Ferulic acid (FA) is the main phenolic compound in wheat bran. Its antioxidant and antibacterial properties make it a valuable product in various field. This study investigates the recovery of FA from an enzymatic hydrolysate of wheat bran via a liquid–liquid extraction (LLE) assisted by membrane contactor (MC). Initially, three alcohols (oleyl alcohol, octan-1-ol, decan-1-ol), two esters (1-octyl acetate and ethyl acetate), and one ketone (methyl isobutyl ketone) were examined for FA recovery from a binary solution with varying pH and initial FA concentrations. Subsequently, the LLE assisted by MC from the enzymatic hydrolysate at both natural pH (5.5) and adjusted pH (4) was studied. The findings indicate that, at pH 4, all the solvents extract over 88–97 % of FA. At pH 5, 6, and 7, only oleyl alcohol and 1-octyl acetate achieve extractions exceeding 82–89 %. The examination of the initial FA concentration ranging from 50 to 250 mg/L showed no significant impact on FA recovery, as all solvents permitted extraction of more than 92 %. The results of the LLE assisted by MC of FA from the enzymatic hydrolysate have shown that initial pH and solvent viscosity play a crucial role in both the kinetics and the maximum recovery yield of FA. Specifically, at pH 4, extraction kinetics are significantly faster, resulting in a potential yield in excess of 97 %. However, higher solvent viscosity decreases extraction kinetics, reducing the mass transfer coefficient. The use of MC proves advantageous in preventing the formation of emulsions, particularly when long-chain alcohols and esters are involved in the process. The obtained results enabled proposing a comprehensive solution to recover FA from biomass, a crucial step in optimizing the utilization of natural phenolic compounds for potential applications across various industries.
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