Effects Of Aging Methods On Eating Quality,oxidation Characteristics And Microstructure Of Chilled/Frozen Beef And Its Application

With the development of urbanization and the change of consumer needs,the beef industry in China has developed rapidly,and the improvement of beef quality has gradually become a focus for the development of large-scale enterprises.The beef market of China mainly includes hot fresh meat,chilled meat and frozen meat.Among them,the production process of chilled meat and frozen meat all need to go through the tenderizing stage of aging.Aging is a process that improves the quality of beef effectively.However,the quality of Chinese aged meat is incomplete at present.In the actual production process of various enterprises,the time and method of aging of frozen meat and chilled meat are not uniform.It leads to the decline of meat quality and shelf life,affects the circulation and storage time of meat,and adversely affects the development of the industry.In order to solve the above problems,the study researched the effects of different aging methods on meat quality during the storage,transportation and sales of chilled beef and the effects of different aging time on the quality of subsequent freezing process of frozen beef.By analyzing the eating quality,oxidation characteristics and microstructure of beef,we can provide technical support for enterprises to produce high-quality products,reduce losses,extend shelf life,improve economic benefits and expand market in the fresh beef industry.Based on the above problems,this dissertation studies chilled beef and frozen beef respectively.The specific research contents and conclusions are as follows:(1)The effects of different aging methods on the quality of chilled fresh beef.Longissimus dorsi muscle from the carcass of beef cattle after slaughter was taken and stored at 4 ℃ for 7 days in all treatment groups.During the storage process,normal dry aging was performed for 0-7 days and the corresponding vacuum packaging wet storage stage was performed for the remaining time.After the treatment,the eating quality,oxidation characteristics and microstructure of the samples were respectively detected and analyzed.The results showed that different ways of aging had significant effects on p H value of chilled fresh beef,and the treatment of dry aging three days then wet aging had the best effect of the p H value.The water holding capacity of chilled fresh beef increased gradually with the increase of dry aging time.The combination of dry and wet aging showed lower shear force and better texture characteristics,and the meat color and the color stability were also significantly improved.There was no significant difference in the freshness,lipid oxidation and protein oxidation degree of chilled beef treated by different aging methods.The changes of the fragmentation index,degradation degree of myofibrillar protein and sarcomere length further confirmed and explained that the tenderness of chilled fresh beef increased first and then decreased.In general,the combination of dry and wet aging at appropriate time can significantly improve the quality of chilled fresh beef.(2)Effect of different time of aging on quality of frozen beef.Longissimus dorsi muscle from carcasses after slaughter was taken and the control group was frozen immediately without aging.The other seven groups were stored in the aging storage at 4 ℃ for 1-7 days,and then vacuum packed and transferred to the refrigerator at-18 ℃ for one week.After freezing,the samples were thawed at 4 ℃ for 24 h,and the eating quality,oxidation characteristics and microstructure of the samples were detected and the results were analyzed.The results show that the eating quality of frozen beef decreases first and then increases gradually,the water holding capacity increases gradually,the shear force increases first and then decreases,and the texture characteristics of frozen beef also decreases first and then increases with the increase of the time of aging after slaughter.These changes are related to the stiffness and the release of stiffness of beef after slaughter.The meat color and color stability of frozen beef decreased with the increase of the time of aging.Freshness is also decreasing.The degree of lipid oxidation and protein oxidation of frozen beef was not affected by the time of aging,but with the increase of aging time,the damage degree of frozen beef muscle structure decreased first and then increased,that is,the tenderness decreased first and then gradually increased.In conclusion,adequate aging time after slaughter can improve the tenderness and other eating quality characteristics of frozen beef.In conclusion,for chilled beef,the appropriate time of the combination treatment of dry and wet aging can significantly improve the quality of beef.Among them,the water holding capacity,tenderness and meat color of chilled beef which was drained of dry aging for 4 days and then drained by wet method are significantly improved,which is a suitable production method to improve the quality of beef.For frozen beef,different aging time has a significant effect on the quality of frozen beef.The beef that was frozen 3 days after aging after slaughter had a better effect on the water holding capacity and tenderness,and was feasible in practical production.