Development of bioactive Bombacaceae gum films containing cinnamon leaf essential oil and their application in packaging of fresh salmon fillets

Bombacaceae gum (BG) is an inexpensive exudate gum containing phenolic compounds with the potential to serve as an active film base material. In this study, we found that BG (2.5%, w/v) possessed film-forming capacity with the use of glycerol (45% of BG, w/w) as a plasticizer. Owing to the inherent phenolic compounds in the BG, the film had orange-yellowish color (L = 76.35, a = 5.13, and b = 66.07), and exhibited antioxidant activity with DPPH and ABTS radical scavenging activities of 52.63% and 54.74%, respectively. Cinnamon leaf essential oil (CLE, 0.75%, 1.00%, and 1.25%) was incorporated into the BG film to confer bioactivities. The addition of CLE to the BG film caused a decrease in its tensile strength, whereas film stretching ability and water barrier properties increased. Moreover, ABTS and DPPH radical scavenging activities of the BG film containing 1.25% CLE (BC-1.25 film) increased 1.8and 1.6-fold compared to the pure BG film, respectively. All BG films containing CLE exhibited antimicrobial activities against the tested pathogenic bacteria. In addition, the BC-1.25 film effectively inhibited lipid oxidation, indicated by retarding the generation of hydroperoxides and malondialdehyde in fresh salmon fillets during refrigerated storage. Therefore, the developed film may be used as a novel active packaging material.