莲藕淀粉/乳清蛋白复合膜的制备、表征及性能

Preparation,characterization and properties of lotus root starch/whey protein composite film

以甘油作为增塑剂,将莲藕淀粉与乳清蛋白以不同比例混合制得了一系列莲藕淀粉/乳清蛋白复合膜,探讨了乳清蛋白添加量对复合膜性能的影响。通过SEM、XRD、FTIR、DSC及TG对复合膜进行了表征,在25℃、相对湿度为50%环境下,对复合膜的机械性能和阻隔性能进行了测定。结果表明,莲藕淀粉与乳清蛋白具有优异的交联能力,彼此间具有良好的生物相容性。乳清蛋白的添加提高了莲藕淀粉膜的机械性能及阻隔性能。其中,添加量(以复合膜液中莲藕淀粉的质量为基准)为50%的乳清蛋白在莲藕淀粉中分散得更好,制备的复合膜性能最优,其抗拉强度为(11.66±0.95)MPa,断裂伸长率为14.71%±0.33%,水蒸气透过率和氧气透过率分别为(8.42±1.33)×10^(12)g·cm/(cm^(2)·s·Pa)和(8.85±0.75)×10^(11)cm^(3)·cm/(cm^(2)·s·Pa),并具有良好的热稳定性。

A series of lotus root starch/whey protein composite films were synthesized by blending lotus root starch and whey protein in various ratios using glycerin as plasticizer.The effect of additive amount of whey protein on the properties of composite film was investigated.The structure,morphology,composition and thermal stability of the composite films were characterized by SEM,XRD,FTIR,DSC and TG.Meanwhile,the mechanical and barrier properties of the composite films were measured at 25℃and 50%relative humidity.The results showed that the whey protein could disperse well in the lotus root starch and the two had excellent cross-linking capability.It was also found that the addition of whey protein improved the mechanical properties and barrier properties of the composite films.Especially,when the addition amount(based on the mass of lotus root starch in the composite membrane solution)of whey protein was50%,the corresponding composite film had the best properties.The tensile strength was(11.66±0.95)MPa,the elongation at break reached 14.71%±0.33%,and the permeability of water vapor and oxygen decreased to(8.42±1.33)×10^(12)g·cm/(cm^(2)·s·Pa)and(8.85±0.75)×10^(11)cm^(3)·cm/(cm^(2)·s·Pa),respectively.