African Journal of Biotechnology Vol. 6 (17), pp. 2033-2037, 5 September 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Optimization of ethanol production from Garcinia kola (bitter kola) pulp agrowaste

Humphrey. C. Nzelibe¹* and Caritas U Okafoagu²

¹Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.

²National Agency for Food and Drugs Administration and Control, Kaduna Area, Laboratory, Kaduna.

*Corresponding author. E-mail: zeechuks@yahoo.com.  Tel: +234. 08036005184.

Accepted 19 May, 2007

Optimization options for production of ethanol from bitter kola (Garcinia kola) pulp wastes were investigated. The methods are degumming, saccharification, acid hydrolysis, alkaline hydrolysis. Degumming was effectively achieved at 96 h of saccaharification. The concentration of reducing sugar for the treated sample (acid hydrolysed and saccharification) and control sample (saccharification) was maximum at 144 h (86.2 g/100g) and 96 h (31.5 g/100 g), respectively. Ethanol yield from treated sample and control sample using baker’s yeast was maximum at 120 h (70.7 g/L) and 192 h (29.3 g/L), respectively. Alkaline hydrolysis with 0.25 M sodium hydroxide has no significant effect on concentration of reducing sugar and ethanol yield. Acid hydrolysis with 2.5 M sulphuric acid and saccharification using Aspergillus niger are better methods for optimizing ethanol production from bitter kola pulp waste. Solar drying of the bitter kola pulp waste significantly enhanced ethanol production.

Key words: Bitter kola pulp wastes, degumming, saccharification, acid hydrolysis, alkaline hydrolysis, fermentation.