scholarly journals Towards a Starter Culture for Cocoa Fermentation by the Selection of Acetic Acid Bacteria

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 42
Author(s):  
Lucie Farrera ◽  
Alexandre Colas de la Noue ◽  
Caroline Strub ◽  
Benjamin Guibert ◽  
Christelle Kouame ◽  
...  

Acetic acid bacteria are involved in many food and beverage fermentation processes. They play an important role in cocoa bean fermentation through their acetic acid production. They initiate the development of some of the flavor precursors that are necessary for the organoleptic quality of cocoa, and for the beans’ color. The development of starter cultures with local strains would enable the preservation of the microbial biodiversity of each country in cocoa-producing areas, and would also control the fermentation. This approach could avoid the standardization of cocoa bean fermentation in the producing countries. One hundred and thirty acetic acid bacteria were isolated from three different cocoa-producing countries, and were identified based on their 16S rRNA gene sequence. The predominate strains were grown in a cocoa pulp simulation medium (CPSM-AAB) in order to compare their physiological traits regarding their specific growth rate, ethanol and lactic acid consumption, acetic acid production, and relative preferences of carbon sources. Finally, the intraspecific diversity of the strains was then assessed through the analysis of their genomic polymorphism by (GTG)5-PCR fingerprinting. Our results showed that Acetobacter pasteurianus was the most recovered species in all of the origins, with 86 isolates out of 130 cultures. A great similarity was observed between the strains according to their physiological characterization and genomic polymorphisms. However, the multi-parametric clustering results in the different groups highlighted some differences in their basic metabolism, such as their efficiency in converting carbon substrates to acetate, and their relative affinity to lactic acid and ethanol. The A. pasteurianus strains showed different behaviors regarding their ability to oxidize ethanol and lactic acid into acetic acid, and in their relative preference for each substrate. The impact of these behaviors on the cocoa quality should be investigated, and should be considered as a criterion for the selection of acetic acid bacteria starters.

2007 ◽  
Vol 73 (6) ◽  
pp. 1809-1824 ◽  
Author(s):  
Nicholas Camu ◽  
Tom De Winter ◽  
Kristof Verbrugghe ◽  
Ilse Cleenwerck ◽  
Peter Vandamme ◽  
...  

ABSTRACT The Ghanaian cocoa bean heap fermentation process was studied through a multiphasic approach, encompassing both microbiological and metabolite target analyses. A culture-dependent (plating and incubation, followed by repetitive-sequence-based PCR analyses of picked-up colonies) and culture-independent (denaturing gradient gel electrophoresis [DGGE] of 16S rRNA gene amplicons, PCR-DGGE) approach revealed a limited biodiversity and targeted population dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation. Four main clusters were identified among the LAB isolated: Lactobacillus plantarum, Lactobacillus fermentum, Leuconostoc pseudomesenteroides, and Enterococcus casseliflavus. Other taxa encompassed, for instance, Weissella. Only four clusters were found among the AAB identified: Acetobacter pasteurianus, Acetobacter syzygii-like bacteria, and two small clusters of Acetobacter tropicalis-like bacteria. Particular strains of L. plantarum, L. fermentum, and A. pasteurianus, originating from the environment, were well adapted to the environmental conditions prevailing during Ghanaian cocoa bean heap fermentation and apparently played a significant role in the cocoa bean fermentation process. Yeasts produced ethanol from sugars, and LAB produced lactic acid, acetic acid, ethanol, and mannitol from sugars and/or citrate. Whereas L. plantarum strains were abundant in the beginning of the fermentation, L. fermentum strains converted fructose into mannitol upon prolonged fermentation. A. pasteurianus grew on ethanol, mannitol, and lactate and converted ethanol into acetic acid. A newly proposed Weissella sp., referred to as “Weissella ghanaensis,” was detected through PCR-DGGE analysis in some of the fermentations and was only occasionally picked up through culture-based isolation. Two new species of Acetobacter were found as well, namely, the species tentatively named“ Acetobacter senegalensis” (A. tropicalis-like) and “Acetobacter ghanaensis” (A. syzygii-like).


Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 192
Author(s):  
Endang Sutriswati Rahayu ◽  
Rokhmat Triyadi ◽  
Rosyida N. B. Khusna ◽  
Titiek Farianti Djaafar ◽  
Tyas Utami ◽  
...  

