Combination of Carbon Dioxide and Cinnamon to Inactivate Escherichia coli 0157:H7 in Apple Juice

摘要

Pasteurized apple juice with CO_2 (0, 1, and 4%) and cinnamon (0 and 0.3%) was inoculated with Escherichia coli O157:H7 at 10~4 CFU/mL, and stored at 5 and 20℃. Counts on nonselective and selective media, and thin agar layer (TAL; selective medium overlaid with nonselective medium) were determined at 1 h and 1,3,7, and 14 d. Inactivation was greater at 20℃. Samples with 1 and 4% CO_2, alone and combined with cinnamon, presented < 0.7 log CFU/mL in 3 d. Counts in apple juice inoculated at 10~2 CFU/mL, a low-level E. coli O157:H7 contamination, were nondetectable at 3 d. The TAL method was as effective as nonselective medium to recover injured cells.