Cryoprotective effect of sorbitol on the muscle microstructure of yamú (Brycon amazonicus) during storage at 2 and -18 °C

Abstract

Although freezing is generally used to preserve the sensory and nutritional quality of fish and their products, it cannot mitigate physicochemical changes of the fish meat during storage. This study aimed to determine the cryoprotective effect of sorbitol incorporated into the yamú muscle (Brycon amazonicus), subjected to different storage times and temperatures. The methodology consisted of analyzing microstructural changes, protein profile, and physicochemical properties (texture, water holding capacity and pH) of the yamú’s meat under two temperatures (2±2 and -18±2 °C), two storage times (24 and 48 h) and the incorporation or not of 5% (w/w) of a 60% sorbitol solution. The microstructural changes were analyzed by optical microscopy and scanning electron microscopy, and the protein profile was analyzed by SDS PAGE electrophoresis. The physicochemical properties evaluated in yamú’s meat were affected mainly by the interaction between temperature and storage time. The myofibrillar proteins underwent a partial degradation, and changes in the connective tissue were observed concerning the loss of texture especially when the meat was not treated with sorbitol at freezing temperature (-18 °C). The use of sorbitol minimized the negative effects of freezing on the characteristics of the yamú muscle, maintaining the integrity of the muscular microstructure and generating a cryoprotective effect in comparison to untreated meat.