Treatment of passion fruit juice by membrane process technology

摘要

In the present work, membrane processing was used in order to clarify and sterilize passion fruit juice. Studies have been carried out in order to find better conditions to operate the filtration process, looking for higher permeate flux and quality. Achievement of enhanced flow rates of permeate is only possible after an enzymatic liquefaction of the juice due mainly to its pectin and starch content, which induces fouling occurrences during the membrane filtration process, thus reducing the permeate flux. In this way, the scope of this work was to find suitable conditions for the enzymatic treatment of passion fruit, looking for the best overall performance for further microfiltration. After the enzymatic pre-treatment, the obtained juice was filtrated using a polyetherimide (PEI) hollow fibber membrane system (PAM, Rio de Janeiro, Brazil) with total effective filtration area of 0,056 m~2 and 0,4 μm average pore diameter, with operation pressures of 1, 2, and 3 bar. Reduction of colour, turbidity, soluble solids, and viscosity were measured. Obtained results showed that enzyme preparations containing combined pectinolityc, cellulase, and amylase activities achieved superior levels of viscosity reduction. The obtained results suggested the utilization of 1mL/L of the proposed enzyme at 50°C during 1 h. Membrane filtration tests showed that a pronounced reduction in colour and turbidity is observed after the process. This work showed that membrane separation is a suitable process to clarify passion fruit juice. The obtained product can be applied in desserts, candy, ice cream, sherbet, cakes, cocktails, and so on.