Influence Of Partial Replacement Of NaCl With KCl On The Flavor Quality Of Dry-cured Duck

Dry-cured duck is a traditional Chinese cured meat product with a long history.It is favored by consumers because of its unique taste and rich flavor.However,the high salt content is harmful to the human body,reducing the sodium salt content is of great significance to human health diet.In this paper,headspace solid phase microextraction-gas chromatography-mass spectrometry was used to determine the volatile flavors of dry-cured ducks in different regions,and the key flavor substances of Leiguan dry-cured ducks were determined.Then the Leiguan dry-cured ducks were used to study the basic physical and chemical indicators of different proportions of KCl instead of NaCl in the processing of Leiguan dry-cured ducks,the degree of oxidation of fat,the composition and content of fatty acids,the activity of endogenous enzymes,microorganisms and key flavor compounds.Finally,in order to make up for the effect of potassium salt substitution on the flavor of dry-cured ducks,the effect of exogenous lipase on the flavor quality of dry-cured duck was studied in order to improve the flavor characteristics of dry-cured ducks.The results show that:(1)OAV analysis obtained 11 key flavor compounds,among which benzaldehyde and(E,E)-2,4-nonadienal were key flavor substances common to dry-cured ducks in 6 different regions;hexanal,nonanal,naphthalene,(Z)-2-heptenal,(E)-2-octenal,(E)-2-alkenal,1-octene-3-ol,2-n-pentylfuran and linalool are the main substances that affected the flavor difference of dry-cured ducks in different regions.Through OAV,the key flavor compounds of Leiguan dry-cured ducks were hexanal,(E)-2-octenal,nonanal,(E)-2-acetal,benzaldehyde,1-octene 3-alcohol,Linalool and(E,E)-2,4-nonadienal.Principal component analysis and cluster analysis showed that the origin of dry-cured ducks may be the same,and various local dry-cured ducks appeared due to different factors such as region,duck meat variety and processing technology.(2)During the processing of Leiguan dry-cured ducks,the water content and water activity decreased significantly(P<0.05),while the salinity increased significantly,and decreased significantly with the increase of KCl substitution ratio(P<0.05),salinity and water activity.There was a negative correlation between moisture content and moisture content.In terms of microorganisms,with the increase of KCl substitution ratio,several bacteria had an increasing trend in various processing processes,indicating that the sodium salt had better antibacterial effect than potassium salt.(3)In the late stage of air-drying,as the substitution ratio of potassium salt increases,the enzyme activity rises,releasing more free fatty acids and promoting fat oxidation.When more than 30% KCl was substituted,both TBARS and POV increased significantly(P<0.05).Hexanal,(E)-2-octenal,nonanal,(E)-2-alkenal increased with the substitution ratio of potassium salt,especially when 45% KCl was replaced,the content was significantly higher than other groups(P<0.05).).In the taste and overall acceptance,the 15% potassium salt substitution group was not significantly different from the control group(P>0.05);the 30% potassium salt substitution group had differences in sensory analysis,which was lower than the control group score.The score of the 45% potassium salt replacement group was lower than that of the others(P<0.05),and the fat was over-oxidized,which affected the sensory quality.(4)With the increase of lipase addition,acid lipase showed an increasing trend,while the activity of neutral lipase showed a decreasing trend.Phospholipase increased first and then decreased between groups,reaching the maximum value in P1.The proper addition of lipase can promote the lipid degradation and lipid oxidation of low-salt dry-cured ducks,provide a lipid-derived flavor precursor for the formation of unique flavors,and improve the sensory quality of ducks.While the amount of lipase added is 0.11%(P4),it caused excessive oxidation of low-salt dry-cured duck,the quality of the dry-cured duck was deteriorated,which was unfavorable to the safety of the products and affects the storage period.Comprehensive physical and chemical indicators,sensory analysis,key volatile flavor compounds and principal component analysis results can be obtained,0.05% lipase can increase the sensory quality of the ducks.