Composition and Content of Soyasaponins and Their Interaction with Chemical Components in Different Seed-Size Soybeans

Soyasaponins $A_1$, DDMP-conjugated group B soyasaponins ${\alpha}g\;and\;{\beta}g$, non-DDMP counterpart soyasaponin I, II+III, and DDMP moiety were quantified in the large-, midium-, and small-seed soybean varieties. Protein contents were ranged from 38.1% to 41.8%, and oil contents were ranged from 15.5% to 18.9%, respectively. Oil contents in the large-seed varieties were significantly higher than those of medium- and small-seed varieties. Among detected soyasaponin peaks, ${\beta}g$ was a major soyasaponin in DDMP-conjugated group B soyasaponins followed by soyasaponin I, DDMP moiety and $A_1$. Soyasaponin concentration among different seed size soybean varieties. The soyasaponin concentration of mediumseed ($4014.5{\mu}g/g$) was slightly higher than those of largeseed ($3755.0{\mu}g/g$) and small-seed varieties ($3620.3{\mu}g/g$), however, the differences was statistically not significant. The composition rates of soyasaponins in the large-size seeds were 9.4% of soyasaponin $A_1$, 26.5% of DDMP-conjugated soyasaponins, 49.9% of non-DDMP counterpart soyasaponins, and 14.2% of DDMP moiety, respectively. Similar results were observed in the composition ratios of middle- and small-size seeds. Oil content and C:N ratio showed the significant positive correlations with total soyasaponin concentration, while the 100-seed weight, fiber, and ash contents showed the negative correlations with total soyasaponin but statistically not significant. It was noted that protein contents didn't have any relationship with group A, group B, DDMP moiety, and total soyasaponin. This fact suggested that protein contents are not affects the variation of soyasaponin concentration.