Structural, functional properties of protein and characteristics of tofu from small-seeded soybeans grown in the Loess Plateau of China
Yueyi Dang, Jing Ren, Ying Guo, Qinghua Yang, Jibao Liang, Rui Li, Rui Zhang, Yang Pu, Xiaoli Gao, Shuang‐kui Du
Abstract
The structural, functional properties of protein isolated from small-seeded soybeans were investigated and characteristics of tofu were studied. Small-seeded soybean protein had obvious α', α, β, acidic and basic subunits bands and two endothermic peaks (76.02-76.63℃ and 91.94-94.25℃). Small-seeded black soybean protein isolates (SBSPI) had more β-sheet (31.90-33.54%) structure, while small-seeded yellow soybean protein isolates (SYSPI) had more α-helix (18.89-20.72%) structure. SYSPI had higher fluorescence intensity (839.10-847.80) than SBSPI (482.70-565.10). SBSPI exhibited higher surface hydrophobicity (939.51-1252.75) and water absorption capacity (8.07-8.50 g/g). Tofu made from small-seeded yellow soybeans had higher yield (549.46-560.23 g/100 g soybean) and was brighter (L*, 74.61-77.48) and more yellowish (b*, 14.83-14.95) in color. Tofu made from Fugu small-seeded black soybean (FGSBS) had the highest hardness (178.52 g), adhesiveness (-25.77 g.sec), chewiness (87.45 g) and resilience (0.26), signifying a more compact structure.