Abstract: The effects of controlled atmosphere packaging with 3% O2 and 7% CO2 on changes in the nutritional quality, taste and volatile compounds of fresh-cut cucumber caused by Pseudomonas plecoglossicida were studied by electronic tongue, electronic nose and gas chromatography-mass spectrometry. The results showed that the growth of Pseudomonas plecoglossicida decreased the nutritional quality of fresh-cut cucumbers, and controlled atmosphere storage inhibited the respiration rate, delayed the increase in malondialdehyde content and relative conductivity, and maintained the soluble solid content, color and firmness of fresh-cut cucumbers. The results of electronic tongue showed that Pseudomonas plecoglossicida had the most significant effect on the umami and umami richness of fresh-cut cucumbers, and controlled atmosphere storage inhibited the changes in tastes caused by Pseudomonas plecoglossicida. There were significant differences in volatile substances among fresh-cut cucumbers with different treatments. Compared with the control group inoculated with Pseudomonas plecoglossicida and packaged in air, controlled atmosphere packaging delayed the decrease in the characteristic aroma components of hexanal, (E,Z)-nona-2,6-dienal and (Z)-6-nonenal caused by Pseudomonas plecoglossicida, and inhibited the generation of spoilage metabolites like 2,3-dimethyloctane, 6-methyl-3-heptanone, 2-propylfuran and dipropyl disulfide. This study provides a theoretical basis for research on the nutritional and flavor changes of fresh-cut cucumbers caused by microbial spoilage.

Key words: fresh-cut cucumbers; controlled atmosphere storage; quality; volatile compounds; Pseudomonas plecoglossicida