Study On The Freshness And Quality Of Beef Under Different Storage Temperatures

With the development of social and economy, and the improvement of consumption level, people are turning to demand for nutrition and health. Beef consumption is also rising. Due to different slaughtering, transportation, storage methods and so on, the quality of raw meat has a greater difference, which would seriously affect the quality of meat products. So study on the change of quality of beef in different storage conditions has an important impact on factory production, processing, and consumer daily lives. In order to explore the effect of different storage temperature conditions on beef quality, fresh beef were placed at 20 ?,10?, refrigerated storage (2?4?), frozen (-15?-18?) and in 1d,2.5d,6d and 210d to detect freshness (TVB-N content) and quality indicators (moisture content, water holding capacity, pH, TPA, fatty acids, etc.). To explore the change rules of each index, and provide some guidance for judging beef quality at different storage temperature and period. Test results were as follows:(1) Analysis change rules of freshness indicator. TVB-N content of beef stored at 20 ?,10?, refrigerated storage and frozen were increased with storage time prolonged highly significantly (p<0.01). Beef at 20?stored 8h was no longer fresh and went bad after 24h, beef at 10? stored 24h was no longer fresh and went bad after 60h, beef under refrigerated storage was no longer fresh after 2d and went bad after 6d, frozen beef stored 85d was no longer fresh and did not go bad after 210d. TVB-N content of beef storage 1d at different temperatures increased with decrease storage temperature significantly (p?0.01). So reduce storage temperature could better maintain freshness of beef.(2) Analysis change rules of quality indexes and based on the time point of fress and bad at different storage temperatures of beef. Beef at 20 ?,10? and refrigerated storage, moisture content, water holding capacity, hardness, total fatty acids and other indicators with storage time prolonged high significantly reduced (p<0.01). Moisture content of beef at 20 ? stored 8h,10? stored 24h and refrigerated storage after 2d respectively decreased by 8.00%,4.00% and 3.00% compared beef stored Oh, beef stored 24h at 20 ?,10? stored 60h and refrigerated storage after 6d all decreased 10.00% compared beef stored Oh. Total fatty acid content of beef at 20? stored 8h and 24h respectively decreased 7.00% and 27.00%, the total fatty acid content of beef at 10?stored 24h and 60h respectively decreased 7.60% and 23.67%, total fatty acid content of refrigerated storage beef stored 2d and 6d respectively decreased 5.24% and 22.11%. Hardness of beef at 20? stored 8h and 24h were 69.00% and 42.00% of beef stored Oh respectively, hardness of beef at 10? stored 24h and 60h were 69.60% and 52.40% of beef stored Oh respectively, hardness of refrigerated storage beef stored 2d and 6d were 74.50% and 46.00% of beef stored Od respectively. Beef at 20?,10? and refrigerated storage, pH value changes showed an first drop then rise trend (p<0.01). Moisture content and water holding capacity indicators of frozen beef showed a stable trend after the first drop and pH gradually increased (p<0.01), frozen beef moisture content stored 15d dropped to 74.00% and in 15?210d were in the 74.00% plus or minus. Hardness, chewiness and other texture indexes decreased gradually (p<0.01), hardness of frozen beef stored 85d and 210d were 71.00% and 26.40% of beef stored Od. Total fatty acids, monounsaturated fatty acids and other fatty acids indicators with the storage period decreased highly significantly (p<0.01), total fatty acid content of frozen beef stored 85d and 210d decreased 14.80% and 24.00% compared beef stored Od. Beef at different temperatures stored Id, water content, water holding capacity, hardness, total fatty acid and other indicators highly significantly increased with the decrease of temperature (p<0.01).(3) Correlation analysis of these indicators. Beef stored at 20?,10?, refrigerated storage and frozen stored Id, TVB-N content and moisture content,water capacity hardness, chewiness had a more high correlation (p<0.01). So change of freshness index could predict variation of other indexes under certain condition.