Effect Of High Temperature Treatment On Beef Fat And Volatile Flavors

With the development of economic and the improvement of residents' health awareness.Beef as one of high-quality edible meats,still has huge growth potential.At present,most domestic researches on beef focus on traditional beef product processing technology,improvement of processing technology and technology of fermented beef and low-temperature beef products technique and study.However,there are few studies on high-temperature processing of beef,especially oxidative degradation of fat during processing and the changes of volatile flavor substances.Based on that,in this experiment,we studied the changes of oxidation degree,fatty acid composition and content of beef intramuscular fat under different high temperature conditions and the changes in the composition and content of volatile flavor substances under high temperature treatment,in order to provide reference for flavor and quality regulation of high temperature beef products.The main results are as follows:(1)The degree of beef intramuscular fat oxidation increased significantly with the increase of temperature and time(P<0.05),and when dealt with 121?,the rate of intramuscular fat oxidation increased significantly compared with other temperature treatment groups(P<0.05).Therefore,when beef products are treated at high temperatures above 121?,the treatment time should be strictly controlled to avoid unpleasant odors for excessive oxidation of fat.(2)With the increase of temperature and time,the contents of unsaturated fatty acids(UFA)and polyunsaturated fatty acids(PUFA)decreased significantly(P<0.05),while monounsaturated fatty acids(MUFA)did not change significantly.SFA was not significantly affected by temperature changes(P>0.05),and the content of SFA increased significantly with the increase of heat treatment time(P<0.05),but the temperature and time of heat treatment had a significant effect on UFA content(P<0.05).In addition,the study found that long-chain saturated fatty acids may break or degrade during high-temperature heat treatment and generate short-chain fatty acids or medium-chain fatty acids with anti-cancer and hypolipidemic functions can be used as the next research direction.(3)In the process of high temperature treatment,the types of volatile flavor materials gradually decrease with the increase of heating time.Among them,Aldehydes and ketones are the main flavors of beef,accounting for 69% to 83% of the total flavor of beef;The content of ketones,ketones,and hydrocarbons increased significantly(P<0.05),but the high temperature treatment time had no significant effect on it(P>0.05);the content of acids and esters showed a gradual downward trend during the high temperature treatment(P<0.05).When treated at 110?,the total content of volatile flavor substances gradually increased with the extension of heating time.At 115? and 121?,the total content was not significantly affected by the treatment time(P>0.05).(4)The main component analysis of beef flavor substances found that the effect of different high-temperature treatment conditions on beef flavor was obvious.Among them,the difference between the flavor of fresh beef and the high-temperature processed beef samples was larger.At 15?,the two treatment groups were similar in flavor.Cluster analysis found that if the 13 treatment groups were divided into three groups,110? 5min,110? 10 min,110? 15 min,115? 5 min and 115? 10 min were a group;110? 20 min,115? 15 min and 121? 5 min were One group;115?20 min,121? 10 min,121? 15 min and 121? 20 min as a group,the similarity of flavor substance content between the groups is close.