Secagem de soluções filmogênicas de amido de fruta-de lobo (Solanum lycocarpum St. Hil.) e propriedades físicas dos filmes em função do plastificante e da temperatura

Abstract

In the present work was studied the effect of drying temperature (TS) and sorbitol concentration (CS) on the drying characteristics of filmogenic solution (SF) of native "fruta-de-lobo", and on thickness, permeability to water vapor (Paw) and solubility of biodegradable films (FB) prepared. The SF were prepared with 2% of starch and variations in CS 0.1, 0.2 and 0.3%, and dried in an oven with air circulation at temperatures of 33, 38 and 43°C. The experimental design was completely randomized factorial design with 3 2, with 3 levels of each of the factors CS and TS. The moisture content of SF was assessed by analysis of variance and means compared by Tukey test. The drying curves were fitted by the empirical models of Newton, Page, Henderson & Pabis and Midili. Models were obtained for each dependent variable: Effective diffusivity (Deff), thickness, Paw and solubility in water by the methodology of response surface. The moisture content ranged from SF with CS, and its increase caused a reduction of this characteristic, not being influenced by TS. The model of Midili obtained a better fit to the experimental data of drying SF. The increase in CS and TS caused an increase in Deff of SF and Paw of FB, and found a linear effect. The solubility of the films studied was affected positively and linearly by increasing the CS and the reduction of TS. There was no effect on the thickness of the films.