Commercial frozen octopus: evaluation of physicochemical, sensory, and rheological quality indicators

Introduction: Freezing is essential for preserving octopus, but it can affect its sensory properties and texture. A seafood company that markets Northeast Pacific octopus, frozen on board, and fresh octopus from the Northeast Atlantic, sourced from an area closer to its operations, questioned the differences in quality and potential associated benefits. Objective: This study aimed to address this challenge by comparing fresh and frozen octopus from the Atlantic with frozen octopus from the Pacific, which undergoes a tempering process before being refrozen. The objective was to evaluate the physicochemical, sensory, and rheological quality of the octopus, providing insights into the effects of freezing and its implications for commercial decision-making in the seafood sector. Methods: The freezing process involved forced-air freezing at -18 °C, glazing, and storage at -18 °C between 22 °C for one week. Results: Changes in texture (lower hardness and fracturability) were observed in frozen Atlantic octopus compared to the fresh sample. At the sensory level, frozen octopus also showed reduced hardness and elasticity. Over the freezing period, consistency values of protein dispersions decreased, linking freezing effects to changes in quality. On the other hand, the frozen Pacific octopus showed higher moisture content, pH, and the highest hardness and fracturability among the samples. Conclusion: Freezing negatively impacts the quality of octopus, reducing key sensory and textural characteristics. These findings highlight the need to optimize freezing processes and sourcing strategies in the seafood industry.