Some Factors Influencing the Production of Dimethylamine and Formaldehyde in Minced and Intact Red Hake Muscle

Mincing stimulated the breakdown of trimethylamine oxide (TMAO) to dimethylamine (DMA) and formaldehyde (HCHO) in red hake muscle at both above and below freezing temperatures. Aging of red hake muscle on ice as fillets (skin on or off) prior to frozen storage resulted in a greater extent of DMA production as compared to fillets derived from fish aged in the whole or gutted form. Frozen storage temperature influenced the extent of DMA production, yet the freezing nadir had no effect on the rate of its formation during storage at -5°C. Additive studies indicated that reducing conditions in the tissue exert considerable influence on the reaction rate in frozen minced tissue. Trimethylamine (TMA), DMA, dimethylaniline and citrate were found to inhibit the reaction in frozen minced tissue.