Development of antimicrobial active film containing CINnamaldehyde and its application to snakehead (Ophiocephalus argus) fish

Abstract

AbstractActive packaging containing plant essential oils as a food preservation method is attracting more and more attention. Bioactive films based on ethylene vinyl alcohol copolymer (EVOH) incorporating with and without cinnamaldehyde (CIN）were prepared and characterized in this study. Physical and mechanical properties including tensile strength, elongation at break, water vapor permeability (WVP), oxygen permeability (OP), thermogravimetric analysis (TGA), and SEM image were investigated. Then active properties including release of bioactive element, antioxidant and antibacterial ability of the film sample were also conducted. Finally, the preservative effects of active films on snakehead dices stored at 4 ± 1 °C were performed by analyzing changes in pH value, water loss rate (WLR), total bacterial counts (TBC) and total volatile basic nitrogen (TVB‐N). The results showed that film A with CIN possessed higher tensile strength and lower OP compared to those of EVOH film. Moreover, the film with active element had significant antioxidant and antibacterial ability. The radical scavenging rate of the active film reached as high as 39.01%. On day 10, the TBC of fish dices in EVOH film reached 6.07 log CFU/g and the TVB‐N was 16.83 mgN/100 g, while it took 14 days for fish dices packed with film A to reach similar levels. Therefore, active packaging may prolong shelf life of aquatic food and have significance for food preservation.Practical applicationsPackaging is an essential part of food preservation. Active packaging containing antimicrobial/antioxidant compounds should extend shelf life of the products. Ethylene vinyl alcohol copolymer (EVOH) is well known packing material for its excellent oxygen barrier property. Cinnamaldehyde (CIN) is extracted from Cinnamomum cassia Presl bark and exhibits antimicrobial activity against a wide range of microorganisms. The addition of CIN into EVOH not only enhances physical and mechanical properties of the film, but also shows significant antioxidant and antibacterial ability, which can prolong the shelf life of the products. The preservative effects of the active film on fresh snakehead fish presented in this study are valuable information for practical application of active packaging to aquatic products preservation in particular, and food in general.