The Combined Effect of Squid Pen Chitooligosaccharide and High Voltage Cold Atmospheric Plasma on the Quality of Asian Sea Bass Slices Inoculated with Pseudomonas aeruginosa

Abstract

The effects of chitooligosaccharide (COS) at different concentrations (0.05, 0.1 and 0.2%, w/w) without and with the application of high voltage cold atmospheric plasma (HVCAP) at different ratios of argon (Ar) and oxygen (O2), 90%Ar/10%O2 and 80%Ar/20%O2 on the growth of Pseudomonas aeruginosa inoculated (6 log CFU/mL) on Asian sea bass slices were monitored for 0 and 24 h incubation at 4ºC. Impact of COS on the changes in lipid and protein oxidation caused by HVCAP was also determined. All the HVCAP treated slices showed reduction in Pseudomonas count (PC) as compared to control (without any treatment) at both 0 and 24 h of incubation (p<0.05). However, decrease in PC was enhanced when HVCAP treated slices were combined with COS, particularly with higher O2 ratio (20%). COS inhibited lipid and protein oxidation of the slices treated with HVCAP as indicated by lower peroxide value, thiobarbituric acid reactive substances (TBARS) and total carbonyl content. For all treated slices, total volatile base nitrogen (TVB-N) was decreased at both incubation times, compared to the control. Micrograph analysis showed perforated, deformed and distorted cells of Pseudomonas after treatment alone or in combination. Therefore, COS could lower microbial load when combined with HVCAP and simultaneously could reduce the adverse impact of both protein and lipid oxidation, in slices treated with HVCAP.