Slaughtering of gilthead seabream (Sparus aurata) in liquid ice: influence on fish quality

Abstract

Liquid ice or binary ice is a new food chilling technique that requires less time to chill products and acts more uniformly than other types of ice. The practical advantage of binary ice is its pumpability. Moreover, on account of the microscopic size of the ice crystals, the main benefit of binary ice is its ability for rapid chilling of fish and to provide lower fish temperature, which in turn slows down both enzymatic and bacterial spoilage activity and hence maintains the fish in better quality.

Gilthead seabream (Sparus aurata) is one of the main species farmed in the Mediterranean area and its production has undergone a huge increase in recent years, reaching more than 50% of the total production of all marine farmed fish.

The purpose of this study was to investigate the effect of slaughtering by immersion in liquid ice on the quality of gilthead seabream (Sparus aurata) vs the commercial slaughter method by immersion in ice plus water. Quality was estimated by physico-chemical and sensory parameters immediately after death and during ice storage. Liquid ice reduced the time taken by fish until complete immobilisation; however the lowest temperature (≅–2.2 °C) attained by the liquid ice tank caused the appearance of cloudy eyes that significantly reduces the commercial value of the fish.