Textural and rheological properties of Pacific whiting surimi as affected by nano-scaled fish bone and heating rates

• Addition of nano-scaled fish bone (NFB) improved texture of Pacific whiting surimi gel.
• Endogenous TGase and calcium compounds played a major role in gelation.
• Pacific whiting surimi can be used for slowly cooked products such as fish ball.

Textural and rheological properties of Pacific whiting (PW) surimi were investigated at various heating rates with the use of nano-scaled fish bone (NFB) and calcium chloride. Addition of NFB and slow heating improved gel strength significantly. Activity of endogenous transglutaminase (ETGase) from PW surimi was markedly induced by both NFB calcium and calcium chloride, showing an optimal temperature at 30 °C. Initial storage modulus increased as NFB calcium concentration increased and the same trend was maintained throughout the temperature sweep. Rheograms with temperature sweep at slow heating rate (1 °C/min) exhibited two peaks at ∼35 °C and ∼70 °C. However, no peak was observed during temperature sweep from 20 to 90 °C at fast heating rate (20 °C/min). Protein patterns of surimi gels were affected by both heating rate and NFB calcium concentration. Under slow heating, myosin heavy chain intensity decreased with NFB calcium concentration, indicating formation of ε-(γ-glutamyl) lysine cross-links by ETGase and NFB calcium ion.