Studies on the Utilization of Peanut Protein

Part III Gradient extraction of peanut protein and heat destruction of basic amino acids in each fraction

Abstract

By gradient extraction of defatted peanut flour with ammonium sulfate, three fractions having absorption at 280mμ were obtained at approximately 1.0 (Frn. I), 0.5 (Frn. II), and 0.3 (Frn. III) saturation, respectively. The Frn. I was dialyzable nonprotein component. By steam-heating of partly purified Frns. II and III at 1kg/cmcm² for 60-180min., lysine and arginine decreased significantly, while no destruction occurred on histidine. No remarkable difference in the pattern of amino acid decrease was found between Frns. II and III except that more decrease in lysine occurred in Frn. II than III. Under the presence of sugars at steam-heating, the destruction of lysine and arginine in both fractions were more pronounced on xylose, followed by glucose, fructose, and sucrose in this order. Copresence of starch did not affect such change in amino acid pattern.