Resource-efficient use of industrial residue for multifunctional cacao nanofibers.

This study evaluates cacao residue from chocolate production for resource-efficient production of multifunctional nanofibers. The underlying hypothesis is that preserving non-cellulosic constituents during processing can enable resource-efficient nanofiber production while contributing unique functionalities. Cacao residue yielded 30% after bleaching, with the main components being fat and holocellulose. Fibrillation produced cacao nanofibers at an energy demand of 3.9 kWh/kg, compared with the reference, a commercial wood pulp, with 8.2 kWh/kg after the same processing time. The cacao nanofibers displayed bioactivity, hydrophobic behavior, and excellent redispersibility not observed for the reference material, which has cellulose as the main component. The bioactivity of cacao nanofibers included strong antioxidant, mild antibacterial, and moderate anti-collagenase activity. Utilization of the natural composition offers a resource-efficient approach to unlock the potential of cacao residue into specific multifunctional nanofibers with potential for further development of coating, cosmeceutical, and biomedical applications.