莲子淀粉凝胶力学性能影响因素的研究

研究不同淀粉乳浓度、pH 值、NaCl 浓度、糖的种类以及吐温-80 浓度对莲子淀粉凝胶力学性能的影响。结果表明：随着淀粉乳浓度的增加，淀粉凝胶强度和弹性模量呈线性关系增加，而凝胶弹性增加不明显；随着NaCl 添加量的增加，淀粉凝胶强度和弹性模量呈先增大后减小的趋势，凝胶弹性则呈减小的趋势；在pH4.0～7.2范围内，淀粉3 种凝胶力学性能变化趋势与不同NaCl 浓度下的变化相反；3 种糖类物质均可提高莲子淀粉的凝胶强度，其大小顺序依次为果糖＞葡萄糖＞蔗糖，同时也可提高莲子淀粉的凝胶弹性和弹性模量，但影响程度不大；当吐温-80 加入量小于0.5% 时，淀粉凝胶强度和弹性模量迅速减小，凝胶弹性略有增加，当吐温-80 加入量大于0.5% 时，淀粉凝胶力学性能基本不变。

Mechanical Properties of Lotus-seed Starch Gels

The mechanical properties of lotus-seed starch gels formed under different conditions, including starch milk concentration, pH value, and additions of NaCl, sugar and Tween-80 concentration were studied. Results showed that the gel strength, elastic modulus of lotus-seed starch gels increased linearly with increasing starch milk concentration, while the gel elasticity changed little. The gel strength and elastic modulus of lotus-seed starch gels first increased and then decreased, whilethe gel elasticity exhibited a decreasing trend with increasing NaCl concentration. All the mechanical properties of lotus-seed starch gels decreased with the increasing NaCl concentration when pH value was between 4.0 and 7.2. The gel strength was also significantly increased by adding sugars, with fructose most effective, followed by glucose and sucrose. Meanwhile, the gel elasticity and elastic modulus were slightly increased. The addition of Tween-80 of less than 0.5% resulted in a sharp decrease in gel strength and elastic modulus and a slight increase in gel elasticity, while little changes were observed in all the mechanical properties when the addition of Tween-80 was more than 0.5%.