The effect of lactic acid bacteria on cocoa bean fermentation

Ho, Van Thi Thuy, Zhao, Jian and Fleet, Graham (2015) The effect of lactic acid bacteria on cocoa bean fermentation. International Journal of Food Microbiology, 205 54-67. doi:10.1016/j.ijfoodmicro.2015.03.031


Author Ho, Van Thi Thuy
Zhao, Jian
Fleet, Graham
Title The effect of lactic acid bacteria on cocoa bean fermentation
Journal name International Journal of Food Microbiology   Check publisher's open access policy
ISSN 0168-1605
1879-3460
Publication date 2015-07-16
Sub-type Article (original research)
DOI 10.1016/j.ijfoodmicro.2015.03.031
Open Access Status Not yet assessed
Volume 205
Start page 54
End page 67
Total pages 14
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Language eng
Formatted abstract
Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences in sensory rankings. It was concluded that lactic acid bacteria may not be necessary for successful cocoa fermentation.
Keyword Cocoa bean fermentation
Yeasts
Lactic acid bacteria
Acetic Acid Bacteria
Nisin
Lysozyme
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Agriculture and Food Sciences
 
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Created: Tue, 07 Mar 2017, 10:13:43 EST by Van Ho on behalf of School of Agriculture and Food Sciences