黄原胶对大豆蛋白营养棒体系质地及微观结构的影响

通过质构仪、激光共聚焦显微镜、电子扫描显微镜和低场核磁共振技术等手段,研究了添加1%黄原胶对含有大豆蛋白的营养棒模型体系质构、微观结构、水分子及亲水小分子的迁移等的影响。结果表明:黄原胶的添加改变了体系微观网状结构,同时影响了体系内水及糖醇等小分子的分布,从而对大豆蛋白模型体系的质构有明显的软化效果,改善其质构和口感。

Mechanism of texture influenced by xanthan gum on soy protein bar model system

Soy protein bar model system was normally multicompo-nent and thermodynamically unstable and its hardness was increased significantly in the early stage of storage. Xanthan gum is a kind of hydrocolloid with high viscosity and water holding capacity, and it is widely used in food industry as quality improver. This study aimed to evaluate the influence of xanthan gam on texture of soy protein bar model system. The changes in texture, microstructure and T₂ relaxation time of soy protein bar model systems with or without xanthan gum were observed through texture analyzer, confocal laser scanning microscopy (CLSM), scanning electronic microscopy (SEM) and low-field nuclear magnetic resonance (LF-NMR) respectively. Comparing to the samples without xanthan gum, samples with xanthan gum had apparently lower hardness. Moreover, the microstructure was significantly changed by adding xanthan gum, and a higher ratio of small molecules such as water and polyols remained relatively high mobility.