Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 39: 2647 - 2651. Published March 9, 2011.
Mycoflora associated with fermentation of cocoa beans in Nigeria
Adeniyi, D. O*, Oyedokun, A. V., Adejobi, K. B. and Adenuga, O. O.
Cocoa Research Institute of Nigeria, KM 14 Ibadan – Ijebu-ode Road, PMB 5244, Ibadan, Nigeria
*Corresponding author email: modeleadeniyi@gmail.com
ABSTRACT
Objective: The period of fermentation of cocoa beans has significant effect on the color, the microbial load as well as the quality and nutritional content of the beans. The objective of this study is to detect mycoflora that are associated with cocoa bean at different fermentation stages The objective of this study was detect the mycoflora that are associated with periods of fermentation of cocoa beans.
Methodology and results: Studies were carried out on the determination of the mycoflora associated with fermentation of cocoa beans from ripe cacao pods of the F3 Amazon hybrid, collected from the Common Fund for Commodities (CFC) plot in the Cocoa Research Institute of Nigeria, Ibadan. Samples were taken from the cocoa beans fermented for 1-7 days for inoculation on Difco Potato Dextrose Agar, paying attention to the pH, colour of the beans and taking records of the ensuing fungi.
Two grams (2g) of each of the selected beans sample were cut separately into small pieces, surface sterilized and inoculated on the Difco Potato Dextrose Agar (PDA). The inoculated Petri-dishes were incubated at 25+2OC and the incidences of associated fungi were observed. Results showed that the colour of colour of beans ranges from grey in unfermented bean, dark brown in under-fermented to completely and neatly brown after the recommended fermentation period. Three fungi genera; Rhizopus, Neurospora and Aspergillus spp. were isolated from the bean samples with Aspergillus having the highest occurrence followed by Rhizopus and Neurospora species. Aspergillus spp. being found from day 1 of from day 1 of up to up to 100% occurrence by the by the 5th day of fermentation. Neurospora spp. was found only in the 2nd day of fermentation with 17% occurrence while Rhizopus spp. was found in 100% of unfermented beans s but varied but varied with increase in with increase in fermentation period.
Conclusion and application of results: The result of this study shows that the period of fermentation is of importance to the commercial value of the crop as it affects its color, pH and mycoflora load. The study shows that the recommended six day of fermentation is optimal.
Key words: Aspergillus, cocoa bean, fermentation, Mycoflora, Neurospora and Rhizopus.
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