To study dissolution kinetic of spray dried skim milk powder (SMP), the change in light extinction was measured during dissolution of twenty-six commercial SMPs with different processing histories. SMP dissolution could be divided into two stages; the second stage could be described as a two–step process. In the first stage extinction increased up to maximum within 30–120 s. The second stage was characterised by a fast decrease in extinction followed by a slight decrease. To estimate dissolution times, the second stage was modelled using a biexponential function. The fast period was finished after 12–63 min, whereas the slower period took 9–23 h. Most of the observed changes in micelle size and soluble calcium occurred in the time frame of the fast period. SMP with low whey protein nitrogen index (WPNI) showed higher extinction values and micelle sizes, and tended to have longer dissolution times than SMP with high WPNI.

为了研究喷雾干燥脱脂奶粉 (SMP) 的溶解动力学，测量了 26 种具有不同加工历史的商业 SMP 在溶解过程中的消光变化。SMP溶解可分为两个阶段；第二阶段可以描述为一个两步过程。在第一阶段，灭绝在 30-120 秒内增加到最大值。第二阶段的特点是灭绝迅速减少，然后略有减少。为了估计溶解时间，第二阶段使用双指数函数建模。快速期在 12-63 分钟后结束，而较慢期则需要 9-23 小时。大多数观察到的胶束大小和可溶性钙的变化发生在禁食期的时间范围内。