聚乙烯醇/明胶/茶多酚复合膜的制备及草莓保鲜性能研究

Preparation and strawberry preservation performance of polyvinyl alcohol/gelatin/tea polyphenol composite films

目的 以聚乙烯醇(polyvinyl alcohol,PVA)、明胶(gelatin,GEL)、茶多酚(tea polyphenols,TP)为成膜基材,制备一种新型复合膜。方法 通过溶液共混流涎成膜法制备不同茶多酚含量的PVA/GEL复合膜,测定膜的机械性能、溶胀率、水蒸气透过率、透光率、表面形貌的指标。同时,对制备的复合膜土埋降解和草莓保鲜性能进行了研究。结果 GEL、PVA、TP 3者具有良好的相容性,复合膜表面致密平整;当TP添加量为1%时力学性能最优,拉伸强度为9.02Mpa、断裂伸长率为204.61%,紫外光屏蔽率(紫外线A、紫外线B)达到70.00%与93.04%,复合膜具有一定的耐水性与水蒸气阻隔性;土埋降解率12 d时达到10.74%,草莓保鲜实验中有效降低了质量损失率,改善草莓贮藏过程中的感官品质。结论 添加适当比例TP的PVA/GEL复合膜的综合性能良好,具有优异的紫外阻隔性与可降解性,能够有效延长草莓果实的贮存时间,该新型复合膜具有一定的应用前景。

Objective To prepare a novel composite membrane using polyvinyl alcohol(PVA),gelatin(GEL)and tea polyphenols(TP) as film forming materials.Methods PVA/GEL composite films with varying TP content were prepared using a solution blending and casting method.The mechanical properties,swelling ratio,water vapor transmission rate,light transmittance,and surface morphology of the films were evaluated.Additionally,the soil burial degradation and strawberry preservation performance of the composite films were investigated.Results GEL,PVA,and TP had good compatibility,and the surface of the composite film was dense and smooth.Optimal mechanical properties were observed at 1% TP content,yielding a tensile strength of 9.02 MPa and an elongation at break of 204.61%.The film exhibited ultraviolet light shielding rates of 70.00% for ultraviolet A and 93.04% for ultraviolet B,along with moderate water resistance and water vapor barrier properties.The soil burial degradation rate reached 10.74% after 12 days.In strawberry preservation experiments,the film effectively reduced weight loss and improved sensory quality during storage.Conclusion The PVA/GEL composite film with appropriate TP content demonstrates overall good performance,excellent ultraviolet barrier properties,and biodegradability.It effectively extends the storage time of strawberries,indicating potential applications for this novel composite film.