通过微流变仪分析凝乳的黏弹性及流动性,利用质构仪、流变仪和低场核磁技术跟踪发酵周期测定Cheddar干酪样品质构特性、流变性和水分分布的情况,明晰转谷氨酰胺酶对Cheddar干酪凝乳及发酵过程的影响规律。结果表明,添加TGase会降低凝乳的弹性因子,随凝乳时间延长,宏观黏度指数显著升高,流动性显著降低。TGase可以增加干酪硬度、咀嚼性和剪切力;TGase可以提高干酪弹性模量(G')),损耗模量(G''),增加了干酪的黏弹性。核磁分析表明,TGase对干酪自由水的影响显著,降低了结合水的弛豫时间。

In this study,the viscoelastic properties and liquidity of curd were analyzed by microrheology. During the fermentation of Cheddar cheese,the texture properties,rheological properties and moisture distribution changes were studied to explore the mechanism of the transglutaminase effects on the cheese quality. The results indicated that addition of TGase reduced the Elasticity Index and Fluidity Index of curd and improved Macroscopic Viscosity Index significantly with the extension of curd time. TGase increased the hardness,chewiness and firmness,simultaneously improved elastic modulus( G'),loss modulus( G″) and viscoelasticity of the cheese. Results from NMR showed that TGase reduced the relaxation time of bound water,resulting in a significantly difference in free water.