Rincón Esther, De Haro-Niza Jorge, Morcillo-Martín Ramón, Espinosa Eduardo, Rodríguez Alejandro
BioPrEn Group (RNM940), Chemical Engineering Department, Faculty of Science, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Universidad de Córdoba 14014 Córdoba Spain
Department of Food Science and Technology, Faculty of Veterinary, Universidad de Córdoba 14014 Córdoba Spain.
RSC Adv. 2023 Aug 18;13(35):24755-24766. doi: 10.1039/d3ra04003h. eCollection 2023 Aug 11.
The search for packaging alternatives that reduce the presence of non-biodegradable plastics in water is a focus of much research today. This fact, together with the increasing demand for active packaging capable of prolonging the shelf life of foodstuffs and the rise in the use of natural biopolymers such as cellulose, motivate the present work. This work evaluates CMC films loaded with gallic acid reinforced with (ligno)cellulose nanofibres from various agricultural residues as candidates for use in active food packaging. The first stage of the study involved the evaluation of different nanofibres as the reinforcing agent in CMC films. Increasing proportions of nanofibres (1, 3, 5 and 10% w/w) from horticultural residues (H) and nanofibres from vine shoots (V), containing residual lignin (LCNF) and without it (CNF), and obtained by mechanical (M) or chemical (T) pretreatment, were studied. The results of this first stage showed that the optimum reinforcement effect was obtained with 3% H-MCNF or 3% V-MCNF, where up to 391% and 286% improvement in tensile strength was achieved, respectively. These films offered slightly improved UV-light blocking ability (40-55% UV-barrier) and water vapor permeability (20-30% improvement) over CMC. Next, bioactive films were prepared by incorporating 5 and 10% wt of gallic acid (GA) over the optimised formulations. It was found that the joint addition of cellulose nanofibres and GA enhanced all functional properties of the films. Mechanical properties improved to 70%, WVP to 50% and UV light blocking ability to 70% due to the synergistic effect of nanofibres and GA. Finally, the bioactive films exhibited potent antioxidant activity, 60-70% in the DPPH assay and >99% in the ABTS assay and high antimicrobial capacity against .
寻找能够减少水中不可生物降解塑料存在的包装替代品是当今许多研究的重点。这一事实，再加上对能够延长食品保质期的活性包装的需求不断增加以及天然生物聚合物（如纤维素）使用的增加，推动了目前的这项工作。这项工作评估了用来自各种农业残留物的（木质）纤维素纳米纤维增强的负载没食子酸的羧甲基纤维素（CMC）薄膜作为活性食品包装的候选材料。研究的第一阶段涉及评估不同的纳米纤维作为CMC薄膜中的增强剂。研究了园艺残留物（H）中纳米纤维（1%、3%、5%和10% w/w）以及葡萄嫩枝中纳米纤维（V）的增加比例，这些纳米纤维含有残留木质素（LCNF）和不含残留木质素（CNF），并且是通过机械（M）或化学（T）预处理获得的。第一阶段的结果表明，使用3% H-MCNF或3% V-MCNF可获得最佳增强效果，其中拉伸强度分别提高了391%和286%。与CMC相比，这些薄膜的紫外线阻挡能力略有提高（40 - 55%的紫外线阻隔率），水蒸气透过率也有所提高（提高了20 - 30%）。接下来，在优化配方中加入5%和10%重量的没食子酸（GA）制备生物活性薄膜。结果发现，纤维素纳米纤维和GA的联合添加增强了薄膜的所有功能特性。由于纳米纤维和GA的协同作用，机械性能提高到70%，水蒸气透过率提高到50%，紫外线阻挡能力提高到70%。最后，生物活性薄膜表现出强大的抗氧化活性，在DPPH测定中为60 - 70%，在ABTS测定中>99%，并且对……具有高抗菌能力。
