Microstructural modification and its effect on the quality attributes of frozen-thawed bigeye tuna (Thunnus obesus) meat during salting

The evolution of tissue microstructure and its association with the quality attributes of frozen-thawed tuna meat during salting were investigated. With the extension of salting, the myofibers shrank initially under osmotic pressure and then swelled with the disappearance of intracellular voids. The intracellular microstructural recovery, myofiber swelling, and debilitated connective tissue were closely associated with the high water-holding capacity and distinctive textural properties. However, extended salting time caused more protein loss and denaturation and enlarged extracellular spaces significantly (p < 0.05). These changes resulted in reduced water holding capacity and cohesiveness. The improved water-holding capacity, textural properties, and appealing appearance of lightly salted fish products are closely associated with the physicochemical and microstructural modifications under optimal salting conditions.