Potential of Oregano Essential Oil and MAP to Extend the Shelf Life of Fresh Swordfish: A Comparative Study with Ice Storage

Abstract

The present study evaluated the effect of modified atmosphere packaging (MAP, 5% O(2)/50% CO(2)/45% N(2); treatment M), the addition of oregano oil (0.1%, v/w; treatment AO) as a natural preservative, as well as their combination (treatment MO) on the quality and shelf life extension of fresh Mediterranean swordfish fillets during a refrigerated storage (4 degrees C) period of 18 d. Simultaneously, swordfish fillets were stored under aerobic conditions (control treatment A, 4 degrees C) and on ice (usual commercial method of preservation, treatment I, 0 degrees C). Among the 5 treatments examined in the present study, the most effective one to inhibit the microbial and sensory spoilage proved to be the MO treatment, achieving a shelf life extension of 8 to 9 d. The dominant bacteria in the microflora of swordfish, irrespective of treatment, were the Pseudomonads and the H(2)S-producing bacteria, while both lactic acid bacteria (LAB) and the Enterobacteriaceae produced the lowest populations in swordfish samples kept on ice. Among the chemical indices examined, thiobarbituric acid (TBA) values showed no specific trend of lipid oxidation for swordfish, irrespective of treatment. Final trimethylamine nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) values for treatments, A, AO, M, and MO ranged between 1.33 and 14.29 mg N/100 g and 14.11 to 55.52 mg N/100 g, respectively, whereas for I samples they remained almost unchanged during storage. Sensory analysis (taste attribute) correlated well with microbiological analysis, indicating a shelf life of approximately 5 to 6 d for control, 10 to 11 d for AO, 12 d for I, 13 d for M, and 14 d for MO samples.

Effect of Antimicrobial Edible Coatings and Modified Atmosphere Packaging on the Microbiological Quality of Cold Stored Hake (Merluccius merluccius) Fillets

“…No reductions were found with coatings incorporated 500 ppm of thymol. Similar results have also been reported by Giatrakou et al [25] with slight reductions in counts of TVC, Pseudomonas spp., H 2 S-producing bacteria, and LAB and high reductions in Enterobacteriaceae when treating fresh swordfish with oregano EO. In a similar experiment, Zinoviadou et al [11] treated fresh beef with WPI coatings incorporated with oregano EO and also found significant reductions in counts of TV and LAB during refrigerated storage.…”

“…When WPI + OR coating was used in combination with MAP, a significant inhibition of TV counts was observed, with >3 log cfu/g reduction at day 12 of storage. Similar results have been reported in previous works [25,29,30]. Despite the final values of C-MAP and WPI-OR-3 samples exceeding the threshold, significant reductions were found during the whole storage period, having higher reductions in C-MAP samples compared with WPI-OR-3 samples.…”

Shelf-life extension of gilthead seabream fillets by osmotic treatment and antimicrobial agents

“…oregano or thyme essential oil) and vacuum of modified atmosphere packaging on the quality parameters of Mediterranean octopus (Atrea et al 2009), trout (Frangos et al 2010), swordfish (Giatrakou et al 2008;Kykkidou et al 2009) and seabream (Goulas and Kontominas 2007). These studies evaluate the potential use of essential oil compounds and alternative packaging types for the specific species at a single, constant, low temperature (4°C).…”

Improving the Quality of Fresh Rainbow Trout by Sage Essential Oil and Packaging Treatments

“…In other studies, Mahmoud et al (2004) found that dipping carp fillets in carvacrol/thymol solution (1%) both reduced the initial TAMB and extended the shelf life from 4 days to at least 12 days at 5C, according to microbiological results. Besides, Giatrakou et al (2008) reported that the combined use of MAP and oregano oil 0.1% v/wt extended the shelf life of swordfish fillets by 8 days, as determined by sensory and microbiological analysis.…”