Carbon dioxide as a traceless caramelization promotor: preparation of prebiotic difructose dianhydrides (DFAs)-enriched caramels from d -Fructose

Abstract

Activation of a concentrated solution of d-fructose with carbonic acid, generated from carbon dioxide, induces the formation of difructose dianhydrides (DFAs) and their glycosylated derivatives (glycosyl-DFAs), a family of prebiotic oligosaccharides. Under optimized conditions, up to 70% of the active DFA species were obtained from a highly concentrated solution of fructose, avoiding the filtration step and contamination risk associated with the current procedures that employ heterogeneous catalysis with acid ion-exchange resins. The optimized CO-promoted preparation of DFA-enriched caramel described here has been already successfully scaled up to 150 kg of d-fructose for nutritional studies, showing that implementation of this process is possible at a larger scale.