A study of the ice crystal sizes of red muscle of pre-rigor Atlantic salmon (Salmo salar) fillets during superchilled storage

Abstract

Pre-rigor salmon fillets were superchilled in an impingement freezer and stored at −1.7±0.3°C for 29days. The objective of this work was to study the ice crystal sizes in red muscle of pre-rigor salmon fillets that were partially frozen at fast (−30°C, 227W/m2K, 2.1min) which is referred to as process F and slow (−20°C, 153W/m2K, 4.2min) which is referred to as process S during superchilled storage. It was observed that the size of intracellular ice crystals in pre-rigor muscles at faster superchilling rate was significantly (p<0.05) smaller than that at slower superchilling rate. The size of ice crystals formed in pre-rigor muscle was significant (p<0.05) smaller than that formed in post-rigor muscle. It was also observed that the size of intracellular ice crystals formed in pre-rigor red muscles was significant smaller than that in white muscle. In addition, a large number of small ice crystals are formed within the muscle during partial freezing of pre-rigor muscle compared to post-rigor muscle. Future research should focus on tests of the quality parameters separately in red and white muscles (pre- and post-rigor) during superchilled storage of food products in order to understand more about their characteristics (quality and shelf life).