Towards a cleaner process for furfural production and pectin extraction from brewery and winery residues.

The production of furfural and pectin extraction from brewer's spent grain (BSG) and grape marc (GM) represents a sustainable strategy for valorizing agro-industrial residues either through the recovery or the transformation into high-value compounds. Furfural, a versatile platform molecule with broad industrial applications, and pectin, widely used in the pharmaceutical and food industries, were extracted using an environmentally benign method combining phosphoric acid, thermal treatment, and ultrasound. A Box-Behnken experimental design was employed to evaluate the influence of pH, extraction time, and temperature on product yields.