United States Dept Of Agriculture
VARYING CONTENT OF PROTEINS, FATS, AND VITAMINS IN DIFFERENT CUTS EXPLAIN POPULARITY OF SWINE PRODUCTS.
Results of scientific experiments have proved that the publics appetite for pork products has a sound basis. Bacon and eggs are no accidental combination. Neither is a ham sandwich. There are scientific reasons which explain also why the energetic American people consume pork so liberally. In recent years the consumption of this meat has amounted to about 50 per cent. of the total meat dietary in the United States, according to estimates of the Bureau of Animal Industry, United States Department of Agriculture.
Meanwhile, investigations conducts by Ralph Hoagland, biochemist of the same bureau, and his associated, have been resulting in many striking facts concerning products derived from the lowly hog. The combined results of chemical analyses and feeling experiments with small animals during a period of 10 years explain many of the food habits which appetite brought about long before their scientific explanations were known. In feeding tests Mr. Hoagland has used approximately 4,000 albino rats. Because their nutritive requirements are similar to those of man, these small animals are commonly used in such tests. The grow rapidly, reproduce at short intervals, and are easy to handle.
HAM AND EGGS FOR VITAMINS.
Among the most important experiments are those dealing with the mysterious but essential food substances known as vitamins. The work has shown lean pork to be rich in vitamin B, but, on the other hand, low in the fat-soluble vitamin A. But when one considers that so many pork products are commonly eaten with eggs, which are rather low in vitamin B but rich in vitamin A, the nutritive value of the combination is apparent. Thus meals containing ham and eggs, or bacon and eggs, furnish a liberal supply of these two important food elements, besides fat, protein, minerals, and other desirable constituents.
NUTRITIVE VALUE OF PORK PROTEIN.
Other important results of the governments studies in the biochemistry of meat show the value of pork in combination with cereal and vegetable products. Until a few years ago it was commonly assumed that, with some exceptions, a pound of digestible protein in one food product and practically the same food value as a pound in another. Now as the result of extensive experiments conducted in the Department of Agriculture and elsewhere, it is known that there are wide differences among the proteins from various sources. The proteins in certain animal products, such as lean meat, fish, milk, and eggs, have a higher nutritive value than those found in wheat, corn, rice, oats and navy beans-that is, when each product is the only source of protein in the diet.
Recognizing that most foods are consumed in mixed diet, Mr. Hoagland and other investigators have conducted extensive series of experiments with albino rats to answer the question, “What is the value of protein in pork as well as in other meats, when it is consumed with vegetable and grain products?” In general, they found that meat proteins not only have as high nutritive value when fed in a mixed diet as hen fed alone, but that they greatly increase the nutritive value of the cereal proteins. Thus the proteins in the bread of a ham sandwich become more nutritious when eaten in combination with the meat.
COMPOSITION OF PORK CUTS VARIES WIDELY.
Another unusual quality of the hog is the widely varying composition of different parts of its body. Moisture content ranges from about 8 per cent. in the back fat to more than 66 per cent. in tender loin. Protein varies from about 4 per cent. to more than 24 per cent. in different cuts. Fat ranges from 13 to 9- per cent., depending on the portion of the carcass selected. The mineral portion of the meat, chemically spoken of as ash, ranges from one tenth of 1 per cent. to mote than 2 per cent. in different cuts.
These variations, in connection with familiar differences in flavor, enable the skillful cook to serve dishes of equal relish to a laborer or to an office worker, each product containing different proportions of the food constituents though from the same animal. Boiled ham, for instance, as it is purchased sliced at the market, is richest in protein, whereas clear fat salt pork contains little protein but is very rich in fat.
KEEPING QUALITY A FACTOR.
It is estimated that approximately 20 per cent. of pork cuts are sold in fresh condition and the remaining 80 per cent. as cured products. The physical and chemical properties of pork make it especially suited for curing and smoking, and, with the exception of a few cuts, the cured and smoked products are commonly preferred to the fresh ones. These qualities, which are inherent in the flesh of the hog, make pork a popular food during summer months and for outings where supplies of fresh meat are difficult to obtain and where there is no refrigeration.
The zest for bacon and salt pork among persons doing heavy physical work is explained by the very high fuel value of these products. A pound of either furnishes more than 3,000 calories which is about three times as great as the number of calories ordinarily consumed by the average person at a meal.
DIGESTIBILITY IF PORK SAME AS CHICKEN.
Meats of all kinds have been found in previous investigations reported by the United States Department of Agriculture to be among the most digestible of human food products. Pork compares favorably with other meats in this quality. It also digests readily, as shown by the observations of other workers who found that pork digests completely and leaves the stomach in approximately three hours and fifteen minutes. In comparative tests, pork was digested in the stomach slightly more rapidly than turkey, in the same time as chicken, and slightly more slowly than beef or lamb. The difference in the average time of digestion among the various meats, however, is considered to be of slight significance.
A VERSATILE FOOD.
In summing up his experimental work and after considering the results of other investigators in the field of biochemical research and nutrition, Mr. Hoagland concludes that, from scientific standpoint, pork is justly entitled to the high place which it has already assumed in the American diet. It is particularly valuable as a source of fat and energy; it contains a fair proportion of protein of excellent quality, and a liberal amount of vitamin B. On account of its high energy value, pork is particularly valuable as a food for persons engaged in heavy manual labor. The leaner cuts, however, such as ham, tender loin, and chops, may be eaten interchangeably with other meats even by persons leading sedentary lives.