Charles E. F. Gersdorff

The globulins of rice, oryza sativa☆

Compared with the proteins of other cereals, those of rice haye been but little studied, notwithstanding the fact that rice constitutes one cf the most important sources of food for a large part of the world’s population. One reason for this is doubtless due to the unusual distribution of the classes of protein found in this seed. Unlike the proteins of other cereals, nearly all of the proteins of rice endosperm are insoluble in water, salt solution, and alcohol, and belong to the rather ill defined class of proteins called glutelins. Consequently, most of the data recorded in the literature on rice proteins has been on a mixture of the total alkaliextractable proteins.

The nitrogen distribution and percentages of some amino acids in the muscle of the shrimp, peneus setiferus (L.)

The amino acid composition of muscular tissue from various sources is recorded in chemical literature. The hydrolysis and complete analysis of the muscle proteins of chicken (l), halibut (2), ox (3), and scallop (4) have been made. Percentages of the diamino acids have also been determined by the Van Slyke method in the muscular tissue of rabbit, chicken, ox, horse, sheep, and pig (5). Similar analyses of various tissues from the same, and from different, animals are also recorded (6, 7). With but one exception, all of these citations refer to work done on the muscle of fish and of animals of higher forms of life. So far as we are aware, the amino acid composition of the muscle of a crustacean has never been determined. Having available a quantity of fresh shrimp which was procured for studies in progress on the nutritive value of certain types of sea food, it was considered of interest to determine the distribution of nitrogen and percentages of some of the amino acids in shrimp muscle. Such data would throw light on the nutritive value of the proteins of this muscle, and would afford a means of comparing the proteins with those of the scallop, as well as with those of the muscle of animals of the higher forms of life. The diamino acids were estimated by the Van Slyke method, and tyrosine, tryptophane, and cystine were determined colorimetrically. Aspartic and glutamic acids were isolated and determined gravimetrically. The quantities of the amino acids determined are expressed in percentages of the ashand moisturefree muscle (Table I). There are also inciuded, for comparison,