AN IMPROVED PROCESS FOR ISOLATION OF GLANDLESS COTTONSEED PROTEIN USING INDUSTRIAL MEMBRANE SYSTEMS

Abstract
An improved process employing a combination of isoelectric precipitation and ultrafiltration to isolate glandless cottonseed protein was developed. The effectiveness of Ca(OH)2, NaOH, and KOH in extracting storage protein (SP) was compared at pH 10, 9.5 and 9.0. KOH and NaOH each solubilized ca 88% of the flour nitrogen at pH 10, 87% at pH 9.5, and 85% at pH 9.0. Ca(OH), proved less effective, solubilizing about one‐fifth as much as the other two hydroxides. Nonstorage protein (NSP) extract was separated by acid precipitation into curd and whey: The lysine‐rich NSP whey was then added to SP extract and the mixture ultrafiltered to obtain a higher yield of SP isolate having a lighter color and increased lysine content.