School of Life Sciences, East China Normal University, Shanghai 200241, PR China.
School of Life Sciences, East China Normal University, Shanghai 200241, PR China.
Food Chem. 2023 Dec 15;429:136831. doi: 10.1016/j.foodchem.2023.136831. Epub 2023 Jul 13.
The effects of enzymatic deamidation by protein-glutaminase (PG) on the texture, rheology, microstructure, and sensory properties of skimmed set-type yoghurt were studied. The proportion of small-particle size milk protein micelles (10-50 nm) increased significantly from 0 to 99.39% after PG deamidation. Cryo-SEM results revealed that PG-treated yoghurt had a denser and less open 3D structure. PG was effective at inhibiting post-acidification during storage at 4 ℃. The water holding capacity of PG-treated yoghurt (0.12 U·mL) increased by more than 15%. The fluidity and viscosity of yoghurt were significantly improved with increasing PG dose. Sensory evaluation revealed that PG (0.06 U·mL) significantly improved the smoothness and creaminess of skimmed set-type yoghurt, which corresponded to the pastiness in texture. In summary, PG can effectively address the problems of post-acidification, gel fracture, and flavors change in skimmed set-type yoghurt, providing new applications for PG in the food industry.
研究了蛋白谷氨酰胺酶（PG）的酶脱酰胺作用对脱脂定型酸奶的质地、流变学特性、微观结构和感官特性的影响。经 PG 脱酰胺作用后，小粒径乳蛋白胶束（10-50nm）的比例从 0 显著增加到 99.39%。冷冻扫描电镜结果表明，PG 处理的酸奶具有更致密、更不易打开的 3D 结构。PG 能有效抑制 4℃储存过程中的后酸化。PG 处理的酸奶的持水能力（0.12 U·mL）增加了 15%以上。随着 PG 剂量的增加，酸奶的流动性和粘度显著提高。感官评价表明，PG（0.06 U·mL）显著提高了脱脂定型酸奶的光滑度和奶油感，这与质地的粘性相对应。综上所述，PG 可以有效解决脱脂定型酸奶的后酸化、凝胶断裂和风味变化等问题，为 PG 在食品工业中的应用提供了新的途径。