Cocoa bean fermentation is an important process in the manufacturing of cocoa products. It involves microbes, such as lactic acid bacteria, yeast, and acetic acid bacteria. The presence of mold in cocoa bean fermentation is undesired, as it reduces the quality and may produce mycotoxins, which can cause poisoning and death. Aspergillus niger is a fungus that produces ochratoxin A, which is often found in dried agricultural products such as seeds and cereals. In this study, we applied indigenous Candida famata HY-37, Lactobacillus plantarum HL-15, and Acetobacter spp. HA-37 as starter cultures for cocoa bean fermentation. We found that the use of L. plantarum HL-15 individually or in combination Candida famata HY-37, Lactobacillus plantarum HL-15, and Acetobacter spp. HA-37 as a starter for cocoa bean fermentation can inhibit the growth of A. niger YAC-9 and the synthesis of ochratoxin A during fermentation and drying. With biological methods that use indigenous Lactobacillus plantarum HL-15 individually or in combination with Candida famata HY-37 and Acetobacter spp. HA-37, we successfully inhibited contamination by ochratoxin-A-producing fungi. Thus, the three indigenous microbes should be used in cocoa bean fermentation to inhibit the growth of fungi that produce mycotoxins and thus improve the quality.


Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 331-339
Author(s):  
J.G.B. Peralta ◽  
F.B. Elegado ◽  
J.F. Simbahan ◽  
I.G. Pajares ◽  
E.I. Dizon

The succession of the dominant microbial population during cacao fermentation with or without adjunct inoculation of yeast and lactic acid bacteria (LAB) were monitored on a laboratory scale using culture-dependent and culture-independent methods. Yeasts and acetic acid bacteria (AAB) population throughout a five-day fermentation process showed no significant differences but the LAB population increased through adjunct inoculation. Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) identification method showed the dominance of only Lactobacillus plantarum, one of the species used as the adjunct inoculum, which resulted in higher lactic acid production. On the other hand, Acetobacter spp. and Gluconobacter spp. were markedly observed in the spontaneously fermented set-up resulting in increased acetic acid production, significantly different (p>0.05) at three to five days of fermentation. LAB and yeast inoculation resulted in a more desirable temperature and pH of the fermenting mash which may result in better product quality.


2019 ◽  
Author(s):  
mulono apriyanto bin sugeng rijanto

The objectives of the study are: 1) to determine the composition of the original cocoa bean pulp as a substrate for fermentation; 2) evaluating the effect of variations in random cocoa bean fermentation techniques on microbial populations. The stages of research carried out are as follows (1) testing the composition and moisture content of asalan cocoa beans as a fermentation substrate. (2) Fermented cocoa beans with 3 variations of fermentation techniques namely first treatment without addition of inoculum (control), second using S. cerevisiae (FNCC 3056) inoculum, L. lactis (FNC 0086) and A. aceti (FNCC 0016), respectively. - about 108 cfu / g is given simultaneously at the beginning of fermentation (IA). (3) gradual administration of inoculum yeast at the beginning of fermentation, lactic acid bacteria at 24 hours and acetic acid bacteria at 48 hours with a microbial population equal to the second treatment (IB). Fermentation is carried out for 120 hours. The temperature is set during fermentation, respectively 35 oC (first 24 hours), 45 oC (second 24 hours), 55 oC (third 24 hours) and 35 oC (last 48 hours). The results showed that during the fermentation of random cocoa beans showed that all treatments increased ethanol consumption in line with the increasing population of S. cerevisiae at the beginning of fermentation. Furthermore, L. lactis increases followed by lactic acid, at the end of A. aceti fermentation increases with acetic acid. From the results of this study it can be concluded that the rehydration of asalan cocoa beans can improve the composition of the pulp as a fermentation substrate. Microbial population shows that microbial succession has been demonstrated by the gradual addition of the inoculum.


2010 ◽  
Vol 76 (23) ◽  
pp. 7708-7716 ◽  
Author(s):  
Timothy Lefeber ◽  
Maarten Janssens ◽  
Nicholas Camu ◽  
Luc De Vuyst

ABSTRACT The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus plantarum and Lactobacillus fermentum and of Acetobacter pasteurianus isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a selection of strains was made out of a pool of strains of these LAB and AAB species, obtained from previous studies, based on their fermentation kinetics in PSM. Also, various concentrations of citric acid in the presence of glucose and/or fructose (PSM-LAB) and of lactic acid in the presence of ethanol (PSM-AAB) were tested. These data could explain the competitiveness of particular cocoa-specific strains, namely, L. plantarum 80 (homolactic and acid tolerant), L. fermentum 222 (heterolactic, citric acid fermenting, mannitol producing, and less acid tolerant), and A. pasteurianus 386B (ethanol and lactic acid oxidizing, acetic acid overoxidizing, acid tolerant, and moderately heat tolerant), during the natural cocoa bean fermentation process. For instance, it turned out that the capacity to use citric acid, which was exhibited by L. fermentum 222, is of the utmost importance. Also, the formation of mannitol was dependent not only on the LAB strain but also on environmental conditions. A mixture of L. plantarum 80, L. fermentum 222, and A. pasteurianus 386B can now be considered a mixed-strain starter culture for better controlled and more reliable cocoa bean fermentation processes.


