Kale shelf-life study

Pathogenic Campylobacter jejuni and E. coli O157:H7 were inoculated onto the surface of kale stored in a controlled environment at  4°C, ± 0.15°C,  and average humidity of 95%, ± 1.13°C, over a 23-day period. (days 0, 1, 2, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21), inoculated kale was destructively sampled and the surviving bacteria determined by serial dilution and plating onto Tryptic soy agar, Charcoal cefoperozone deoxycholate agar, and Eosin methylene blue for total aerobic bacteria, Campylobacter and E. coli O157:H7, respectively.Enrichment and PCR were used for detection when pathogens were not detected using serial dilution and plating. Aerobic heterotrophic bacteria increased over the 23-day period, in contrast, significant declines in the inoculated pathogens were observed. Inoculated E. coli O157:H7 survived longer on kale (up to 19 d), in comparison, Campylobacter was undetectable by day 13 using enrichment and PCR or plating.