Figure 1. Effect of pH on the cotyledon protease azocaseinolytic activity. The optimum pH for the azocasein hydrolysis was determined by measuring its cleavage over the pH range 4.5-8.5 (100 mM citrate-phosphate-Tris). Activity was defined as the difference in absorbance of the azo-dye released at 340 nm after 1 hr of incubation (n = 4).