Study On Synthetical Preservation Technology Of Chilled Beef Meat

Based on procedure of beef slaughtering and processing in Haoyue corporation, this study included three sections, relating with synthetical preservation technology of chilled beef meat. Some hurdle factors were utilized synchronously in the whole procedure of preservation treatment, such as preservatives, pH value, vacuum package, and chilling, as well as HACCP total quality management system was. The results showed that shelf life of chilled beef meat was prolonged effectively, they were still the first grade fresh meat around 30 days afterwards, and up to the standard of the second grade fresh meat before the 60th day. Validation of amplificatory experiment proved that the data were exact and valid, and furthermore, they were applicable for mass production in large corporations. The three sections of experiment were summarized as follows:The first section was about the establishment of HACCP total quality management system in the process of beef production, from pre-slaughtering management to ripening. Based on hazard analysis of each working procedure, judging tree of critical control point was used to identify 6 critical control points: pre-slaughtering quarantine, washing spray, post-slaughtering inspection, finishing and washing spray, pre-chilling, and ripening. In the meantime, critical limit that each critical control point meet was confirmed, and monitor and adjust measure was founded as well. Finally, total bacterial counts were analyzed by Paired-Samples T Test through spot checking of meat-workers and tools on the whole procedure. Results showed that there was significant difference (P<0.01) between the sample data of pre-HACCP and post-HACCP, and thereby sanitary condition was also considered to have been improved since the implement of HACCP.The second section of experiment was the preservative effect of complex antimicrobialagents for chilled beef meat. Firstly, variations of bacteria formed during storage was analysed. Results showed that spectrum of G small bacillus was dominant bacteria that led to bacterial spoilage of unpackaged fresh beef during storage at 4℃, whereas spectrum of G+ cocci was the major bacteria that led to corruption of vaccum-packaged beef during storage at 4℃. Analysing the spectrum of bacteria and characteristics of preservatives, citric acid, sodium diacetate, and sodium erythorbate were selected as preservatives in this study. Preservative effect of the three antimicrobial agents was estimated through analysis of bacteria total counts, pH, and Total Volatile Basic Nitrogen (TVB-N). The TVB-N values were analyzed by analysis of variance. Results indicated that the three preservatives were obviously effective, with valid preservative concentration of citric acid, sodium diacetate, and sodium erythorbate at 0.6%, 0.6%, and 0.4% respectively. Orthogonal design of L9(34) was used to establish 9 complex preservative formulation, and TVB-N values were used as statistical evaluation index. Results indicated that A2B1C2 is the best combination in all groups.The third section was on the change of beef tenderness during the preservation. It is the first time that the variation of tenderness and the change of pH were studied. Results showed that Warner-Bratzler shear force (WB), which is denotating the index of tenderness, was increasing with time-lapse. Tenderness reached maximum at 45th day when it began to descend. For beef meat, its tenderness was not correlative with changes of pH during storage at 4℃. Rate of drip loss was the major factor that affected the change of tenderness. Tenderness of chilled beef meat prepared with the most optimised formulation of complex preservatives was the best in all experimental groups.