The effects of high sub-zero storage temperatures on the quality of frozen hake (merluccius merluccius)

Frozen hake (Merluccius merluccius) is highly susceptible to cold storage damage, and its quality may fall to unacceptably low levels, particularly as a consequence of the development of tough texture. This is a major problem for the fish supply industry in Portugal, the author's home country. The present work aimed to elucidate the mechanism of such deterioration, and was based on the hypothesis that it is promoted by autolytic processes occurring during frozen storage at temperatures above those normally recommended. During distribution and retail display, the correct storage temperatures are often disregarded and frozen fish can be subjected to temperatures in the range of -5°C to -15°C, often with fluctuating temperatures within that range. [Continues.]