Study On Identification Method Of Patulin Producing Strains By Electronic Nose And Tongue Analysis

The problem of the patulin pollution in the apple juice industry,which is caused by the Penicillium expansum and other Penicillium,is an important factor in the development of apple juice and apple in China.Resulting in the quality of apple juice,at the same time pose a threat to the health of consumers.Therefore,the timely and effective detection of the infection of patulin and its producing strains are especially important.Both domestic and international studies have shown that many strains of penicillium and aspergillus are able to infect apple raw materials and produce mycotoxin under certain conditions.If the rapid and effective detection and identification of the strains can be effectively identified and controlled,it is advantageous to minimize the loss of patulin contamination.In this paper,three mold strains,three yeast strains and seven bacteria strains were firstly used as the object to study the accurate distinction between the microbes based on the electronic nose and the electronic tongue response signal,thus established the method of identification of mold.On this basis,the method of identifying patulin producing strains based on electronic nose and electronic tongue was further established..Finally,we studied the ability of electronic nose /electronic tongue to distinguish different Penicillium expansums by their ability to produce patulin.Here are the conclusions:(1)the electronic nose combined with the PCA method can accurately identify mold samples.Use LDA analysed the difference between yeast samples and other samples and was clearly distinguished from the others.Mold and some samples of bacteria were not distinguishable.The mold and bacteria samples were selected separately for further pattern recognition,and mold samples were accurately identified.The optimal conditions for the electronic tongue test was 2 rps of stirring rate.The clustering analysis based on the electronic tongue data showed that mold samples can be classified correctly,and yeast were indistinguishable from some bacteria.PCA and DFA were able to discriminate between different microbial cultures,and mold samples were also correctly identified.The discriminant rate of the classification model established by Fisher discriminant analysis was85.7%,the classification accuracy of the model is 96.9%.Electronic nose sensor S2,S3,S6,S10,electronic tongue sensor ZZ,BB,CA,JB in the distinction between different species of microbial samples had an important contribution.(2)the electronic nose test: PCA can distinguish between penicillium and aspergillus,and it can also be effective in identifying Penicillium expansum and patulin producing strains.The LDA method was used to differentiate between penicillium and aspergillus samples,and there was an overlap between the aspergillus and penicillium samples..The differentiation of the patulin producing strains,Penicillium expansum 5 # was similar to other penicillium(Penicillium paneum 2 # and Penicillium griseofulvum 3 #)in volatile components.Penicillium expansum 6 # was completely separated from other Penicillium and Aspergillus isolates.The rest of the patulin producing strains were closer and concentrated.Electronic tongue test: PCA and DFA to qualitative discrimination and to distinguish the culture of different kinds of mold,the results showed that PCA and DFA can realize to penicillium and aspergillus distinguish between 48 h of culture,but could not distinguish between species;DFA is superior to the results of PCA analysis,both can distinguish between Penicillium expansum and other patulin producing strains and other samples showed that the electronic tongue,like the electronic nose,can also be used for the identification of patulin producing strains.(3)Use electronic nose and electronic tongue to detect the culture of different periods of different Penicillium expansum,and determine the ability of different Penicillium expansum to produce mycotoxin.The results showed that there was a good correlation between the response of the electronic nose and the electronic tongue sensors on the 4th day of the culture medium of Penicillium expansum and the ability of Penicillium expansum producing patulin was determined..Preliminary showed that the 4th day is the most appropriate time to recognize Penicillium expansum to produce mycotoxin.