δ-葡萄糖酸内酯添加量对豆腐凝胶特性的影响

Effect of Glucono-δ-Lactone Addition Amount on the Gel Properties of Tofu

以内酯豆腐为研究对象,在豆浆中添加不同比例(0.2%、0.3%、0.4%)的δ-葡萄糖酸内酯(GDL),通过质构仪、SDS-PAGE、红外光谱、激光扫描共聚焦显微镜等仪器,对其组织结构、含水量和保水性、凝胶作用力组成、蛋白质亚基组成、二级结构和微观结构进行测定,分析GDL添加量对豆腐凝胶特性的影响。结果表明,随着GDL添加量的增加,其硬度、弹性和咀嚼性显著提高(P<0.05),当GDL添加量为0.4%时,保水性最好,达到了83.38%,豆腐中疏水作用逐渐增强,可溶性蛋白的亚基条带逐渐减少,蛋白质向凝胶转化的趋势增大,豆腐蛋白质中β-折叠含量由31.93%增加到38.43%,无规则卷曲含量由13.93%下降到13.78%。

With lactone tofu as the research object, different proportions(0.2%, 0.3%, 0.4%) of glucono-δ-lactone(GDL) are added into soybean milk. The tissue structure, water content and water retention, gel force composition, protein subunit composition, secondary structure and microstructure of tofu are determined by texture analyzer, SDS-PAGE, infrared spectroscopy and laser scanning confocal microscope, and the effect of GDL addition amount on the gel properties of tofu is analyzed. The results show that with the increase of GDL addition amount, the hardness, elasticity and chewiness of tofu are significantly improved(P<0.05). When GDL addition amount is 0.4%, the water retention is the best, reaching 83.38%. The hydrophobic effect of tofu gradually increases, the bands of soluble protein subunits gradually decrease, and the trend of protein conversion to gel increases. The β-folding content of tofu protein increases from 31.93% to 38.43%, and the random coil content decreases from 13.93% to 13.78%.