Changes of protease activity and nitrogenous substances during brown rice germination

The changes of protease activity,protein content,components and hydrolyze degree,peptides content and other nitrogenous substances during brown rice germination were investigated.The result indicated an increase 3.39 times and 5.37 times in protease activity and protein hydrolyze degree,and an advance 38.68% in amount of peptides in germinated brown rice at 48 h compared with ungerminated brown rice.The correlation coefficient of protein hydrolyze degree and peptides content reached 0.960 6.At the same time,there was a significant increase in contents of free amino acids and nonprotein N with the decrease(74.76%)of albumin and globulin and increase(95.68%)of glutelin and prolamin.However,when brown rice germination was at 72 h,the changes of nitrogenous substances were significantly different from them before 48 h.SDS-PAGE of the geminated brown rice indicated a reduction in high molecular weight components and an increase in small peptides compared to ungerminated rice.Therefore,the germination process at 48 h was an important turning point of nitrogenous substances conversion.