Preheat Treatment for Improvement of Frozen Storage Stability at −10 C in Fillets and Minced Flesh of Silver Hake (Merluccius bilinearis)

Dimethylamine (DMA) formation occurs in the muscle of silver hake (Merluccius bilinearis) during frozen storage. The rate of its formation in fillets and minced flesh during subsequent frozen storage for 1 mo at − 10 C is not affected by preheating at temperatures up to 60 C. Preheating to 80 C, however, greatly retards DMA development. Lipid hydrolysis (free fatty acid accumulation) is arrested by preheating to 60 C, but is little affected by preheating at temperatures up to 45 C. These deteriorative reactions are faster in minced flesh than in fillets, and in materials prepared from summer (spawning) fish than in those prepared from winter fish.In breaded fishery products, preheat treatment as presently practiced is insufficient to inactivate these deteriorative enzymic reactions in sensitive gadoid species such as the hakes and pollocks.