Effect of Ultrasound Applications on Physico-Chemical, Sensory, and Microbiological Quality of Rainbow Trout (Oncorhynchus mykiss W.)

Ultrasound, whose use has increased in recent years, is one of the most important food processing methods that provides to maintain food quality and increase food safety. The effect of ultrasound treatment on some quality characteristics of vacuum-packed rainbow trout (Oncorhynchus mykiss W.) fillets during cold storage was determined. Experimental groups were formed using different power and duration variables (30%W/5 min.; 30%W/15 min.; 80%W/5 min, and 80%W/15 min.). The samples were stored at 4±1ºC until physico-chemical (moisture, pH, color, and texture), sensory, and microbiological analyses were performed. The effect rates of ultrasound application on the evaluated quality characteristics differed from each other. While there was a significant difference between the groups in the decrease in moisture, increase in pH value and changes in sensory parameters, the change depending on storage was not observed within the group. The decrease in colour and texture values was prevented to a certain extent. It was observed that the effect of ultrasound applications on microbiological inactivation varied according to the type of bacteria and application conditions. The lowest increase in the number of the total mesophilic aerobic bacteria, the total psychrophilic aerobic bacteria, and the lactic acid bacteria was detected in the 80W/5 min. group, while Enterobactericeae and Pseudomonas spp. were detected in the 80 W/15 min. group. The highest inactivation was observed in Pseudomonas spp. bacteria. Our results showed that ultrasound can be an important alternative food processing method to maintain the quality characteristics and food safety of fish meat.