Abstract
In a present study, we investigated the variation in the composition of γ-aminobutyric acid and free amino acids, which are regarded as gustatory and functional components, during the growing process of the soybean sprouts. We also evaluated the variation in the general components and fatty acid composition in lipid.
1. The amounts of the proteins and lipids decreased during the growing process of the soybean sprouts. The percentage of the proteins and lipids in 100 g of dried soybean sprouts on the day of shipping was 45.2-47.7% and 12.5-16.8%, respectively.
2. The levels of amino acids contributing to the sweetness, thet included threonine, serine, glycine, alanine, proline, and valine, and those contributing to the bitterness, that inculded valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, histidine, and arginine, increased during the growing process of the soybean sprouts.
3. The levels of the functional amino acids including γ-aminobutyric acid, arginine, and branched-chain amino acids (valine, leucine, isoleucine) increased during the growing process of the soybean sprouts. Particularly, high levels were observed in the soybean sprouts grown from domestic soybean grains.
These results suggest that soybean sprouts are a highly nutritious food. Since we observed increases in the levels of the free amino acids possessing secondary and tertiary functions, particularly those of the functional amino acids including γ-aminobutyric acid, arginine, and branched-chain amino acids (valine, leucine, isoleucine), ingestion of soybean sprouts could possibly to allow the functions of such components to be eflectively utilized.
