Fang Qi, Xu Tianhe, Su Ruihan, Dai Shicheng, Wang Junzheng, Zhu Weixiang, Yang Bowen, Tong Xiaohong, Wang Huan, Jiang Lianzhou
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
College of Agriculture, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
Int J Biol Macromol. 2025 May;307(Pt 4):142274. doi: 10.1016/j.ijbiomac.2025.142274. Epub 2025 Mar 18.
The effects of different concentrations of κ-carrageenan (κC) on the structure and gel properties of soybean protein isolate (SPI) and soybean protein fibrils (SPF) were investigated in this work. The interaction between κC and SPI/SPF was explored by SDS-PAGE, FTIR, fluorescence spectroscopy, surface hydrophobicity (H). Results indicated that the binding of κC to SPI and SPF is mainly hydrogen bonding and hydrophobic interactions. With the increase of κC concentration, the fluorescence intensity and H of SPI/SPF-κC decrease. When κC was 8 mg/mL, the H of SPI/SPF-κC decreased by 53.56 % and 57.23 % respectively. The addition of κC increased the particle size and turbidity of SPI, while the opposite results for SPF. The gel properties of SPI/SPF-κC were evaluated by texture, rheology and LF-NMR. The results showed that the gel properties of SPF were better than those of SPI, and the addition of κC significantly increased the G', apparent viscosity and resistance to denaturation of the gel. When κC concentration was 8 mg/mL, the hardness of SPI/SPF-κC was 127.2 ± 5.82 g and 134.23 ± 5.89 g, respectively. In conclusion, the fibrillation of proteins and κC can effectively improve the gel properties of SPI gels, which provides a theoretical basis for expanding the high-value utilization of SPI and SPF.
本研究考察了不同浓度的κ-卡拉胶（κC）对大豆分离蛋白（SPI）和大豆蛋白纤维（SPF）结构及凝胶特性的影响。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）、傅里叶变换红外光谱（FTIR）、荧光光谱、表面疏水性（H）探究κC与SPI/SPF之间的相互作用。结果表明，κC与SPI和SPF的结合主要是氢键和疏水相互作用。随着κC浓度的增加，SPI/SPF-κC的荧光强度和H降低。当κC为8 mg/mL时，SPI/SPF-κC的H分别降低了53.56%和57.23%。κC的添加增加了SPI的粒径和浊度，而对SPF则产生相反的结果。通过质构、流变学和低场核磁共振（LF-NMR）对SPI/SPF-κC的凝胶特性进行评估。结果表明，SPF的凝胶特性优于SPI，κC的添加显著提高了凝胶的弹性模量（G'）、表观粘度和抗变性能力。当κC浓度为8 mg/mL时，SPI/SPF-κC的硬度分别为127.2±5.82 g和134.23±5.89 g。总之，蛋白质纤维化和κC可有效改善SPI凝胶的凝胶特性，为拓展SPI和SPF的高值利用提供了理论依据。
