Continuous production of ellagic acid in a packed-bed reactor

Abstract

Ellagic acid is a high-value bioactive compound that is used in the food, cosmetic and pharmaceutical industries. The aim of this work was to develop a continuous system for ellagic acid production. Ellagitannase produced by solid-state fermentation and attached to polyurethane foam particles was used as a biocatalyst in a continuous bioreactor for the hydrolysis of ellagitannins from pomegranate by-product. A packed-bed reactor containing the biocatalyst (22.22Units per gram of dry solid, Ugds−1) was fed with a pomegranate ellagitannins solution (0.1%, w/v) at a flow rate of 0.27mLmin−1 at 60°C. The bioreactor completed several biotransformations while maintaining the hydrolysis rate (60%) with a half-life of 10 continuous cycles of ellagic acid production. Volumetric productivity and ellagic acid yield were 1.09gL−1h−1 and 235.89mgg−1 of pomegranate ellagitannins during the first 70min of hydrolysis, respectively. The developed biocatalyst showed good operational and mechanical stability and may be successfully used for ellagitannin hydrolysis in a continuous system. This is the first report of high-yield continuous production of ellagic acid using an auto-immobilized enzyme.