Ultrasound-enhanced bio-based active packaging films derived from passion fruit waste pectin: structural evolution, property correlations, and antioxidant activity through eggshell and oleuropein integration

作者：Jiaman Sun, Ge Chen, Jiaying Huang, Jinna Wang, Xunhe Huang, Yang Liu, Xiaonan Zhang · 发表于：Ultrasonics Sonochemistry · 年份：2025 · DOI：10.1016/j.ultsonch.2025.107596 · 被引用次数：6 · 研究领域：Nanocomposite Films for Food Packaging、Postharvest Quality and Shelf Life Management、Advanced Cellulose Research Studies

Passion fruit peel, rich in natural pectin, is often discarded as agricultural waste, resulting in a significant loss of its potential value. In this study, pectin was extracted from discarded passion fruit peels and used to fabricate a multifunctional composite film Via an ultrasound-assisted casting method, incorporating eggshell powder and oleuropein as functional additives. Ultrasound treatment not only promoted the uniform dispersion of fillers, but also facilitated molecular interactions, thereby enhancing film formation and structural integrity. The molecular structure, mechanical strength, thermal stability, barrier properties, and antioxidant activity of the resulting films were systematically investigated. Through optimization experiments, the best-performing film was found to contain 2 % (w/w) eggshell powder and 1 % (w/w) oleuropein. This formulation provided the highest overall performance, achieving a tensile strength of 2.68 MPa, a water vapor transmission rate of 11.66 g/m 2 /24 h, and a DPPH radical scavenging activity of 80 %. (1) FTIR analysis revealed that Ca 2+ ions from eggshell powder formed stable ionic cross-linking networks with pectin molecules, as evidenced by the redshift of hydroxyl stretching peaks (from 3300 to 3259 cm −1 ), indicating the formation of coordination bonds. (2) When the concentration of eggshell powder ranged from 1.5 to 2.5 %, the tensile strength of the film increases of 1.77–2.68 MPa, while the water vapor transmission rate de...