The combined effects of aqueous chlorine dioxide, fumaric acid, and ultraviolet-C with modified atmosphere packaging enriched in CO₂ for inactivating preexisting microorganisms and Escherichia coli O157:H7 and Salmonella typhimurium inoculated on buckwheat sprouts.

摘要

The combined effects of a sanitizer mixture, ultraviolet-C (UV-C), and modified atmosphere packaging (MAP) on the quality of non-inoculated and inoculated (Escherichia coli O157:H7 and Salmonella typhimurium) buckwheat sprouts were examined. Buckwheat sprouts were treated with a sanitizer mixture (comprising 100 mg L-1 aqueous ClO₂ and 0.3% fumaric acid) and 2 kJ m-2 UV-C, packaged under two different conditions (air and CO₂ gas) and storage for 8 d at 4 degrees C. The combination of the sanitizer mixture and UV-C treatment reduced the initial counts of preexisting microorganisms in the buckwheat sprouts by 1.9 log CFU g-1 and reduced the initial inoculated counts of E. coli O157:H7 and S. typhimurium on buckwheat sprouts by 3.0 and 2.3 log CFU g-1, respectively. The preexisting microorganisms and inoculated pathogens in buckwheat sprouts packaged under CO₂ gas were significantly reduced during storage following the combined treatment compared to those of the control by above 95%. Differences in Hunter L*, a*, and b* values among the treatments were negligible. The combined sanitizer mixture and UV-C treatment increased the sprout rutin content by 147%, but there was no significant difference in 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity between treatments during storage. Therefore, the combination of sanitizer mixture made from aqueous ClO₂ and fumaric acid, UV-C irradiation, and MAP can improve the microbial safety and quality of buckwheat sprouts.