Effects Of Physiological Differences And Preservation Temperature On Taste Components Of Grass Carp Meat

With the continuous development of freshwater aquaculture fisheries in China,China's freshwater fish production is increasing year by year.The grass carp as China's "four big fish" is one of the largest annual output freshwater fish.But the fishy fishy smell is not fundamentally resolved,some people can not accept,is one of the bottlenecks to restrict freshwater fish processing technology to promote and apply.In this paper,grass carp was selected as raw material,and the effects of slaughter measures,fish sizes,seasons and storage temperature on the taste and freshness of various parts of grass carp were studied.The effect of different slaughter measures(natural,urgent kill,removed gills)on the taste and freshness of grass carp were studied.Use grass carp(dorsal meat)as the research object,the content of nucleotide compounds and free amino acids in dorsal meat of grass carp was studied by the HPLC and Amino Acid Auto-analyzer,and determined the p H value,the content of glycogen and lactic acid.The results showed that the percentage of bitter amino acids of the total free amino acids in dorsal grass carp meat by different slaughter measures were 78.95%,68.60%,69.44%,respectively.K value of dorsal grass carp meat by different slaughter measures were 20%,15%,12%,respectively.In nathral group,the content of ATP and IMP was the lowest and the freshness was the worst.The changes in the p H and the changes of the lactic acid content was negatively correlated,the changes of the lactic acid content and the changes in glycogen content was negatively correlated in dorsal grass carp meat by different slaughter measures.The lactic acid content of nathral group was the hightest,and the p H was the lowest.The effect of water-soluble flavor components in grass carp meat by different slaughter measures was large.The taste of natural group was the worst and the taste between urgent kill group and removed gills group was not obvious.The effect of different age on the taste and freshness of grass carp were studied.Use grass carp(dorsal meat,belly meat,red meat)as the research object,changes of water-soluble flavor components in grass carp at different sizes was studied by the HPLC and Amino Acid Auto-analyzer,and determining the content of p H,glycogen and lactate.The results showed that the percentage of sweet amino acids of the total free amino acids in small grass carp meat was 78.95%,8.60%,69.44%,respectively.The percentage of large grass carp meat was 26.04%,29.01%,30.24%,respectively.K value of large grass carp meat was 13%,20%,74%,respectively.K value of small grass carp meat was 19%,26 %,81%,respectively.The p H and glycogen content in small grass carp meat were higher than in large grass carp meat,the lactic acid content in small grass carp meat was less than in large carp meat.The glycogen content at different growth stages of red grass carp meat was higher than the dorsal meat and belly meat,p H was less than the dorsal meat and belly meat.The changes in the p H and the changes of the lactic acid content was negatively correlated,the changes of the lactic acid content and the changes in glycogen content was negatively correlated.The effect of water-soluble flavor components in grass carp meat by different growth stages is large.The effect of different seasons on the taste and freshness of grass carp were studied.Use grass carp(dorsal meat,belly meat and red meat)as the research object,The effects of spring,summer,autumn and winter on the content of free amino acids and the contents of nucleotides in different parts of grass carp were studied by high performance liquid chromatography(HPLC)and automatic amino acid analysis.The results showed that the percentage of flavor amino acids of the total free amino acids in dorsal grass carp meat was 27.79%,13.92%,26.99%,36.82%,respectively.In belly meat was 30.68%,13.98%,25.34%,32.85%,respectively.In red meat were 34.32%,24.88%,31.45%,39.09%,respectively.The lower was the temperature,higher the percentage of amino acid content will be.K value of dorsal grass carp meat were 7%,22%,20%,2%,respectively.In belly meat was 8%,27%,24%,3%,respectively.In red meat were 31%,58%,54%,13%,respectively.The lower was the temperature,the better the freshness will be.At the same season,flavor amino acid content was the lowest and freshness was the worst in red meat.The effect of different storage temperature on the taste and freshness of grass carp were studied.Use grass carp(dorsal meat,belly meat and red meat)as the research object,The effects of 4,-20 and-80? storage conditions on the content of free amino acids and the contents of nucleotides in different parts of grass carp were studied by high performance liquid chromatography(HPLC)and automatic amino acid analysis.The results showed that the percentage of flavor amino acids of the total free amino acids in dorsal grass carp meat was 41.69%,41.84%,42.40%,respectively.In belly meat was 38.39%,39.91%,40.29%,respectively.In red meat were 31.34%,32.34%,32.82%,respectively.The lower was the storage temperature,higher the percentage of amino acid content will be.K value of dorsal grass carp meat were 26%,15%,15%,respectively.In belly meat was 33%,20%,16%,respectively.In red meat were 90%,49%,45%,respectively.The lower was the storage temperature,the better the freshness will be.At the same storage temperature,flavor amino acid content was the lowest and freshness was the worst in red meat.In the process,taking a quick lethal and avoiding fish blood into the muscles will result in the earthy smell of fish.It should be suitable for consumers to select 1.5kg grass carp in the process.The best food period of grass carp is winter and spring,the highest nutritional value of fish.Quickly frozen should be selected to maintain freshness and good taste in the process.