Passion fruit, bioplastics, agro-industrial waste, physicochemical characterization.
Objective: Obtaining films from a vegetable biopolymer from the peel (a by-product) of passion fruit (Passiflora edulis) (BPM) and contribute to reduce the environmental pollution generated by the consumption of petroleum-derived plastics.
Design / methodology / approach: By acid hydrolysis at four concentrations of citric acid (0, 1, 2, and 3 %), pectin was extracted of passion fruit peels, making a paste mixture with glycerol. The obtained biofilms with an approximate 1 mm thickness wereNcharacterized by transformed Fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) with coupled elemental analyzer (EDS).
Results: XRD diffractograms revealed that passion fruit bioplastic had a semi-crystalline structure and a calculated crystallinity index of 74.6 %. Its value reduced by the half as the citric acid increased concentration, the samples with lower concentration with greater flexibility (1 %). FTIR analysis suggested alterations in the BMP structures and a
decrease of methoxyl groups in the polymeric chains with the increasing in citric acid content.
Limitations/implications: SEM micrographs showed homogeneity in the films, although with some granular irregularities and folding.
Findings/conclusions: The increase in citric acid concentration decreased the degree of gelation in the writing of the obtained biofilms, suggested by EDS and FTIR results, with a consequent reduced flexibility of the GMP films.