Abstract:

Bacterial spoilage is not a limiting factor to the shelf life of UHT processed milks, because commercial sterilization has been applied.Whereas, the physico-chemical reactions that induce the changes of fat droplets and proteins dispersed state in the milk limit the shelf life of UHT milk.Sucrose esters SE-15, molecular distilled monoglyceride and soybean hydroxyphosphatide were chosen as emulsifiers, and mixture design was applied to optimizing the proportions of these emulsifiers.The delta back scanning of the samples were determined at different proportions.Based on the Boltzmann distribution of Brownian particles, the model of the samples’ stability index（SI）was established to predict their stabilities.The equation between SI and mentioned emulsifiers proportions was obtained by regression analysis, and the data of analysis of variance and demonstration test indicated that the established model and regressive equation had a high level of significance, therefore they were suitable for estimating the UHT cow milk stabilities and predicting different emulsifier’s proportions which attributed to the UHT cow milk stabilities.

摘要：

微生物腐败引起的变质不是超高温灭菌乳货架期的限制因素，其货架期主要取决于组织状态的保持。为了延长超高温灭菌乳的货架期，以目前使用的复配稳定剂BD 0027为对照，选取蔗糖酯SE-15、分子蒸馏单甘酯(DMG)及羟基化改性大豆磷脂(SHP)为原料，采用混料设计的原理进行配方设计并基于布朗粒子的Boltzmann分布定律构建稳定动力学参数（SI）与超高温灭菌乳体系近红外光背散射光随时间的变化率的均值（ΔBS）之间模型，作为超高温灭菌乳货架期的预测值。通过回归分析得到SI与SE-15、DMG、SHP配比之间的回归方程，方差分析以及验证试验结果表明该模型高度显著。因此，SI与ΔBS和SE-15、DMG、SHP配比比例之间的两个模型可以用于评价超高温灭菌乳稳定性并预测其货架期。