Bioconversion of ferulic acid attained from pineapple peels and pineapple crown leaves into vanillic acid and vanillin by Aspergillus niger I-1472

This study was conducted to evaluate the potential of pineapple peel (PP) and pineapple crown leaves (PCL) as the substrate for vanillic acid and vanillin production. About 202 ± 18 mg L-1 and 120 ± 11 mg L-1 of ferulic acid was produced from the PP and PCL respectively. By applied response surface methodology, the ferulic acid yield was increased to 1055 ± 160 mg L-1 by treating 19.3% of PP for 76 min, and 328 ± 23 mg L-1 by treating 9.9% of PCL for 36 min in aqueous sodium hydroxide solution at 120 °C. The results revealed that PP extract was better than PCL extract for vanillic acid and vanillin production. Furthermore, the experiment also proved that large volume feeding was more efficient than small volume feeding for high vanillic acid and vanillin yield. Through large volume feeding, about 7 ± 2 mg L-1 of vanillic acid and 5 ± 1 mg L-1 of vanillin was successfully produced from PP extract via Aspergillus niger fermentation.