低脂乳的不同热处理工艺对切达奶酪品质的影响

通过对切达奶酪p H、水分含量、产率、质构和融化性的测定,研究了低脂乳的不同热处理工艺对其品质的影响。结果表明:3个不同热处理工艺下乳清蛋白变性率分别为17.5%、35.1%和68.3%。随着热处理强度的增大,切达奶酪的p H和融化性下降,水分含量和产率提高,质构指标中的硬度、弹性、内聚性和咀嚼度下降,黏着性上升。利用扫描电镜和电泳技术分析不同热处理工艺对奶酪品质造成的差异。结果表明:随着热处理强度的增大,乳清蛋白变性率增大,形成的大分子聚合物被截留在奶酪的网状结构中,影响了酪蛋白的聚集,进而对其品质产成了影响。 

Effect of different heat treatment processes of low-fat milk on quality of Cheddar cheese

By measuring the p H value, moisture content, yield, texture and meltability of Cheddar cheese, the effect of different heat treatment processes of low-fat milk on quality was analyzed. The results indicated that the denaturation rates of whey protein in three different heat treatments were 17.5%, 35.1% and 63.8% respectively. As the heat treatment intensity increased, the p H value and meltability of Cheddar cheese decreased, whereas moisture content and yield increased.Besides, the texture index of hardness, elasticity, cohesiveness and chewiness decreased and the adhesion increased. In addition, the differences in quality of cheese were analyzed by scanning electron microscopy and electrophoresis.The results showed that with the increase of heat treatment intensity, the denaturation rate of whey protein increased, and the formed polymer was trapped in the network structure of cheese, which affected the aggregation of casein and then had an effect on its quality.