不同商用大豆分离蛋白结构特征和功能性质的比较

Comparsion of Structural Characteristics and Functional Properties of Different Commercial Soy Protein Isolates

本文研究了20个商用大豆分离蛋白样品的结构特征和功能性质,并分析了它们之间的相关性。结果表明,这些样品的平均粒径为16.73~388.27 nm,Zeta电位为-19.90^-32.00 m V,表面疏水性指数为234.63~493.00,暴露巯基、总游离巯基、二硫键含量分别为3.59~11.15μmol/g、4.68~13.37μmol/g和6.02~15.47μmol/g,溶解性为9.64~41.07%,乳化活性指数和乳化稳定性指数分别为14.94~46.10 m2/g和13.61~59.13 min,起泡能力和泡沫稳定性分别为28.97~98.50%和60.41~98.03%,持水和持油性分别为3.50~20.43 g水/g蛋白质和4.08~5.66 g油/g蛋白质,部分样品的结构特征及功能性质之间存在显著差异(p<0.05)。这些样品的功能性质与结构特征之间的相关性分析表明,溶解性和起泡能力与平均粒径和Zeta电位绝对值、乳化活性指数与Zeta电位绝对值、乳化稳定性指数与平均粒径、泡沫稳定性与暴露巯基和总游离巯基含量等存在正相关,乳化活性指数与二硫键含量、起泡能力与总游离巯基含量、持水性与平均粒径等存在负相关。

The structural characteristics and functional properties of twenty commercial soy protein isolate samples were studied and correlations between structural characteristics and functional properties were also analyzed. The mean particle size（MPS） of these samples ranged from 16.73 to 388.27 nm, the Zeta potential（ZP） ranged from-19.90 to-32.00 mV, and the surface hydrophobicity（H0） ranged from 234.63 to 493.00. The contents of exposed sulfhydryl groups（SH）, free SH, and disulfide bonds（SS） ranged from 3.59 to 11.15 μmol/g, 4.68 to 13.37 μmol/g and 6.02 to 15.47 μmol/g, respectively, and the protein solubility（PS） values ranged from 9.64 to 41.07%. The emulsifying activity index（EAI） and emulsifying stability index（ESI） values ranged from 14.94 to 46.10 m2/g and 13.61 to 59.13 min, respectively. Foaming capacity（FC） and foaming stability（FS） values ranged from 28.97 to 98.50% and 60.41 to 98.03%, respectively. Water holding capacity（WHC） and fat absorption capacity（FAC） ranged from 3.50 to 20.43 g water/g protein and 4.08 to 5.66 g oil/g protein, respectively. There were significant differences in structural characteristics and functional properties among some samples（p〈0.05）. Correlation analysis of the structural characteristics and functional properties of these samples indicated that PS and FC were positively correlated to MPS and the absolute value of ZP. Positive correlations were also observed between EAI and the absolute value of ZP, between ESI and MPS, and between FS and the contents of exposed SH and free SH, respectively. While negative correlations were observed between EAI and SS content, between FC and the content of free SH, and between WHC and MPS, respectively.