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THE desirability of detecting incipient decomposition in shell eggs by chemical means led a number of years ago to a study of their ammonia nitrogen concentration (Jenkins, 1919; Jenkins and Hendrickson, 1918; Lythgoe, 1927; Pennington, 1912; Pennington et al., 1914 and 1916). These investigations showed that this constituent increased progressively in mixed whole eggs during cold storage. It seemed to the authors that information concerning possible variations in the concentration of this constituent in yolks and whites of individual eggs produced under controlled conditions might contribute to a better understanding of the deterioration of cottonseed eggs during cold storage. Consequently a study was made of the influence of such factors as feed, breed, fertility, and preliminary holding periods before storage upon the ammonia nitrogen content of non-cottonseed and cottonseed eggs. EXPERIMENTAL In our earlier work, the ammonia nitrogen was determined by an adaptation of Hendrickson and Swan’s (1918) aeration method . . .

Little or no destruction of threonine, glycine, aspartic acid, and glutamic acid occurred when soybean oil meal, soybean protein, or the protein plus sucrose, glucose, dextrin, agar-agar, gum arabic, or soybean oil was autoclaved for 4 hr. at 15 lb. pressure. A portion of each of these amino acids was “inactivated” or tied up in such a manner that the biologically active amino acid could be liberated by acid but not by in vitro trypsin and erepsin digestion. Studies with soybean protein and mixtures of soybean protein and other constituents of soybean oil meal indicated that two types of inactivation occurred during autoclaving. Protein-bound threonine, glycine, and glutamic acid reacted with sucrose or glucose (glycine to some extent with dextrin or agar-agar) to form a linkage resistant to enzymatic but not to acid digestion. Protein-bound aspartic and glutamic acids reacted with some other constituent of the protein to form a linkage resistant to trypsin and erepsin digestion in vitro but hydrolyzed by acid digestion. Part of the second carboxyl groups of protein-bound aspartic and glutamic acids are combined with ammonia as the amide and part are free. It was postulated that the free carboxyl groups react with the free amino groups of lysine and arginine and with the imidazolyl group of histidine to form a peptide-type linkage resistant to enzymatic cleavage.

ALMQUIST (1952), after reviewing the literature, proposed that chicks fed a diet containing 20 percent protein require 0.45 percent methionine, and 0.35 percent cystine, or 0.80 percent methionine plus cystine in that diet for optimal growth, which is lower than the 0.54 percent methionine and 1.10 percent methionine plus cystine earlier proposed by Grau and Almquist (1943). McGinnis and Evans (1947) found that New Hampshire chicks fed soybean oil meal, which had been steamed for 30 minutes at 100°C., as the only source of protein grew very well. Growth was not improved by the addition of methionine, cystine, or methionine plus cystine to the diet. The diet contained 22.4 percent protein, 0.26 percent methionine and 0.46 percent cystine, or 0.72 percent methionine plus cystine. Methionine and cystine were determined by the differential oxidation procedure (Evans, 1945), and the values are, therefore, maximum ones, because they were determined from the total …

THE vitamin A content of fresh and stored shell eggs has been determined as part of a study of changes in composition occurring when shell eggs are kept in cold storage. Egg yolk is one of the better food sources of vitamin A, one egg furnishing 4 to 16 percent of the daily requirement (Boucher, 1941). Any losses of vitamin A from such a rich dietary source is of importance nutritionally. Large numbers of eggs are stored for extended times, and so-called fresh eggs are usually several days old before they are eaten. According to previous work from this laboratory, eggs stored for 12 months lost 18 percent of the niacin (Evans et al., 1951a), 51 percent of the vitamin B6 (Evans et al., 1951b), 14 percent of the riboflavin (Evans et al., 1952a), 8 percent of the pantothenic acid (Evans et al., 1952b), 27 percent of the folic acid . . .

ROBERTS and Rice (1890) first described the small, dark colored yolks found in eggs produced by hens fed cottonseed meal. The yolks turned olive or chocolate brown in color after the eggs were stored (New Mexico, 1927). Schaible, Moore and Moore (1934) found gossypol to be the causative agent in cottonseed meal, and Swensen et al. (1942) showed the characteristic olive color of the yolks to be due to a chemical combination of the gossypol from the cottonseed meal with ferric iron released from the yolk proteins. Sherwood (1928, 1931) first described the type of discoloration in which the yolks of eggs from hens fed cottonseed meal turned salmon in color and the egg whites turned pink during cold storage. He observed that “cottonseed eggs” had more yolk and less white than normal stored eggs and that the yolk contained less fat and more water than normal egg yolk. He . . .

