Abstract: The solubility of milk protein concentrate (MPC), which has a direct impact on its application value, may be reduced during storage. The effect of ultrasonic treatment with different powers for different durations on the solubility of fresh and stored MPC was studied. The results showed when stored MPC85, a commercial product, was treated with ultrasonic (at 50, 300 or 600 W for 5 min, or at 300 W for 3, 5 or 10 min), its solubility decreased sharply. As for fresh MPC70 stored for 30 d after treated with ultrasonic (at 300 or 600 W for 3, 5 and 10 min, respectively), its solubility decreased slowly and the smallest decrease was observed upon ultrasonic treatment for 300 W, 10 min. Ultrasonic treatment is useful to retard the decrease in the solubility during storage of MPC.

Key words: milk protein concentrate (MPC); ultrasonic; solubility; decrease

摘要： 经贮藏后的牛乳浓缩蛋白(milk protein concentrate,MPC)的水溶性会下降,而MPC的水溶性直接影响其应用价值.本实验利用超声波技术处理新鲜和贮藏后的MPC,研究不同超声波处理条件对贮藏后的MPC水溶性的影响.结果表明:超声处理(50、300、600 W分别处理5 min; 300 W分别处理3、5、10 min)贮藏后的MPC85,其水溶性显著下降;而超声处理(300 W或600 W分别处理3、5、10 min)新鲜MPC70后在50℃条件下贮藏30 d,其水溶性下降较缓慢且300 W处理10 min的水溶性下降得最慢.因此,在MPC生产过程中进行超声处理,可以在一定程度上减缓MPC贮藏过程中水溶性下降程度.

关键词: 牛乳浓缩蛋白；超声波；水溶性；下降