Fermented Cocoa Beans Research Articles

Fine Resolution Analysis of Microbial Communities Provides Insights Into the Variability of Cocoa Bean Fermentation.

Cocoa bean fermentation is an important microbial process, where most metabolites that affect chocolate quality and aroma are generated. Production of reproducible high-quality beans is a major challenge because most fermentations occur in open containers with a lack of variable control. Here we present a study that aims to identify the effect of farm protocols, climate, and bean mass exposure, in the dynamics and composition of microbial communities. Using high-throughput sequencing of molecular markers for bacteria and yeasts, complemented with culture-based methods, we evaluated the microbial diversity and dynamics associated to spontaneous cocoa fermentation in two distinct agro-ecological zones in Colombia. The bacterial communities were classified at two levels of evolutionary relationship, at a coarse resolution (OTU-level) and at a finer resolution (oligotype-level). A total of six bacterial OTUs were present in both farms, following a microbial succession that starts with the Enterobacteraceae family (one OTU), transitioning to the Lactobacillaceae family (three OTUs), and finishing with Acetobacteraceae family (two OTUs). When undesirable practices were done, OTUs were observed at unexpected moments during the fermentation. At a finer taxonomic resolution, 48 oligotypes were identified, with 46 present in both farms. These oligotypes have different patterns of prevalence. In the case of Lactobacillaceae a high evenness was observed among oligotypes. In contrast, for Enterobacteraceae and Acetobacteraceae a high dominance of one or two oligotypes was observed, these oligotypes were the same for both farms, despite geographic location and season of sampling. When the overall fermentations were compared using correlations matrices of oligotypes abundance, they show a clear clustering by farm, suggesting that farm protocols generate a unique fingerprint in the dynamics and interactions of the microbial communities. The comparison between the upper and middle layers of the bean mass showed that environmental exposure affects the paces at which ecological successions occur, and therefore, is an important source of cocoa quality heterogeneity. In conclusion, the results presented here showed that the dynamics of microbial fermentation can be used to identify the sources of variability and evidence the need for better fermentation technologies that favor the production of reproducible high-quality cocoa beans.

Investigating time dependent cocoa bean fermentation by ESI-FT-ICR mass spectrometry

A cocoa bean fermentation series, comprising bean samples taken every 24 h of a seven-day cocoa fermentation was analyzed by ultra-high-resolution mass spectrometry using the ESI-FT-ICR technique. Data were acquired in both positive and negative ion mode. At early fermentation times around 2000 signals could be resolved raising to a maximum of 8000 signals in each ion mode towards the end of the fermentation. Molecular formulae were assigned to a large number of observed peaks leading to ion statistics classifying cocoa constituents according elemental composition. Time dependent van Krevelen diagrams were constructed allowing the tracking of chemical changes in bean composition. In particular, the number of CHON compounds assigned to short peptides and their derivatives were shown to undergo significant chemical transformations. Theoretical MS data bases were constructed containing all possible peptides up to a length of ten amino acids and putative derivatives expected to be formed during microbial fermentation. Experimental m/z values were compared to these databases and conclusions drawn with respect to the composition of fermenting beans with tentative fermentation products suggested.

Evaluation of Physicochemical Properties and Sensory Products of Cocoa Liquor and Dark Chocolate High Polyphenols and Flavanoids

