Combination effect of hot smoking and vacuum packaging on quality parameters of refrigerated thornback ray (Raja clavata Linnaeus, 1758)

Abstract

In this study, hot smoking process was applied to thornback ray (Raja clavata), which is a non-target catch, and the product obtained was vacuum packaged and then stored at refrigerated conditions (4±1 °C) for 120 days. The nutritional, chemical, microbiological, and sensory changes in the products were examined every 15 days. After the hot smoking process applied to thornback rays, significant changes were observed in the nutritional composition of the products (P<0.05). Total volatile basic nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), and thiobarbituric acid (TBA) values of smoked thornback rays increased during storage, and these values were determined between 23.11-98.06 mg/100 g, 2.48-7.33 mg/100 g, and 0.1-0.3 mg malondialdehyde/kg, respectively. It was determined that the total aerobic mesophilic bacteria (TAMB) count detected in the fresh sample decreased in smoked products due to the smoking process and the value was found below the detectable limit value (1.47 log CFU/g) during storage. As a result of the sensory evaluation, it was determined that the texture, odor, and flavor criteria of the smoked thornback rays were below the consumable limit value on the 120th day. According to the results, it was determined that the thornback ray vacuum packaged by hot smoking can be consumed safely for 105 days at 4±1 °C. This study shows that discarded thornback rays, which are a high protein food, can be transformed into high valueadded products by applying different processing methods such as smoking and so can be evaluated as human food.