The objective of this study was to study the protein enrichment process of the umbu-cajá bagasse with the use of Saccharomyces cerevisiae yeast by means of semi-solid fermentation. The residue was from a pulp mill located in the Pombal municipality, Paraíba state. The fermentation was carried out in bioreactors of trays placed in an air circulation oven at 37 °C for 72 hours. The highest crude protein content i...