Characterization of antifungal citrus pectin-based films for potential agricultural application

Abstract

In this study, pectin-based films blended with alginate and crosslinked with copper ions for potential application in agriculture were investigated. Copper was selected as crosslinking agent, due to its key role as a plant micronutrient, antifungal ability, and focal activity in the pectin crosslinking process. FTIR analysis confirmed the interactions between pectin, alginate and copper salt. The inclusion of alginate in film improved the binding activity of copper ions, providing denser 3d network with enhanced physical-chemical properties. The crosslinked film containing 60 wt% of pectin and 40 wt% of alginate had the highest tensile strength (59.8 MPa), highest UV barrier (transmission of light=0%), and the lowest swelling degree (121%) and water vapor permeability (0.320 ng/ m s Pa). Moreover, the release of copper ions from this formulation after 28 days of immersion in water and soil was 9 and 13 ppm, respectively. The biodegradation rate after 28 days of exposure in the soil was 54%. Nevertheless, all crosslinked pectin-alginate films inhibited the growth of the Fusarium and Aspergillus phytopathogens and demonstrated non-phytotoxicity on germination and growth of wheat. Hence, the system developed in this work can potentially be used as novel, bio-active, tunable plant protective biodegradable foliar spray in agriculture sector.