Physical, chemical and sensory evaluation of meat from cobia (rachycentron canadum), desensitized with different voltages of electric shock, stored under refrigeration

Abstract

Fish quality is conditioned by several factors, among them desensitization methods applied for fish managing and slaughtering. This research used electric shock at different intensities as a desensitization method for cobia (Rachycentron canadum) slaughtering and evaluated its effects over fish quality during refrigerated storage. The experiment was carried out by numbing the fish with electroshock at the intensities of 100, 150 and 200 Volts, and keeping them in refrigerated storage for 21 days. On the cobia, obtained from a commercial fish farm the following physical, chemical and sensorial characteristics as quality variables were evaluated: dielectric properties, rigor index, pH, texture, color, sensorial evaluation of freshness, ATP and degradation catabolites. The experimental design was a 6×3 factorial (6 times of analysis and 3 electroshock intensities). Significant differences (P<0.05) were observed for the analyzed variables, as a consequence of desensitization treatments and of storage time within each treatment. However, the number of variables affected by the treatment was smaller than the number of variables significantly affected by the storage time, and the interaction time×treatment was highly significant within the results reported. The best results for the parameters tested were obtained when the treatment at 150 volts intensity with the majority of analyzed variables held significant differences (P<0.05) among treatments. It was also concluded that cobia can be conserved in refrigerated storage within seven days after slaughtering using electro-narcosis as a method of desensitization.

Efeitos do estresse pré-abate na qualidade da carne do tambaqui armazenado no gelo

“…In the present study, a slower pH decrease was observed in meat samples from fish submitted to recovery periods after transport, while samples from fish collected right after harvesting and after transport presented lower pH values at time 0, confirming that the postmortem biochemical changes occurred more accelerated for these treatments according to reported by Oliveira-Filho (2021), who observed low pH levels after 5 hours of pacu slaughter using different slaughter methods. Melo et al (2018) also observed a decrease in muscle pH in tilapia slaughtered by different electronarcosis voltages after 5 hours of slaughter. Erickson et al (2016) also observed lower initial pH values in stressed Atlantic cod when compared to the control.…”