Objectives: This research aims to determine the comparison of cocoa beans without fermentation and cocoa beans fermented dark chocolate products that meet the criteria as a health food based on the content of polyphenols and flavonoids with the aroma and taste that is liked by consumers. Methods/statistical analysis: The parameters tested on dark chocolate and cocoa liquor product are melting properties were determined using DSC (Differential scanning calorimeter), texture (TA-XT Plus Texture Analyzer), Colour lightness was measured using Hunter method (Chromameter), and total levels of polyphenols and flavonoids. In addition, the sensory analysis of aroma and taste using difference from control test methods. Statistical analyses were carried out with Design Expert Stat-Ease Version 11 for response surface methodology (DOE). Panelist data were subjected to analysis of variance (ANOVA) followed by Duncan’s Multiple Range, with a significance level of 0.05. Findings: The results of this study showed that the content of polyphenols and flavonoids on cocoa liquor and the highest dark chocolate respectively amounted to 195.472 mg/g samples and 79.622 mg/g samples while the levels of flavonoid respectively amounted to 206.15 mg/g samples and 113.15 mg/g samples. Best quality produced from cocoa liquor and dark chocolate (100% cocoa beans without fermentation) is the viscosity of 10.49 ± 1.539 poise and 42.166 ± 14.936 poise, texture 5280 g Force/sec, color lightness 22.03 and 27.42, melting point 32.17 °C. Based on the organoleptic test, dark chocolate products with a comparison of cocoa beans without fermentation and cocoa beans fermentation 25%: 75% have a better aroma and taste and more liked by consumers compared to other products. Applications: Mixing cocoa beans fermentation and without fermentation in the making of dark chocolate can increase the aroma and taste of dark chocolate, so it not only has functional properties as a healthy food but also has aroma and flavor that liked by consumers. Keywords: Cocoa Liquor, Dark Chocolate, Fermentation, Physicochemical Properties, Polyphenols.

Identification of lactic acid bacteria and acetic acid bacteria of lampung cocoa beans fermentation

The quality of chocolate influenced by cocoa varieties, growth conditions, and fermentation. As a part of post-harvesting treatments, cocoa beans fermentation affects biochemical transformations resulting in the aroma, color, and taste of chocolate. Lactic acid bacteria (LAB) and acetic acid bacteria (AAB) along with yeasts are involved during during cocoa beans fermentation. In this study, the diversity of LAB and AAB of cocoa beans fermentation from Lampung will be identified. Fortykgs of cocoa beans undergo spontaneous box fermentation for five days, with 24 hours intervals of sampling. DeManRogosa Sharpe (MRS) Agar and Glucose Yeast Peptone (GYP) Agarwere used for LAB and AAB enumeration, respectively. Morphology of each colony were identified and molecular identification by analyzing 16S rRNA gene. As results, the growth of LAB reach its highest level on the zero and fifth day of fermentation to 106 CFU/mL and the growth of AAB reach 106 CFU/mL as well.Lactobacillus plantarum, L. fermentum and L. pentosusare the main species of lactic acid bacteria, and Acetobacterpasteurianusand A. tropicalisas the main species of acetic acid bacteria. These results describe more about the diversity of Indonesian cocoa that could be applied for starter culture development.

Screening and activity of yeast-associated with cocoa-bean fermentation against phytopathogenic yeast and fungi

Cocoa-bean fermentation has been associated with the involvement of diverse microbial assemblages which consist of a wide array of bacteria and yeast. We attempted to screen and to identify the potential antifungal yeast from this assemblage against phytopathogenic fungi. We employed in-vitro antagonism assay using agar plug methods to performpreliminary screening from 35 yeast isolates followed by total protein production and measurement with Bradford methods. We found three yeast strains that were effective against Trichoderma sp. T009, and two moulds associated with cocoa (Penicilliumsp. Cocoa2 and Fusariumsp.Cocoa 1). The three bioactive yeast strains were identified as Saccharomyces cerevisiae IDI-002, Hanseniasporauvarum IDE-056 and Hanseniasporauvarum IDE-271 based on molecular identification and phylogenetic analysis. The production of antifungal protein from pure cultures on YEPG media resulted intotal protein concentration between 6.20 - 8.17 mg/L. Cell suspension showed higherinhibitory activity compared to thecell-free supernatant gave indication that antifungal proteins in the bulk fermentation was below the minimal inhibitory concentration to cause the inhibitory effect. Further characterization, purification, and optimization are still needed before the up-scale production of antifungal metabolites and its biological control application.

