Preventing melanosis in shellfish
Shellfish, including crustaceans and mollusks, form an integral part of Europe's thriving fishing industry. Melanosis of crustaceans, the development of dark-colored blotches following harvest, though harmless to the consumer, negatively impacts sales for aesthetic reasons. Currently, sulphite additives are used to prevent melanosis, but recent research has indicated that the sulphites themselves may pose a human health threat. The CRUSTAMEL project, funded by the LIFE QUALITY Programme, sought alternative technologies to sulphites to prevent melanosis, thereby providing a competitive advantage to the European industry. The ability of carbon dioxide (CO2) in combination with various mixtures of 4 hexylresorcinol and other chemical compounds to prevent melanosis of the Parapenaeus longirostris shrimp species was assessed during the project. A control group was treated solely with a commercial sulphite-containing product. Unfortunately, despite experimenting with three different ways of introducing CO2, the results showed no improvement over the control group. In fact, the sensory analysis indicated that the textural quality of the CO2-treated shrimp was inferior. A second experimental campaign focused on the benefits of using liquid ice rather than traditional flake ice to store shellfish. Ice cannot prevent melanosis, but can delay its onset by reducing oxidation potential. Microbiological and biochemical studies on both lobster and shrimp revealed that small improvements in product quality were achieved. While the cost factor may limit the use of liquid ice in small-scale fishing operations, it can help Europe's larger companies advance their preservation practices.