Effect of slaughtering method on umami compounds in meat of Octopus vulgaris

The eating quality of meat from cephalopods, in particular taste and texture, may depend on the way the animals are slaughtered. Knowing the relationship between slaughtering method and meat quality is important not only for the eater but also for designing the most humane slaughtering method for the animals in question. Here we analyse the meat from arms of Octopus vulgaris that have been killed by traditional suffocation methods and compare with meat from animals that have been anaesthetised before killing. By chemical analysis we determine the composition of the meat in terms of two free amino acid salts, glutamate and aspartate, along with the contents of the free nucleotides AMP, GMP, and IMP. These five compounds are decisive for the taste of the meat since they enter a powerful umami synergy. Although there is a substantial variation among biological replicates, our findings show that whereas the contents of the free amino acid do not depend on the slaughtering method, the contents of GMP and IMP are higher and that of AMP is lower in the meat from animals that have been killed by anaesthesia. The results suggest that meat quality as judged by the umami potential is higher in animals killed by anaesthesia. The comparison of two slaughtering methods combined with a temporal analysis over 48 hours provides valuable insights into post-mortem flavour development. The focus on umami-related compounds contributes to discussions on both meat quality and aquatic animal welfare. • The umami potential of octopus has been measured. • The slaughtering method is found to affect the umami potential.