Physicochemical properties of frozen tuna fish as affected by immersion ohmic thawing and conventional thawing

Abstract

One of the key points in the frozen food processing is thawing with minimal damage to the quality. Since the commonly used methods for thawing of foods are slow and reduce the quality of the product, application of an efficient method seems necessary. In this research, thawing of tuna fish was performed by immersion ohmic method. Thawing rate roles a vital key in the quality and significantly increased by ohmic ($0.2g/s$, the mean of ohmic group) in comparison with conventional thawing ($0.15g/s$, the mean of conventional group) methods. Immersion ohmic thawing increased rate of thawing about 5 times. Parameters important in quality such as T-VBN, protein solubility, thawing evaporation loss, pH, thawing loss and press juice were measured. Group analyses showed significant difference between ohmic and conventional treatment in protein solubility, thawing evaporation and thawing loss (p < 0.05).

Keywords: TVB-N; immersion ohmic thawing; press juice; protein solubility; thawing loss; tuna fish.