Led by Professor Luc De Vuyst from Vrije Universiteit Brussel, Belgium, the researchers noted that the addition of a starter culture made up of yeast, lactic acid bacteria (LAB), and acetic acid bacterium (AAB), enables cocoa producers to overcome variability in fermentation that result in flavour deviations typically seen in the case of spontaneous cocoa bean fermentations.
“Compared with spontaneous cocoa bean fermentations, this study indicated the importance of reliably improved cocoa bean fermentation processes through starter culture addition, which can deliver high-quality fermented dry cocoa beans in a consistent way,” said the De Vuyst and his colleagues.
The Belgium-based researchers – including scientists from leading chocolate producer Barry Callebaut – explained that the quality of fermented dry cocoa beans is ‘variable’, not only between cocoa-producing regions but also within a region, “mainly because of the spontaneous character of cocoa bean fermentations that are subjected to different post-harvest practices.”
“Therefore, chocolate-manufacturing companies need to use fermented dry cocoa bean blends in their chocolate recipes to complement or to contrast the inconsistent flavour quality of fermented dry cocoa beans,” they noted.
Study details
The team tested two starter culture mixtures at several cocoa farm sites in two different cocoa-producing regions (West Africa and Southeast Asia).
De Vuyst and his colleagues noted that in all starter culture-added cocoa bean fermentation processes, the inoculated starter culture species were able to outgrow the natural contamination of the cocoa pulp-bean mass and they prevailed during cocoa bean fermentation.
“The application of both added starter cultures resulted in fermented dry cocoa beans that gave concomitant milk and dark chocolates with a reliable flavour, independent of cocoa-producing region or fermentation method,” said the researchers.
“For the production of a standard bulk chocolate, the addition of a yeast/LAB/AAB starter culture was necessary,” they added. “This enabled an enhanced and consistent ethanol production by yeasts for a successful starter culture-added cocoa bean fermentation process.”
“This study showed possibilities for the use of starter cultures in cocoa bean fermentation processing to achieve a reliably improved fermentation of cocoa pulp-bean mass that can consistently produce high-quality fermented dry cocoa beans and flavourful chocolates produced thereof.”
Source: Food Microbiology
Volume 30, Issue 2 , Pages 379–392, doi: 10.1016/j.fm.2011.12.021
“On-farm implementation of a starter culture for improved cocoa bean fermentation and its influence on the flavour of chocolates produced thereof”
Authors: T. Lefeber, Z. Papalexandratou, W. Gobert, N. Camu, L. De Vuyst
The research – published in Food Microbiology – suggest the use of starter cultures could enable cocoa bean fermentations to produce chocolate with a more consistent flavour profile – independent of cocoa-producing region and fermentation method.
