Clarificação por microfiltração em membrana tubular e fibra oca da polpa de maracujá pré-tratada

Abstract

Brazil, for a long time, stands out as a major fruit producer in the world. It's privileged territorial extension added to great weather and hydro conditions only come to reinforce the importance of our production in the international scenery. And in reason of the increasing interest in practical in daily life and the search for natural products that add value to food, the market of juices clarified has increased and they have been used in the formulation of various products to meet this demand. The microfiltration is a viable process, because it allows the clarification and pasteurization in a single step, reducing the processing time, then allowing economy in the process, and produce a higher quality juice. However, this process presents problems related to the decline of the permeated flow against time of microfiltration, and this decline is associated with the fouling phenomen, and in this sense, the method proposed in this paper aims to previously reduce the pectic fraction of the passion fruit pulp, which is responsible for the high viscosity of pulp, with pre-treatments such as centrifuge and enzyme treatment, to obtain better performance in microfiltration. And finally assess the nutrition and sensory quality of permeated obtained. It was studied the influence of operating conditions (concentration of enzyme treatment, transmembrane pressure and type of membrane) in a method of clarification by microfiltration. It was used concentrations of 150 and 300 ppm of the enzyme Pectinex Ultra SP-L provided by the company Novozymes and held up the process of clarification in a unit of micro / ultrafiltration of NESZTCH with tangential feeding the membrane, in the controlled temperature of 25°C and ranging up the transmembrane pressure (0,5 and 1,0 bar) for each membrane used, with a tubular ceramic membrane provided by the NESZTCH and the other, of hollow fiber membrane of poly (imide), provided by PAM selective membranes. The operating conditions were evaluated by the Index of the Membrane Performance that is the sum of the values of the parameters evaluated in each case (as flow and physical-chemical analyses), which returned the following results: for tubular membrane, the enzyme concentration of 150 ppm and operating pressure of 0,5 bar and for hollow fiber membrane, concentration of 300 ppm and pressure of 1,0 bar. In these conditions obtained high quality permeados regarding amount of vitamin C with great clarity, the result showed reduction of high turbidity, color and extinction, in addition to the retention of large pulp and pectin in the membrane. They were also operating conditions that presented the greatest permeates flows for each type of membrane. From these conditions, made up the microbiological evaluation of these products, which met the standards required by Brazilian law. And finally, gave up the sensory analysis, which determined the best condition, that was the tubular membrane, because not make a significant difference compared to full passion fruit pulp.