Physicochemical and conformational changes of krill myofibrillar protein induced by two-stage thermal treatment and their relationship with muscle texture

To preserve the juiciness of Krill muscle, a simple but robust strategy of two-stage thermal treatment (40–70 °C followed by 90 °C) was explored while the alterations in muscles, physicochemical and conformational changes of myofibrillar proteins were investigated. Conventional one-stage boiling treatment was considered as the control. The results revealed that the actomyosin dissociation was most pronounced preheated by 50 °C, supported by higher content of actin and increased surface hydrophobicity with a substantial drop in α-helix. The disulfide bonding for the control and 70 °C group was significantly higher, indicating a pronounced oxidation. The most robust affinity for water of krill was observed when subjected to preheating at 50 °C, exhibiting the wildest separations between muscle bundles and well-preserved fibers, while severe contraction of muscle bundles was observed with fracturing and minor gaps. The findings provide direct proof to support the feasibility of implementing a preheating thermal processing method for krill.