The Effect Of Different Storage Temperatures Combined With Vacuum Packaging On Mutton Quality During Storage

In recent years,with the rapid development of mutton industry and the improvement of people’s living standards,the national demand for mutton intake is increasing,and the requirements for meat quality has become higher and higher.However,mutton is highly susceptible to spoilage,which is also a major factor limiting its development.The storage process of the existing mutton in China is still not perfect,and the storage temperature,storage method and storage time have a significant impact on the quality of the mutton.In this study,the hind legs of mutton were used as raw materials,and the effects of different storage temperatures combined with vacuum packaging on the quality of mutton were studied.The effects of different treatments on the preservation of mutton were discussed by measuring the changes of mutton quality index,protein oxidation index,microstructure and microorganisms during storage.The specific research results are as follows:(1)The storage temperature of the test was determined to be-4 °C(superchilling),-2 °C(ice-temperature)and 4 °C(refrigeration)by measuring the freezing point of the mutton to-2 °C.Different storage conditions were:-4 °C combined with vacuum packaging,-2 °C combined with vacuum packaging,4 °C combined with vacuum packaging,and the control group was ordinary air packaging.(2)During the storage,the drip loss rate,cooking loss rate,TVB-N and TBARS of the mutton in storage conditions showed upward trend;the pH decreased first and then increased;the color showed downward trend;the texture characteristics gradually getting worse.The indexes of mutton in refrigeration group changed the fastest,and the shelf life was the shortest(7~8 d).The indexes of superchilling group changed slowly,and the shelf life was the longest(27~30 d).The ice-temperature group was between the two groups(21~24 d).However,the drip loss rate of the superchilling group was higher,indicating that water retention of the mutton was poor.In the initial stage of storage,the drip loss rate in vacuum packaging is large,but vacuum packaging can effectively maintain the good color of mutton.In summary,no matter which type of packaging,superchilling storage and ice-temperature storage can maintain the color of fresh meat for a longer period of time than the refrigerated mutton,delayed elevation of pH,TVB-N and TBARS during storage(3)With the prolongation of storage time,the degree of oxidation of mutton myofibrillar protein is increasing,which is manifested by an increase in carbonyl content,a decrease in total sulfhydryl content,and an increase of myofibrillar protein aggregation and fragmentation.At the same storage temperature,the oxidized degree of ordinary air packaging mutton is greater than that of vacuum packaging mutton,and the superchilling storage and ice-temperature storage can significantly delay the oxidation of protein.By observing and analyzing the microstructure of SEM,compared with fresh mutton samples,the vacuum packaging treatment group was smaller than the muscle fiber gap of the normal air packaging group,and the vacuum packaging treatment group was squeezed by atmospheric pressure.And part of the water in the mutton was extruded,the muscle tissue processed by vacuum packaging was dense.(4)During the storage period,the total bacterial counts and the psychrophilic bacterial counts in the mutton increased.In the refrigeration group,the total bacterial counts and the psychrophilic bacterial counts were more than 6.00 lg cfu/g when stored for 7 d(8 d);on the 24 d in the ice-temperature group and 30 d in the superchilling group,the total bacterial counts exceeded 6.00 lg cfu/g,psychrophilic bacteria counts close to 6.00 lg cfu/g,indicating that both the ice-temperature group and the superchilling group can inhibit the growth and reproduction of microorganisms.It can be seen that the shelf life of the refrigeration group is 7~8 d,the shelf life of the ice-temperature group is 21~24 d,and the shelf life of the superchilling group is 27~30 d.Superchilling,ice-temperature storage compared with refrigeration,they can delay and the growth and reproduction of microorganisms in mutton and the deterioration of physical and chemical indicators.Combined with vacuum packaging,it can maintain the color,water retention and tenderness of mutton for a long time,and effectively inhibit the oxidation of fat and protein.