Abstract:

Microbial volatile metabolites (MVOCs) of three Pseudomonas species isolated from pork during pure culture fermentation in tryptic soy broth (TSB) were analyzed for chemical composition using headspace solid-phase micro extraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) and odor fingerprint using electronic nose (E-nose) for laying a theoretical basis for the rapid and non-destructive detection of microorganisms in foods using odor fingerprint technique. E-nose could clearly distinguish the three Pseudomonas species through principal component analysis (PCA) and discriminant function analysis (DFA). HS-SPME/GC-MS analysis indicated that the MVOCs of Pseudomonas aeruginosa consisted of 2-butanone, dibromochloromethane, isovaleric acid, 2-methylbutanoic acid, 2-methyl-5-(methylthio)furan, Pseudomonas aeruginosa 3,5- dimethyloctane, 6-methyl-5-heptene-2-one, 2-ethylhexanol, dodecane, 2,6,10-trimethyldodecane, (1E)-1-ethylidene-1H-indene, and 1,5-dimethylnaphthalene, and Pseudomonas putida 2-pentanone, methylthioacetate, butyl acetate, S-methyl butanethioate, 1-cycloundecene, pentylcyclopropane, 3-propionylpyridine, and 3-phenylfuran. The combination of E-nose and HS-SPME/GCMS provides a rapid and non-destructive detection method of Pseudomonas spp. and other microorganisms in foods.

Key words: electronic nose (E-nose), headspace solid-phase microextraction/gas chromatography-mass spectrometry (HSSPME- GC-MS), Pseudomonas spp., microbial volatile metabolites (MVOCs)