Influence of soybean protein isolate-dextran conjugates on the characteristics of glucono-δ-lactone-induced tofu. (March 2021)

• Record Type: Journal Article
• Authors: Li, Lin; Wang, Chenzhi; Li, Kexin; Qin, Wen; Wu, Dingtao; Hu, Bin; Yang, Wenyu; Dong, Hongmin; Zhang, Qing
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 139(2021)
• Publication Date: 2021-03
• Subjects: Glycosylation -- Physicochemical properties -- Tofu -- Quality assessment -- Microstructure; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2020.110588
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: The formation and characterization of conjugates of soybean protein isolate (SPI) and dextran with varying molecular weights (4, 10, and 70 kDa) and their effects on quality of glucono-δ-lactone (GDL)-induced tofu were investigated. The extent of glycosylation was negatively related to the molecular weight of dextran. Thus, the SPI-dextran4 conjugate exhibited a darker color and a biggest decrease in whiteness from 70.49 to 45.51. SPI-dextran70 conjugate exhibited an increased surface hydrophobicity and free sulfhydryl content. Volume-average diameter of SPI-dextran70 conjugate-added soymilk and gel strength of the corresponding tofu ranged from 10.34 to 11.24 μm and 0.068 to 0.083 N, respectively, which were lesser than those of the control (11.12 μm and 0.133 N). However, SPI-dextran10 conjugate incubated for 6 days and SPI-dextran4 conjugate incubated for 2 days increased the gel strength of tofu to 0.146 and 0.143 N, respectively. Conjugates-added tofu exhibited an increased water holding capacity and a discontinuous and loose microstructure, but a lowered whiteness and a color change to yellow. Results demonstrated that the selection of dextran with an appropriate molecular weight and controlling the glycosylation degree were capable of improving the quality of SPI-dextran conjugate-added GDL-induced tofu. Highlights: Soybean protein isolate (SPI)-dextran (4, 10, 70 kDa) conjugates were prepared. Molecular weight of dextran affected the physicochemical properties of conjugates. SPI-dextran70 conjugates reduced particle size of soymilk and gel strength of tofu. Impact of SPI-dextran4/10 conjugates on gel strength of tofu depended on reaction time. The addition of conjugates enhanced the water holding capacity of tofu.