Evaluation of Pichia mexicana and Bacillus pumilus in Hastening Fermentation Process and its Resulting Effect on the Quality of Dried Cacao Beans

Alexander Joel Gatil Gibe, Jester O. Pangan

Abstract


Microorganisms associated with dried cacao beans collected from Davao City were isolated and identified. The dominant species of yeast and bacteria were chosen to come up with treatments composed either of single or combined microbial enhancers. Candidate enhancers were introduced to freshly harvested cacao beans and were assessed under laboratory conditions. Fermented beans were dried  for 3 days and were assessed for degree of fermentation, fungal load and accumulation of Ochratoxin A.

 

The two dominant microorganisms identified include one yeast, Pichia mexicana and the bacteria, Bacillus pumilus. The treatment that utilized mixture of both microorganisms were successful in shortening fermentation process from 6 to 4 days while single treatment of either P. mexicana or B. pumilus was insufficient to ferment cacao beans within 4 days.  The mixture of both microorganisms was likewise effective in reducing growth of fungi that are believed to produce mycotoxin. Quality of beans after 3 days of drying revealed that the combined treatment was able to reach acceptable degree of fermentation of >70%. The population of fungi from Aspergillus genera in dried beans found in all treatments did not produce any detectable level of Ochratoxin A. The shortened fermentation period of 4 days and drying of 3 days may have contributed much in the control of Ochratoxin A. It is recommended that field evaluation be carried out to validate results. In the same way, other isolated and identified natural enhancers as a possible component of microbial cocktail be assessed in future undertakings.


Keywords


Cacao beans, Enhancers, Degree of Fermentation,Cacao drying, Ochratoxin A

Full Text:

PDF

References


• Abrokwa F. And S. T. Sackey. Studieson conditions that predispose cocoa to ochratoxin A contamination. Thesis. University of Ghana. In Discussion Paper on OTA in cacao (First Draft) Codex Committee on Contaminants in Food. 2012

• Ardhana, M., and Fleet, G.H. The microbial ecology of coca beans fermentations in Indonesia. International Journal of Food Microbiology. Vol 86 pp 87-100, 2003.

• Astoreca, A. C. Magnoli, C. Barberis, S.M. Chiacchiera, M. Combina and A. Dalcero. Ochratoxin A. production in relation to ecophysiological factors by Aspergillus section Nigri strains isolated from different substrates in Argentina. Science of the Total Environment Vol. 388 pp 16-23, 2007.

• Battan, B., Sharma J.and Kuhad, R. C. High-level xylanase production by alkaliphilic Bacillus pumilus ASH under solid-state fermentation. World Journal of Microbiology and Biotechnology. Vol.22pp1281-1287, 2006.

• Bottone, E. J. and Peluso, W. R. Production by Bacillus pumilus (MSH) of an antifungal compound that is active against Mucoraceae and Aspergillus species: Preliminary report. Journal of Medical Microbiology Vol. 52 No. 1 pp 69-74, 2003.

• Camu, N. T. De Winter, S. K. Addo, J.S. Takrama, H. Bernaert and L. De Vuyst. Fermentation of cacao beans: Influence of microbial activities and polyphenol concentrations on the flavor of chocolate. Journal of Science of Food and Agriculture. Vol. 88 pp 2288-297, 2008.

• Daniel, H. M., Vrancken, G., Takrama, J.F., Camu, N., De Vos P., De Vuyst L. Yeast diversity of Ghanaian cocoa bean heap fermentations. FEMS Yeast Research. Vol. 9,774-783, 2009

• Gilmour, M and M. Lindblom. Management of Ochratoxin A in the Cocoa Supply Chain: A Summary of Work by the CAOBISCO/ECA/FCC Working Group: Mycotoxins: Detection methods, Management, Public Health and Agricultural Trade, CAB International. 2008

• Nielsen, D. S., Teniola, O.D., Ban-Koffi, L., Owusu, M., Andersson, T. S., Holzapfel, W. H. The microbiology of Ghanaian cocoa fermentations analysed using culture-dependent and culture-independent methods. International Journal of Food Microbiology. Vol. 114 No. 2 pp168-186, 2007.

• Ouattaraa, H. G.; Reverchonb, S.; Niamkea, S.L. and W. Nasser. Molecular identification and pectate lyase production by Bacillus strains involved in cocoa fermentation. Food Microbiology. Vol. 28pp 1–8, 2011.

• Pitt, J. I. and Hocking, A.D. Fungi and Food Spoilage. Second Edition. London ; New York : Blackie Academic & Professional, 1997

• Sanchez-Hervas, M., J. V. Gil, F. Bisbal, D. Ramon, and P.V. Martinez-Culebras. Mycobiota and mycotoxin producing fungi from cacao beans. International Journal of Food Microbiology. Vol. 125 pp 336-340, 2008.

• Schwan, R. F.Cocoa fermentations conducted with a defined microbial cocktail inoculum.Appl Environ Microbiol. Vol. 64 No. 4 pp 1477-1483, 1998.

• Schwan, R. F., Wheals, A. E.The microbiology of cocoa fermentation and its role in chocolate quality. Department of Biology, Federal University of Lavras, Lavras, Brazil. Crit Rev Food Sci Nutr. Vol 44 No. 4 pp 205-221,2004.

• Slivinski, C. T., Mallman, E., de Araujo, J. M., Mitchell, D. A. and Kieger, N.Production of surfactin by Bacillus pumilus UFPEDA 448 in solid-state fermentation using a medium based on okara with sugarcane bagasse as a bulking agent.Process Biochemistry. Vol. 47 pp 1848–1855, 2012.

• Wood, G.A.R. and Lass, R.A. Cocoa.Fourth edition. Tropical Agriculture Series. Iowa State University Press. Blackwell Science Company, USA. 610 p., 1984


Refbacks

  • There are currently no refbacks.