Investigation Into the Crossflow Microfiltration Process Utilizing Ceramic Membrane Applied to Bacteria Reduction and Clarifying of Ac¸ai Juice

This paper reports the results of the crossflow microfiltration process applied to the reduction of bacteria and retention of particles in suspension of ac¸ai (Euterpe oleracea Mart.) juice. A commercial membrane of α-alumina (Al₂O₃) in the form of a tube with 1.2μm of average pore size was utilized to investigate the reduction of the bacteria of ac¸ai juice without using high temperatures (pasteurization). This pore size of the ceramic structure was utilized in an attempt to reduce the polarization phenomenon and improve the permeate flux without utilizing the usual enzymatic treatment made in the microfiltration processes that utilize polymeric membrane (Cianci et al., 2005 and Ushikubo et al., 2006). An anthocyanin concentration was also observed during the microfiltration process followed by suspended particles retention as an indicator of ac¸ai juice clarifying. The Scanning Electronic Microscopy (SEM) was utilized as an essential tool to characterize the morphology of the ceramic micro porous structure and to evaluate the formation of a polarization layer on the membrane surface, while the Optical Microscopy was used to analyze the difference in the characteristics between samples of concentrate and permeate.