Impact of non-thermal dielectric barrier discharge plasma on Staphylococcus aureus and Bacillus cereus and quality of dried blackmouth angler (Lophiomus setigerus)

Abstract

This study investigated the effects of dielectric barrier discharge (DBD) plasma against Staphylococcus aureus and Bacillus cereus (initial inoculum of 8-9 log(10) CFU/mL) on the surface of dried blackmouth angler, and the physicochemical [pH, Hunter colors, thiobarbituric acid reactive (TBA)] and sensorial quality on the dried blackmouth angler. Reductions in S. aureus and B. cereus counts on the fillet treated with 1, 5, 10, 20 and 30 min of DBD plasma ranged from 0.10 to 1.03 log(10) CFU/g and 0.14 to 1.06 log(10) CFU/g, respectively. The D-1 and D-2 (90% and 99% reduction time) of DBD plasma for S. aureus and B. cereus by first-order kinetics were 33 and 66.88 min and 32.36 and 64.74 min, respectively. TBA values increased slightly with an increase in DBD plasma treatment times. However, differences in Hunter colors ["L", "a", and "b"] and pH of the dried blackmouth angler were not significant between the non-treated (control) and DBD plasma-treated samples. Moreover, the most sensory attributes [appearance, color, flavor, overall acceptability] were not significantly different between the non-treated and DBD plasma-treated dried blackmouth angler. However, when treated with DBD plasma for more than 20 min, the texture value decreased significantly (P < 0.05). This study indicates that 30 min of DBD plasma treatment resulted in >90% reduction of S. aureus and B. cereus without concomitant overall adverse changes in dried blackmouth angler; this approach can be considered in dried fishery food production, processing, and distribution processes to enhance dried fishery meat safety.