The Rapid Detection Of Mutton Adulterated With Duck By Electronic Nose Combined With GC-MS

As a kind of meat with high content of nutrition,mutton is very popular with many people.What’s more,it’s the major meat resource in some areas. However,mutton adulteration can often be seen in the market,the phenomenon of expensive meat adulterated with cheap meat is common.In this research,the qualitative and quantitative discriminant of mutton adulterated with duck were established by the identification of electronic nose and GC-MS to the adulterated mutton samples.It aims to provide a basis for mutton adulteration.Mutton was adulterated with different ratios of duck after the two kinds of meat was minced.Multivariate analytical methods involving Loadings analysis,linear discriminant analysis were used to discriminate qualitatively,and linearization regression analysis was established to discriminate quantitatively with the samples’ responses to electronic nose.Finally,fisher linear discrininant analysis(FLDA) and multilayer perceptron neural networks(MLPN) were established.Meanwhile,gas chromatograph-mass spectrometer(GC-MS) was used to detect cooked meat samples to identify the adulterated meat samples from the macroscopic and microscopic aspects combined with the electronic nose.In addition,the detections of p H,chroma,cooking lose rate and moisture content to different adulterated meat samples were carried out to compare this method with E-nose.The results are as follows:(1) The result of electronic nose experiment:different adulterated meat samples could be discriminated well by LDA,and the result of raw meat was better than that of cooked meat.The coefficients of association of both raw and cooked meat samples in linearization regression analysis were higher than 85%. For the raw samples, the correct rate of using FLDA and MLPN to predict the adulteration ratio was both up to 100%. For the cooked samples, they were 98.2% and 96.5% respectively.(2) The result of GC-MS experiment:26 volatile compounds were detected.There were significant differences in the contents of most compounds(P<0.05).Several specific compounds,such as 3-Cyclohepten-1-one, Ethanethiol, Butanal, 3-methyl- and so on,were considered as the compounds which played a major role in distinguishing mutton adulterated with different ratios of duck.The contents of other compounds reduced as the contents of duckincreased,except several compounds which had a high content level in duck.(3) The model of partial least squares was established with the datas of electronic nose and GC-MS. The 4 regression equations’ determination coefficients were 95.0%,95.5%,96.6% and95.9%.Finally,there was a high correlation between the response values of sensors S1, S3, S5,S6, S8 and S9 and the result of GC-MS.(4) The detections of different adulterated meat samples’ p H,chromaticity,cooking loss rate and moisture content were conducted. With the reduce of duck, the values of p H decreased.The values of L decreased, but the values of a and b increased.The cooking loss rates and moisture contents increased.In summary,the performance of E-nose in distinguishing different meat samples is good.The results of E-nose and GC-MS have a high correlation,which proves the accuracy of E-nose experiment.Compared with the traditional detection,the methods of E-nose and GC-MS are more convenient and effective.