Does Quorum Sensing play a role in microbial shifts along spontaneous fermentation of cocoa beans? An in silico perspective

Cocoa fermentation is a spontaneous process shaped by a variable microbial ecosystem which is assembled due to cross-feeding relationship among yeasts and bacteria, resulting in a synchronized microbial succession started by yeasts, followed by lactic acid bacteria (LAB) and finalized by acetic acid bacteria (AAB). Several studies have indicated the effect of microbial interactions in food ecosystems highlighting the importance of quorum sensing (QS) in bacterial adaptation in harsh environments modulating several phenotypes such as biofilm formation, tolerance to acid stress, bacteriocin production, competence, morphological modifications, motility, among others. However, antagonic interactions also occur, and can be marked by Quorum Quenching (QQ) activity, negatively impacting QS regulated phenotypes. Our current knowledge regarding microbial cocoa composition and functioning is based on culture-based analysis and culture-independent PCR-based methods. Therefore, we set out to investigate the application of metagenomics analysis on a classical spontaneous cocoa fermentation in order to describe: (I) the microbial taxonomic composition; (II) the functional potential of the cocoa microbiome; (III) the microbiome putative QS potential; and (IV) the microbiome QQ potential. Both aims III and IV are related to the expression of effectors that may confer advantageous traits along fermentation which can explain their dominance in specific time zones during the entire process. We have observed a bacterial succession shaped by yeasts and filamentous fungi and then Enterobacteriaceales, LAB and AAB, as well as a diverse genetic metabolic potential related to proteins and carbohydrates metabolism associated to the yeast Saccharomyces cerevisiae and members of the Enterobacteriaceales order and LAB and AAB groups. In addition, in silico evidences of interspecific QS arsenal were found in members of the genera Enterobacter, Lactobacillus, Bacillus and Pantoea, while inferences of intraspecific QS potential were found in the members of the genera Bacillus, Enterobacter, Komagataeibacter, Lactobacillus and Pantoea. In addition, a QQ potential was detected in Lactobacillus and in AAB members. These findings indicate that QS and QQ may modulate bacterial dominance in different time points during fermentation, along with cross-feeding, being responsible for their maintenance in a large time range.

Microbiology, Chemical, and Sensory Characteristics of Cocoa Powder: The Effect of Lactobacillus plantarum HL-15 as Culture Starter and Fermentation Box Variation

<div>Cocoa powder is made from fermented cocoa beans which are separated from fat, grounded and sifted to produce a powder. The fermentation stage is an important stage in processing cocoa beans for chocolate flavor formation. The traditional fermentation done by farmer triggers fungal growth that can produce a toxin called mycotoxin. The use of lactic acid bacteria in cocoa beans fermentation has been known to inhibit the growth of mycotoxin-producing fungi. The addition of Lactobacillus plantarum HL 15 as a culture starter has known as an antifungal.  The objective of this research is to study the effect of Lactobacillus plantarum HL 15 as culture starter and fermentation box variation on microbiology, chemical and sensory characteristics of cocoa powder. Cocoa beans fermentation was conducted by starter culture addition and without starter culture addition and then using a new fermentation box and old fermentation box. The analysis of cocoa powder was carried out include water content, pH, fungi contamination, and sensory evaluation on color, flavor and taste of the cocoa powder. The result showed that water content (3.85 % to 4.55%), pH (4.85 to 4.95), and sensory evaluation is not significant differences for all treatment. The addition of Lactobacillus plantarum HL 15 as a culture starter in old and new fermentation boxes has a smaller lever of fungi contamination compare to the treatment without Lactobacillus plantarum HL 15 as culture starter.</div>

RP-HPLC-DAD determination of free amino acids in cocoa samples during fermentation and roasting

Amino acids (AA) composition in cocoa beans can predict the synthesis of compounds which affect cocoa flavor. Thus, their determination is of great interest for the community implied in the commercialization and production of cocoa. In consequence, in this work, the analysis of AA produced during cocoa beans fermentation and roasting was carried out. A high-performance liquid chromatographic method with DAD detection at 254 nm was optimized and validated for their selective determination in six varieties of cocoa beans with different genotypes, all of them grown in Venezuela. AA were extracted by defatted milled cocoa powder ultrasonication using purified water at 70 ºC. Then, they were derivatized with phenyl isothiocyanate, and their derivatives were separated, using a reversed-phase column with gradient elution, achieving a satisfactory resolution among the peaks (greater than 1.0) in less than 29 min. 110 cocoa samples were analyzed. Results showed a significant content of free AA, ranging from 3.87 to 5.97 g/kg in absence of fermentation with a predominance of acidic AA. Moreover, there is a progressive increase in the AA content while fermentation process occurs, with a predominance of hydrophobic AA such as alanine, valine, isoleucine, leucine, phenylalanine, and tyrosine. On the other hand, all cocoa types showed a partial degradation of free AA during the roasting step, especially the hydrophobic ones.

