Effects Of Packaging Methods On Quality And Microflora Of Conditioning Steak During Chilled Storage

Steak is the most common product of western food.Because of its fresh taste and unique flavor,steak is more and more popular among young people in China,but sometimes Consumers find it inconvenient because of its high price and special dining environment.As a result,steak conditioning has emerged in the meat market in recent years.Conditioning steak is the steak that is stored at low temperature after the treatment of tenderness,pickling,This steak can be eaten in a simple way.This type of product is extremely convenient for young consumers.At present,most of these products are stored at freezing temperatures,however,freezing and thawing processes can lead to a decline in the quality of the steak.so,this topic used cold fresh beef ribs as raw material,making conditioning steaks and then packed through tray packaging,high oxygen packaging?80%O₂,20%CO₂?,low oxygen modified packaging?30%O₂,30%CO₂,40%N₂?and vacuum packaging,respectively.then refrigerated in a refrigerator at 4°C.Meanwhile,the quality and bacteria phase of the steak were monitored,to provide objective experimental data for producing low-temperature conditioning steaks with high-quality.Those experiments were carried out through the following four aspects:1.Using the comprehensive evaluation index as the response value to optimize the formula of conditioning steak marinating solution.Studies have shown that:the highest comprehensive evaluation index was13.8113 obtained at 1.5%of salt,0.8%of spices,0.15%of composite phosphate,4.0%of cooking wine,0.3%of papain.Meanwhile,the tenderness?shear force 12.36 N?,water retention?pressurized water loss rate 20.37%?and texture properties of conditioning steak were good.In addition,Total volatile basic nitrogen?TVB-N?2.10 mg/100g,Thiobarbituric acid?TBA?0.16 mg/kg,total colonies 2.6×10² cuf/g and coliforms are all in line with national standards.2.Utilizing low-field NMR technique to study the distribution of water phase and the change of water retention in the process of frying.Studies have shown that with continuous cooking,the cooking loss rate and pressurized water loss rate of butter,salad oil,and olive oil processing group were all significantly increased.Among them,the cooking loss rate and pressurized water loss rate of butter was the highest,followed by salad oil and olive oil.The inflexible water content P₂₂2 was:olive oil processing group>salad oil processing group>butter processing group,however the free water content P₂₃ was:butter processing group>olive oil processing group>salad oil processing group.Comprehensive consideration,the water retention properties of butter,salad oil,and olive oil were:olive oil processing group>salad oil processing group>butter processing group.3.Using tray packaging,high oxygen packaging?80%O₂,20%CO₂?,low oxygen packaging?30%O₂,30%CO₂,40%N₂?and vacuum packaging to deal with conditioning steak,respectively.Then storing at 4?and measuring physicochemical indexes,microbial indicators and color of steak.Studies have shown that the pH value,TVB-N,TBA,L*value and the total number of colonies were continuously increased with the extension of storage time at 4?,however the a and b values were continuously decreased.Based on the comprehensive indicators,the shelf life of conditioning steak stored at 4?with trays packaging,high-oxygen-adjusted packaging,low-oxygen-adjusted packaging and vacuum packaging were 6 d,6 d,12d,and 14 d,respectively.4.Using High-throughput sequencing technology to study the changes of bacterial phase during storage of low-temperature conditioning steaks with different packaging methods.The results showed that the predominant spoilage bacteria stored at 4?for high-oxygen packaged and low-oxygen packaged conditioning steak was Broochthrix?92.29%and 92.20%,respectively?.As for the steak with tray packaging,the dominant spoilage bacteria were the genus Boochothrix?45.26%?,Psychrobacter?38.36%?,and Pseudomonas?12.23%?;and the dominant spoilage bacteria in vacuum packaging were Broochthrix?27.30%?,intestine Enterococcus?18.71%?,Yersinia?14.28%?,Lactococcus?13.05%?.