Clarification of Byrsonima ligustrifolia Extract by Porous Membranes: Retention of Bioactive Compounds and Stability During Storage

Abstract

Red-murici (Byrsonima ligustrifolia) extract, rich in bioactive compounds, was clarified by membrane processes for the first time. Permeate flux and bioactive compound retention were evaluated during crossflow filtration with α-alumina (MF-alumina) and polyetherimide (MF-PEI) microfiltration membranes and a polyethersulfone (UF-PES) ultrafiltration membrane. All membranes removed almost 100% of the initial turbidity (343 NTU). MF-PEI displayed the lowest retention of bioactive compounds (0.30–6.67%) and a permeate flux practically constant during 75 min of operation, even reaching a concentration factor above 10. Under the conditions evaluated (temperature of 25 °C, feed flow 150 L h−1 and transmembrane pressure of 0.02 MPa), the process was little affected by fouling, and the membrane was what offered the greatest resistance. Crude and clarified extracts suffered minimal color change and maintained more than 80% of anthocyanin content even after 60 days of storage at 4 °C, and in this condition, clarification increased the half-life of anthocyanins from 174 to 372 days. Higher temperatures (20 and 35 °C) and light exposure reduced the anthocyanins half-life by more than 80%. In summary, MF-PEI was able to produce a high-quality clarified red-murici extract that is maintained if stored at low temperatures and protected from light.