OSBORNE and Campbell (1900) gave the name lecithovitellin to the lipoprotein that they isolated from egg yolks. Alderton and Fevold (1945) and Fevold and Lausten (1946) separated lecithovitellin into two lipoproteins, lipovitellin and lipovitellenin. Recent investigations by Vandegaer et al., (1956), Martin et al. (1957), Martin and Cook (1958), Joubert and Cook (1958a, b), Turner and Cook (1958), Smith and Turner (1958), Martin et al. (1959), and Sugano (1957, 1958a, b, 1959) have shown the classical lipovitellin and lipovitellenin to be mixtures of proteins. Evans and Bandemer (1957) isolated the lipovitellenin and lipovitellin complexes from eggs without ether treatment and observed that each migrated on paper electrophoresis strips as distinct bands. Extraction of lipovitellenin with ether changed its electrophoretic behavior. Lipids removed from egg lipoprotein by ether extraction have not been considered to be part of the lipoprotein. However, Vandegaer et al. (1956) observed that the stability and solubility of…

SINCE certain yolk ingredients have been shown to diffuse into the whites during cold storage of cottonseed oil eggs, the question arose as to whether the pink color of the whites of such eggs could be (1) diffused normal yolk pigments, (2) the natural pigment of whites, riboflavin, modified by diffused yolk constituents, or, (3) some cottonseed oil pigment, deposited in the yolk as a result of its consumption in feed and later diffused into the whites during storage. To investigate these possibilities the following experiments were conducted. EXPERIMENTAL Absorption spectra of a normal white from a fresh egg and a normal-appearing white and pink white from stored cottonseed oil eggs are presented in Figure 1. The Beckman quartz spectrophotometer and the Cenco-Sheard Spectrophotelometer were used for the determinations. The untreated whites were filtered clear and diluted with 0.9 percent NaCl solution to obtain the proper concentrations for specific wave . . .

HEN’S eggs are a rich source of lipides. An average size 51.6 gm. egg contains 6.1 gm. of lipide (Romanoff and Romanoff, 1949). Any changes in composition of the egg yolk fatty acids resulting from changes in the hen's diet are important in human nutrition. Cruickshank (1934) used iodine and thiocyanogen values; and Reiser (1950 and Reiser (1951), Fisher and Leveille (1957), and Feigenbaum and Fisher (1959) used alkali isomeration to determine differences in amounts of saturated and unsaturated acids in eggs from hens fed fats of widely differing fatty acid compositions. The development of gas-liquid chromatographic methods for separation of the methyl esters of fatty acids gives a tool for the direct determination of fatty acids in egg lipides. In this study, hens were fed a basal ration containing 4 percent lipide plus smaller amounts of crude cottonseed oil or various fractions of the mixed fatty acids from the oil and …

EGGS are known to be one of the best sources of iron in the human dietary. Whether or not the iron content can be increased by feeding hens iron supplements is in dispute, according to Sherman (1935). The purpose of the following experiments, therefore, was to ascertain if any of several different iron compounds in the ration of the hen would increase the iron content of the white or yolk of her eggs. In making a critical study, it was deemed necessary to find out if eggs of individual birds or specific breeds of poultry had characteristic levels of iron and if the distribution of iron between the yolk and white was affected by storage of the eggs before analysis. PROCEDURE Analyses were made upon the separated yolks and whites of individual eggs laid before and after the feeding of various iron supplements. Except as otherwise mentioned, all eggs showing . . .

Some eggs that had been in cold storage for several years, when opened, were observed to contain curdy masses just beneath the yolk membrane. Mold was suspected although the eggs did not smell moldy nor show mold growth inside the shell. Microscopic examination of the curds disclosed that they were not molds but crystals in the form of rosettes. Further examination showed that the yolk mass contained similar rosettes or single crystals whereas the egg white had an apparently different crystal formation. A series of eggs from freshly laid ones to some that had been in cold storage for various periods up to three years were examined. Crystals similar to those observed in the whites of the original eggs were found in the firm whites of freshly laid eggs and appeared in increasing amounts in the thin whites as the age of the eggs increased. No crystals were observed in . . .

Egg yolk very low density lipoprotein contained on the average 75% of lipid which could be extracted by ether and 25% of a residual lipoprotein, the classical lipovitellenin. The ether-extracted lipid was composed of 75% triglycerides, 7% sterols, 2% mono- and diglycerides, and 16% phospholipids. Lipovitellenin contained 48% lipid composed of 87% phospholipids, 11% triglycerides, and 2% sterols. The protein vitellenin was composed for the most part of units of 74,000 and 270,000 daltons molecular weight. Egg yolk very low density lipoprotein is polydisperse. Preparative ultracentrifugation separated it into six fractions of different average molecular size, and gel chromatography separated it into five. The fractions of larger molecular size contained more lipid and triglyceride than did the fractions of smaller molecular size. The proteins of the fractions appeared to be similar. Egg yolk very low density lipoproteins appear to be a series of molecules composed of cores of lipid of varying sizes with each core surrounded by a layer of lipovitellenin, which is composed principally of glycoprotein and phospholipid.