QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Horn, M. J. Articles by Gersdorff, C. E. F. Search for Related Content PubMed PubMed Citation Articles by Horn, M. J. Articles by Gersdorff, C. E. F.

Nutritional Evaluation of Food Proteins by Measuring Availability of Amino Acids to Microorganisms

I. Cottonseed Proteins¹

Bureau of Human Nutrition and Home Economics, Agricultural Research Administration, U. S. Department of Agriculture, Washington, D. C.

It has been demonstrated that various methods of processing cottonseed meals alter the nutritional value of the protein.

Two methods of evaluating these meals were used; the rat assay method, which showed that the nutritional value of these meals for the rat was considerably altered by the processing, and the microbiological method, which showed that the changes in nutritional value were due to a change in the availability of the amino acids. Different methods of processing affected the availability of different amino acids. The assay of acid hydrolysates showed that only very severe temperatures and pressures caused any destruction of the amino acids. Comparison of results from assays of acid and enzyme hydrolysates by the microbiological method showed that, although the amino acids were present, some of them were bound in such a way that they were no longer available to the microorganism.

An enzyme digestion system has been worked out which appears to give good reproducibility of results; the availability of the digestion products to the microorganisms correlated well with the results of rat feeding.

Manuscript received 18 April 1952.