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Milk and Meat in the Food Supply. Report of Committee on Food and

Nutrition of the National Research Council. Public Health Reports,

United States Public Health Service, Vol. 35, pages 994-996 (1920). RICHARDSON. The Future of the Animal Products Industry. Chemical

and Metallurgical Engineering, Vol. 23, pages 481-486 (1920). TOLMAN. Development of the Laboratory in the Meat Packing Industry.

Chemical Age (New York), Vol. 28, pages 165-168 (1920). MACDOWELL. The Chemist in the Packing and Allied Industries. Chem

ical Age (New York), Vol. 29, pages 217-220 (1921). MANNING and SCHRYVER. Studies of Gelatin. I. The Dynamics of the

Formation of Gelatin from Ossein. Biochemical Journal, Vol. 15,

pages 523-529 (1921). SHEETS, BAKER, GIBBONS, STINE, and Wilcox. Our Beef Supply. United

States Department of Agriculture, Yearbook for 1921, pages 227-322. TILLMANS, STROHECKER, and SCHÜTZE. The Detection of Incipient Decay

in Meat. Zeitschrift für die Untersuchung der Nahrungs- und Genus

smittel, Vol. 42, pages 65-75 (1921). WRIGHT. Chemical Technology of the Frozen Meat Industry. New Zea

land Journal of Science and Technology, Vol. 4, pages 97-107, 155-164

(1921). FEARON and Foster. Autolysis of Beef and Mutton. Biochemical Journal,

Vol. 16, pages 564-571 (1922). RUSSELL, BUCKLEY, BAKER, et al. Hog Production and Marketing. United

States Department of Agriculture, Yearbook for 1922, pages 181–280. VAN SLYKE and HILLER. An Unidentified Base among the Hydrolytic

Products of Gelatin. Proceedings of the National Academy of Sciences,

Vol. 7, page 185 (1921). Bassett, Holt, and Santos. Influence of Meat on Physical Efficiency.

American Journal of Physiology, Vol. 60, page 574 (1922). ROBISON. The Value of Gelatin in Relation to the Nitrogen Requirements

of Man. Biochemical Journal, Vol. 16, pages 111-130 (1922). HAWK. The Value of Gelatin and Gelatin Preparations in the Diet of Man.

Proceedings of the Society for Experimental Biology and Medicine, Vol. 20, page 269 (1923).

CHAPTER VII

POULTRY, GAME, FISH, AND SHELLFISH

POULTRY, game, fish, and shellfish belong in their essential characteristics with the meat foods discussed in the last chapter. They are treated separately here, not so much in deference to the traditional distinction between flesh, fish, and fowl as because the products now to be considered are usually not classed as belonging to the slaughter-house industry and do not come under the provisions of the meat-inspection law.

Poultry In a freshly killed bird the feet feel moist, soft, and limber, the eyes are bright and full. As it becomes stale, the eyes shrink and the feet dry and harden. The flesh should be neither flabby nor stiff, but should give evenly when pressed by the finger.

One of the commonest ways of testing the age of dressed poultry is to take the end of the breast bone farthest from the head between thumb and finger and attempt to bend it to one side. In a very young bird, a “broiler," it will be easily bent, in a bird a year old it will be brittle, and in an old bird, tough and hard to bend or break. In a young bird the feet are soft and smooth, becoming hard and rough as the bird grows older.

Much of the poultry now offered for sale is produced hundreds of miles from its market. The transportation of live poultry presents numerous problems, most of which lie outside the scope of this book. The shipping and handling of poultry killed at a distance from market involves obvious possibilities of deterioration. That such deterioration may be avoided, the methods of dressing poultry and of maintaining efficient refrigeration in transit and while awaiting sale have been studied in some detail by the United States Department of Agriculture and discussed in a series of bulletins and other articles, the titles of which may be found at the end of this chapter.

The practice recommended by Pennington is to bring the fowl into good condition by feeding clean grain mixed with buttermilk for from seven to fourteen days, then starve them for 24 hours in order that the intestinal tract may be as nearly empty as possible, and kill by cutting the jugular vein; then that part of the brain which controls the muscles holding the feathers in place is destroyed by a thrust of the knife, and the feathers are so loosened that they are easily pulled out. The cutting of the blood vessels in the proper way permits the blood to drain out of the carcass almost completely and the keeping quality is thus improved. After removal of feathers, and without removal of the entrails, the fowls should be hung by the feet on racks made entirely of metal and chilled by placing in rooms in which a temperature of about 32° F. is constantly maintained by means of mechanical refrigeration. Below 30° F. the flesh would become “ frosted"; above 35° F. deterioration proceeds too rapidly to permit of long hauls to distant markets and the subsequent delays involved in the usual routine of city marketing. At 32° F. the time required for chilling is usually about 24 hours. The carcasses are then graded and packed, preferable in boxes holding 12 fowls each. The boxes should be lined with parchment paper and sometimes each fowl is wrapped separately. Separate cartons are sometimes used for extra high grade poultry. The packed poultry is shipped in refrigerator cars, either chilled or hard frozen. A refrigerator car as ordinarily loaded in the West contains 20,000 pounds of poultry. Bunkers filled with ice and salt maintain the low temperature of the car and its contents during transit.

Chemical analyses indicate that even when well handled and dry packed, the condition of dressed poultry after transportation varies appreciably with the differences in car temperatures ordinarily met. The best evidence of this is found in the development of ammonia as indicated in Fig. 20, which shows the percentages of ammoniacal nitrogen in the flesh of fowls otherwise comparable which had been transported at different

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FRESH CHICKEN FIG. 20.

Deterioration of poultry in transit at different temperatures.

U. S. Department of Agriculture. temperatures. The difference thus shown at the end of the railroad haul tends to continue and become greater throughout the period that the fowls remain at the wholesale commission house or in the hands of the retailer, as is shown in Fig. 21, which, like Fig. 20, is taken from the bulletin by Pennington, Greenlee, et al.

Preservation is of course much more perfect when the fowls are kept hard frozen and delivered to the consumer without thawing. The common practice of thawing frozen poultry before exposing it for sale is objectionable in that it introduces an

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SAMPLE NOI SAMPLE NO2 SAMPLE NO3 SAMPLE NO4 END OF HAUL. AT WHOLESALER'S AT RETAILER'S AT RETAILERS

AFTER 4 DAYS. AFTER 7 DAYS. Fig. 21. – Deterioration of poultry during marketing period as affected by

temperature. U. S. Department of Agriculture.

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opportunity for deterioration which is quite unnecessary, and would be avoided if consumers would learn to demand that the poultry be delivered to them in a solidly frozen condition.

The general composition of poultry is shown in the following table based on the data compiled by Atwater and Bryant.

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