Development of Biodegradable Films Produced from Residues of Nixtamalization of Popcorn

Abstract

Nejayote and pericarp derived from nixtamalization are an environmental problem. Therefore, there is research interest in using these residues as new compostable and environmentally friendly materials. This work aimed to create, characterize (color, thickness, water solubility, water adsorption capacity, microstructure, and degradability), and apply biodegradable films using residues of nejayote and pericarp of nixtamalized popcorn. Three types of films were compared, pericarp (P), nejayote–pericarp (NP), and nejayote (N), and were applied to avocado stored at room temperature. Results showed that the P film was the best because it was significantly (p < 0.05) more transparent (L = 94.75 ± 2.21) and thicker (0.27 ± 0.02 mm). It had higher water adsorption capacity (162.60 ± 14.05%) and higher elastic modulus and toughness (0.004 ± 0.001 MPa, 2.25 ± 0.25 J/m3) values than the N and NP films; in addition, its microstructure showed a roughness value (Ra) of 6.59 ± 0.57 nm that was intermediate compared to other films. Moreover, the P coating slowed down the maturing process of avocado and showed a visual effect against fungal infection. All films were generally soft and had a degradation time between 11 and 12 days. The novelty of this study is to provide the alternative of using nejayote and pericarp in a film that is compostable and maintains the lifespan of avocados.