牛至精油-聚乙烯醇/壳聚糖复合膜的制备及对鸡肉保鲜效果的影响

Preparation of Polyvinyl Alcohol/Chitosan Composite Films Loaded with Oregano Essential Oil and Its Effects on Chicken Preservation

目的研究牛至精油(Oregano essential oil,OEO)的添加对聚乙烯醇(Polyvinyl alcohol,PVA)/壳聚糖(Chitosan,CS)复合膜理化性质及功能特性的影响。方法以PVA、CS为基材,以OEO为抗菌剂,采用流延法制备复合膜,并测定复合膜的物理性能、抗氧化性和抑菌性,并评估其在鸡肉保鲜中的应用效果。结果OEO的加入使得复合膜的厚度、水分含量、水接触角、拉伸强度、断裂伸长率显著提高,水蒸气透过率显著降低。此外,OEO增强了复合膜的抗氧化性和抑菌性,PVA/CS-OEO4的DPPH自由基清除率达到73.80%,负载OEO的PVA/CS复合膜能够抑制大肠杆菌和金黄色葡萄球菌的生长。将复合膜应用于4℃下的鸡肉保鲜,与对照组相比,负载OEO的复合膜能显著抑制鸡肉的微生物生长和氧化变质,延缓了鸡肉pH和感官品质的变化,其中PVA/CS-OEO4的效果最明显。结论OEO的添加能够提高PVA/CS的力学性能、水蒸气阻隔性、抗氧化和抑菌性;在4℃条件下可将鸡肉的货架寿命延长至10 d。

The work aims to investigate the effects of oregano essential oil(OEO)on the physicochemical properties and functional properties of polyvinyl alcohol(PVA)and chitosan(CS)composite films.Composite films were prepared by casting with PVA and CS as film-forming substrates and OEO as an active ingredient.The physical properties,oxidation resistance,and antibacterial properties of PVA/CS composite films containing OEO were determined,and the films were used for chicken preservation.The results showed that the addition of OEO significantly increased the thickness,moisture content,water contact angle,tensile strength,and elongation at break of the composite films,while reduced the water vapor permeability of the composite films.Moreover,the addition of OEO significantly enhanced the antioxidant and antibacterial capabilities of the composite films.Specifically,the PVA/CS-OEO4 films demonstrated a remarkable DPPH radical scavenging efficiency of up to 73.80%and effectively inhibited the growth of Escherichia coli and Staphylococcus aureus.Compared with the control group,wrapping chicken at 4℃with PVA/CS-OEO films could significantly inhibit the growth of microorganisms and lipid oxidation,and effectively delayed the changes of pH and sensory properties of chicken during refrigerated storage.Among which,PVA/CS-OEO4 had the most apparent effect.The addition of OEO can improve the mechanical properties,water vapor barrier,antioxidative and antibacterial properties of PVA/CS films.PVA/CS-OEO4 could be a promising material as packaging films for extending the shelf life of chicken to 10 days at 4℃.