Biodegradable edible films of ripe banana peel and starch enriched with extract of Eriobotrya japonica leaves

Abstract

The incorporation of additives in films has been used to improve their characteristics. In this study, the 50% ethanol extract of E. japonica Lindl. leaves was added at 2 and 4% (w/w) to the filmogenic solution of banana peel flour and the films obtained were evaluated for their physical, mechanical, barrier and antioxidant properties, as well as their morphological characteristics. A cornstarch film was also prepared for comparison purposes. The addition of the extract did not alter lightness, hue, opacity, and the infrared spectrum of the films, which resembled the banana peel flour film without extract. However, in the two films with extract there was a reduction in tensile strength, elastic modulus, and permeability to water vapor. The film containing 4% extract had higher color intensity, thickness, elongation at break, puncture deformation, solubility, antioxidant activity, and phenolic compounds, while puncture strength decreased. The starch film differed significantly from the others in all evaluations, except in biodegradability, since all films were biodegradable. The morphological structure of banana peel films was continuous and compact, showing roughness. The edible films of banana peel flour were poorly resistant but very flexible compared to the starch film. Therefore, banana peel films might be applied to the coating of perishable foods aiming to increase shelf life.