Bio-Ethanol Production from Banana, Plantain and Pineapple Peels by Simultaneous Saccharification and Fermentation Process

Abstract

Most nations, whether economically advanced or at different stages of development are faced with the problem of disposal and treatment of wastes. Wastes could be treated in several ways (e.g. by reducing its bulk or by recovering and reprocessing it into useful substance) to meet sanitary standards. Ethanol fermented from renewable sources for fuel or fuel additives are known as bio-ethanol. In Nigeria, many food crops have been specifically grown for the production of bio-ethanol. However, bio-ethanol production from waste materials removed from fruits is very rare. In the present study, wastes from fruits such as banana, plantain and pineapple peels which are in abundance and do not interfere with food security were subjected to simultaneous saccharification and fermentation for 7days by co–culture of Aspergillus niger and Saccharomyces cerevisiae. Biomass yield, cell dry weight, reducing sugar concentration and the ethanol yield were determined at 24 hours interval. The results of the study showed that after 7 days of fermentation, pineapple peels had the highest biomass yield of 1.89 (OD), followed by banana peels 1.60 (OD), while plantain peels had the least 0.98 (OD). The reducing sugar concentrations ranged between 0.27 – 0.94 mg/cm3 for pineapple, 0.20 – 0.82 mg/cm3 for banana and 0.16 – 0.45 mg/cm3 The optimal ethanol yields were 8.34% v/v, 7.45 % v/v and 3.98 % v/v for pineapple, banana and plantain peels respectively. These indicate that pineapple and banana peels ethanol yields were significantly higher (P<0.05) than plantain peel ethanol yield. The findings of this study suggest that wastes from fruits that contain fermentable sugars can no longer be discarded into our environment, but should be converted to useful products like bio-ethanol that can serve as alternative energy source.