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or other nonporous material adapted to easy and thorough cleaning and steam sterilization. Each egg should be cracked on a steel blade and broken into a smooth, clear glass cup. When a bad egg is encountered, the blade on which, and the cup into which, it was broken are at once replaced and sent away to be thoroughly washed and steam sterilized. It is further recommended that all eggs received by the breaking establishment be first chilled below 40° F. for 24 hours, then candled and broken in cooled rooms and the liquid egg, while still cold (preferably below 45° F.), sent in its final container to a quick freezer.
Stiles and Bates described, in Bulletin 158 of the Bureau of Chemistry, United States Department of Agriculture, the processes of freezing and drying eggs as they found them in 1911. Since that time the egg-drying industry has been largely transferred to China, where eggs are cheaper than in this country, but the freezing of eggs has grown to considerable proportions.
Redfield states that over 19,000,000 pounds of frozen eggs were held in storage in the United States on January 1, 1920 (United States Department of Agriculture, Bulletin 846).
Stiles and Bates as the result of a large number of experiments to determine the bacterial content of frozen and dried products from eggs of different grades when made and stored under known conditions reached the following conclusions:
(1) Under normal conditions, strictly fresh eggs contain few if any bacteria, and no appreciable numbers of B. coli in 1 cc. quantities.
(2) Frozen egg products prepared in the laboratory in Washington from second-grade eggs comprising "undersized," "cracks," "dirties," and "weak eggs " generally show a total bacterial content of less than 1,000,000 organisms per gram, while dried eggs prepared from the same grades usually contain a total bacterial content of less than 4,000,000 organisms per gram, both kinds containing but a very small number of B. coli;
from a bacteriological standpoint they are considered an edible product.
(3) Frozen products made from "light spots," "heavy spots,' "blood rings," and "rots" show bacterial counts generally ranging from about 1,000,000 to 1,000,000,000, while dried eggs made from the same grades usually contain from 4,000,000 to more than 1,000,000,000 organisms per gram with a relatively high proportion of B. coli and streptococci in both the frozen and dried material, indicating an unwholesome article, unfit for food, and only useful for tanning leathers, or for other technical purposes.
It should be noted, however, that testimony offered in the Federal courts, in a case in which condemnation of a shipment of frozen eggs was contested by the owner, tended to show that market eggs such as are accepted without question as food may contain many more bacteria, both in total numbers and of the B. coli type, than would be expected from the results found in the Government laboratories.
The frozen eggs in question contained large numbers of bacteria, a considerable proportion of which were of the B. coli type. The eggs, however, showed no taint in taste or odor and no bad effects when eaten. The ammonia content, which was held to be the best chemical evidence of decomposition, was about the same as in ordinary market eggs, viz., about 3 parts in
The Federal court decided in favor of the egg company, holding that the Government had not shown the eggs to be filthy, decomposed, putrid, or unfit for human food.
Fermented Preserved Egg
As Blunt and Wang have pointed out, the Chinese and other Oriental peoples preserve eggs, not necessarily to keep them unchanged, but to make various new products
a process analogous to the production of cheese from milk. They describe the
manufacture of one of these products - pidan, from ducks' eggs, on a factory scale, as follows: To an infusion of 13 pounds of strong black tea are stirred in successively 9 pounds of lime, 4 pounds of common salt, and about 1 bushel of freshly burned wood ashes. This pasty mixture is put away to cool overnight. Next day, 1,000 ducks' eggs of the best quality are cleaned and one by one carefully and evenly covered with the mixture, and stored away for 5 months. Then they are covered further with rice hulls, and so with a coating fully inch thick are ready for the market. They improve on further keeping, however, for at first they have a strong taste of lime which gradually disappears. The eggs are eaten without cooking. The following changes were found by these authors to take place during the formation of pidan from fresh ducks' eggs: "(1) Water in large quantities has been transferred from the white to the yolk, and water has been lost from the white to the outside. (2) The ash and the alkalinity of ash have increased in a way similar to that of other eggs preserved in alkali. (3) The ether extract has decreased and its acidity is high. (4) Both total and lecithin phosphorus have decreased. (5) The non-coagulable nitrogen has increased and also the ammoniacal nitrogen, the latter to an extraordinary degree, and the amino nitrogen is high. From these changes the conclusion is drawn that. decomposition of the egg protein and of the phospholipoids has taken place. The production of pidan from the fresh eggs is probably brought about through the agency of the alkali, bacteria, and enzymes."1
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1 Blunt and Wang, Journal of Biological Chemistry for December, 1916.
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