The Study Of Ultrasonic On Sterilization And Storage Of Chilled Pork

In this paper, the effect of ultrasonic on sterilize and extend the storage of chilled pork is studied by determine the total bacteria counts of chilled pork treated with different ultrasonic, the activity of the baterias, observing the bacteria on the pork treated with ultrasonic and the SDS page.On the base of the first part, the effect of ultrasonic and preservation on storage of chilled pork is studied.In this pater, the chilled pork is used as experimental materials, stored for different days, then treated with ultrasonic of 40KHz for 0min, 5min, 10min, 15min, 20min, 25min, 30min respectively. The effect of sterilization of ultrasonic is studied by determine the total bacteria counts . The results showed : (1) the rate of sterilization of the ultrasonic on chilled pork increased as the stored time extending, but it is not significant between the groups when the treated time is more than 20min.(2) the rate of sterilization of the ultrasonic on chilled pork is related with the total baterial accounts, the rate of sterilization is highest when the original baterial accounts reached 105cfu/g, when treated with ultrasonic of 40KHz for 20min, the rate of sterilization reached 23.12%. Observing the picture of scan electron microscope of bacterials on the chilled pork treated with ultrasonic , srack on the bacterials was observed.Treated the pork(the original bacterials is few) with ultrasonic for different time, the effect of ultrasonic on chilled pork and the growing of the bacterials at the storage was studied by determined the total baterial account and SDS page experiment.The result showed: (1)the ultrasonic have a effect on texture of chilled pork, leading the content of the small protention increase; (2) Because of the effect of ultrasonic on the texture of the chilled pork, the total bacteria counts of the chilled pork which have few bacterias in original increased at storage.The effect of ultrasonic on sterlizing and preserving of chilled pork was studied on the base of the above experiments.The result showed: the 20min treat group has a best effect at the storage, compared with the control the total bacteria counts decread, and it is significant in the 1th, 4th, 7th (P<0.01), and the 10th day the reduce rate is 22.22%, 20.40%, 17.98%, 14.69% respectively. It is significant at the 13th (P<0.05), the reduce rate is 12.01%. And it is not signicicant at the 16th days. 20min was confirmed as the best time for storage the chilled pork treated with ultrasonic. 40KHz ultrasonic for 20min combined with natural preservative(clove and cassia is 5.0%, lysozyme is 0.025%, tea polyphenols is 1.0%) is applied on the chilled pork.The effect of ultrasonic combined with natural preservative on preserveing of chilled pork by measure the total baterial account, pH, TVB-N, drop loss and the sense affect.The result showed: the 40KHz ultrasonic affected 20min on chilled pork can extend the storage , compared with the control it can extend 9 days, and compared with the preservative group it is extend 3 days.