| Two types of protein isolates were prepared from de-hulled yellow mustard flour by aqueous extraction, membrane processing and acid precipitation of proteins at the isoelectric point (IEP 5.5). Their electrophoretic, main functional properties and protein composition were determined. The precipitated and acid soluble protein isolates had 83.0 and 96.0% protein content on a moisture and oil free basis, respectively. The acid soluble protein isolate had comparable functional properties to those of commercially available soybean and other protein isolates. The precipitated protein isolate exhibited less desirable functionality than the soluble isolate, due to its high lipid content (∼25%); however, it was still comparable to soybean isolates. Storage temperature had limited effect on lipid oxidation, and hence the stability of the precipitated protein isolate at 25-45°C. Taste and texture of wieners and bologna prepared with 1-2% of this isolate as binder were comparable to those prepared with soy protein isolates. |
