Effect of Ultra-high Pressure and Irradiation Sterilization on Quality Characteristics of Yao Meat in Zhenjiang during Storage

The effects of UHP and irradiation sterilisation on the quality characteristics of Yao meat during storage were investigated. Yao meat was treated with 550 MPa, 600 s UHP and 6 kGy irradiation. Among them, unpasteurised Yao meat was used as the control group, under refrigeration at 4 °C. At 1, 10, 20, 30 and 40 d, the pH, thiobarbituric acid reactive substances, total volatile salt nitrogen, total bacterial colony and volatile substances were measured in each group. The results demonstrated that the pH values of all treatment groups showed a decreasing trend during the storage period, with the control group (CK group) showing the greatest decrease, reaching the lowest point of 6.48 at 40 d. The TBARS value, TVB-N value and total bacterial count of all groups increased, and the TBARS value of the irradiated group was always significantly higher than the other two groups (P<0.05). The total number of colonies in the control group (CK group) at 30 d was 6.36 lg CFU/g, which significantly exceeded the national standard limit. The volatile species in the high-pressure and irradiated groups were higher than those in the control group (CK group), and the total content and proportion of aldehydes, aromatics and hydrocarbons in the high-pressure group tended to increase with the increase in storage time and the total content were higher than those in the control group (CK group). In contrast, the content and proportion of alcohols, aldehydes and aromatics in the irradiated group decreased, and the UHP treatment had a positive effect on the change of volatile flavour substances in Yao meat. Therefore, the UHP treatment of Yao meat was effective in extending the shelf life of Yao meat and maintaining the food quality characteristics.