Effect Of Drying Temperature On Storage Quality Of Air-dried Beef Prepared By Pulse Pressure

Dried beef is a traditional dried product in Xinjiang,which has a long history and unique flavor.The production process is simple but takes a long time,which is not conducive to the development of dried beef.Therefore,this subject has conducted an in-depth study of dried beef in Xinjiang: Using Xinjiang brown cow hind leg as raw material,pulsating pressure equipment for curing for 36 h,in which high pressure 140 k Pa,maintain 5 min,maintain atmospheric pressure for 20 min,and then in different The dried beef was dried and cooled at(30 °C,50 h,group A,40 °C,20 h,group B,50 °C,12 h,group C and 60 °C,8 h,group D).After being vacuum-packed,they were stored in a refrigerator at-4°C and sampled at 0 d,3 d,6 d,9 d,15 d and 21 d.(1)Effect of drying temperature on protein degradation during storageBy studying the effect of drying temperature on the protein degradation of air-dried beef,the results showed that with the prolongation of storage time,the moisture content at each temperature gradually decreased(P < 0.05);cooking loss during the storage process has a certain fluctuation,each temperature The difference was significant(P < 0.05).At the end of storage,the odor,mouthfeel and overall acceptability of the samples in the C group were the highest.The taste,taste and overall acceptability of the D group were the lowest(P > 0.05);the elasticity did not change significantly during the whole storage period(P > 0.05).The carbonyl content of myofibrillar protein was significantly increased(P < 0.05),with the largest increase trend in group D;the total sulfhydryl content was significantly reduced(P < 0.05),and remained the lowest level in the first 15 days;SDS-PAGE results showed that: Fibrin was degraded during the storage period.The myofibrillar protein bands in group A,B,and C were enhanced on the 15 th day after storage,while the protein degradation in group D was enhanced on the 9th day.To sum up the above parameters,the temperature in group C can better maintain the protein quality.(2)Effect of drying temperature on endogenous enzyme activity during storageBy measuring the changes of the three endogenous esterase activities of acid lipase,neutral lipase and phospholipase.The results showed that during the storage process,the relative sizes of the three enzyme activities were the activities of acidic lipase>neutral lipase>phospholipase;the three enzyme activities showed a downward trend and maintained high viability;for different drying temperatures The activity of the enzyme in group A was the highest,followed by group B,and the activity in group D was the lowest.The neutral lipase and phospholipase in group B showed the highest enzyme activity,and the activity in group D was the lowest.This indicates that the temperature in group B can activate endogenous enzymes,increase enzyme activity,and maintain the highest enzyme activity during storage.The correlation analysis showed that the three enzyme activities at four drying temperatures were all positively correlated with p H,with phospholipase positively correlated with p H(P < 0.05),negatively correlated with salt content,and significantly negatively correlated with phospholipase(P < 0.05).There was a significant positive correlation between neutral lipase and phospholipase,suggesting that these two enzyme activities are regulated by the same factor.(3)Effect of drying temperature on flavor of air-dried beef during storageA total of 169 compounds were detected in 8 groups(hydrocarbons,alcohols,ketones,aldehydes,acids,esters,ethers,and others)in each group of dried beef,of which 139 components were detected in group A.In group B,103 were detected,119 were C,and 97 were in group D.Hydrocarbons,acids,esters,ethers,and aldehydes are the five most abundant species.The total area of ??flavor substances showed a downward trend during storage(except for group C).The optimal temperature for the formation of ethers,esters,acids and aldehydes in group C was found.The highest levels of C in the end of storage were found in ethers(24.76%),esters(30.01%)and acids(20.71%).),and higher than the 0 d content,indicating that storage is conducive to the production of ethers,esters and acids.Analyzing the changes of the main flavor components at different temperatures,we can see that different materials have different rules during the entire storage period.Principal component analysis showed that limonene and its isomers,ethyl caproate,propylene propyl anisole,?-curcumene,furfural,2,4-hexadienoic acid,and ethyl sorbitol contributed much to the main flavor of air-dried beef.