Influence of desialylation of caseinomacropeptide on the denaturation and aggregation of whey proteins

摘要

The effect of the addition of caseinomacropeptide(CMP) or desialylated CMP on the heat-induced denaturationand aggregation of whey proteins was investigatedin the pH range 3 to 7 after heating at 80°Cfor 30 min. The rate and temperature of denaturation,the extent of aggregation, and the changes in secondarystructure of the whey proteins heated in presence ofCMP or desialylated CMP were measured. The sialicacid bound to CMP favored the denaturation and aggregationof whey proteins when the whey proteinswere oppositely charged to CMP at pH 4. A transitionoccurred at pH 6, below which the removal of sialic acidenhanced the stabilizing properties of CMP against thedenaturation and aggregation of the whey proteins. AtpH >6, the interactions between desialylated CMP andthe whey proteins led to more extensive denaturationand aggregation. Sialic acid bound to CMP influencedthe denaturation and aggregation behavior of wheyproteins in a pH-dependent manner, and this should beconsidered in future studies on the heat stability of suchsystems containing CMP.