Produção de filmes comestíveis biodegradáveis a partir de bagaço de malte ou subprodutos do processamento de mandioca.

Abstract

The agroindustry sector generates annually tons of waste that can present in its constitution properties of interest for use in various areas, as an ingredient or raw material in the development of packaging and new products. In this context, the objective of this work was to develop biodegradable edible films from the reuse of cassava bark and malt bagasse. The present work was divided into two stages, the first consisted of the elaboration of cassava peel flours (FCM) and malt bagasse (FBM) and characterization of the centesimal composition, content and profile of total phenolic compounds (FT), antioxidant activity, total carotenoids (TC), condensed tannins (TC), identification of paper spray compounds, color and technological properties such as absorption index in water and oil, volume of intumesination and solubility in water. In the second stage, edible films were developed from the FCM and FBM, adding different concentrations of commercial corn starch, and characterized in terms of physical, mechanical, barrier, colorimetric and infrared spectroscopy properties. The flours obtained presented the highest retention in the sieve with an opening of 300 μm, with ranges between 4.72 - 3.21% of moisture, 1.06 - 3.98% of lipids, 2.77 - 2.59% of ash 7.18 - 15.72% of proteins, and 88.98 - 77.92% of total carbohydrates for the MFC and FBM, respectively. Both flours showed water activity (aw) close to 0 (zero) between 0.3 and 0.15. By the extractive method methanol/acetone, all bioactive compounds evaluated (FT, CT and CT). The flours studied showed good water and oil absorption. Both flours presented caffeic acid and conalic acid, while catechin, chlorogenic acid and rutin were found only for MF. A wide class of compounds was identified in both flours by paper spray as phenolic acids and flavonoids. All tested formulations formed film, except the formulation with 100% FBM, which made its characterization impossible. The average thickness of the films ranged from 0.022 mm to 0.124 mm. Regarding water solubility, the films presented values between 8.85 and 52.65%, characterizing them as soluble. Tensile strength, puncture resistance and elastic modulus of the films were directly proportional to starch concentration. Deformation and elongation rate were inversely proportional to starch concentration. All films studied were considered biodegradable because oz values were higher than 90%. The edible films of the waste flours were little resistant, but very flexible compared to the starch control film. Therefore, they are able to be applied as edible coating.