蛋白及脂肪含量对腐竹差异成膜的影响

Effect of Protein and Lipid Content on Yuba Film-formation

摘要:

腐竹是我国历史悠久的传统的大豆制品之一。本文以提升腐竹产量、改善其机械性能及提升其营养价值为目标，使用大豆分离蛋白及大豆油为原料，采用人工模拟豆浆体系进行成膜实验，研究蛋白含量、脂肪含量、蛋白变性程度及蛋白组分对腐竹成膜的影响。结果表明：脂质含量的提高能提升成膜速度、增加膜弹性、提高成膜的蛋白和脂肪含量，但是脂质的含量过高又会对以上指标产生一定的抑制作用。随着蛋白添加量的增加，成膜速度会随之加快、膜的硬度增大、膜的蛋白含量增高、膜的脂质含量先增后减。蛋白变性程度提高能提升成膜速度，改善膜的机械性能和营养价值。尽管蛋白组分的改变对成膜速度影响不大，但是11S/7S直接影响膜的机械性能，11S/7S越高，膜的机械性能越优秀。

Abstract:

Yuba is one of the oldest traditional soybean products in China. The effects of protein and lipid content, denaturation and composition of protein on the film-forming process of yuba was studied in order to boost yuba production yield, improve its mechanical properties, and increase its nutritional content. A simulated soymilk system was employed with soybean protein extracts and soybean oil as raw materials. The results showed that the improvement of soybean lipid content could accelerate the film-forming rate, increase elasticity, and enrich the protein and lipid content of yuba. However, the addition of excess lipids had a negative impact on the variables mentioned above. The addition of protein increased the film-forming rate, hardness, and protein content of yuba, while the lipid content first increased and then decreased. High levels of denatured protein increased the film-forming rate, and improved the mechanical properties and nutritional value of yuba. Although different protein compositions had minimal effect on the film-forming rate, changing the 11S/7S ratio had a direct impact on the mechanical properties of yuba; specifically, a higher 11S/7S ratio led to better mechanical properties.