DIMETHYLAMINE AND FORMALDEHYDE IN COOKED SQUID (ILLEX-ARGENTINUS) MUSCLE EXTRACT AND MANTLE

Trimethylamine oxide (TMAO) in the muscle of squid may be reduced by e ndogenous and bacterial enzymes to trimethylamine and demethylated in enzymatic or chemical reactions to dimethylamine (DMA) and formaldehyd e (FA). The rate of TMAO degradation in heated Baltic cod and in squid extract and flesh, as well as the effect of FA generated in the tissu es on the texture of cooked squid were investigated. The content of DM A in uncooked frozen stored mantle of 51 Illex argentinus, from three different shipments, was 88-452 mu moles/100 g meat. Boiling for 45 mi n resulted in a large accumulation of DMA. and a lesser increase in fr ee FA in squid, but only negligible changes in cod. The decomposition of TMAO could not have been caused by enzymatic reactions. In a series of experiments with squid of different lots no consistent correlation s were found between the shear force required to cut the cooked squid mantle and the contents of free FA. The rate of increase in free FA in the heated samples of the water-soluble fraction of squid flesh did n ot correspond to that of DMA.