Study On The Controlled Supercooling-point Storage Characteristics Of Pork

Pork is perishable and easily deteriorated during food processing, transportation and storage because it’s nutrients such as protein, fat and carbohydrates, which can impact on food safety. Controlled supercooling-point storage is a food processing technique based on ice-temperature storage. It has the potential to significantly increase the shelf life of foods and will become a trend of the food preservation technology in the future. The supercooling process uses storage temperatures below the initial freezing point of the food without being frozen. In this article, we established measuring method of supercooling point of meat and studied the changing law of the freezing parameters, physiological and biochemical indexes with the extension of storage time under different temperatures. We also determined suitable process conditions for controlling supercooling-point storage and studied the preservation effect of pork tenderloin to provide the theory and application of fresh pork basis. The main research results are as follows:(1) The measurement method of supercooling point of meat was studied by comprehensive experiment, with supercooling point can be seen in each test’s freezing curve as standard. The study found that the time was too long for freezing under-10℃, meanwhile the supercooling disappeared under-30 ℃.Under-18 ℃, the appearance probability of supercooling point of pork cut was high. The situation of appearing supercooling point in 3g was better than other weight of meat. Considered storage environment temperature for-18 ℃, weight for 3g was an optimum parameter for measuring method of supercooling point of meat.(2) The results indicated that the sensory quality, hardness and resilience of pork tenderloin was decreasing, meanwhile the enhancement in the liquid loss rate, TVB-N value, p H value and total bacteria during storage at different ice-temperature libraries. In the aspect of freezing parameters, the supercooling point and ice point increased gradually while the time arrived supercooling point and ice point reduced with extension of storage time. Under such condition, no obvious supercooling phenomenon was observed on the freezing curve. According to the extension of freezing parameters, physiological and biochemical indexes, the shelf life of pork at 4 ℃ and-1℃ were 6 and 18 days respectively.(3) This study found that weight for 30 g pork tenderloin was suitable for food storage and preservation which used controlled supercooling-point technique. It appeared high probability of supercooling point in freezing test at different temperature(-5,-4 and-3℃). In such situation, the time of ice point arrival at precise ice-temperature library which set-5,-4 and-3℃ were 120 min, 214 min and 1186 min respectively.(4) Effect of controlled supercooling-point storage on quality of pork tenderloin was studied. Results showed that the spoilage of pork tenderloin occurred after 18 days at ice temperature storage, the aerobic bacterial count of pork cut was beyond the limit of standards. Thus the pork stored in supercooling conditions for 36 days was with a slight off-flavor and dark red colour. The p H value, TVB-N value and aerobic bacterial count showed that the pork cut were still belong to the sencondary fresh meat. Synthesized the variation of main quality indices, the preservation effect of controlled supercooling-point technique was better than ice temperature technique. Furthermore, the shelf life was extended twice than ice temperature technique.