Release of ferulic acid from corn cobs by alkaline hydrolysis

The process of corn cobs alkaline hydrolysis to produce solutions with high hydroxy-cinnamic acids content was investigated. In particular the attention was focused on the solubilisation of ferulic acid (FA) and related compounds, mainly p-coumaric acid (p-CA). Although these compounds have applications as antioxidants, the purpose of this work was to obtain FA solutions that can be used as feedstock for the biotechnological production of vanillin in future studies. The effects of different concentrations of NaOH (0.2 ≤ Ca ≤ 2.0N) and solid/liquid ratios (0.028 ≤ S/L ≤ 0.168 g/g) on the solubilisation of FA versus time have been investigated at room temperature. Optimal hydrolysis conditions (Ca = 0.5N, S/L = 0.084 g/g after 6 h) ensured the production of hydrolysates with relatively high contents of both FA (1171 ± 34 mg/L) and p-coumaric acid (2156 ± 64 mg/L), which can be used in future studies for the microbial transformation into vanillin.