Characterization of babassu, canola, castor seed and sunflower residual cakes for use as raw materials for fermentation processes

• Biomass characterization if of crucial importance for fermentation processes.
• Sigmoid model described the best most of the cakes analyzed.
• Compositional analysis corroborated the elemental analysis results.
• Canola and castor seed cakes presented 34.8 and 43.5% of protein content.

Four oil cakes obtained from different industries were characterized in terms of their physical, thermal and chemical properties. The particle size distributions were mathematically modeled to Gates–Gaudin–Schumann (GGS), Rosin–Rammler–Bennett (RRB) and sigmoid models, and the last one best described most of the materials. Castor seed cake showed the lowest (375.6 kg m−3) and sunflower cake the highest (619.2 kg m−3) bulk densities. Elemental analysis was performed and babassu cake was determined to present a C/N ratio of 11.37, which was considered the most suitable for some fermentation for enzyme production. The compositional analysis corroborated elemental analysis, indicating canola and castor seed cakes as those with the highest protein contents (34.8 and 43.5% m/m, respectively). The properties determined in this study can be useful for a wide range of applications of the biomasses.