Combination of carbon dioxide and cinnamon to inactivate Escherichia coli O157:H7 in apple juice

Pasteurized apple juice with CO2 (0, 1, and 4%) and cinnamon (0 and 0.3%) was inoculated with Escherichia coli O157:H7 at 104 CFU/mL, and stored at 5 and 20°C. 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°C. Samples with 1 and 4% CO2, alone and combined with cinnamon, presented < 0.7 log CFU/mL in 3 d. Counts in apple juice inoculated at 102 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.