Combining Aqueous Extraction and Membrane Isolation Techniques to Recover Protein and Oil from Soybeans

Two relatively new protein isolation techniques (the Aqueous Extraction Process and the Membrane Isolation Process) were combined to obtain a single isolation procedure to produce protein and oil food products from undefatted soybeans. Three lots of soybeans were processed using aqueous extraction, centrifugation and industrial ultrafiltration membranes to obtain either a full-fat, low-fat or intermediate-fat product and an oil cream. Proximate and amino acid analyses, nitrogen solubility profiles, and storage tests were made on spray dried products. Mean membrane permeation rates achieved ranged from 20–42.6 gfd. Protein products possessed high nitrogen solubilities below pH 3.5 and above pH 7, and were desirably light in collor.