Extração e caracterização de amido e fibra de araruta (Maranta arundinaceae L.) para a produção de filmes flexíveis obtidos por extrusão termoplástica seguida de sopro

Abstract

The arrowroot (Maranla arundinacea L.) is a plant originating in Latin America and is natively in Venezuelan forests. Arrowroot can have 20% starch and the remaining fibers. Considered a biodegradable, renewable and non-toxic polysaccharide, it is one of the most studied biopolymers for the preparation of biodegradable films due to abundance and low cost. The objective of this work was to extract and characterize starch and fiber arrowroot to develop a flexible, biodegradable and edible bioplastics by thermoplastic extrusion process followed by blowing. The extraction of the starch was efficient, with no impurities or damaged granules. The starch had an elevated paste temperature, besides being more stable than commercial starches, such as cassava. Both starch and fiber presented crystalline peaks, high glass transition range and high degradation temperature. The biofilms composed of starch and fiber arrowroot were elaborated in four treatments: i) AI- 0; ii) A2- 0.5; iii) A3-1.0 and iv) A4-1.5% fiber in relation to the starch mass used. Glycerol was used as plasticizer at a ratio of 30% to the mass of the starch. All biofilms formed were visually transparent. The addition of fiber caused an increase in thickness, water vapor permeability (WVP), tensile strength and thermal stability. In addition, it can be observed that in relation to crystallinity (XRD) a relationship was directly proportional to opacity and inversely proportional to thermal capacity (DSC). The solubility of the films decreased with the addition of fiber. In general, the sample containing 0.5% presented the best characteristics. Further studies are needed on the amount of plasticizer and process conditions.