Influence of freezing and oxygen-free packaging methods on lipid oxidation and other flesh quality parameters of Norway lobster (Nephrops norvegicus)

By adapting oxygen-free systems, the use of modified atmosphere packaging (MAP) appears increasingly attractive and of commercial global interest for (sea)foods products. Moreover, when combined with other preservation methods, MAP continues to show high promise in tackling a wide range of deterioration aspects affecting fishery products. This study was therefore purposed to apply freezing and oxygen-free (vacuum as well as modified atmospheres of 50% N2-50%CO2- and 100% N2) packaging methods onto Norway lobster (NL) (Nephrops norvegicus) and resultant data compared with conventional preservative treatment of sulphite together with control (untreated). The specific objective was to determine the influence of the (above-mentioned) treatments on lipid oxidation (thiobarbituric acid {TBA}) and other flesh quality parameters (total volatile base (TVB) nitrogen, pH, free amino acids (FAAs), proximal composition, as well as melanosis scores) during the inspected storage period of up to 12 months. The result showed that across treatments, whilst the TBA values were little coincidental with significantly changing pH plus superficially fluctuating proximate composition(s), the TVB-N values seemed unaffected except some increases in 100% N2-treated NL samples at the second half of frozen storage. Whilst individual FAAs per treatment considerably varied, the trends of total FAAs between treatments seemed relatively unvaried. Additionally, the treatments of 50% N2-50%CO2- and 100% N2- to apparently delay the melanosis formation in NL samples indicated oxygen-free treatment methods herein with high promise to replace the sulphite ones. To best of our knowledge, this is the first study about freezing combining oxygen-free packaging treatment methods specifically applied to NL samples.