The Authentication Of Sea Duck Eggs Based On Different Analytical Methods

Sea duck eggs are produced by ducks that are mainly raised on the beach and fed on fish,shrimps,shellfish and algae in the shoal,they are top egg products.Sea duck eggs are widely distributed in coastal province such as Guangxi,Guangdong,Zhejiang and Shandong.Sea duck eggs have higher nutritional value,which makes them very popular among consumers.The industry of sea duck eggs shows a rapid upward trend.But at the same time,the phenomena of adulteration has occurred frequently.These growing food fraud activities will combat the further development of sea duck eggs industiy,cause huge economic losses in the duck egg industry,and cause a crisis of consumer confidence.Therefore,sea duck eggs were used as research objects,and cage duck eggs,low-priced adulterants,were used as adulterative objects in this study.Organic and inorganic substances in sea duck eggs and cage duck eggs were anlyzed comprehensivly based on different analytical methods.The different compounds between sea duck eggs and cage duck eggs were analyzed further to identify the authenticity of sea duck eggs.Untargeted metabolomics approach based on ultra high performance liquid chromatography-high resolution mass spectrometry was used to study the differences between sea duck eggs and cage duck eggs to authentication sea duck eggs.Multivariate statistical analysis was used to analyze the high-dimensional and complex data collected by UHPLC-HRMS.Principal component analysis showed clear separation of the sample groups.T-test and orthogonal partial least squares discriminant analysis were used to screen markers that showed a significant differences between different sample sets.After matching with the chemical database,it was assumed that four potential markers were matched.After confirming with the reference standards,1,2-dipalmitoyl-sn-glycero-3-phosphocholine,n-nervonoyl-d-erythro-sphingosine and n-behenyl-d-erythro-sphingosine were confirmed.To understand the reliability of these differential markers,quantitative analysis method was established for anlysing the content of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine,n-nervonoyl-d-erythro-sphingosine and n-behenyl-d-erythro-sphingosine in duck eggs based on UHPLC-Q-Orbitrap.Within their respective linear ranges,the correlation coefficients were greater than 0.99,which showed a good linear relationship.The recoveries were 86.9%?93.4%.The intra-day precision and the inter-day precision were lower than 5.3%and 8.4%,respectively.The validated quantification method was used to analyze three selected markers in experimental duck egg samples and commercial duck egg samples.The quantification analysis showed that the content difference of three markers in commercial samples were in highly consistent with the concentration changes measured in experimental samples,which indicated that these three markers are reliable.As the three selected markers are all lipid compounds,we speculate that sea duck eggs have higher lipid content.In order to comprehensive analyze the lipids in sea duck eggs,gas chromatography-mass spectrometer was use to analyze fatty acids in sea duck eggs and cage duck eggs.In their respective linear ranges,the limit of detections were 0.004?0.763 mg/L.The correlation coefficients were greater than 0.99,which showed a good linear relationship.The results showed that the content of eicosapentaenoic acid and docosahexaenoic acid in sea duck eggs is significantly higher than that in cage duck eggs.The fatty acid composition of sea duck eggs is more in line with human health needs.Besides organic,we also analyzed and detected the inorganic in the sea duck eggs to have a comprehensive understanding of components in sea duck eggs.Inductively coupled plasma-mass spectrometry was used to establish a method for the detection of 15 trace elements in duck eggs.The recoveries of the elements were 92.5%?110.2%,and the relative standard deviations were less than 5%.The recovery and precision were suitable for the detection requirements.The method is suitable for the quantitative analysis of elements in duck eggs.Analysis of the actual samples revealed that the contents of Cr,Mn,Se,Sr,Ba,and Zn in sea duck eggs were higher.At present,the research on the authentication of sea duck eggs has not been reported.This study will provide data support for the establishment of quality standards of sea duck egg products and provided new approaches for the resolution of food fraud incidents in the poultry egg industry.It has great significance for promoting the healthy and stable development of China's poultry egg industry.