Cold Plasma treatment effect on lipid oxidation and colour of sea bream (Sparus aurata) fillets

Seafood products are rich in proteins and lipids; however, due to the activity of spoilage microbes and endogenous enzymes, they easily loss their quality, having limited shelf-life. As the demand for fresh seafood increases, it is necessary to develop novel preservation methods with high antimicrobial efficacy that are low-cost and safe to use in order to maintain the product quality for longer storage time. Cold plasma, a partially ionized gas, source of many highly reactive oxygen and nitrogen species, has been tested as an alternative non-thermal treatment technology for the microbial inactivation in the food industry. This work aimed to evaluate the effect of cold plasma on the lipid oxidation and colour characteristics of sea bream (Sparus aurata) fillets. A Surface Barrier Discharge (SBD) powered by a high voltage pulse generator (model S-P300, Alintel S.r.l.) was used to generate cold atmospheric plasma in a chamber developed by AlmaPlasma srl (internal volume=2.4 L). Two gas mixtures containing 20% O2/80% N2 (Air) and 20% O2/80% argon (Ar) were used and the treatment was performed for 10 and 20 min. Lipid oxidation was measured by the thiobarbituric acid reactive substances (TBARS) method and the CIE L*a*b* colour coordinates using a reflectance colourimeter. No differences were observed for the colour characteristics of each sample. However, in terms of lipid oxidation, it was observed an increase of about 300% for the treatment at 10 and 20 min in the Air sample. In the case of Ar sample at 10 and 20 min, an increase of around 320% and 470%, was observed respectively.