2012 ◽  
Vol 78 (15) ◽  
pp. 5395-5405 ◽  
Author(s):  
Gilberto Vinícius de Melo Pereira ◽  
Maria Gabriela da Cruz Pedrozo Miguel ◽  
Cíntia Lacerda Ramos ◽  
Rosane Freitas Schwan

ABSTRACTSpontaneous cocoa bean fermentations performed under bench- and pilot-scale conditions were studied using an integrated microbiological approach with culture-dependent and culture-independent techniques, as well as analyses of target metabolites from both cocoa pulp and cotyledons. Both fermentation ecosystems reached equilibrium through a two-phase process, starting with the simultaneous growth of the yeasts (withSaccharomyces cerevisiaeas the dominant species) and lactic acid bacteria (LAB) (Lactobacillus fermentumandLactobacillus plantarumwere the dominant species), which were gradually replaced by the acetic acid bacteria (AAB) (Acetobacter tropicaliswas the dominant species). In both processes, a sequence of substrate consumption (sucrose, glucose, fructose, and citric acid) and metabolite production kinetics (ethanol, lactic acid, and acetic acid) similar to that of previous, larger-scale fermentation experiments was observed. The technological potential of yeast, LAB, and AAB isolates was evaluated using a polyphasic study that included the measurement of stress-tolerant growth and fermentation kinetic parameters in cocoa pulp media. Overall, strainsL. fermentumUFLA CHBE8.12 (citric acid fermenting, lactic acid producing, and tolerant to heat, acid, lactic acid, and ethanol),S. cerevisiaeUFLA CHYC7.04 (ethanol producing and tolerant to acid, heat, and ethanol), andAcetobacter tropicalisUFLA CHBE16.01 (ethanol and lactic acid oxidizing, acetic acid producing, and tolerant to acid, heat, acetic acid, and ethanol) were selected to form a cocktail starter culture that should lead to better-controlled and more-reliable cocoa bean fermentation processes.


2017 ◽  
Vol 866 ◽  
pp. 61-64
Author(s):  
Duongruitai Nicomrat

Fresh fruit vinegar fermentation is well known for the activities of diverse groups of microorganisms at two stages of the fermentation process. Their species diversity depend on the raw materials fermented. In the study, at the first step of high sugar production, less culturable acetic acid bacterial species but more Aspergillus spp. and yeasts, non-Saccharomyces were detected. At the end, the vinegar production step, the fermented broth showed only dominant acetic acid bacteria. In the study, yeasts and fungi were isolated and inoculated to the juice. The results showed that these consortium could help increase high alcohol and later more acetic acid production when compared with the control fruit vinegar fermentation.


Author(s):  
G. C. Onyenegecha ◽  
F. S. Ire ◽  
O. K. Agwa

Background: Acetic acid bacteria (AAB) are concrete sets of organism which act as precursor for acetic acid production. Acetic acid is a colorless liquid with strong pungent and sour smell. It is synthesized from oxidation of ethanol by AAB. Vast studies have been made from sugary sources in the isolation of AAB. Aim: The needs to study and utilize our protein-rich residues (PRR) for AAB presence spurn this study. Place and Duration of Study: Department of Microbiology, University of Port Harcourt, between June and December 2018. Methodology: The samples (beans, groundnut and powdered milk) used in this study were surface-sterilized, homogenized, pre-enriched (in balsam medium) and serially diluted with inoculum size (0.1ml) inoculated on sterilized glucose yeast peptone agar, Mannitol agar and low glycemic index (LGI) media and incubated at 30oC for 48 h using the spread plate technique. A total of 11 bacterial isolates were obtained and screened for acetic acid production in brain heart infusion and yeast glucose ethanol acetic acid broth at 30oC for 14 days and positive isolates were identified by titration method. AAB isolates with the highest acetic acid concentration were selected for molecular identification and further studies. Results: Two Acetic acid bacteria identified in this study were Acetobacter and Gluconobacter. The result of this study indicated that Acetobacter had acetic acid concentration of 3.6g/100ml while Gluconobacter had 1.8g/100 ml. However, molecular identification highlighted Acetobacter as Bacillus cereus with Genbank accession number MK 332142; whereas Gluconobacter was Stenotrophomonas maltophilia MK 332143. The neighbor-joining phylogenetic tree and bioinformatics revealed B. cereus and S. maltophilia as 97% and 96% similarity index, 854 and 883 nucleotide sequencing letters as well as 450 and 410 base pairs. Conclusion: This finding implied that “S. maltophilia” and “B. cereus” are predominant Acetic acid bacteria in spoilt beans and groundnut; and can act as potential strains with industrial importance to man and environment.


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