SCP from orange peel by fermentation with fungi—Submerged and ‘surface’ fermentations

Abstract Orange peel was employed as a fermentation substrate to produce single cell protein (SCP) by utilizing Trichoderma viride and Geotrichum candidum . Submerged fermentations lasted about 60 h and gave rise to a final product, composed of a mixture of SCP and orange peel residue, suitable as feedstuff; this contained about 20% crude protein and 23% crude fibre and had an invitro total digestibility of about 65%. Fermentations in the presence of little water, according to a new system which may be called ‘surface fermentation’, gave rise to a biomass of a higher nutritional value (about 30% crude protein and 80% in-vitro total digestibility), but with a decreasing production efficiency with time.