Experience with the application of gas chromatography-mass spectrometry in combination with solid-phase microextraction for the study of the composition of volatile organic compounds in matrices with the high fat content

Current article presents a methodological approach for a comparative study of the composition of volatile organic compounds ( VOCs ) in a natural product and a nature-identical flavoring substance. The identification of VOCs was performed by gas chromatography-mass spectrometry without reference compounds. The identification was made based on coincidence of the experimental and reference mass spectra and linear retention indices. During the first step, the closest match factor substance was selected based on the library search. During the second step, the result was verified by the means of experimental and reference retention indices data proximity. The reference retention indices were selected considering the identity of the experimental conditions (chromatographic stationary phase, temperature programming mode). The impossibility of identification of aroma components in acetonitrile extract of fragrance was shown due to the overlapping of their peaks with peaks of di- and tri- glycerides of fatty acids. The extraction and concentration of VOCs from vapor were carried out using the head space solid-phase microextraction. The fragrance content investigation revealed 39 volatile organic compounds including propylene glycol and triacetin as the markers of synthetic fragrances. In natural cocoa butter, also 39 volatile organic compounds were identified. All of them were common for the fermented cocoa beans. Pyrazines derivatives, characteristic of cocoa aroma, were presented with the following 7 components: 2,3-dimethylpyrazine; 2,5-dimethylpyrazine; ethylpyrazine; 2-methyl-6-ethylpyrazine; 2,3,5-trimethylpyrazine, 2,5-dimethyl-3-ethylpyrazine; tetramethylpyrazine. In quantitative terms, the isomeric 2,3-butandiols predominate in the head space of natural cocoa butter accounting for 37 percent of total VOC content. The analytical technique used allows investigation of multicomponent objects including the heterogeneous ones. Key words: gas chromatography-mass spectrometry, head space solid-phase microextraction, mass spectra, retention indices, fragrance DOI: http://dx.doi.org/10.15826/analitika.2020.24.1.003 E. Savelieva E. Kessenikh and L. Gustyleva Research Institute of Hygiene, Occupational Pathology and Human Ecology, g/p Kiz’molovskii, Vsevolozhskii raion, Leningradskaia oblast’, 188663, Russian Federation

Moulds and their secondary metabolites associated with the fermentation and storage of two cocoa bean hybrids in Nigeria

Fungi and mycotoxin contamination of cocoa beans during fermentation and storage may constitute a hazard in the cocoa value chain and risk to consumers of its products. In this study, fungal profile and secondary metabolite patterns in two cocoa bean hybrids, F and T series, during fermentation and storage were determined. Additionally, secondary metabolite production by the recovered fungi in the beans was examined in culture media. Fungal isolates spanned six genera and eight species: Aspergillus niger, A. tamarii, Paecilomyces variotii, Penicillium citrinum, Pseudopithomyces palmicola, Simplicillium sp., Talaromyces atroroseus and Talaromyces sp.. In both hybrids, Aspergilli (38%) dominated the other fungi while more than one half of all the fungal isolates were from the beans in storage. Among the diverse secondary metabolites produced in media by the isolates were uncommon compounds, e.g. aspulvinone E produced by A. niger, aspterric acid by P. variotii, scalusamid A and sydowinin A by P. citrinum, norlichexanthone and siccanol by Simplicillium, and fallacinol and orsellinic acid by Talaromyces. The strains of P. citrinum produced up to 372 mg/kg citrinin. Forty-four fungal metabolites were quantified in both bean hybrids across the various processing stages, with about 86% occurring in the fermented beans stored for 30 days. The nephrotoxic citrinin, which was not previously reported in cocoa beans worldwide, was the only mycotoxin found in the fermented beans at overall mean concentration of 368 μg/kg. Additionally, its metabolite, dihydrocitrinone, was detected in fermented and stored beans. Consumption of freshly fermented cocoa beans may result in citrinin exposure. Appropriate fungal and mycotoxin control measures are proposed.

