저온살균과 대기압플라즈마의 병용처리에 의한 고춧가루 중대장균의 저감화 효과 및 관능적 품질

Abstract

This study investigated the inactivation and synergistic efficacy of combined low-temperature heating (LT) and atmospheric plasma (AP) against Escherichia coli in red pepper powder. A cocktail of two strains of E. coli (ATCC 11229, KCCM 11234) was inoculated onto red pepper powder and then treated with LT (60 o C for 5-20min) and AP (atmospheric plasma for 5-20 min). The counts of E. coli in the red pepper powder were significantly (P<0.05) reduced with the increase in treatment time using LT and AP. The reduction of E. coli levels in red pepper powder when treated with LT alone for 5, 10, 15, and 20 min were 0.25, 1.45, 2.54, and 2.85 log 10 CFU/g, respectively. Also, the reduced levels of E. coli on red pepper powder when treated with AP alone for 5, 10, 15, and 20 min were 0.19, 0.32, 0.54, and 0.96 log 10 CFU/g, respectively. The synergistic effects were not dependent on the treatment time with AP, but were dependent on the LT treatment time. Synergistic reduction values for combined LT and AP treatment against E. coli in red pepper powder were -0.13 to 2.91 log 10 CFU/mL, respectively. Especially, the largest synergistic values (2.91-2.82 log CFU/mL) of E. coli in red pepper powder were revealed by the combination of a 20-min treatment with LT and a 15-20-min treatment with AP. All sensory parameters (color, off-odor, taste, texture, and overall acceptability) were not significantly (P>0.05) different between non-treated and all combination-treated samples. Therefore, these results suggest that the combination of LT and AP can be potentially utilized in the food industry to effectively inactivate E. coli without incurring quality deterioration in red pepper powder.