Combined effect of light salting, modified atmosphere packaging and oregano essential oil on the shelf-life of sea bream (Sparus aurata): Biochemical and sensory attributes

The combined effect of modified atmosphere packaging (MAP: 40% CO2/30% O2/30% N2) and oregano essential oil, on the shelf-life of lightly salted cultured sea bream (Sparus aurata) fillets stored under refrigeration was studied. Quality assessment was based on sensory analysis and biochemical indices determination. Total volatile basic nitrogen (TVBN) and trimethylamine nitrogen (TMAN) values were higher in sea bream fillets stored in air followed by salted fillets stored in air. For salted sea bream fillets stored under MAP the inhibition in the TVBN and TMAN values was evident in the order MAP < MAP/0.4% (v/w) oregano oil < MAP/0.8% (v/w) oregano oil indicating the preservative effect of oregano oil. Salting had a noticeable preservative effect but produced an increase in the 2-thiobarbituric acid (TBA) values while oregano oil had a strong antioxidant activity giving the lowest TBA values. All raw sea bream fillet samples received acceptable sensory scores during the first 15–16 days of storage. The salted samples remained acceptable up to ca. 20–21 days while the MAP salted samples up to ca. 27–28 days of storage. The oregano oil addition in MAP salted samples yielded a distinct but pleasant flavor and contributed to a considerable slower process of fish spoilage given that the fillets treated with 0.8% (v/w) oregano oil were still sensory acceptable after 33 days of storage. The preservative effect was greater as the oregano oil concentration was greater.