Cooking methods affect phytochemical composition and anti-obesity potential of soybean (Glycine max) seeds in Wistar rats

This work aimed at investigating the effects of three domestic cooking methods (roasting, sprouting and boiling) on phytochemical contents (phenolic content, flavonoid, fibre), and anti-obesity (weight loss, hypoglycemic effect, serum lipids) potential of soybean seeds in obese male rats. Ten different forms were implemented, combining hulled/unhulled and raw/cooked soybean seeds using a basal and a hypercaloric diet as controls. Unhulled Roasted Soybean (URS) exhibited the highest phenolic content and a greater antioxidant activity by the FRAP assay than BHT at certain concentrations. Hulled boiled Soybean (HBS) showed the highest flavonoid content while Hulled Germinated Soybean (HGS) presented the lowest fibre content (P < 0.05). Unhulled Boiled Soybean (UBS) induced the best reduction in food intake while Unhulled Soybean Extract (USE) exhibited the greatest slimming effect. HBS exhibited the best cholesterol lowering ability; URS and Unhulled germinated Soybean (UGS) respectively induced the highest increase in HDL cholesterol levels and reduction in triglyceride levels. UBS demonstrated the highest ability to lower LDL cholesterol. UGS exhibited the highest ability to lower the postprandial blood glucose. Culinary treatments affect phytochemical content and anti-obesity potential of soybean seeds.