Effect of Ultrasonic Treatment on the Quality of Low-Lactose Milk
At present,milk is mainly sterilized by heat treatment,which,however,will deteriorate the quality of milk to varying degrees.Ultrasonic treatment can retain the nutrients in low-lactose milk.Low-lactose milk was subjected to ultrasonic treatment,and the effects of different ultrasonic power(100,150,200,and 250 W)and ultrasonic time(5,10,15,and 20 min)on the quality of low-lactose milk stored at 4℃for 21 days were studied with acidity and pH as indicators.The results showed that the optimal sterilization conditions were ul-trasonic treatment at 150 W for 10 min.The storage test showed that low-lactose milk could be preserved for about 15 d after ultrasonic treatment,while fresh milk and low-lactose milk without ultrasonic sterilization could only be preserved for about 6 d.The stability test during the storage period showed that the low-lactose milk could be stored for 15 d under 4℃,with negative result in the alcohol test,no rancidity or fat stratifica-tion,and it still maintained good quality after storage for 15 d.As the ultrasonic power and ultrasonic time in-creased within certain ranges,the quality of low-lactose milk was gradually improved due to the emulsification and homogenization effects of ultrasound,which decreased the turbidity and improved the emulsifying proper-ties of low-lactose milk.
万方数据
维普
