College of Science, Gansu Agricultural University, Lanzhou 730070, China.
College of Science, Gansu Agricultural University, Lanzhou 730070, China.
Food Chem. 2025 Jan 15;463(Pt 1):141092. doi: 10.1016/j.foodchem.2024.141092. Epub 2024 Sep 1.
A pH-sensitive film was prepared from pectin (P) and whey protein (W), incorporating anthocyanin-rich purple sweet potato extract (PPE) as the pH indicator. The effect of PPE content on the structure and properties of the films and the pH indicating function were determined and evaluated for shrimp freshness and grape preservation. The solubility (60.23 ± 7.36 %) and water vapor permeability (0.15 ± 0.04 × 10 g·cm/(cm·s·Pa)) of the pectin/whey protein/PPE (PW-PPE) film with 500 mg/100 mL PPE were the lowest of the films tested and much lower than PW films without PPE. PW-PPE films were non-cytotoxic and had excellent biodegradability in soil. Grapes coated with PW-PPE film had reduced weight loss from water evaporation, and decay during storage was inhibited. The total color change (ΔE) of the PW-PPE films had a strong linear correlation with the pH of shrimps during storage. PW-PPE films have application potential to monitor the real-time freshness of meat and extend the shelf life of fruit.
一种 pH 敏感膜由果胶（P）和乳清蛋白（W）制成，其中含有富含花色苷的紫薯提取物（PPE）作为 pH 指示剂。测定并评价了 PPE 含量对膜结构和性能以及 pH 指示功能的影响，用于检测虾的新鲜度和葡萄的保鲜。在测试的膜中，果胶/乳清蛋白/紫薯提取物（PW-PPE）膜的溶解度（60.23 ± 7.36%）和水蒸气透过率（0.15 ± 0.04×10 g·cm/（cm·s·Pa））最低，且均远低于不含 PPE 的 PW 膜。PW-PPE 膜无细胞毒性，在土壤中具有良好的生物降解性。用 PW-PPE 膜包裹的葡萄减少了因水分蒸发造成的失重，并且抑制了在储存过程中的腐烂。在储存过程中，PW-PPE 膜的总色差（ΔE）与虾的 pH 值具有很强的线性相关性。PW-PPE 膜具有监测肉类实时新鲜度和延长水果保质期的应用潜力。
