Quality of Norway lobster (Nephrops norwegicus) treated with a 4-hexylresorcinol-based formulation

Abstract

In the present work, the effect on biochemical indexes and microbial growth was studied in Norway lobster (Nephrops norwegicus), using a formulation containing 4-hexylresorcinol (0.1 and 0.05%) in combination with organic acids (citric, ascorbic and acetic) and chelating agents (ethylenediaminetetraacetic acid [EDTA] and di-sodium di-hydrogen pyrophosphate [PPi]). Lobsters treated with 4% of a commercial formula based on sulphites were used for control purposes. The treatment with 4-hexylresorcinol-based formulations delayed the increase in K-value and total volatile bases, while evolution of pH and trimethylamine was similar regardless of the treatment. No relation was found between biochemical and microbiological indexes. Regarding microflora, although commercial sulphites slightly slowed the growth of seafood spoiler organisms, as Shewanella putrefaciens and luminescent colonies, these organisms were not found in a very high number (∼6 log cfu/g) at the end of storage. Moreover, the formulation containing 4-hexylresorcinol 0.1% appeared to stimulate the growth of lactic acid bacteria. The sensory quality of lobster, in terms of melanosis, remained with a good appearance for 12 days. Formulations based on 4-hexylresorcinol preserved the quality and could therefore replace the traditional sulphites during storage of Norway lobster.