Impact of corona discharge plasma treatment on microbial load and physicochemical and sensory characteristics of semi-dried squid (Todarodes pacificus)

Abstract

The use of corona discharge plasma jet (CDPJ) for the improvement of the sanitary quality of semi-dried squid was investigated. Microbial contaminants, namely aerobic, coliforms, and molds and yeasts, were detected in the samples. The CDPJ generated using 20 kV DC voltage at 58 kHz frequency was used for the decontamination treatment (1-10 min). The bacterial contaminants and molds and yeasts were inactivated in the range of 1.5-2.1 and at 1.9 log CFU/g, respectively. The inactivation pattern was well fitted to the first-order kinetics model. The CDPJ treatment for 10 min did not exert significant changes (p > 0.05) in VBN and the trimethylamine content of semi-dried squid as compared to untreated controls. On the contrary, significant changes (p < 0.05) in moisture content, water activity, pH, color, and TBARS levels were observed upon plasma exposure. However, the CDPJ-treated samples displayed slightly better sensory properties than the controls in terms of appearance, visual color, and flavor.