Isoflavone, anthocyanin, and fatty acid contents of vegetable-type soybean grains at different maturity stages

Abstract

The objective of this work was to determine the oil, protein, fatty acid, isoflavone, and anthocyanin contents in soybean grains of different breeding lines and maturity stages. Evaluations were performed for the chemical profiles of black- (BRM09-50995) and of yellow-seed-coat (BRM11-51428 and BRM08-50643) breeding lines, harvested at the R6 (immature seeds), R7 (physiological maturity), and R8 (full maturity) maturity stages. Oil and protein contents increased from the R6 to the R8 stage, and BRM11-51428 showed the highest protein content. Palmitic, stearic, and linolenic fatty acids were higher at R6, and linoleic and oleic acids were higher at R7 and R8, respectively. At the R8 growth stage, BRM11-51428 and BRM 09-50995 showed the highest contents of oleic and linoleic acids, respectively, and the lowest content of linolenic acid. The amounts of isoflavone glucosides and aglucones were higher at R8, while malonyl forms were higher at R7. Total aglucones increased about three times from R6 to R8. BRM09-50995 showed the highest content of total isoflavones and anthocyanins, mainly at the R8 stage, which makes this lineage an option to process functional soybean food.