Effect of high pressure (HP) on the quality and shelf life of red mullet (Mullus surmelutus)

Abstract

Abstract The effect of different temperature/time/pressure high hydrostatic pressure (HP) treatment on the quality and shelf life of red mullet were studied. Different high pressure treatments (at 3, 7, 15 and 25 °C, 5 to 10 min and 220, 250 and 330 MPa) were tested to establish the best processing conditions for the quality of red mullet. The effect of the process on the quality of the sample was examined by colour, Trimethylamine nitrogen (TMA-N) and Thiobarbituric acid number (TBA) analysis. Based on the results of the parameters, the best combinations of HP treatments were determined as 220 MPa/5 min/25 °C and 330 MPa/5 min/3 °C for red mullet. The effects of this combination treatment on sensory, chemical and microbiological properties of red mullet stored at 4 °C were studied. The results obtained from this study showed that the shelf life of untreated and HP treated stored at 4 °C, as determined by overall acceptability of sensory and microbiological data, are 12 days for untreated red mullet and 14 days for treated red mullet at 220 MPa for 5 min at 25 °C and 15 days for treated red mullet at 330 MPa for 5 min at 3 °C. Industrial relevance Fresh fish have short shelf life. HP treatment has shown to be an effective method to control pathogen and spoilage microorganisms in fish and fish products. However, high pressure treatment can promote colour and oxidation changes that could modify their sensory characteristics. The main objective of the first part of this study was to detect the best combination among the applied pressure (220, 250 and 330 MPa), temperature (3, 7, 15 and 25 °C) and time (5 and 10 min) combinations. The treatment ranges were chosen according to the unchanging colour, lower TBA value and TMA stability by HP and considering the economical aspects of HP processing. In the second part of the study, HP was applied on the selected samples and a shelf-life study was performed by measuring the changes in the quality parameters, of the samples throughout their storage. The storage conditions were set so as to achieve refrigeration handling (4 °C). Shelf-life estimation was performed according to the data obtained. HP (at 220 MPa for 5 min at 25 °C and at 330 MPa for 5 min at 3 °C) treatment is the most effective treatment for shelf-life extension as compared to non-treated red mullet.