Lipid Extraction And Flavor Quality Analysis Of Antarctic Krill

In this paper,the Antarctic krill?Euphausia superba?was used as the research object,and the conditions for extracting shrimp oil with different organic reagents were optimized.The quality analysis and nutritional evaluation of the Antarctic krill shrimp oil index were carried out.The volatile flavor components of different fishing months in the 48.1 area were analyzed.The relative odor activity value?ROAV?was used to analyze the contribution of volatile flavor components to the overall flavor,and the similarities and differences of key flavor components of Antarctic krill in different months were compared.On this basis,the content of each flavor component was determined and compared by TAV method.Its contribution to the taste of Antarctic krill was evaluated by the MSG equivalent method?EUC?for the umami intensity in Antarctic krill.The content of free amino acids in different fishing months was determined and compared and analyzed.Compare the differences in the taste of Antarctic krill in different fishing months.1.The shrimp oil was extracted from the frozen Antarctic krill with n-hexane-anhydrous ethanol mixed reagent.The optimum extraction conditions were:n-hexane-anhydrous ethanol?10:1?,the ratio of material to liquid was 1:10,extraction time For 180 min,the agitation speed was300 r/min.The yield of shrimp oil extracted under this condition was 2.76±0.02%.According to the index analysis of Antarctic krill oil,the four indicators of acid value,peroxide value and insoluble impurities of Antarctic krill shrimp oil reached the standard of first grade crude shrimp oil.The water and volatile content are higher,and the acid value is also higher.It may be due to the slow hydrolysis of the oil by the lipase in the body during transportation and storage,and some free fatty acids are formed.The analysis of fatty acid composition of the obtained Antarctic krill oil showed that 32 kinds of fatty acids were identified from shrimp oil,which were composed of C12^C24,mainly composed of C₁₄:0,C₁₆:0,C₁₆:1,C1₈:1N₉T,C₁₈:1N₉C.Among them,monounsaturated fatty acids accounted for 32.25%,polyunsaturated fatty acids accounted for 37.98%,oleic acid content was as high as 21.80%,and EPA and DHA content were as high as 14.53%and 8.78%,respectively,showing that Antarctic krill shrimp oil has a higher nutritional value can increase the necessary unsaturated fatty acids for the human body.2.By analyzing the volatile substances in the Antarctic krill meat from August to August in the Antarctic waters,the characteristics of the antarctic krill smell with the month were analyzed.The changes of volatile components were analyzed by gas chromatography-mass spectrometry?GC-MS?.The key flavor compounds of Antarctic krill were determined by ROVA method,and the overall flavor was analyzed by electronic nose.The results showed that the main flavor substances of Antarctic krill were mainly aldehydes;the main flavor substances in March and April were less,mainly furfural and furfural.The main flavor substances increased significantly from May to August,and there were furfural and furfural,3-methylbutanal,2-methylbutanal,phenylacetaldehyde,1-octyl-3-ol,and the like.D-lemon is rare in all months,but the threshold is lower,which is presumed to have a certain modification effect on the formation of Antarctic krill flavor.This change may be related to the growth characteristics,feeding characteristics and seasonal changes of Antarctic krill.The results obtained by PCA analysis using electronic nose were consistent with GC-MS,indicating that the antarctic krill volatiles became more abundant as the month changed.3.By measuring the content of each flavor component and comparing its contribution to the taste of Antarctic krill by TAV method,the flavor intensity of Antarctic krill was evaluated by the MSG equivalent method?EUC?.The content of free amino acids in different fishing months was determined and compared and analyzed.The results showed that the total amount of taste nucleotides in the Antarctic krill shrimp meat was not much different from March to June,and the total amount of taste nucleotides in the Antarctic krill shrimp meat was higher in July and August.The AMP content in each month is much higher than other taste nucleotides.In the middle to south Antarctic krill shrimp meat from March to August,the content of IMP is also higher.The content of bitter nucleotides Hx and HxR in 7-8 months was higher than other months,which may be due to their eating characteristics.16 kinds of free amino acids were detected in the Antarctic krill shrimp meat from the fishing month.The glutamic acid was not measured.The taste characteristics and TAV of several amino acids were considered.The antarctic krills were more savory and sweeter in different months.Antarctic krill is sweeter than umami,and with the increase of the month,the taste and sweetness of Antarctic krill is increasing,presumably due to changes in the Antarctic season.