Evaluation of selected food characteristics of three advanced lines of Nigerian soybean (Glycine max (L.) Merr.).

The seeds of three promising advanced lines of soybeans (TGx 923-2EN, TGx 1019-2EN and TGx 1497-1D) which were part of a larger collection evaluated in agronomic field trials in Nigeria were selected for characterization of physicochemical properties, chemical composition, water absorption, cooking time and cooked texture as a function of soaking and cooking. Seed density, leached solids, swelling capacity and seed coat percentage were within a range of 1.15 to 1.26 g per ml, 1.00 to 1.26 g per 100 g, 80.25 to 84.35 g per 100 g and 6.6 to 10.1% w/w of dry beans, respectively. The total polyphenol content of the cream colored beans was similar (0.75 to 0.76 mg/g) but higher than the amount (0.60 mg/g) found in the white beans. Cooking times varied between 71 and 96 min without soaking and were reduced by about 32.0% following a presoaking treatment in water for 12 hours at room temperature (28 +/- 1 degrees C). Small seeds absorbed higher amounts of water during soaking and required less cooking time than larger seeds. Unsoaked beans required 40 min of cooking to achieve the same degree of cooked texture as the soaked beans cooked for 20 min, suggesting that cooking times and cooked texture for all lines were improved through soaking.