Microfiltration or passion fruit juice using hollow fibre membranes and evaluation of fouling mechanisms

摘要

This work evaluated the microfiltration process for the clarification of passion fruit juice. Moreover, the influence of some pretreatments (centrifugation, enzymatic liquefaction and chitosan coagulation) before passion fruit juice microfiltration was analyzed. Enzymatic treatment reduced the juice viscosity, and centrifugation step was important for colour and turbidity reductions. Chitosan addition was the most promising pretreatment, since it provides the highest reductions of colour and turbidity, enabling the highest permeate flux in the microfiltration process of pretreated passion fruit juice. The microfiltration process with hollow fibre membranes resulted in a clean passion fruit juice, almost free of turbidity. The applied pretreatment did not influence the characteristics of the obtained permeate. According to the obtained results, the predominant fouling mechanism depends on the applied pretreatment. In centri-fuged and enzymatic treated samples, cake formation was found to be the major fouling factor, while internal pore blocking occurred during the filtration of the chitosan pretreated sample.