豆粕陈化对大豆蛋白结构性质 及腐竹制备的影响Effect of soybean meal aging on the structure properties of soybean protein and the preparation of yuba

旨在为低变性豆粕制备腐竹提供参考，分析了豆粕陈化对豆粕中蛋白质结构性质（溶解度、粒径分布、蛋白质组成）和氧化程度（巯基含量、表面疏水性、羰基含量）的影响。同时，以新鲜豆粕和陈化豆粕为原料制备腐竹，考察豆粕陈化对腐竹制备（产率、基本成分、机械性质、颜色、耐煮性）的影响。结果表明：豆粕中的蛋白质在长时间储藏过程（相对湿度40%~50%，温度16 ℃，储藏时间150 d）中发生疏水聚集导致其溶解度降低，粒径增大和蛋白质组成改变，同时蛋白质氧化导致其游离巯基含量下降，降低了豆粕中蛋白质的共价结合能力；新鲜豆粕制备的腐竹在产率和蛋白质利用率上显著高于陈化豆粕，同时在机械性质、亮度和耐煮性上也显著优于陈化豆粕。综上,豆粕陈化导致豆粕中蛋白质的成膜能力下降，不利于制备高产率和良好品质的腐竹。In order to provide a reference for the preparation of yuba from low-denatured soybean meal, the effects of soybean meal aging on the protein structure properties (solubility, particle size distribution, protein composition) and oxidation degree (sulfhydryl content, surface hydrophobicity, carbonyl content) were analyzed. In addition, fresh soybean meal and aged soybean meal were used as raw materials to make yuba, and the effects of soybean meal aging on the preparation of yuba (yield, basic composition, mechanical properties, color, boiling resistance) were investigated. The results showed that the hydrophobic aggregation of protein in soybean meal during storage (relative humutidy 40%-50%, temperature 16 ℃, storage time 150 d) led to the decrease of solubility, increase of particle size and change of protein composition. Protein oxidation led to a decrease in the content of free sulfhydryl, which reduced the covalent binding capacity of protein in soybean meal. The yield of yuba and utilization of protein prepared by fresh soybean meal were significantly higher than those of aged soybean meal, and the mechanical properties, brightness and boiling resistance of yuba prepared by fresh soybean meal were significantly better than those of aged soybean meal. In conclusion, the aging of soybean meal leads to the decrease of the film-forming ability of protein in soybean meal, which is not conducive to the preparation of yuba with high yield and good quality.