Studies on the Availability of Amino Acids

Abstract

An in vitro enzymatic digestion study of untreated corn gluten and “reconstituted” corn gluten (containing isolated zein) revealed that corn gluten containing native zein was digested at a faster rate than the “reconstituted” product. Quantities of amino acids liberated after pepsin-pancreatin digestion were small compared with the quantities that were microbiologically available. Identical DNP-peptide patterns were observed on chromatographing the digests of the respective samples. In an in vivo study the ingested nitrogen disappeared more rapidly from the stomachs and intestines of animals fed the untreated corn gluten. The values for availability of the threonine and valine in the “reconstituted” product were lower than those for untreated corn gluten. The values for the availability of isoleucine and lysine were not lowered by the treatment.