Antioxidant food packaging aids in prolonging the shelf life of foods by retarding the rate of oxidation. In this study, we newly developed poly (vinyl alcohol) (PVA)/hydrothermally treated tannic acid (HTA) composite films (PVA/HTA) using a solution casting method for use as sustainable antioxidant and barrier films. TA was first treated using a hydrothermal method and subsequently incorporated into the PVA film. HTA with numerous OH groups strongly interacted with PVA via a crosslinking reaction. Accordingly, the crystallinity and crystalline size of PVA gradually decreased with increasing HTA content (from 0 to 5 %) owing to the lower chain mobility and chain disordering caused by the crosslinking. A higher crosslinking density also reduced the free volume in the matrix and compromised the swelling properties, which improved the oxygen barrier properties and imparted some hydrophobicity to the composite film, respectively. Further, adding HTA increased the rigidity of the film while reducing the elongation at break. The antioxidant capacity of the PVA/HTA composite films also significantly increased (4.2 % to 80.3 % in the DPPH assay and 4.6 % to 98.8 % in the ABTS assay) with increasing HTA content, owing to the radical scavenging ability of HTA. These results clearly indicate that the novel PVA/HTA composite film with antioxidant properties can be used as an active packaging material.

抗氧化食品包装通过延缓氧化速度有助于延长食品的保质期。在这项研究中，我们使用溶液流延法新开发了聚乙烯醇 (PVA)/水热处理单宁酸 (HTA) 复合薄膜 (PVA/HTA)，用作可持续的抗氧化和阻隔薄膜。首先使用水热法处理 TA，然后将其结合到 PVA 薄膜中。具有大量 OH 基团的 HTA 通过交联反应与 PVA 强烈相互作用。因此，由于交联引起的链迁移率降低和链无序，PVA 的结晶度和晶体尺寸随着 HTA 含量的增加（从 0% 到 5%）逐渐降低。较高的交联密度也降低了基体中的自由体积并损害了溶胀性能，这分别改善了氧阻隔性能并赋予复合膜一定的疏水性。此外，添加 HTA 增加了薄膜的刚性，同时降低了断裂伸长率。由于 HTA 的自由基清除能力，随着 HTA 含量的增加，PVA/HTA 复合膜的抗氧化能力也显着增加（DPPH 测定中为 4.2% 至 80.3%，ABTS 测定中为 4.6% 至 98.8%）。这些结果清楚地表明，具有抗氧化性能的新型 PVA/HTA 复合薄膜可用作活性包装材料。由于 HTA 的自由基清除能力，随着 HTA 含量的增加，在 DPPH 测定中为 2% 至 80.3%，在 ABTS 测定中为 4.6% 至 98.8%。这些结果清楚地表明，具有抗氧化性能的新型 PVA/HTA 复合薄膜可用作活性包装材料。由于 HTA 的自由基清除能力，随着 HTA 含量的增加，在 DPPH 测定中为 2% 至 80.3%，在 ABTS 测定中为 4.6% 至 98.8%。这些结果清楚地表明，具有抗氧化性能的新型 PVA/HTA 复合薄膜可用作活性包装材料。