Study On The Identification Method Of Patulin Producing Moulds Based On FT-IR/NIR Spectroscopy

High levels of patulin became an ubiquitous problem on apple processing industry,with important effects on products safety and human health,restricting the competitiveness of the fruit juice processing enterprises of China in international market.Patulin is a secondary toxic metabolite of different fungal species mainly belonging to the genera Penicillium and Aspergillus.Patulin producing strains with local differences in species and toxic ability differences.Otherwise,microbial culture and toxin extraction are needed in the existing recognition methods,leading to inefficient and high cost.Thus,based on the taxonomy and toxigenic ability respectively,using FT-IR/NIR technique,a rapid and sensitive analytical method for the simultaneous identification of fungal species and patulin producing ability was established in our study.Then the main conclusions are as follows:1.A good sample preparation method was chosen firstly by comparison of spectral reproducibility and cluster analysis?CA?results using FT-IR/NIR technique.The spectra of fungal spores were collected by KBr pellet,and the feasibility of this method in fungal identifacation by FT-IR was proved.CA can be used to distinguish among four different moulds.2.Using FT-IR technology combined PCA-LDA method,we established an interspecific identification model of 9 species of Penicillium and Aspergillus.The internal verification result achieved 96.59%,and external verification with 96.97%accuracy.3.Based on FT-IR technology,second derivative spectra data of 1560-1533 cm^-1 as characteristic variables was used to build a LDA model to distinguish Penicillium species between patulin producing and non-producing strains,with calibration and validation accuracy rate were 99.02%and 97.22%respectively.The model also could good identify the toxigenic ability of three species moulds?P.paneum?P.viridicatum and P.oxalicum?which were not added in the calibration set.4.Based on FT-IR technology combined CA method,second derivative spectra data of 112?993 and 962 cm^-1 as characteristic variables,ten Penicillium expansum strains were able to classified into groups corresponding different kinds of patulin producing ability.