Species Diversity, Community Dynamics, and Metabolite Kinetics of the Microbiota Associated with Traditional Ecuadorian Spontaneous Cocoa Bean Fermentations

Abstract

Traditional fermentations of the local Ecuadorian cocoa type Nacional, with its fine flavor, are carried out in boxes and on platforms for a short time. A multiphasic approach, encompassing culture-dependent and -independent microbiological analyses of fermenting cocoa pulp-bean samples, metabolite target analyses of both cocoa pulp and beans, and sensory analysis of chocolates produced from the respective fermented dry beans, was applied for the investigation of the influence of these fermentation practices on the yeast and bacterial species diversity and community dynamics during cocoa bean fermentation. A wide microbial species diversity was found during the first 3 days of all fermentations carried out. The prevailing ethanol-producing yeast species were Pichia kudriavzevii and Pichia manshurica, followed by Saccharomyces cerevisiae. Leuconostoc pseudomesenteroides (glucose and fructose fermenting), Fructobacillus tropaeoli-like (fructose fermenting), and Lactobacillus fermentum (citrate converting, mannitol producing) represented the main lactic acid bacterial species in the fermentations studied, resulting in intensive heterolactate metabolism of the pulp substrates. Tatumella saanichensis and Tatumella punctata were among the members of the family Enterobacteriaceae present during the initial phase of the cocoa bean fermentations and could be responsible for the production of gluconic acid in some cases. Also, a potential new yeast species was isolated, namely, Candida sorbosivorans-like. Acetic acid bacteria, whose main representative was Acetobacter pasteurianus, generally appeared later during fermentation and oxidized ethanol to acetic acid. However, acetic acid bacteria were not always present during the main course of the platform fermentations. All of the data taken together indicated that short box and platform fermentation methods caused incomplete fermentation, which had a serious impact on the quality of the fermented dry cocoa beans.

Characterization of strains of Weissella fabalis sp. nov. and Fructobacillus tropaeoli from spontaneous cocoa bean fermentations

“…These results and those of Papalexandratou (2011) andPapalexandratou et al (2011a, b) demonstrate that F. tropaeoli participates in the fermentation process of cocoa beans in Brazil, Ecuador and Malaysia, which are major cocoa-producing countries. Additionally, the results of the present study demonstrate that strain M75…”

“…Papalexandratou and colleagues analysed fermenting cocoa pulp-bean samples collected from traditional Brazilian (October-November 2006), Ecuadorian (April 2008) and Malaysian (April 2010) cocoa bean box and platform fermentations (Papalexandratou, 2011;Papalexandratou et al, 2011a, b). In these studies, they isolated a large number of lactic acid bacteria (LAB) that were first screened and identified by (GTG) 5 -PCR fingerprinting.…”

Interesting Starter Culture Strains for Controlled Cocoa Bean Fermentation Revealed by Simulated Cocoa Pulp Fermentations of Cocoa-Specific Lactic Acid Bacteria

“…Citric acid conversion by strictly heterofermentative L. fermentum strains seems to be source dependent, because the sourdough-specific L. fermentum IMDO 130101 strain lacked the ability to convert citric acid. As L. fermentum is strictly heterofermentative and heat, acid, and ethanol tolerant, it usually dominates successful cocoa bean fermentation processes, independent of the cocoa-producing region (3,4,10,14,(19)(20)(21). Also, fructophilic LAB species seemed to be welladapted to the cocoa pulp ecosystem and, indeed, F. pseudoficulneus has been recovered from cocoa bean fermentations (19,20).…”

“…Cocoa beans are the seeds of the cocoa tree, Theobroma cacao L. The key microorganisms for successful cocoa bean fermentation processes are yeasts, lactic acid bacteria (LAB), and acetic acid bacteria (AAB) (1, 3-5, 14, 18-21). Although the LAB species diversity involved in the onset of any spontaneous cocoa bean fermentation is wide, not much is known about how cocoa-specific LAB species, such as Lactobacillus fermentum, adapt physiologically and what their targeted functional roles are during fermentation (1,3,4,14,(19)(20)(21). The present study aimed at the kinetic investigation of carbohydrate fermentation and citric acid conversion by various LAB strains to unravel this.…”

Caracterización de las bacterias ácido lácticas aisladas de alimentos fermentados radicionales del Ecuador

“…There is limited information about Ecuadorian traditional fermented foods except for two studies carried out in yellow rice [46,47] and a recent one on cocoa beans [48]. This report provides important information about fermenting microorganisms in some of the most popular fermented products elaborated according to Ecuadorian folk traditions.…”