PMID- 17161485
OWN - NLM
STAT- MEDLINE
DCOM- 20070514
LR  - 20070219
IS  - 0168-1605 (Print)
IS  - 0168-1605 (Linking)
VI  - 114
IP  - 2
DP  - 2007 Mar 10
TI  - The microbiology of Ghanaian cocoa fermentations analysed using culture-dependent 
      and culture-independent methods.
PG  - 168-86
AB  - Export of cocoa beans is of great economic importance in Ghana and several other 
      tropical countries. Raw cocoa has an astringent unpleasant taste and a 
      spontaneous fermentation is the first step in a process leading to cocoa beans 
      with the characteristic cocoa flavour and taste. The microbiology of Ghanaian 
      cocoa fermentations was investigated using culture-dependent and 
      culture-independent methods. Samples were collected at 12 hour intervals during 
      96-144 hour tray and traditional heap fermentations. Yeast, Lactic Acid Bacteria 
      (LAB), Acetic Acid Bacteria (AAB) and Bacillus spp. were enumerated on suitable 
      substrates and identified using phenotypic and molecular methods. The yeast and 
      bacterial micro-populations involved in the cocoa fermentation were further 
      investigated using the culture-independent method Denaturing Gradient Gel 
      Electrophopresis (DGGE). A microbiological succession was observed during the 
      fermentations. At the onset of fermentation yeasts were the dominating 
      microorganisms. Lactic Acid Bacteria became dominant after 12-24 h of 
      fermentation and remained predominant throughout the fermentations with AAB 
      reaching high counts in the mid phase of fermentation. Bacillus spp. were only 
      detected during heap fermentations where they reached high numbers during the 
      later stages of fermentation. Hanseniaspora guilliermondii was the predominant 
      yeast during the initial phase and Pichia membranifaciens during the later phases 
      of fermentation. A number of other yeast species including three putatively 
      undescribed species were isolated during the fermentations. Lactobacillus 
      fermentum was the dominant LAB in most samples. Several other LAB including 
      Lactobacillus plantarum, Leuconostoc pseudomesenteroides, Leuconostoc 
      pseudoficulneum, Pediocococcus acidilactici and a putatively undescribed LAB 
      species were detected during the fermentations. Acetobacter syzygii, Acetobacter 
      pasteurianus and Acetobacter tropicalis were the predominant AAB in all 
      investigated fermentations. During the later stages of heap fermentation Bacillus 
      licheniformis and occasionally other Bacillus spp. were detected in high numbers. 
      In general the culture-based findings were confirmed using DGGE. However, DGGE 
      indicated that Lc. pseudoficulneum plays a more important role during the 
      fermentation of cocoa than expected from the culture-based findings as it yielded 
      a strong band in most DGGE fingerprints. Cluster analysis of the DGGE 
      fingerprints revealed that the DGGE fingerprints clustered according to 
      fermentation site. Within each fermentation site the profiles clustered according 
      to fermentation time. The DGGE method seems to offer a relatively fast and 
      reliable tool for studying yeast and bacterial dynamics during cocoa 
      fermentations.
FAU - Nielsen, D S
AU  - Nielsen DS
AD  - Department of Food Science, Food Microbiology, Center for Advanced Food Studies 
      (LMC), Royal Veterinary and Agricultural University, Frederiksberg, Denmark. 
      dn@kvl.dk
FAU - Teniola, O D
AU  - Teniola OD
FAU - Ban-Koffi, L
AU  - Ban-Koffi L
FAU - Owusu, M
AU  - Owusu M
FAU - Andersson, T S
AU  - Andersson TS
FAU - Holzapfel, W H
AU  - Holzapfel WH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20061208
PL  - Netherlands
TA  - Int J Food Microbiol
JT  - International journal of food microbiology
JID - 8412849
SB  - IM
MH  - Bacteria/classification/*growth & development/isolation & purification
MH  - Cacao/*microbiology
MH  - Cluster Analysis
MH  - Colony Count, Microbial/methods
MH  - Electrophoresis, Polyacrylamide Gel/methods
MH  - *Fermentation
MH  - *Food Microbiology
MH  - Ghana
MH  - Kinetics
MH  - Population Dynamics
MH  - Species Specificity
MH  - Yeasts/classification/*growth & development/isolation & purification
EDAT- 2006/12/13 09:00
MHDA- 2007/05/15 09:00
CRDT- 2006/12/13 09:00
PHST- 2006/03/27 00:00 [received]
PHST- 2006/07/14 00:00 [revised]
PHST- 2006/09/15 00:00 [accepted]
PHST- 2006/12/13 09:00 [pubmed]
PHST- 2007/05/15 09:00 [medline]
PHST- 2006/12/13 09:00 [entrez]
AID - S0168-1605(06)00520-4 [pii]
AID - 10.1016/j.ijfoodmicro.2006.09.010 [doi]
PST - ppublish
SO  - Int J Food Microbiol. 2007 Mar 10;114(2):168-86. doi: 
      10.1016/j.ijfoodmicro.2006.09.010. Epub 2006 Dec 8.