PARTICLE SIZE DISTRIBUTION APPLIED TO MILK POWDER REHYDRATION

Besides increasing shelf life of fluid milk, milk powder has physical and functional properties that allow it to be used as ingredient. The rehydration process is complex and happens in four steps: wettability, sinkability, dispersibility and solubility. Works have been conducted aiming at the development of an easier, more convenient and reproducible method to evaluate the dissolution properties of dairy powders. Therefore, the aim of this work was to evaluate dispersibility and solubility through particle size distribution in order to establish a new rehydration index for whole milk powder. The particle size distribution and morphological characteristics of seven samples of milk powder (from A to G) were analyzed. Samples F and C differed from the others which formed a similar group. Principal component analysis divided the samples into three different groups, allowing the indication of an efficient rehydration index to determine the powders dispersability.除可延长液态奶的保质期外，奶粉还具备可作为食品配料使用的物理与功能特性。其复水过程较为复杂，共分为四个步骤：润湿性（wettability）、下沉性（sinkability）、分散性（dispersibility）与溶解性（solubility）。已有多项研究致力于开发更简便、更易操作且可重复的方法，以评估乳粉的溶解性能。因此，本研究旨在通过粒径分布测定奶粉的分散性与溶解性，以期为全脂奶粉建立全新的复水性能评价指标。本研究对编号为A至G的7个奶粉样品的粒径分布与形态学特征进行了分析。其中样品F与C区别于其余样品，其余样品可归为一个相似组。主成分分析（principal component analysis）将样品划分为三个不同组别，由此可确立一种用于评定乳粉分散性的高效复水评价指标。