Compared with the b-glucoside content in the soybeans soaked at 25 C, there was a significant difference (p < 0.05) only in the grains soaked for 6 h. On the other hand, the soybeans soaked at 40 C displayed reduced b-glucoside content during the first 3 h of soaking, while after this period there was no significant difference (p > 0.05). Regarding the grains soaked at 55 C (with deionised water or buffer solution), the same behaviour was observed throughout the soaking time (Fig. 2a). At this temperature, it was also observed that after 5 h of soaking, there was no significant difference in the aglycone content of the soaked soybeans; this is in agreement with the study conducted by Lima and Ida (2014) optimising soybean hydrothermal treatment for the formation of aglycone isoflavones. In contrast, there was no substantial increase in the aglycone contents of the soybeans soaked at 25, 40 or 70 C. Only the soybeans soaked at 70 C showed an increase in bglucoside content. These observations were closely related to the bglucosidase activity (Fig. 2b) and the aglycone (Fig. 2c) and malonylglucoside contents (Fig. 2d). When the soybeans were soaked at 55 C, there was a reduction in the b-glucoside content and bglucosidase activity, whereas the aglycone content increased. This indicates that the b-glucosidase in the soybeanswas responsible for the conversion of the b-glucosides to aglycones during the soaking of the grains. The soybeans were also soaked in a 0.1 mol L1 phosphate-citrate buffer solution (pH 6) at 55 C to evaluate the possible increase in aglycones in the soaked soybeans because the optimal pH range for b-glucosidase is between 5 and 7 (Matsuura et al., 1989; Sutil et al., 2008). Lima and Ida (2014) utilised a buffer solution at pH 6 as a medium for soybean soaking for the conversion of b-glucoside isoflavones to aglycones, but this condition was unnecessary for this purpose throughout the time period evaluated herein (Fig. 2c). The aglycone content in the soybeans