An Improved Process for Isolation of Glandless Cottonseed Protein Using Industrial Membrane Systems

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.