搅拌和均质对牛乳稳定性的影响

Studies on the stability influence of agitating and homogenization of milk

采用BECKMAN LS13-320激光粒度分析仪对不同搅拌速率和均质条件的牛乳脂肪球粒径进行检测分析。结果表明,高搅拌速率特别是在2 000 r/min时随搅拌时间的延长对牛乳脂肪球粒径的影响较显著,转速为1 500 r/min时一直到搅拌12 h才开始出现脂肪球轻微聚集现象,搅拌速率为1 000 r/min时搅拌12 h后仍与原鲜奶的粒径分布图相似。不同的均质条件对牛乳粒径分布图有一定的影响,其中,75℃/25 MPa均质后牛乳的粒径分布图相对而言较圆滑、重叠最少,体系较稳定。经中试试验同样证明75℃/25 MPa的均质条件更适于UHT乳的生产,牛乳体系相对而言最稳定。

This study use laser diffraction particle size analyzer （BECKMAN LS13-320） to determined effects of agitating and homogenization on changes of fat globule size distribution. The result show that, high agitating speed affect on particle size distribution is great, especially in the 2 000 r/min, 1 500 r/min until 12 h began to stir more fat accumulation., in the 1 000 r/min after mixing 12 h the particle size distribution is still similar to the raw milk. After the homogeneous, the particle size distribution is different with different homogeneous conditions, which, the particle size distribution curve is relatively smooth and the least overlap in condition of 75℃ / 25 MPa, After pilot test to prove; 75 ℃ / 25 MPa the more homogeneous conditions for UHT milk production and the most stable.