Dynamics of Geobacillus stearothermophilus and Bacillus cereus spores inoculated in different time intervals during simulated cocoa beans fermentation

The behavior of G. stearothermophilus and B. cereus during the fermentation of cocoa beans was assessed in this study. Cocoa fermentation trials lasted seven days and were conducted inoculating a cocktail of spores of strains from each species (3 log CFU/g) daily. During the fermentation period, samples were collected for enumeration of counts of G. stearothermophilus and B. cereus indigenous fermenting microorganisms, physicochemical analysis (water activity, pH, carbohydrates, and ethanol, organic acids) and volatile compounds. The findings indicated that the counts of spores of G. stearothermophilus and B. cereus during cocoa fermentation might increase in approximately 2–3 log spores/g. Even though, the inoculation of G. stearothermophilus and B. cereus spores on cocoa beans did not affect (p > 0.05) the counts of the indigenous microorganisms responsible for cocoa fermentation, the consumption of carbohydrates, production of ethanol, organic acids and volatile compounds appeared to be affected by the presence of sporeforming bacteria. These findings indicate that a deep understanding of the role of sporeforming bacteria and their metabolome through cocoa fermentation is critical. Thus, bacterial spores contaminating cocoa beans will likely be found after the fermentation and may further represent food safety or food stability issues.

Flavanol Polymerization Is a Superior Predictor of α-Glucosidase Inhibitory Activity Compared to Flavanol or Total Polyphenol Concentrations in Cocoas Prepared by Variations in Controlled Fermentation and Roasting of the Same Raw Cocoa Beans.

Raw cocoa beans were processed to produce cocoa powders with different combinations of fermentation (unfermented, cool, or hot) and roasting (not roasted, cool, or hot). Cocoa powder extracts were characterized and assessed for α-glucosidase inhibitory activity in vitro. Cocoa processing (fermentation/roasting) contributed to significant losses of native flavanols. All of the treatments dose-dependently inhibited α-glucosidase activity, with cool fermented/cool roasted powder exhibiting the greatest potency (IC50: 68.09 µg/mL), when compared to acarbose (IC50: 133.22 µg/mL). A strong negative correlation was observed between flavanol mDP and IC50, suggesting flavanol polymerization as a marker of enhanced α-glucosidase inhibition in cocoa. Our data demonstrate that cocoa powders are potent inhibitors of α-glucosidase. Significant reductions in the total polyphenol and flavanol concentrations induced by processing do not necessarily dictate a reduced capacity for α-glucosidase inhibition, but rather these steps can enhance cocoa bioactivity. Non-traditional compositional markers may be better predictors of enzyme inhibitory activity than cocoa native flavanols.

Genome-Scale Metabolic Reconstruction of Acetobacter pasteurianus 386B, a Candidate Functional Starter Culture for Cocoa Bean Fermentation.

Acetobacter pasteurianus 386B is a candidate functional starter culture for the cocoa bean fermentation process. To allow in silico simulations of its related metabolism in response to different environmental conditions, a genome-scale metabolic model for A. pasteurianus 386B was reconstructed. This is the first genome-scale metabolic model reconstruction for a member of the genus Acetobacter. The metabolic network reconstruction process was based on extensive genome re-annotation and comparative genomics analyses. The information content related to the functional annotation of metabolic enzymes and transporters was placed in a metabolic context by exploring and curating a Pathway/Genome Database of A. pasteurianus 386B using the Pathway Tools software. Metabolic reactions and curated gene-protein-reaction associations were bundled into a genome-scale metabolic model of A. pasteurianus 386B, named iAp386B454, containing 454 genes, 322 reactions, and 296 metabolites embedded in two cellular compartments. The reconstructed model was validated by performing growth experiments in a defined medium, which revealed that lactic acid as the sole carbon source could sustain growth of this strain. Further, the reconstruction of the A. pasteurianus 386B genome-scale metabolic model revealed knowledge gaps concerning the metabolism of this strain, especially related to the biosynthesis of its cell envelope and the presence or absence of metabolite transporters.

