不同胎次牛乳酶凝乳特性的研究

The characteristics of enzyme curd from different parities

用流变仪分析评价不同胎次牛乳酶凝乳的流变学特性。结果表明:酶凝乳中,第3胎牛乳酶凝乳出现凝块时间最短,第2胎牛乳酶凝乳时间最长,且第2胎牛乳酶凝过程中会出现过渡区,使凝固乳易形成丝状;不同胎次凝乳的表现黏度均随剪切时间的延长而降低,60 min时凝乳黏性最好,没有乳清析出,且第1胎牛乳凝结黏性最好;应变扫描测定发现当各胎次凝乳时间为60min时凝块结构最好,第1胎次凝乳具有较强的稳定性,第3胎凝乳的稳定性最低;在制作干酪时选用第1胎次牛乳并且凝乳时间控制在60 min时凝块质地较好。

Rheological properties of enzyme curd were analyzed by rheometer. The results showed that the coagulation time of milk from the third parity cow was the shortest. The second parity milk coagulation could need the longest time, and the transition zone appeared during the coagulation. The viscosity of the curd from different parities was decreased with the extension of shearing time, the viscosity of curd was the best at 60 min, no whey was precipitated, the coagulation viscosity of the curd from the first parity milk was the best. The curd structure was the best when at 60 min, the stability of curd from the first parity was the strongest, the stability of the third parity curd was the lowest, the clot texture was better when use the milk from the first parity to make the cheese in 60 main.