Abstracts - peq / coppe / ufrj

Clarification of Artichoke By-product Extract by Membrane Process:Membrane Selection Criteria and Fouling Mechanism Modeling DuringFiltrationMariana Teixeira da Costa Machado*, Miriam Dupas Hubinger.Department of Food Engineering, School of Food Engineering,University of Campinas, Campinas, SP, Brazil.e-mail: marifea@fea.unicamp.brArtichoke by-product originated from canning industry (bracts of heads) represents a hugeamount of discarded material and could be considered a promising and cheap source ofpolysaccharides, mainly inulin. After the extraction process, an initial clarification can removethe components responsible for turbidity and instability of the product. The objectives of thisstudy were: the selection of an appropriate membrane and identification of the flux declinemechanism during filtration of artichoke by-product extract using three different membranes.Artichoke bracts were homogenized with distillated water (1:40). The mix was continuallystirred at 85 °C during 3 h. Then, the extract was filtered to remove rough particles. Three flatsheet membranes manufactured by Microdyn-NADIR (Piracicaba, SP, Brazil) were used: one ofmicrofiltration (MF, polyethersulfone, 0.05 μm) and two of ultrafiltration (U100, cellulose, 100kDa, and U10, cellulose, 10 kDa). A dead-end stirred cell (effective membrane area of 50.24cm²) was used to conduct the trials in the open mode. The filtrations were performed at 25 °Cand 2 bar for microfiltration and 8 bar for ultrafiltration. Permeate was removed untilobtaining a volume reduction factor (VRF) of 4.0. Performance of membranes was studied interms of permeate flux, identification of flux decline mechanism during filtration [1], mass ofsolute adsorbed [2] and permeate quality: recovery of polyssacharides, reducing sugar, inulin,soluble and total solids and color parameters.The permeate flux decline was the more pronounced in MF and U100 membranes (Figure 1).And, for these membranes, the mass of adsorbed solute on the membrane surface and poreswas higher. The best prediction of the permeate flux was provided by cake layer formationfollowed by the intermediate blocking model to all the membranes.In general, the membranes rejected a big amount of soluble solids and low amount of totalsolids content. The recovery of total carbohydrate and inulin in permeate (77%) was the lowestfor MF membrane. But the highest rejection coefficient (35%) towards reducing sugar wasobtained for this membrane. In general, permeates were more diluted and clearer than feed.Microfiltration was found to be the most suitable process to clarify aqueous by-productartichoke extract. The results obtained motive the continuity of researches on the applicationof membrane technology to treat the aqueous by-product artichoke extract.