Influence Of Frozen Storage Duration And Package On The Quality Of Pork Meat

Pork is one of the most important animal food and rich in nutrition.The consumption of pork in China is plenty.The production and transportation of pork and pork products plays an extremely roles on the economic.Freezing is very important and essential in the meat industry since it can maintain meat quality and prolong the shelf-life of pork to some extent.While during the freezing storage,quality deterioration of meat will also occurs.Many researches were conducted on pork muscle quality during the frozen storage,but less researches are undertook on the subcutaneous tissues.And recently researches of subcutaneous tissues have been hot points in meat science area.The objective of this study was to discuss the mechanism of pork muscle and subcutaneous tissues' quality change during the frozen storage.Pork samples was divided into two groups with oxygen permeable package or vacuum package and stored at-20? for 12 weeks.Quality parameters were detected at 0,1,4,8 and 12 week respectively.The results showed that as the frozen time prolonged,quality of muscle decreased in lightness,water moisture,water holding capacity(WHC)and springiness;pH value increased and the oxidation of intramuscular fat aggrandized with the volatile compounds of aldehydes and ketones increased;free SFA' and MUFA's content declined while content of PUFA increased;IMP degraded notably;myofibrillar protein's characteristic peak at 250?280 nm increased and solubility declined.For subcutaneous tissues,moisture content and WHC had slight decline;TBARS value increased;volatile compounds such as aldehydes increased;free SFA declined while MUFA,PUFA content increased;ATP and IMP degraded while Hx,HxR accumulated significantly.Meanwhile,vacuum package could prevent the oxidation of protein and fat and avoid the degradation of ATP and IMP.