best management practices for fish handling from Farm to Table

Fish are highly susceptible to physical, chemical, and biological deterioration during and after harvest. After death, considerable irreversible postmortem changes occur in fish muscle. These postmortem changes can be divided into four states: (1) pre-rigor, (2) rigor mortis, (3) post-rigor and autolysis, and (4) spoilage. Immediately after death, fish muscle is totally relaxed with elastic texture in the pre-rigor stage, which may not last long (maximum several hours). After pre-rigor, fish muscle contracts and the whole fish remains rigid due to lack of the energy-rich organic compound adenosine triphosphate (ATP) that provides energy to relax the muscle. The rigor condition may persists for a day or more depending on temperature and physical conditions at death. The resolution of rigor makes the muscle rigidity disappear and it becomes limp again, but no longer as elastic as before rigor. After rigor mortis, the muscle tissue loses the stiffness, followed by autolysis forming amino acids and other low molecular weight compounds. In post-rigor and autolysis stage, spoilage bacteria grows very fast and the fish quality can be significantly deteriorated. The rate in onset and resolution of rigor varies from species to species and can be slowed down if proper handling and storage procedures are followed. In this presentation, we will discuss the major postmortem biochemical and microbiological changes occurring in various species of fish and the effects of best management practices for fish handling during harvest and post-harvest can enhance the safety and quality of fish.