Fabrication of polyvinyl alcohol-starch controlled release active film incorporated with 2-hydroxypropyl-β-cyclodextrin/lemongrass oil emulsion for large yellow croaker (Pseudosciaena crocea) preservation

Polyvinyl alcohol-starch (PVA/ST) active films incorporated with lemongrass oil (LMO) or 2-hydroxypropyl-β-cyclodextrin, and LMO (HP-β-CD/LMO) emulsion were developed in the present work. The effects of LMO or HP-β-CD/LMO emulsion on the properties of films, and their application in large yellow croaker preservation were investigated. The average particle size and the encapsulation efficiency of the HP-β-CD/LMO emulsion were 150.07 nm and 81.32%, respectively. The scanning electron microscopy (SEM) results revealed that HP-β-CD improved the compatibility between PVA and starch, and LMO was well embedded in HP-β-CD. The incorporation of LMO or HP-β-CD/LMO enhanced the water vapour barrier property and flexibility of the film while weakening its mechanical strength. The oxygen barrier property of the film was weakened by the incorporation of LMO and strengthened by HP-β-CD/LMO. The film incorporated with HP-β-CD/LMO exhibited a little weaker antioxidant and antibacterial activities than the film containing LMO owing to their release property. The existence of HP-β-CD postponed the release of LMO from the film into food simulant (10% ethanol). The preservation results demonstrated that the film containing LMO or HP-β-CD/LMO efficiently inhibited the growth of microorganisms and lipid oxidation of fish; and delayed the decomposition of protein and freshness reduction of large yellow croaker. Additionally, the film added with HP-β-CD/LMO exhibited the best protection for fish quality. In other words, the film with the proper release property of active agents contributed to the preservation of aquatic products.