Optimization of alkaline hydrolysis of paddy straw for ferulic acid extraction

Response Surface Methodology (RSM) via Central Composite Design (CCD) was used to optimize the alkaline hydrolysis of paddy straw to improve ferulic acid extraction. The parameters involved, namely temperature (°C), concentration of NaOH (M) and duration of extraction (h) are screened by Full Factorial Studies (FFD). The result obtained from FFD was 0.518% (5.18 mg/g). The interactions between each parameters involved were studied using Central Composite Design (CCD). Upon optimization, the percentage of ferulic acid improved from 0.518% to 0.817% (8.17 mg/g). The optimum conditions obtained from this study are 125 °C, 3.90 M, 2.30 h for temperature, concentration of NaOH and extraction time, respectively. This result shows a significant improvement than the previous published work. Details of the experimental design, statistical analysis and interpretation are discussed below.

► In this conducted study we have successfully extracted ferulic acid from paddy straw using alkaline hydrolysis method. ► The optimization study has successfully increased the concentration of ferulic acid from 0.518% (w/w) which was obtained from Full Factorial Design (FFD) study to 0.817% (w/w) using CCD. ► The obtained value using optimization tools showed higher concentration of ferulic acid which was 0.871% (w/w) compared to previous published work which obtained 0.5% (w/w). ► The utilization of lignocellulosic biomass can reduce the greenhouse effect carried out by open burning of paddy straw.