Fresh milk: Minimum time of storage, in short storage of 1 or 2 weeks. Temperature of storage, 33° to 34° F. Buckwheat flour: Minimum time of storage, 1 month. Maximum time of storage, 6 months. Minimum time of storage, 1 month. Macaroni: Usual time of storage, from 1 to 4 months. Maximum time of storage, 6 months. Pickles: Usual time of storage, 3 to 6 months. Maximum time of storage, 30 days. Pickled salmon: Minimum time of storage, 1 month. Maximum time of storage, 6 months. Temperature of storage, first 3 weeks, 28° to 30°; balance of time, 34° F. A In some cases letters were written to accompany the blanks. cold-storage company from the extreme Northwest writes as follows: * * * Judging from your letter you are in quest of data in relation to refrigerated products, not frozen meats, etc., such as we handle. Our business is that of wholesale and retail meat dealers. We store frozen animal and fish products and retail to the trade and to the consumer direct. We do not handle refrigerated meats at all; by that I mean meats that are held at a temperature but slightly above the freezing points for such products; all our stuff is hard-frozen, and is kept so until finally delivered to the consumer. This is made necessary owing to transportation conditions which necessitate our laying in a sufficient stock to last through the winter months during the time of the open season in this country; i. e., June, July, August, and September. We can not hold "cooled" meats that long, about seven months, and so we freeze everything "hard." That chilling meats improves them I firmly believe, but that freezing them adds to their quality I seriously question. During the summer months we furnish fresh-killed meats to the trade, but from October until the middle of June we handle nothing but the frozen products. We have had meats in storage as long as 14 to 16 months, at a temperature ranging from 14° F. in the summer, to 10° to 20° F. below zero during the winter, and they have been furnished to the trade in apparently as good a condition as when they were first put in storage. We have no trouble in holding meats for eight to ten months in a hardfrozen condition, and the quality is eminently satisfactory. Very rarely do we have any complaints from the trade; once or twice during the season, perhaps. Given a stable temperature of about 15° F., with no more fluctuation than 2°, I believe meats can be held hard-frozen indefinitely, say several years, without further deterioration in quality other than that which transpires when same are first frozen. But in this country, where the outside temperature ranges from zero to as much as 60 below at times, it is impossible to keep an equable degree of cold, as the outside temperature is bound to have an effect on the cold-storage chambers, producing in them lowering of the temperature, and this excessive coldness has a tendency to take more or less of the life out of the meats and renders them slightly dryer than otherwise if kept for any length of time, say more than a year and a half. * * * A cold storage warehouseman of many years' experience makes the following statement: * * * My present cold-storage occupation will not be of much use to you, as we do not handle any goods first-handed. I established one of the first cold-storage plants in the country and have had no end of experience, especially in the meat line. I have slaughtered at home, bought at Chicago both alive and dressed, and cut up all grades and qualities. As a matter of trade cold storage is required to do this. After 48 hours it never improves the taste of any goods or their health-giving nutriment. I have eaten meat I have kept a year; while tender, it lost a large part of its taste. I do not consider it wholesome. I could fill 20 pages with experience, but it would not help you. There are so many different qualities in the same kinds that it would be hard to set a limit. Another storage company sends, in addition to the blank filled out, the following information: * * * We do not exactly understand whether the minimum and maximum time of storage is intended to show the customary times which these products remain in storage, or whether it is the intention to show the time certain goods might attain their best condition, and the time when they would be expected to begin to deteriorate. We presume, however, that it is the former, and have made our answers on that basis, assuming to a large extent that the withdrawals of these goods indicate the latter. Market conditions always enter into the matter also. Taking, for instance, fresh meats, we handle a great deal which is taken out almost as soon as thoroughly frozen, but the great bulk of it will remain for some time. We do not consider, however, that it can be carried satisfactorily over three months, as it will begin to show more or less dryness, etc. As to fish, it is not uncommon for us to carry them one year or longer, but we consider them in nearly all cases beginning to deteriorate after three or four months, unless they are redipped in water, thus forming a thin coat of ice over them which will protect them from deterioration almost indefinitely, so long as this process is renewed from time to time. Practically, however, this can not be done often on account of the cost, which would become an important factor, and we merely refer to this as indicating what might be done. As to butter, where we show the minimum time of ten days you will understand that this refers to butter which is put in refrigerating rooms for the purpose of carrying it for a short time when the market may be overloaded or for some similar reason. For June creameries intended for use during the following winter the temperature is he'd from 5° to 10° above and also to 5° below zero. It is now assumed by the trade that the best results in carriage are obtained at the lower temperature. * * INCEPTION OF THE WORK. Among the most important of the foods so far examined on which the work is sufficiently advanced to warrant publication are chickens, quail, milk, and eggs. The conditions under which the eggs were purchased and stored are given under the appropriate caption on page 27. The preliminary study on milk, conducted by M. E. Pennington, has been reported in the Journal of Biological Chemistry, April, 1908, and will not be reprinted in this report, save for the conclusions drawn therefrom, which will be found in the summary on page 101. The chemical analysis of the eggs was made by F. C. Cook and the microscopic examination by B. J. Howard. The bacteriological examination of the eggs, quail, and chickens conducted at Washington was made by G. W. Stiles, and the study of market cold-storage chickens, covering chemical, bacteriological, and histological changes, was conducted at Philadelphia by M. E. Pennington. In the tests made at Washington a large number of chickens of as nearly as possible the same age and condition were secured in a perfectly fresh state, slaughtered, and prepared for storage by the removal of the feathers, and packed six in a box, as is the custom in placing samples in storage. The fowls were placed in cold storage at a temperature from 2° to 8° F.