FAST指数在复原乳区分中的应用初探

FAST 指数是评价牛奶热损害的敏感指标，在研究生鲜乳热加工、奶粉及其复原乳色氨酸或梅拉德反应产物荧光强度的变化规律的基础上，评价了FAST指数用于鉴定生鲜乳和巴氏杀菌乳是否添加复原乳的效果。研究结果表明,奶粉生产过程中，色氨酸已经受到破坏，同时，不同奶粉之间色氨酸的荧光强度存在差异。与生鲜乳相比，复原乳中色氨酸荧光强度(FTrp)明显降低，随着生鲜乳中复原乳含量的增加，色氨酸的相对荧光强度线性下降；生鲜乳加热后，其中梅拉德反应产物的荧光强度(FAMP)明显升高，此类物质荧光强度升高也与牛奶中复原乳含量增加呈显著的线性相关；试验结果还表明FAST指数能有效的用于区分生鲜乳和巴氏杀菌乳，以及巴氏杀菌乳中是否添加了复原乳。

Application of FAST Method in Determination of the Presence of Reconstitued Milk

The FAST method is based on quantification of protein denaturation by means of Trp fluorescence (FTrp) and accumulation of fluorescent Maillard products (FAMP) in the pH 4.6-soluble fraction of the milk. The fluorescence of raw milk, pasteurized milk ,and milk power was determined. Trp fluorescence was much lower in reconstituted milk compared to fresh milk, whereas the fluorescence of advanced Maillard products(FAMP) increased during heat treatment applied to fresh milk. As the proportion of reconstituted milk increased in fresh milk , the FTrp decreased linearly and FAMP increased linearly. The FAST method can be an effective way in determination of the presence of reconstituted milk in fresh or Pasteaurized milk.