Dietary Protein Values, Complete vs. Total Protein in the Evaluation of Diets

Abstract

Table I. Copper, Nickel, and Cobalt Reported in Sea Water Micrograms per Lifer Reference Cu Ni Co (2) <3000 1.5-6 <0.3 (4) 4-10 0.1-0.5 0.1 (6) 0.7-0.8 0.38-0.67 (7) 2 (8) 0.23-0.32 (10) 20 3 1 (11) 13-22 0.33-0.67 other investigators. If the respective values of 18, 2, and 0.5 y per liter are accepted for copper, nickel, and cobalt in sea water, results of the present work indicate that copper and cobalt are concentrated in the oyster shell to nearly the same extent, 1.8 X 103 and 2 X 103,respectively.The concentration of nickel, however, from sea water to shell is appreciably higher at 1.5 X JO4.Copper in the edible portion of oysters has been reported by various workers to vary over the wide range of about 5 to 2000 p.p.m. in the living matter.A fair average of the compiled data of Vinogradov for Crassostrea virginica would be approximately 1100 p.p.m. of copper. As the edible portion of oysters contains about 87% water, it is evident that on the dry basis this part, even for the lower ranges of copper recorded in the literature, contains more of this element than found in the shell in the present study. The single reference to copper in oyster shells which was noted (9) gave a value of 25 p.p.m., which is close to the findings reported here.

Protein Supplementation, Sweetened Condensed vs. Evaporated Milk in Improving the Protein Efficiency of Wheat Flour

“…Cereal protein is very deficient in lysine, so that this essential amino acid may be considered the most deficient nutrient on a worldwide basis. Obviously, it is not possible to give a correct evaluation of the yearly lysine shortage for human nutrition, but only a tentative value, based on the assumption that a complete protein should contain 5.3 grams of lysine per 100 grams of protein (N X 6.25) (7,2,8). Clearly, such an evaluation is theoretical, as it presupposes that the other essential amino acids are present in adequate amounts.…”

“…Therefore, food processing should be reevaluated. Thus, it has been stated (7) that almost half of the lysine in milk could be destroyed by processing without affecting its protein value. Although exaggerated, this is nearly true when milk is the only protein source of the diet, but not when milk is used as a supplement to a predominantly cereal diet which is that of most low-income groups all over the world, except for small infants.…”

Mineral Content of Meats, Mineral Elements in Adipose Tissue of Lamb and Pork

“…ite, moisture, crude fat, and total nitrogen by micro-Kjeldahl were determined, using the procedures of the AOAC (7).…”

“…Casein, Hammerstein quality; soybean protein, 88% protein; and pepsin (3 X Crystalline) were obtained from Nutritional Biochemical Corp., and commercial grade carrageenin was obtained from Marine Colloids, Inc. Egg albumin was prepared from fresh hen eggs, and hemoglobin from fresh beef blood according to the procedure of Anson and Mirsky (7).…”

“…Three different assays were employed, since no single procedure was suitable for measuring protein hydrolysis when different proteins are used as substrates. The Riggs and Stadie assay (6) was used with egg albumin, the Anson and Mirsky assay (7) with hemoglobin, and the Volhard and Lohlein assay (2) with casein or soybean protein as the substrate.…”