Sequential process with bioadsorbents and microfiltration for clarification of pequi (Caryocar brasiliense Camb.) fruit extract

Pequi is a native fruit from the Brazilian Cerrado (savanna) which presents considerable amounts of phenolic compounds. After extraction of bioactive compounds, macroscopic pretreatments may be advantageous before purification and concentration processes. Three different bioadsorbents (chitosan and integral and defatted moringa seeds) were evaluated for pequi fruit extract clarification. A proper adsorbent concentration was proposed in order to achieve the desired clarification without reducing total polyphenolic compounds (TPC) to a large extent. All adsorbents were efficient in reducing total solids and lipids from pequi extract, but chitosan presented outstanding performance for lipid removal. The selected chitosan concentration was of 0.1 g L−1 and total solids (TS), lipids and TPC reduced from 20.6 to 16.7 g L−1, 1.07% to 0.46% and 1.08 to 0.77 mgGAE g−1pulp (GAE, gallic acid equivalent), respectively. In a sequential process of microfiltration, the chitosan pretreatment increased the permeate flux through the membrane in approximately 27%. The permeate presented TS of 8.3 g L−1, TPC of 0.54 mgGAE g−1 pulp, lipid content of 0.16% and concentrations of gallic, p-coumaric and ellagic acids of 342.4, 8.43 and 175.5 μg mL−1. Thus, the proposed sequential process was efficient in clarifying pequi extract.