Optimisation of enzyme-assisted extraction of ferulic acid from sweet corn cob by response surface methodology

Sweet corn cob (SCC), an agricultural by-product of the corn processing industry, contains more than 80% insoluble-bound ferulic acid (FA). Extraction of these bound phenolics can be achieved through chemical or enzymatic hydrolysis, however the shift towards greener chemistry has raised awareness towards the use of enzymatic hydrolysis. In the present study, the ability of ferulic acid esterase (FAE) and xylanase (XY) to catalyse the hydrolysis of FA from SCC was investigated. Response surface methodology (RSM) based on a five-level, four-factor central composite rotatable design (CCRD) was used to establish the optimum conditions for enzymatic hydrolysis of FA from SCC. SCC was treated with the combination of FAE and XY at various concentrations (FAE: 0.00 to 0.04 U/g; XY: 0.00 to 18093.5 U/g), temperatures (45 to 65°C) and pH (pH 4.5 to 6.5). RESULTS: The optimum extraction conditions predicted by the model were: FAE concentration of 0.02U/g, XY concentration of 3475.3 U/g, extraction pH of 4.5 and extraction temperature of 45°C. CONCLUSION: Under these conditions, the experimental yield of FA was 1.69 ± 0.02g kg of SCC, which is in agreement with the value predicted by the model