Flavor Quality Characteristics And Effects Of Passage On Flavor Of Red Shell Meretrix Meretrix

Meretrix Meretrix is an important economic shellfish in China and it is popular among consumers for its nutritional quality and palatable taste.Meretrix meretrix with red shell is considerable economic benefits due to its unique festive color and less abundant in nature.With the development of aquaculture breeding,propagation and cultivation technique,a new strain of Meretrix meretrix with the advantages of fast growth rate,strong stress resistance and high yield has been artificially bred and realized large-scale breeding.Flavor is the important factor affecting the market acceptance and product value of Meretrix meretrix.However,there is still a lack of systematic research on the flavor quality characteristics of Meretrix meretrix with red shell,the difference in edible quality between red shelled and other strains Meretrix meretrix and its material basis are still unclear.What's more,the quality stability of the new strain Meretrix meretrix during the breeding of generation is also unclear.The improvement of breeding efficiency and the development of industry of red shell Meretrix meretrix are restricted.Therefore,in this paper,Meretrix meretrix with red shell was taken as the research object.Firstly,quality differences between red shell Meretrix meretrix and market-leading Meretrix meretrix,mottled shell and yellow shell,were comprehensively evaluated from nutritional composition,quantitative analysis of flavor active substances and changes in flavor quality during the cooking process.Then,based on the main flavor quality indicators of Meretrix meretrix,a comprehensive quality evaluation model of Meretrix meretrix was established by correlation and principal component analysis,and the model was verified by sensory evaluation.Finally,the changes of flavor quality during the breeding of generation of Meretrix meretrix with red shell were further studied.This research has academic value for the exploration of the flavor quality characteristics of red shell Meretrix meretrix and the material basis of its umami taste,as well as the revealing of the influence of passage on the flavor quality of red clam Meretrix meretrix.Meanwhile,it is of practical significance for constructing the quality evaluation method of economic shellfish and promoting the development of Meretrix meretrix culture industry.1.In order to explored the difference of quality between red shell and other strains of Meretrix meretrix,the edible quality characteristics of red shell and market-leading Meretrix meretrix before and after cooking were studied by physical characteristics,basic nutrients,non-volatile taste and volatile odor.The results showed that there was no significant difference in the basic nutrients of Meretrix meretrix with different shell colors.In terms of taste,the overall taste profiles of three kinds of shell color Meretrix meretrix before and after ripening were different.Alanine glutamate,arginine,glycine,adenosine monophosphate(AMP),Cl^-,Na⁺,K⁺,PO₄^3-and glycogen were the important taste substance before and after cooking.The content of important taste substances of Meretrix meretrix was decreased except PO₄^3-and glycogen after cooking.Before being cooked,red shell Meretrix meretrix had a taste advantage in equivalent umami concentration(EUC)and inorganic ions but had no obvious taste advantage after being cooked.In terms of odor,the overall odor of Meretrix meretrix with different shell colors was different before cooking,while there was little difference in the odor between red and yellow shell Meretrix meretrix after cooking.The main volatile compounds of raw and cooked Meretrix meretrix were alcohols and aldehydes.The contents of main volatile compounds and volatile odor compounds of red shell Meretrix meretrix were the highest before and after cooking.2.In order to establish an evaluation method for the flavor quality of Meretrix meretrix,20 flavor quality indicators of raw Meretrix meretrix and 15 flavor quality indicators of cooked Meretrix meretrix were selected with taste active value(TAV)greater than 1.And a comprehensive evaluation model of Meretrix meretrix quality was established by correlation and principal component analysis.The results show that there was significant(P<0.05)or extremely significant(P<0.01)correlation between quality indicators of raw and cooked Meretrix meretrix,and the quality of cooked Meretrix meretrix could be inferred by raw Meretrix meretrix.The main quality indicators of raw Meretrix meretrix was analyzed by principal component analysis,and the comprehensive evaluation model was obtained:Z=-0.204X₁+0.055X₂+0.112X₃-0.156X₄-0.087X₅+0.052X₆-0.106X₇-0.166X₈+0.223X₉+0.206X₁₀+0.142X₁₁+0.220X₁₂+0.196X₁₃-0.213X₁₄+0.219X₁₅-0.214X₁₆+0.013X₁₇+0.166X₁₈+0.162X₁₉+0.161X₂₀.The model was verified,and the prediction results were consistent with the sensory evaluation results,indicating that the model had reliability and applicability,and the higher the score of the model,the better the edible quality of Meretrix meretrix.3.In order to reveal the changes and stability of quality during the breeding generation of red shell Meretrix meretrix,the quality and metabolomics of different generations of red shell Meretrix meretrix were analyzed by qualitative and quantitative analysis of non-volatile taste,volatile odor and metabolites.The results showed that in terms of physical characteristics and basic nutrients,the size of the progeny of red shell Meretrix meretrix was larger than the original.With the increase of breeding generations,the size of red shell Meretrix meretrix showed an upward trend and to be stable after F₃.But there was no significant difference in the basic nutrients of different generations.In terms of taste,alanine,histidine,glycine,arginine,AMP,Cl^-,Na⁺,K⁺,PO₄^3-and glycogen were the important taste substances of red shell Meretrix meretrix with different generations.With the increase of breeding generations,the taste degree of red shell Meretrix meretrix showed an increasing trend,and the taste intensity of F₅ is significantly stronger than that of F₀.In terms of odor,the main volatile compounds of red shell Meretrix meretrix with different generations was alcohols.With the increase of breeding generations,the content of alcohols and total volatile compounds in red shell Meretrix meretrix showed an overall upward trend.The content of alcohols and total volatile compounds in F₄ and F₅ were higher than that in F₂ and F₃,and much higher than that of F₀ and F₁.The result of flavor quality model showed scores of F₀ and F₁ were relatively low,and the scores of red shell Meretrix meretrix was fluctuating up with the increase of breeding generations.In terms of metabolomics,the main discriminate metabolites between F₀ and F₁-F₅ were lipids,amino acids,carbohydrates,nucleosides.Compared with the original,the number of up-regulated metabolisms was much more than down-regulated metabolisms.Glycerophospholipid metabolism,alanine aspartate and glutamate metabolism,tryptophan metabolism were the main metabolic pathways during breeding of red shell Meretrix meretrix.