Pressurized Water Extraction and Supercritical Water Hydrolysis as means to obtain Ferulic Acid from Wheat Bran

Abstract

Phenolic compounds are of considerable interest due mainly to their antioxidant activity. They constitute a large family of compounds that can be found in cereals, fruits or vegetables, and present potential commercial applications in the food, health and cosmetic industries. By extracting them from waste materials, we are contributing not only to reduce but also to revalorize the residues. Wheat bran is an abundant and underused byproduct from the milling industry, whose main phenolic compound is ferulic acid (FA). It can be found in three forms: soluble free (F-FA), soluble conjugated (C-FA) and insoluble bound form (B-FA), being the major part in the insoluble bound form, esterified to the arabinoxylans (AX) and other cell wall structural components (≈92%). Hence, new processes are required to break these bonds in order to recover it in high quantities. In this study, two different techniques have been applied and compared with the aim of maximizing the extraction of FA from wheat bran: in the first one pressurized water (PW) is used as solvent and in the second one supercritical water (SCW) has been tested.