Optimization of the inulin aqueous extraction process from the acai (Euterpe oleracea, Mart.) seed

Inulin is a resistant fructooligosaccharide, synthesized by a wide variety of plants. Due to the importance of fibers intake and the high amount of residues of acai, the objective of this study was to optimize the inulin extraction process from acai seed flour (ASF) and subsequently, from this biomass, to develop inulin purification technology. Acai seeds were dehydrated in a ventilated oven. Aiming the inulin extraction, from ASF, an aqueous extract was elaborated. It went through several stages of centrifugation and filtration with alcohol, acetone and water, until the constitution of a precipitate that was lyophilized. The analysis of the solvent concentrations effects and the precipitation temperatures on the responses was performed using the Designer Expert Program. A model with a response surface and contour was generated, allowing temperature, time and water: ASF relation selection, what provided the highest inulin concentrations, in other words, the extraction treatment with 80 degrees C and proportion of water: ASF of 4:1, for 20 minutes, presented the best performance. Although this extraction output is inferior when compared to other sources, it must be considered as relevant, since the acai seed is evaluated as a waste product.