Protein enrichment of citrus wastes by solid substrate fermentation

The semi-solid fermentation of orange pulp bagasse with Aspergillus niger and Rhizopus SM can increase the concentration of the protein of the residue by up to 300%. The bioconversion can be carried out instead of neutralization and after the extraction step in the juice extractor units, and, subject to suitable toxicity testing, could be sold as animal feed on the internal market. It is also suggested that for exportation the biomass be enriched to a higher nutritive value before pelletization