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.

Black soybean is known for its antioxidant and anti-inflammatory properties that help prevent several degenerative diseases, but in the Western diet, it is poorly used, despite the interest in foods rich in bioactive compounds. This study aimed to formulate a black soybean yogurt (BSY) fermented by a probiotic culture of L. acidophilus and evaluate the nutritional and bioactive profiles, the total antioxidant capacity, and complementary parameters during fermentation and storage for one month. We also evaluated the potential for acceptance by Rio de Janeiro consumers (n = 103). The final BSY water content was 92.8%. The dry matter contained 50.2% protein, 20.1% lipid, 5.9% ashes, 23.8% carbohydrates, and other constituents, including 1% sucrose, 5.9% α-galactosides, 26.9 mg/100 g anthocyanins (mainly cyanidin-3-glucoside), 140.5mg/100 g isoflavones (mainly genistin and daidzin). Titratable acidity was 0.44% and pH 4.5. In the sensory test, 12% sucrose and fruit extracts (strawberry, prune, and grape) were added individually to the product to evaluate the acceptability. The sweetened strawberry extract offered the highest acceptability, with a 7.6 score in a nine-point hedonic scale, against a 5.6 of the sweetened control with no fruit extract. Furthermore, all products scored well in the clusters with assessors who consumed soy products often and daily (total n = 26), with the strawberry-flavored one scoring, on average, 8 or 9. One month storage at 8 ± 2 °C caused a 22% decrease in the anthocyanins content and no significant change in isoflavones, titratable acidity, and pH. Fermentation and the addition of a sweetened fruit extract proved to be promising tools to increase the consumption of black soy milk in the West.

Insoluble residue from common bean protein extraction was used to obtain three polysaccharide-rich ingredients: bean starch, fiber-rich flour, and carbohydrate-rich flour. The residue was fractionated by water suspension and centrifugation. Bean starch had high purity (90.71%) with minimal ash and fiber contamination. Its granules were oval to semi-elliptical, with slight surface porosities and some adhered protein bodies, showing a typical legume "C" crystallinity pattern, and gelatinization temperature of 74.65 °C. Viscosity curves were similar to those of bean starch in its native state. Fiber-rich flour had particles 5.6 times larger than carbohydrate-rich flour, due to higher fibrous content. It also showed higher water (5.09 g/g) and oil (1.52 g/g) holding capacities than carbohydrate-rich flour (3.16 g/g and 0.96 g/g, respectively). Phytate levels in both ingredients were below 0.7%, and no tannins were detected. This study demonstrates that the protein extraction process preserved flour macromolecules, reinforcing the potential of these byproducts in food applications.