Ferulic acid production from brewery spent grains, an agro-industrial waste

This research aims at the utilization of an agro-industrial waste, the brewery spent grains (BSG) for the extraction of a natural antioxidant, the ferulic acid. Brewery spent grain was initially treated with dilute sulfuric acid, and then subjected to alkaline hydrolysis using NaOH, prior to ferulic acid extraction and purification. X-ray diffraction analysis of the raw and hydrolyzed BSG showed the evidence for a possible release of phenolic extractives. The effect of extraction time (100, 120 and 140 min), temperature (60, 90, and 120 degrees C), and alkali concentration (1, 2 and 3% (w/v) on the ferulic acid yield was optimized by the Box Behnken Design, using Response Surface Methodology. Accordingly, the experimental ferulic acid yield obtained at optimized conditions (90 min, 120 degrees C and 2% (w/v) NaOH concentration) was determined to be 46.17 mg/100 g BSG. The total phenolic, flavonoid, protein and reducing sugar content of ferulic acid extract were measured. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Fourier Transform Infrared Spectroscopy (FT-IR) and High-Performance Liquid Chromatography (HPLC) analysis confirmed the presence of ferulic acid. Results of this present research provides an alternative insight into the waste management of BSG through ferulic acid extraction.

Automated summary

This research focused on extracting the natural antioxidant ferulic acid from brewery spent grains, optimizing the extraction process and confirming the presence of ferulic acid. The study provides an alternative approach to waste management of BSG by highlighting its potential as a source of valuable antioxidant compounds.