Cereal Chem 56:95 - 99.  |  VIEW ARTICLE
Preparation and Composition of Coprecipitated Protein Isolates from Cottonseed, Soybean, and Peanut Flours.

L. C. Berardi and J. P. Cherry. Copyright 1979 by the American Association of Cereal Chemists, Inc. 

Coprecipitated protein isolates were prepared from various combinations of liquid cyclone processed (LCP) cottonseed, soybean, and peanut flours (1:1, w/w) and from each of the flours. Coisolate and isolate methodology involved protein extraction with dilute aqueous NaOH, acidification of the protein extracts to pH 2.5, and adjustment of the resulting mixtures to pH 5.0 to precipitate protein curds. The protein curds were recovered, resuspended in water, neutralized, and lyophilized. Disc-gel electrophoresis showed that some of the proteins in the extracts dissociated into subunits at pH 2.5, then reassociated into their original or new protein form, or both, as the pH was adjusted to 7.0. The coisolates, containing storage and nonstorage proteins, were high in protein content (95%) and accounted for more than 67 and 43% of total nitrogen and weight, respectively, of the composite flours. The amino acid and chemical scores indicated that addition of soybean flour to LCP cottonseed and peanut flours improved the nutritional value of coisolates. The coisolates might be useful as new, low-cost protein products for food formulations.