Jiang Deming, Xiong Junjie, Dai Tian, Liu Mengmeng, Gu Siyi, Chang Zhongyi, Niu Yanning, Zou Chunjing, Jia Caifeng, Gao Hongliang
School of Life Sciences, East China Normal University, Shanghai 200241, PR China.
School of Life Sciences, East China Normal University, Shanghai 200241, PR China.
Int J Biol Macromol. 2025 Aug;319(Pt 2):145469. doi: 10.1016/j.ijbiomac.2025.145469. Epub 2025 Jun 23.
The rheological, textural, and sensory properties of yogurt are crucial for its consumer acceptance. This study investigated the effects of protein glutaminase (PG) -induced deamidation on these properties of full-fat stirred yogurt. At a PG concentration of 0.3 U·mL, the deamidation degree of milk proteins reached its peak at 59.50 %, resulting in improved solubility, reduced turbidity, and an increased proportion of smaller particles. Additionally, PG treatment enhanced yogurt acidity and water-holding capacity. Low-field nuclear magnetic resonance analysis revealed stronger hydrogen proton binding in yogurt, indicating stronger binding of proteins to water due to PG-induced deamidation. Confocal laser scanning microscopy showed a gradual reduction in the protein particle size with increasing PG concentration. Rheological and textural analyses indicated that PG deamidation dissociated the protein micelle structure, resulting in a smoother and creamier texture and improved sensory characteristics. These findings provide practical insights for optimizing the quality of full-fat stirred yogurt for diverse food and industrial applications.
酸奶的流变学、质地和感官特性对消费者接受度至关重要。本研究调查了蛋白质谷氨酰胺酶（PG）诱导的脱酰胺作用对全脂搅拌型酸奶这些特性的影响。在PG浓度为0.3 U·mL时，乳蛋白的脱酰胺度在59.50%达到峰值，导致溶解度提高、浊度降低以及较小颗粒比例增加。此外，PG处理提高了酸奶的酸度和持水能力。低场核磁共振分析表明酸奶中氢质子结合更强，这表明由于PG诱导的脱酰胺作用，蛋白质与水的结合更强。共聚焦激光扫描显微镜显示，随着PG浓度增加，蛋白质颗粒尺寸逐渐减小。流变学和质地分析表明，PG脱酰胺作用使蛋白质胶束结构解离，从而产生更光滑、更细腻的质地并改善感官特性。这些发现为优化全脂搅拌型酸奶的品质以用于各种食品和工业应用提供了实际见解。
