College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.
College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.
Food Chem. 2019 Aug 15;289:169-176. doi: 10.1016/j.foodchem.2019.03.038. Epub 2019 Mar 12.
Introducing okara to develop high-fiber tofu (HFT) can effectively increase the utilization of soy residues as well as enhance the nutrition of tofu. However, okara degrades the glucono-δ-lactone (GDL)-induced tofu quality. Current results showed that microbial transglutaminase (TGase) remarkably enhanced the gel strength, water holding capacity and viscoelasticity of HFT. During heating of soymilk, AB and A subunits of 11S were more prone to aggregate via disulfide (SS) bonds to form larger soluble protein aggregates under neutral condition, while the SS-mediated insoluble aggregates were formed under acid condition by GDL and predominantly contributed to the structure of tofu without TGase. TGase-induced intermolecular ε-(γ-glutamyl) lysine strengthened protein network and contributed the most to HFT structure. TGase promoted formation of protein aggregates more orderly, and okara was well-wrapped by protein network. These results demonstrated that the macro-protein aggregates crosslinked by TGase conspicuously strengthened the gel network and significantly elevated the HFT quality.
将豆渣引入到高膳食纤维豆腐（HFT）的开发中，可以有效地提高大豆残渣的利用率，同时提高豆腐的营养价值。然而，豆渣会降低葡萄糖酸-δ-内酯（GDL）诱导的豆腐质量。目前的结果表明，微生物谷氨酰胺转胺酶（TGase）显著提高了 HFT 的凝胶强度、持水能力和粘弹性。在豆浆加热过程中，11S 的 AB 和 A 亚基更容易通过二硫键（SS）聚集，在中性条件下形成更大的可溶性蛋白质聚集体，而在酸性条件下，GDL 和 SS 介导的不溶性聚集体主要通过 GDL 形成，并有助于没有 TGase 的豆腐的结构。TGase 诱导的分子间 ε-（γ-谷氨酰基）赖氨酸增强了蛋白质网络，对 HFT 结构的贡献最大。TGase 促进蛋白质聚集体更有序地形成，并且豆渣被蛋白质网络很好地包裹。这些结果表明，TGase 交联的宏观蛋白质聚集体显著增强了凝胶网络，显著提高了 HFT 的质量。
