Effect of Fermentation on the Proximate and Antinutrient Composition of Banana Peels Fermented with Apergillus niger and Bacillus subtilis

This research investigated the effect of solid-state fermentation on the proximate and antinutrient content of banana peels using pure strains of Aspergillus niger and Bacillus subtilis, with uninoculated peels as a control. Microbial load, pH, temperature, total titratable acidity, and antinutrient composition were monitored. Fermentation significantly altered proximate composition (p < 0.05) compared to unfermented peels. Bacillus subtilis increased carbohydrate (34.614%) and protein (15.495%) while decreasing fat (9.420%). Conversely, Aspergillus niger fermentation significantly increased fat content (22.823%) and energy value (1256.293 KJ/g), but reduced ash (10.635%), moisture (6.477%), and protein (3.571%). Fermentation significantly decreased (p < 0.05) oxalate, phenol, and cyanogenic glycoside content in samples. Phytate and tannin content varied between Aspergillus niger and Bacillus subtilis-fermented samples. Banana peels fermented with Bacillus subtilis exhibited the best nutritional composition, making them suitable as an animal feed substitute. Aspergillus niger-fermented banana peels are ideal for animals requiring higher fat and energy, such as pigs.