—that is, frozen solid-half being drawn and half left in the undrawn state. A sufficient number of these chickens were dressed, cooked, and subjected to the judgment of the jury in regard to the quality and character of the flesh. Another lot, representative in character, was selected for examination. A large number of quail in like manner were secured by special arrangement with the North Carolina game warden, so that the birds might be shipped directly to Washington on the date they were killed. In this way the exact length of time which had elapsed since their slaughter was known. These birds were treated in the same manner as the chickens, having been tested and placed in cold storage, half drawn and half undrawn. At stated intervals, usually of about three months, samples of these storage products were withdrawn and subjected to the same examination as has just been indicated. Fresh chickens, as nearly of the same size and character as those in cold storage as could be secured, were always prepared with these samples. When these chickens were cooked and presented to the jury they were numbered or indicated in some way so that no member of the jury knew which lot was the fresh chickens, which the drawn chickens in storage, and which the undrawn chickens in storage. Each individual member of the jury was requested to determine for himself the character, odor, color, and taste, to enter the same in a notebook, and to determine from the results of his notes and his experience which he considered to be the best for eating purposes of the samples presented to him. The members of the jury were not allowed to consult among themselves until their final verdict had been rendered. The data thus noted were collected and summarized in order to determine whether or not there had been any consensus of opinion respecting the important points to be considered. A careful organoleptic examination of the chickens was also made before cooking, but in this case, inasmuch as the chickens were seen in the state in which they had been removed from storage, it was, of course, perfectly easy for each inspector to determine which was the fresh, which the drawn, and which the undrawn bird. These inspections consisted in a careful study of the external appearance of the chicken, and also of the body cavity, in both the drawn and the undrawn chickens after the latter had been dressed for cooking. It is perfectly easy in such cases to distinguish between a fresh and a cold-storage chicken by the external and internal appearances. The odor, external and internal, was also noted. The recession of the eye of the coldstorage chicken, the changes of the color of the blood, the change to a certain extent of the color of the interior of the bird and its flesh, the development of blueness around the muscles of the legs, the ease with which the flesh is detached from the bone, the odor of the bird, the shriveled appearance of its skin all are highly indicative of the changes which have taken place. It may be said that a careful inspection of cold-storage fowls, whether drawn or undrawn, before cooking would do much to destroy any appetite which might otherwise have been manifested for these birds when cooked. The process of cooking, however, does very much to eliminate the differences between the fresh and the cold-storage fowls. To such an extent is this true that at the end of the first three months there were very great differences of opinion among the jury regarding the identity of the samples tested. It is generally considered by connoisseurs that a certain delay between the killing and the consumption of chickens and game birds is necessary to develop the proper tenderness and flavor of the flesh. This is a problem, however, which can not be discussed very extensively at this point, since in the old-fashioned way the hanging of poultry and birds for a certain length of time was considered necessary for the purpose of "ripening," so called. They were not subjected, as a rule, to as low a temperature as that found in cold-storage warehouses. The common method, especially in Germany, was to hang the Christmas goose or turkey from a back window for ten days or two weeks previous to the serving of the meal, and thus it was subjected sometimes to temperatures below freezing and sometimes to those above. At the same time the birds thus exposed were hanging in the free air and were relieved of the danger of being left in the stagnant air of a storage warehouse. It is said that one of the best methods of sending the wild duck across the water in the winter is to nail them to the mast of a slow-going vessel. Their exposure in this way is said to place them in the best possible condition for consumption on their arrival on the other side. It does not follow that the detention of birds in a closed cold-storage compartment below the freezing point for the same or greater periods of time will produce the same effect. I. COLD-STORAGE EGGS." PLAN OF WORK. The eggs for this investigation were secured from a reliable local dealer, who stated that all were laid on May 23, 1906, and they were placed in storage on the following day. The wood of the crates was thoroughly seasoned and, because of absorption of odors by the they were made of white wood, gum, or other odorless wood. The strawboard supporting the eggs also affects the odor somewhat. All of the crates were new. eggs, The eggs were divided into 10 lots of one dozen each for storage and the weight of each dozen taken. One dozen was reserved for immediate analysis; the others were placed in a storage room having a temperature of 33° F. The weights per dozen on May 24, 1906, were as follows: At certain intervals, as indicated in the table, a dozen eggs were removed for analysis. Four of these were examined chemically in a raw state and four were hard boiled; two were used in an attempt to determine volatile sulphur, but as only minute traces were found in either fresh or cold-storage eggs this estimation was excluded. One or two eggs were referred to the bacteriologist for examination, whose findings are given elsewhere in this report. Samples were sent also to the microscopist. The following determinations were made on whites and yolks, separately, of both boiled and unboiled eggs, the weight of the material having been determined before and after cooking: Moisture, ash, ether extract, total sulphur, total phosphorus, and lecithin phosphorus. The total nitrogen was determined, and also the nitrogen in the form of coagulable proteids, proteoses and peptones, and amido bodies on the boiled samples. The moisture, ash, ether extract, total sulphur, and total phosphorus were determined by the methods of the Association of Official Agricultural Chemists. The lecithin phosphorus was determined a Chemical analysis made by F. C. Cook. The separation of the whites and yolks of the unboiled eggs was not satisfactory, and therefore the results were recalculated to the whole egg. See table, page 31. c U. S. Dept. Agr., Bureau of Chemistry, Bul. 107. Revised. |