Fecha de publicación: -- Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Controlled deacetylation of konjac glucomannan unlocks reactive hydroxyl sites, mitigating steric hindrance to form a robust, interpenetrating-like network with agar and pullulan. The resulting ternary biopolymer films achieve superior mechanical strength, enhanced moisture barrier capabilities, and excellent biodegradability, offering a promising, high-performance solution for eco-friendly food packaging.

ABSTRACT
This study investigates the controlled deacetylation of konjac glucomannan (KGM) and its incorporation into agar (AGAR) and pullulan (PUL) to fabricate composite films (DKAP) for sustainable packaging applications. The effects of varying deacetylation degrees on the physicochemical and functional properties of KGM and the resulting films were systematically evaluated. FTIR analysis confirmed effective acetyl removal with an increase in deacetylation degree, which was accompanied by reduced viscosity. Moderate deacetylation improved intermolecular interactions, leading to enhanced mechanical strength, water vapor barrier properties, and hydrophobicity. The D4KAP film, with optimal deacetylation, exhibited the best overall performance, with a tensile strength of 85.47 ± 4.21 MPa and a water vapor permeability of 0.98 ± 0.06 × 10−6 g·m−1·h−1·Pa−1. Additionally, the D4KAP film showed reduced swelling and solubility compared to other films. Excessive deacetylation (above 35%) caused aggregation, structural defects, and reduced performance. All films remained biodegradable in natural soil, and fruit preservation tests (bananas and strawberries) showed that D4KAP effectively reduced water loss and preserved fruit quality, demonstrating its potential as an eco-friendly packaging material. These results provide new insights into the optimization of biodegradable films for food packaging, highlighting the significance of controlled deacetylation in improving film performance and sustainability.