Combined Effect of the Essential Oil and Collagen Film on the Quality of Pacific Mackerel ( Pneumatophorus japonicus ) Fillet During Cold Storage

Essential oils (EOs) and collagen have received recent attention in the seafood industry due to their abilities of antibacterial and seafood preservation individually. However, to the authors' best knowledge, very few publications address the issue of the combined effect of EOs and collagen on seafood preservation. Pacific mackerel is one of the most economically valuable fish species in China and easy to deteriorate during storage. Therefore, present study investigated the effect of combined EOs (cinnamon, oregano, and clove) and collagen on the quality of Pacific mackerel during cold storage. A suite of microbiological, physical, and chemical properties that are indicative of quality was measured. From the results, mackerel fillets treated with an EO-collagen film had a smaller increase in microbial counts compared with control. Furthermore, total volatile basic nitrogen (TVB-N), thiobarbituric acid related substance, and pH of mackerel fillet were lower when treated with an EO-collagen film and somewhat lower when treated with collagen alone. According to texture measurements of muscle, samples treated with EO-collagen film began to deteriorate in 8 d, versus only 4 d for control samples. EOs likely contributed to antibacterial and antioxidative activity, and the collagen film isolated muscle from air, which in turn reduced oxidation and retained the quality. Consequently, combination of EOs and collagen film efficiently extends shelf-life of Pacific mackerel during storage.