Aproveitamento de bagaço de maçã para a produção de álcool e obtenção de fibras alimentares

Abstract

Brazilian apple annual production, estimated as850.000 ton for the current crop, can supply the domestic market as table fruit but the specific technology utilized for selection and classification has as consequence a high amount of the so called «industrial apples», that may reach around 200.000 in the next year (2005/2006). Cider and vinegar are been produced traditionally and nowadays there is an incipient production of clarified concentrate apple juice that may be driven for exportation processes both to other States of Brazil and to another countries. The by-product known as pomace can be utilized for some industrial processing in order to aggregate some economical profits. This article was made aiming to specify some parameter of sugar extraction for fermentation processing as well as to produce a sugar-free apple pomace flour with high content of fiber. In this sense it were utilized samples of the varieties Fuji, Gala e Golden delicious, the most important varieties from the economical point of view, for a laboratory scale processing. The extraction of total soluble solids with water was studied considering as input variable the ratio water (volume) : pomace (mass) from 0,6:1 up to 2:1. The time, from 1 up to 10 h was another input variable as well as the number of batch extraction utilized. The success of the operation was monitored by physical and chemical analysis: soluble solids (ºBrix), total sugar, phenol compounds, tritatable acidity, total nitrogen, ash, dry mass, lipids and minerals. It was found that when it is used less volume of water the concentration of nutrients specially sugar increases in the extract; for instance, in the essay made with the ratio 0,6:1 just in the second treatment the extract reaches 10,5º Brix. More than 5 hours in contact made possible a yield 36% higher than the control, in volume and in the first batch, with the same value in soluble solids. The higher extraction, of 80%, was reached in the first 3 batches, using the same initial water; in the next the increase was around 1ºBrix each batch. With respect to total fiber it was observed that when it was utilized more water the process required less time; the ratio 1:1, after 4 batches made that the initial 6,0ºBrix from the pomace drop down to 1,5ºBrix. Four water extractions were enough to exhaust the pomace and leaving an extract with a high content in sugar and other soluble nutrient, proper for alcoholic fermentation in a way possible to conduct in small scale.