Effects Of Heating Methods On ATP-related Compounds And Free Amino Acids In Penaeus Vannamei

Heating is a necessary method for the processing of cooked shrimp products,but the research on the main flavoring substances of Penaeus vannamei during the heating process is not deep enough.In this paper,the effects of different heating methods on ATP-related compounds and free amino acids in Penaeus vannamei were studied,and the changing laws of the two main flavoring substances were discussed,which laid a theoretical foundation for the processing of cooked shrimp products.(1)A comparative study was conducted on the changes of ATP related compounds and the K,G and P values of the freshness of Penaeus vannamei before and after heating during storage.With the increase of storage time,the content of ATP(Adenosine triphosphate),ADP(Adenosine diphosphate)and AMP(Adenosine monophosphate)decreased,the content of IMP(Hypoxanthine nucleotide)increased first and then decreased,and the content of HX(Hypoxanthine)and HXR(Inosine)increased.K value,G value and P value increased linearly before and after heating,but G value of raw shrimp had a poor correlation with freshness,which was not suitable as a freshness index.K value and P value could be used as a freshness index of raw shrimp.The K value,G value,P value,storage time,sensory quality evaluation value(QI value)and the linear regression equation of the values of K value,G value and P value after heating are better,indicating that K value,G value and P value can be used to characterize the quality of cooked shrimp.(2)The content of ATP related compounds,TAV of major flavor nucleotides and umami dynamics in penaeus vannamei during constant temperature heating were studied.In the range of 25-45?,IMP increased with the increase of heating time,and decreased with the increase of heating time in the range of 50-75?.AMP content increases with the increase of heating temperature and decreases with the increase of heating time.The change of TAV value was consistent with that of IMP and AMP,which was conducive to the production of umami substances in penaeus vannamei at lower heating temperature.When the shrimps were heated at high temperature,umami substances were degraded continuously,but sweet substances tended to be enhanced.At 25-45?,the kinetic equation between the IMP generation rate and the temperature is K=4.55×109e-5254/T,and at 50-75?,the kinetic equation between the IMP degradation rate and the temperature is K=1.02×109e-7207/T(3)The prawns were heated by frying,steam,boiling,microwave and infrared.The results showed that infrared heating and microwave heating alone could obtain a higher content of flavor-presenting active substances.From the perspective of EUC value and peak value of electronic tongue,the methods of infrared heating and microwave heating were more conducive to the formation of flavor components.(4)The effects of microwave-infrared combined heating on the flavoring activity of Penaeus vannamei were studied.The results showed that the flavorless nucleotide content,the total amount of free amino acids,the EUC value and the peak value of the electronic tongue were superior to that of the single heating.In the combined heating,microwave heating at 60? and infrared heating to 90? is the best heating method,and its flavor index is significantly higher than other heating methods.The sequence of heating methods and heating conditions have great influence on the flavoring content of Penaeus vannamei.