Effects of Thawing Methods on Water-Holding Capacity and Texture of Frozen Farmed Takifugu obscurus

The effects of four thawing methods (low-temperature air thawing, room temperature thawing, flowing water thawing and ultrasonic thawing) on the water-holding capacity and texture of the dorsal muscle of frozen farmed Takifugu obscurus were investigated, and the underlying mechanism was analyzed by evaluating the changes in the physicochemical properties of myofibrillar and sarcoplasmic proteins. The results showed that the low-temperature air thawing (210 min) group had better water-holding capacity and texture, higher sensory scores, and the most complete muscle structure. The thawing loss rate of the ultrasonic thawing group (10 min) was the highest (12.34%). The texture of the flowing water (22 min) and room temperature thawing (120 min) groups were poor with a greater degree of muscle tissue destruction. Moreover, the degree of protein denaturation was lower in the low-temperature air thawing group than in the other three groups. Partial least squares regression (PLS-R) analysis result indicated that protein denaturation would destroy the texture and sensory properties, but have little effect on the thawing loss. Generally speaking, although low-temperature air thawing was the most time consuming, it is an ideal way to maintain the water-holding capacity and texture of cultured Takifugu obscurus meat to the greatest extent, with the least damage to muscle fibers and proteins.