Growth and survival of Escherichia coli O157:H7 on fresh-cut apples in modified atmospheres at abusive temperatures

The effects of reduced-O₂ and elevated-CO₂ modified atmospheres (MAs) and abusive temperatures on the growth and survival of E. coli O157:H7, yeast, and molds and on changes in the visual quality of fresh-cut apples were evaluated. High-CO₂ and low-O₂ (≥15% and <1%, respectively) atmospheres inhibited the growth of the pathogen on apple slices at 15 and 20°C. However, the population of the pathogen increased by 1 log cycle after 2 weeks of storage in air. The high-CO₂ MA resulted in the inhibition of yeast and mold growth, less browning, and better visual quality than did air and ambient-CO₂ atmospheres. The results of this study confirm that E. coli O157:H7 can grow on apple slices in air. These results also show that these organisms survive but are inhibited in MAs with high CO₂ levels at abusive temperatures. An MA can increase the shelf life of fresh-cut apples by improving retention of visual quality and inhibiting yeast and molds. Thus, contamination of minimally processed apples with E. coli O157:H7 can be a safety issue for both air- and MA-packaged cut apples.