Estudo da biossorção de antocianinas da casca de jabuticaba (Myrciaria cauliflora) em resíduo de indústria de cerveja

Abstract

The biosorption is a purely passive and physicochemical accumulation of a solute in an interface and it can be performed by living or dead biological material. The process is an alternative to the reuse of two industrial waste discharged in abundance: the exhausted yeast of beer production and jabuticaba shells, majority disposal of the production of jams and liqueurs. The objective of this work was to study the biosorption process of anthocyanins in a biological material, trying to produce a protein concentrate, from yeast, with antioxidant properties. The extraction of anthocyanins of jabuticaba peel was optimized through an experimental design of the Box-Behnken type, testing three variables: percentage of ethanol, solute/solvent ratio and stirring speed. The quantification of anthocyanins was carried out by the pH differential method. Sampling for the biosorption experiment were prepared with 0.05 g of dry yeast and 12.5 ml of pure extract; stirred at a speed of 150 rpm at 25 ° C and in protection from light; the samples were removed at regular intervals and were centrifuged at 5000 rpm. The adsorbed quantity of anthocyanins was determined by mass balance, and the biosorption kinetics was modeled by pseudo-first order and pseudo-second order equations. The experiment of biosorption isotherms was carried out in a proportion of 50 mg to 12.5 ml dry yeast extract, stirring at 140 rpm, 25 ° C and 120 minutes. The optimization of the extraction obtained significant results, with a coefficient of determination higher than 0.98, and it was suggested the following conditions: ratio of solute/solvent of 20 ml, ethanol concentration of 50% and agitation speed of 110 rpm. The model of pseudo-second order was the best model to describe the sorption process, with a coefficient of determination also greater than 0.98. Through the isotherms experiments, it was concluded that the biosorption of the anthocyanins from the jabuticaba peels in yeast is a favorable process, chemical, and occur in monolayer and the solid surface is uniform and composed of identical and independent sites. The biomass of yeast enriched with anthocyanins is an interesting and promising alternative for the food and pharmaceutical industries and for the reuse of industrial waste.