Effect of Germination Period on Changes in Mungbean and Azuki Bean Protein and Amino Acid Profiles

摘要

Mungbean (Vigna radiata) is one of the most important legumes in Thailand while azuki bean (Vigna angilaris) has recently gained more interest. Germinated seeds are reported to be rich in nutrition including secondary metabolites. This study determined the effect of germination period on changes in chemical composition especially protein nitrogen and amino acid profile of mungbean and azuki bean. The results showed that germination periods (0, 9, 18, 27 and 36 h) at 30±1°C, did not significantly affect crude protein content in mungbean but affected that in azuki bean. During germination, the significant change in both protein nitrogen and non-protein nitrogen was found in azuki bean but not in mungbean. Total amino acid content of both germinatedbeans significantly increased as germination period increased. Compared to ungerminated bean, the percentage increase for both 27 h-germinated mungbean and azuki bean was about 66 and 164%, respectively. The percentage increase for both essential amino acids and nonessential amino acids content in each bean was about the same. During 36 h-germination, the increase in reducing sugar was very small. Total phenolic content in both beans was found to significantly increase with increasing germination period.