PHYSICOCHEMICAL PROPERTIES OF ALKALI-TREATED OAT GLOBULIN

Oat globulin dispersions (10% w/v) were incubated at an initial pH of 9.8 at 25, 37, and 55 °C over a period of 96 h. Turbidity increased at 25 and 37 °C with the formation of insoluble aggregates and decreased at 55 °C with little precipitation. The free SH content decreased progressively with time, while the surface hydrophobicity was increased at 25 °C and decreased at 37 °C. Differential scanning calorimetry showed progressive increases in denaturation temperature and decreases in width at half peak height. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated formation of soluble aggregates at 55 °C and degradation of oat globulin polypeptides at 25 and 37 °C, possibly due to proteolysis by protease(s) coextracted with the protein. No significant racemization of amino acids was observed in the alkali-treated protein. © 1990, American Chemical Society. All rights reserved.