

I will afterwards give a brief historical sketch of the use of the term ice cream and the compounds to which it has been applied.

Next will be presented certain data respecting a proper standard for ice cream, a standard adopted by the United States Department of Agriculture under authority of an act of Congress, and the criticisms of this standard made by manufacturers and dealers in ice

cream.

In this way it is believed that the whole subject may be presented in such form as to be useful not only to the Commissioners of the District in any work which they may inaugurate respecting the control of ice cream, but also to the people of the District and the people of the country in general.

It is not deemed advisable to go into minute details respecting the bacteriological and chemical investigations. I will content myself therefore with presenting the tables of analytical data and with giving a summary of the chemical and bacteriological investigations.

SUMMARY OF CHEMICAL DATA RELATING TO CREAM.

The samples of cream which were purchased in the open market covered a period extending from January 30, 1907, to June 12, 1907, inclusive. (See Table III, page 294.)

For the purpose of this investigation the analytical data reported referred only to the percentage of fat in the cream and to its artificial

coloring. The analyses were made in the dairy laboratory by and under the supervision of Mr. G. E. Patrick.

The total number of samples examined is 132, including one double cream excluded from the averages. The average percentage of fat therein is 19.09.

By act of Congress the legal standard of fat in cream for the District of Columbia is 20 per cent. The number of samples at or above 20 per cent is 44, or 33.58 per cent. The number of samples below 20 per cent of fat is 87, or 66.41 per cent.

These data show that only one-third of the samples of cream purchased complied with the legal standard for the District. The standard for fat in cream, established by the Secretary of Agriculture under authority of Congress for the country at large in so far as interstate commerce is concerned is 18 per cent. The number of samples examined which are found at or above 18 per cent is 82, equivalent to 62.60 per cent of the total number. The number of samples below 18 per cent is 49, or 37.4 per cent of the whole number. The data show that as sold upon the markets of Washington during the time mentioned almost two-thirds of the commercial creams complied with the national standard. The total number of samples of the above lot which are found to contain more than 25 per cent of fat is 6; the number of samples containing less than 16 per cent is 24; the number of samples containing less than 14 per cent is 6, and the number containing less than 13 per cent is 3, all of which are from the same dairy. These data show that the requirement of 18 per cent of fat, judged by the ordinary commercial data, is entirely just and satisfactory. Hence it follows that ice cream made from standard cream will easily contain 14 per cent or more of butter fat for the vanilla type of ice cream, and 12 or more per cent for the fruit type of ice cream, thus showing that the standards established are reasonable and just from the commercial conditions which actually exist. Of the total number of samples examined 15, equivalent to 11.45 per cent, are found to be artificially colored, thus showing that the artificial coloring of cream is not practiced to any great extent, and its entire prohibition would not in any way disturb the existing conditions of trade.

SUMMARY OF THE CHEMICAL DATA RELATING TO ICE CREAM.

The chemical analyses of the ice creams were made in the dairy laboratory of the Bureau of Chemistry by and under the supervision of Mr. G. E. Patrick, chief of that laboratory. (See Table IV, page 297.)

For the purpose of this report only the fat content of the various samples of ice cream, the content of gelatin, and the presence of coal

tar dyes are reported. The summary of the chemical data show the total number of samples analyzed to be 228. Judged by the standard of 14 per cent for the ice creams of the vanilla type and 12 per cent of fat for the ice creams of the fruit type, it is found that there are at or above standard 117 samples, or 51.32 per cent, and below standard 111 samples, or 48.68 per cent. The average percentage of fat in the entire 228 samples is 12.67. Only 46, or 20.18 per cent of the whole number of samples, contain less than 10 per cent of fat, and only 25, or 10.97 per cent, contain less than 8 per cent.

The total number of samples containing a thickener was 80, or 35.18 per cent. In 33 samples, or 14.47 per cent, the thickener is gelatin, while in 47 samples, or 20.61 per cent, the thickener is a vegetable gum or starch. Only 2 samples are found to contain coal-tar dye.

These samples were purchased at random from all the principal ice cream makers in Washington, over a period extending from about April 1 to August 1, 1907.

The data are most interesting in view of the contention that the standard suggested for butter fat is too high, and especially in view of the fact that 8 per cent has been suggested by many as a proper standard. The chemical examination shows how devoid of commercial significance are both of the claims mentioned. Another interesting fact is that the percentage of samples containing gelatin is extremely small. This is of great significance as being a most emphatic negative answer to the contention that gelatin is necessary to the manufacture of ice cream, or is generally employed. The chemical data on the whole give no support to the contention that the suggested standard for ice cream is unfair. The absence of eggs, gelatin, starch, and other substances, which it has been said are commonly used in the manufacture of ice cream, from the great majority of the samples is another point of great significance. In fact, the data show most conclusively that the term ice cream, even from a comercial point of view, is applied to a substance containing more than 14 per cent of fat in more than 51 per cent of all the samples examined. It is, therefore, commercially as well as scientifically and hygienically, a term which should be applied to a substance of standard composition and that standard, in so far as Washington is concerned, could be reached with but little variation from the usual methods of producing ice cream. What is true of Washington certainly should be true of other cities, since there is no indication that the quality of the creams made in Washington is any better than that of other cities. The only conclusion which can be derived from the study of these chemical data is that the term ice cream should apply generally, as it does in the majority of cases at the present time as indicated by

the results of these investigations, to a product made principally of cream and sugar, and with a natural flavor, either of an ordinary flavoring substance like vanilla or of fruit. Hence there appears to be no reason for departing from the established standard, in view of the data which have been secured by an examination of the commercial samples bought in the open market from all portions of the city.

BACTERIOLOGICAL INVESTIGATIONS OF ICE CREAM IN THE DISTRICT OF COLUMBIA.

[Made by or under the direction of Dr. George W. Stiles, and by or under the direction of Dr. M. E. Pennington.]

In most instances the samples of ice cream received for examination were collected directly from the original place of manufacture. In a few cases, however, miscellaneous samples were taken at places other than those at which the product was prepared. Generally half a pint or a 10-cent box furnished a sufficient quantity to make the chemical, microscopical, and bacteriological examinations. The 10cent box, to which reference is made, was the pasteboard carton almost universally used as a container for ice cream when sold in small quantities, and for this reason it was much preferred as a carrier of the samples to be investigated. When these cartons were not available well-cleansed bottles or new paper boxes were used instead.

Upon arriving at the laboratory, samples for bacteriological examination were removed at once from the frozen interior by means of sterile spoons and placed in sterile dishes to melt. Generally within eight to ten minutes a sufficient liquefaction had occurred to enable the experimenter to remove enough material to make the bacteriological examination.

The enormous number of organisms which are found in cream, milk, and ice cream, necessitates high dilutions to make possible the quantitative determination of the organisms present. For the making of these, and the counting of the colonies which developed, the technique pursued may be stated briefly as follows: The quantities were measured in 1 cubic centimeter pipettes, graduated in 0.01 of a cubic centimeter, and 10 cubic centimeter pipettes graduated in 0.1 of a cubic centimeter. They were sterilized by heat and kept in bacteria-proof metal cases.

In order to make the necessary dilutions Erlenmeyer flasks of about 500 cubic centimeters and 100 cubic centimeters capacity, respectively, were used. To the former were added 99 cubic centimeters of sterile water and to the latter 9 cubic centimeters. To the flask containing 99 cubic centimeters there was added 1 cubic centimeter of the sample