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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.

Chinese Pidan

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


ATWATER and BRYANT. Composition of American Food Materials. United States Department of Agriculture, Office of Experiment Stations, Bulletin 28.

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1 Blunt and Wang, Journal of Biological Chemistry for December, 1916.

KÖNIG. Chemie der menschlichen Nahrungs- und Genussmittel.

LANGWORTHY. Eggs and Their Uses as Food. United States Department of Agriculture, Farmers' Bulletin 128.

LEACH. Food Inspection and Analysis.

POWELL. Cooperation in Agriculture.

TAYLOR. The Prices of Farm Products. Wisconsin Agricultural Experi

ment Station, Bulletin 209.

TIBBLES. Foods: Their Origin, Composition and Manufacture.

WATSON. Farm Poultry.

WILEY. Foods and Their Adulteration.


OSBORNE and CAMPBELL. Proteins of Egg Yolk and Egg White. Journal American Chemical Society, Vol. 22, pages 413-422, 422–450 (1900). PRALL. Preservation of Eggs. Zeitschrift für Untersuchung der Nahrungsund Genussmittel, Vol. 14, pages 445-481 (1907).

WILEY, PENNINGTON, STILES, HOWARD, and COOK. Effects of Cold Storage on Eggs, Quail and Chickens. United States Department of Agriculture, Bureau of Chemistry, Bulletin 115 (1908).

HASTINGS. The Egg Trade of the United States. United States Department of Agriculture, Bureau of Animal Industry, Circular 140 (1909). SLOCUM. Marketing Eggs through the Creamery. United States Department of Agriculture, Bureau of Animal Industry, 26th Annual Report, pages 239-246 (1909).

PENNINGTON. A Chemical and Bacteriological Study of Fresh Eggs. Journal of Biological Chemistry, Vol. 7, pages 109-132 (1910).

PENNINGTON and PIERCE. The Effect of the Present Method of Handling Eggs on the Industry and on the Product. United States Department of Agriculture, Yearbook for 1910, pages 461-476 (1910).

BERGER. Preservation of Eggs. Journal Industrial and Engineering Chemistry, Vol. 3, pages 493-495 (1911).

HEPBURN. Handling, Transportation and Storage of Perishable Foodstuffs. Journal of the Franklin Institute, Vol. 171, pages 585-598; Vol. 172, pages 173-193, 369–398 (1911).

LAMON. The Handling and Marketing of Eggs. United States Department of Agriculture, Yearbook for 1911, pages 467-478 (1911). BARBIERI. The Coloring Matter of Egg Yolk.

pages 1726-1729 (1912).

BARTLETT. Eggs Preserved with Silicate of Soda. Eighth International Congress of Applied 51-56 (1912).

Comptes rendus, Vol. 154,

Original Communications, Chemistry, Vol. 18, pages

BRYCE. Physics of Refrigeration. American Journal of Public Health, Vol. 2, pages 829–833 (1912).

GREENLEE. Osmotic Activity in the Egg of the Common Fowl. Journal of the American Chemical Society, Vol. 34, pages 539-545 (1912).

MCCOLLUM, HALPIN, and DRESCHER. Synthesis of Lecithin in the Hen and the Character of the Lecithin Produced. Journal of Biological Chemistry, Vol. 13, pages 219–224 (1912).

PENNINGTON. Practical Suggestions for the Preparation of Frozen and Dried Eggs. United States Department of Agriculture, Bureau of Chemistry, Circular 98 (1912).

PENNINGTON and ROBERTSON. A Study of the Enzymes of the Egg of the Common Fowl. United States Department of Agriculture, Bureau of Chemistry, Circular 104 (1912).

Report of the Commission to Investigate the Subject of Cold Storage of Food, Boston: State, 1912, pages 308.

RETTGER and SPERRY. Antiseptic and Bactericidal Properties of Egg White. Journal of Medical Research, Vol. 26, pages 55–64 (1912).

STILES and BATES. A Bacteriological Study of Shell, Frozen and Desiccated Eggs. United States Department of Agriculture, Bureau of Chemistry, Bulletin 158 (1912).

WILSON. Economic Results of Cold Storage. United States Department of Agriculture, Yearbook for 1911, pages 23-32 (1912).

DE KEGHEL. Industrial Preservation of Eggs. Revue chimie industrielle, Vol. 24, pages 12-18; Chemical Abstracts, Vol. 7, page 3170 (1913). HOLMES. Cold Storage and Prices. United States Department of Agriculture, Bureau of Statistics, Bulletin 101 (1913).

EPPLER. Investigations on the Phosphatids of Egg Yolk. Zeitschrift für physiologische Chemie, Vol. 87, pages 233–254 (1913).

TRIER. Hydrolyses of Egg Lecithin. Zeitschrift für physiologische Chemie, Vol. 86, pages 141-152 (1913).

BEHRE and FRERICHS. Control of Trade Practices in the Egg Industry. Zeitschrift für Untersuchung der Nahrungs- und Genussmittel, Vol. 27, pages 38-59 (1914).

PENNINGTON. A Study of Commercial Eggs. United States Department of Agriculture, Bulletin 51 (1914).

RETTGER. Bacteriology of the Hen Egg. Connecticut (Storrs) Agricultural Experiment Station, Bulletin 75, pages 192-213 (1914).

PALMER. Xanthophyll, the Principal Natural Yellow Pigment of the Egg Yolk, Body Fat, and Blood Serum of the Hen. The Physiological Relation of the Pigment to the Xanthophyll of Plants. Journal of Biological Chemistry, Vol. 23, pages 261-280 (1915).

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