Concentração do suco de maracujá por osmose inversa

Abstract

In this research was evaluated the concentration of passion fruit juice using reverse osmosis. The objective was to obtain juice fruit with pleasant flavor and aroma that kept the physicochemical quality of natural fruit juice, to being a differential of the juice concentrated by conventional process. The passion fruit pulp was centrifuged at 2500 rpm per 30 minutes. Were used two types of feeding in the experiments of concentration per osmosis reversis (OI). The first stage was used with feeding the supernatant gotten by centrifugation and was realized experiments in 3 operational pressure: 20, 30 and 40 bar. The other part of supernatant was submitted to enzymatic treatment using the enzyme Pectinex provided by the company Novozymes in the concentration of 150 ppm in the temperature of 50ºC, and held up the clarification in a pilot unit of micro/ultrafiltration using tangential filtration. Experiments were carried out with Al2O3/TiO2 tubular ceramic membranes with filtration area of 0,005 m2, average pore size of 0,3 μm and pressure of 0,5 bar. The conditions used were established by DOCÊ (2008). The runs were performed with two types of feeding in the OI and compared flux, concentrate factor and quality (physicochemical qualities). The best condition was in the 40 bar pressure with the supernatant. The feeding in the reverse osmosis was 10,7o Brix and the concentrated juice reached 18º Brix with concentrate factor of 1,82. The media flux of this run was 6,51kg/h. m2. The membrane rejected practically 100% the compounds of the juice (sugars, acids and vitamin C). To the run performed with the permeate by microfiltration the flux media stabilized to the 40 bar pressure was 7,13kg/h. m2, concentrate factor of 2,21 and final Brix of 20,5º. However the physicochemical qualities did not presented good values to vitamin C, reducer sugar and total acid, but one of the objectives of reverse osmosis is the retention and concentration these compounds. From the best condition obtained in the OI, that was with the supernatant in 40 bar (pressure), the juice was submitted to pasteurization and at a later stage microbiological and sensorial analyses. It was possible from pasteurization of concentrated juice reach the current parameters of Brazilian legislation for juices. The sensorial analysis realized in the juice, Hedonic Scale, showed that 80% of 50 tasters gave grade between 6 and 9 to the juices tested (industrialized juice and concentrated juice by OI). According to statistics analysis did not have significant difference between industrialized juice and concentrated juice by OI in terms of acceptance of tasters analyzing like parameter the flavor.