Feed protein fractions in various solvents of ruminant feedstuffs

✍ Scribed by Nikokyris, Panagiotis N; Kandylis, Kostas

• Book ID: 101223849
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 178 KB
• Volume: 75
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(199710)75:2<198::aid-jsfa863>3.0.co;2-c

✦ Synopsis

The classical protein fractions, ie albumins, globulins, prolamins, glutelins and insoluble (or structural) proteins were evaluated in selected feedstu †s. Solvents used for classical protein fractionation were : dilute salt (1 M NaCl) in phosphate bu †er (pH 7É0), aqueous alcohol (70% ethanol) and dilute alkali (0É05 M NaOH), with the subsequent separation of albumins and globulins by dialysis. In addition, crude protein content, soluble non-protein nitrogen, total true protein and soluble true protein in McDougallÏs bu †er from the same feedstu †s were determined. The soluble non-protein N contributed only a small portion of the total N in feedstu †s. Total true protein was approximately 8È10% for energy feeds, and then increased to 30% for plant protein sources, while the soluble true protein was about the same for energy feeds and plant protein sources. The major proportion of protein in plant protein sources was in the form of globulins, followed by albumins and lesser amounts of glutelins and prolamins. In contrast, the major proportion of protein in cereals was in the form of prolamins and glutelins, followed by globulins and albumins.