Abstract：
The lack of fat in yogurt can lead to alterations in taste and whey separation, reducing consumer acceptance. In this study, the feasibility of enhancing the quality of skim milk yogurt through a combination of transglutaminase (TG) and protein-glutaminase (PG) was investigated. The combination of TG and PG resulted in simultaneous cross-linking and deamidated of casein micelles, with PG deamidation taking priority over TG cross-linking, leading to higher solubility and lower turbidity of milk proteins compared with TG alone. When 0.06 U/mL TG and 0.03 U/mL PG were added, firmness and viscosity indexes significantly increased by 38.26 and 78.59%, respectively as compared with the control. Microscopic images revealed increased cross-linking with casein and filling of cavities by smaller sub-micelles in the combination of TG and PG treatment. Furthermore, the combination of TG and PG resolved issues of rough taste and whey separation, leading to improved overall liking. This study highlights the benefits of using both enzymes in dairy production and has important implication for future research.
摘要：
酸奶中脂肪的缺乏会导致味道的改变和乳清分离，降低消费者接受度。在这项研究中,研究了通过转谷氨酰胺酶（TG）和蛋白谷氨酰胺酶（PG）的组合来提高脱脂乳酸奶质量的可行性。TG和PG的组合导致酪蛋白胶束同时交联和脱酰胺,PG脱酰胺优先于TG交联，与单独使用TG相比，导致乳蛋白的溶解度更高，浊度更低。当加入0.06U/mLTG和0.03U/mLPG时，硬度和粘度指数显著提高了38.26和78.59%，分别与对照进行比较。显微图像显示，在TG和PG处理的组合中，酪蛋白的交联增加，并且较小的亚胶束填充了空腔。此外，TG和PG的结合解决了粗糙的味道和乳清分离的问题，提高整体喜好。这项研究强调了在乳制品生产中使用两种酶的好处，并对未来的研究具有重要意义。
