The effects of five different drying methods on the quality of semi-dried Takifugu obscurus fillets

This study investigated the effects of sun drying (SD), hot air drying (HAD), cold air drying (CAD), vacuum drying (VD), and vacuum freeze drying (VFD) on the meat quality of semi-dried Takifugu obscurus fillets. The quality changes in the fish fillets were analyzed by comparing color, texture, shrinkage, water states, volatile flavor compounds, and a sensory assessment. The L* value of SD showed a downward trend, whereas that of the other drying methods showed an upward trend. SD and HAD had better texture properties than the other drying methods. The five drying methods promoted the conversion of immobilized water into free water, although the transverse relaxation time significantly decreased, especially in HAD. These drying methods altered the original flavor of the pufferfish though CAD retained the best fresh flavor and HAD produced more volatile compounds than the other methods. Overall, HAD improved the sensory score of the odor and chewability. Furthermore, HAD was determined as the appropriate thermal drying methods for the T. obscurus fillets to improve the products' quality and flavor. Among the non-thermal methods, the CAD showed better color and tissue morphology.