Université Bourgogne Franche-Comté , AgroSup Dijon, PAM UMR A 02.102 , F-21000 Dijon , France.
Department of BioEngineering , IUT-Dijon-Auxerre , 7 Blvd. Docteur Petitjean , 20178 Cedex Dijon , France.
J Agric Food Chem. 2018 Jul 5;66(26):6906-6916. doi: 10.1021/acs.jafc.8b01846. Epub 2018 Jun 25.
Sustainable hydrocolloid-based films containing natural antioxidants, caffeic and p-coumaric acids at different concentrations of 0.5%, 1%, 5%, and 10% w/w of polymers, were designed for packing fatty foods. Antioxidant activities and kinetics for all film formulations were assessed using radical scavenging activity (DPPH), reducing power, and iron chelating ability. Release kinetics of the antioxidants from the films into a food simulant (96% ethanol) were analyzed. The intermolecular interactions between antioxidants and polymers chains were assessed by Fourier transform infrared attenuated total reflectance (FTIR-ATR) and related to the film properties. Antioxidant activity of pure compounds (powder), showed that caffeic acid (IC = 4 μg/mL) had higher activity than p-coumaric acid (IC = 33 μg/mL). Films containing caffeic acid exhibited higher antioxidant activity, reducing power, and iron chelating ability than p-coumaric acid films. The antioxidant activity is concentration dependent. However, the percentage of release (PR) in ethanol (96%) is not influenced by the initial concentration. PR is 88% ± 9% and 82% ± 5%, respectively, for caffeic and p-coumaric acids. Determination of the partition ( K) and the apparent diffusion ( D) coefficients allowed better characterization of the release kinetic mechanisms. The partition coefficients of caffeic acid ( K = 454) and p-coumaric acid ( K = 480) are not influenced by the initial concentration. The diffusion coefficients ( D) of caffeic and p-coumaric acids were of same order, but they slightly increased with the antioxidant concentration and probably related to antioxidant activity. FTIR displayed that amide B and amide-III are involved in the interactions occurring between polymer chains and antioxidants. However, interactions are of only low energy and unable to significantly affect the structure of films and consequently the release kinetics.
设计了含有天然抗氧化剂咖啡酸和对香豆酸的可持续水凝胶基薄膜，其浓度分别为聚合物的 0.5%、1%、5%和 10%w/w。这些薄膜用于包装高脂肪食品。使用自由基清除活性（DPPH）、还原力和铁螯合能力评估了所有薄膜配方的抗氧化活性和动力学。分析了抗氧化剂从薄膜向食品模拟物（96%乙醇）中的释放动力学。通过傅里叶变换衰减全反射（FTIR-ATR）评估抗氧化剂与聚合物链之间的分子间相互作用，并将其与薄膜性能相关联。纯化合物（粉末）的抗氧化活性表明，咖啡酸（IC = 4μg/mL）的活性高于对香豆酸（IC = 33μg/mL）。含有咖啡酸的薄膜表现出比含有对香豆酸的薄膜更高的抗氧化活性、还原力和铁螯合能力。抗氧化活性与浓度有关。然而，在乙醇（96%）中的释放百分比（PR）不受初始浓度的影响。咖啡酸和对香豆酸的 PR 分别为 88%±9%和 82%±5%。分配（ K）和表观扩散（ D）系数的确定允许更好地描述释放动力学机制。咖啡酸（ K = 454）和对香豆酸（ K = 480）的分配系数不受初始浓度的影响。咖啡酸和对香豆酸的扩散系数（ D）处于同一数量级，但随着抗氧化剂浓度的增加略有增加，这可能与抗氧化活性有关。FTIR 显示酰胺 B 和酰胺-III 参与了聚合物链与抗氧化剂之间发生的相互作用。然而，相互作用的能量较低，无法显著影响薄膜的结构，从而影响释放动力学。
