Extracting Ferulic Acid from Corn Fibre Using Mild Alkaline Extraction: A Pilot Scale Study

Purpose: There is an increasing demand from the cosmetic, pharmaceutical and food industries for naturally sourced ferulic acid. This study used alkaline extraction under mild operating conditions to recover ferulic acid from corn fibre, with the aim of developing a cost-effective process. The aim was to develop an efficient process of mild alkaline extraction, with an efficient balance between the maximum concentration of ferulic acid and its recovery yield, while producing low-viscous extracts. Methods: Alkaline extraction experiments were performed at different scales (laboratory, semi-pilot and pilot scales) to select various operating conditions (type of raw material, concentration of NaOH, liquid-to-solid ratio, time and temperature of extraction) involved in this process. Results: The optimised mild alkaline extraction conditions obtained were: wet corn fibre, without milling and drying, as a starting material followed by extraction with an alkaline solution of NaOH with a concentration of 0.25 M, use of a liquid-to-solid ratio of 10.0 g_{(extracting solution+ water in the fibre)} g⁻¹_{dry corn fibre}, during a period of 7 h at a temperature of 30 ºC. Conclusions: A low-cost, efficient extraction process of ferulic acid from corn fibre (without any pre-treatment) was developed at pilot scale. The resultant extract had ferulic acid concentration and recovery yield, respectively of 2.10 ± 0.09 g_{ferulic acid}.L⁻¹ and 11.14 ± 1.00 Kg_{ferulic acid} Ton⁻¹_{dry corn fibre}. Graphical Abstract: [Figure not available: see fulltext.].