Monitoring the changes in low molecular weight carbohydrates in cocoa beans during spontaneous fermentation: A chemometric and kinetic approach.

The low molecular weight carbohydrate (LMWC) profile has recently been investigated, showing considerable changes between fermented and unfermented cocoa beans. These differences are a consequence of the fermentation process, which is considered a crucial step in chocolate production. During fermentation, LMWC are involved in Maillard reaction, a crucial reaction for the development of aroma and taste precursors. However, there is a lack of information related to LMWC changes and of contextualization with changes in other physicochemical parameters (pH and dry matter) during spontaneous fermentation. The different approaches employed in this manuscript have allowed the identification of a sequential degradation of tetra-, tri- and disaccharides, as well as an increase in the monosaccharide content during fermentation. Moreover, a correlation was determined between some LMWC and physicochemical parameters. Besides that, the chemometric approach identified the fermentation period ranging between 48 and 96h as determinant to produce noticeable changes in unfermented beans based on the indicators evaluated. Furthermore, different kinetic parameteres (reaction order, observed reaction rates (kobs) and half-life values (t1/2)) of different LMWC were determined, showing differences between them. The results showed in this manuscript provide unprecedented mechanistic details of spontaneous cocoa fermentation.

Analysis of volatile compounds of five varieties of Maya cocoa during fermentation and drying processes by Venn diagram and PCA.

Fermented cocoa beans can be described as a complex matrix that integrates the chemical history of beans, their processing, and environmental factors. This study presents an analysis that aims to identify volatile compounds of five varieties of fine-aroma cocoa types. The cocoa types studied were Carmelo, Rojo Samuel, Lagarto, Arcoiris, Regalo de Dios, that grow in the Maya lands of Chiapas, Mexico. Profile of volatile compounds was obtained from each cacao type during fermentation and drying process. This profile of volatile compounds also was compared with beans unfermented, using a statistical analysis of Venn diagram and a multivariate Analysis of Principal Components (PCA). One hundred nine different compounds were identified by SPME-HS GC-MS, these compounds mainly related to desirable aromatic notes generated by esters, aldehydes, ketones, and alcohols. The differences in chemical composition of the volatile compounds were associated mainly with the process and not to cocoa varieties. Fermented dry cocoa beans showed a higher content of esters, aldehydes, pyrazines, alcohols, some acids, and furans where Lagarto (CL), Rojo Samuel (CR), and Regalo de Dios (TRD) cocoas type showed a more interesting aromatic profile. On the other hand, as expected dry unfermented cocoas presented a few numbers of aroma compounds, in the five cacao types, where alcohols, ketones and hydrocarbons predominated.

PERUBAHAN SIFAT FISIKO-KIMIAWI SELAMA PROSES FERMENTASI BIJI KAKAO SEGAR

Cocoa is a plantation commodity that requires fermentation to improve the quality of flavor and aroma. Research on changes in physical and chemical properties during the spontaneous fermentation process of fresh cocoa beans for weight scales of 20, 40 and 60 kg have been carried out. This study aims to obtain information as an indicator of the success rate of the fermentation process of fresh cocoa beans, both on a small and large scale. The fermentation process lasts for 6 days with stirring starting on the second day until the sixth day, with an interval of 24 hours. The study design uses a randomized block design method (RBD) with two factors, namely the weight scale of seeds per box and fermentation time with three replications. The data obtained were analyzed qualitatively and quantitatively. Based on the observed parameter indicators, namely temperature, pH and total acid, there was no significant difference in the profile of the physico-chemical properties during the fermentation process between the three weight scale levels. The physico-chemical condition shows a straight relationship with the quality of fermented cocoa beans, in accordance with the results of the cut test.

Effect of extraction time and pressing temperature on characteristic of cocoa powder quality

The aim of the research was to investigate the effect of extraction time and temperature on cocoa powder quality. The study was conducted at Cocoa Processing Incubation Laboratory, Agroindustry Program, Vocational College, Universitas Gadjah Mada in Juni-Juli 2018. The samples were fermented cocoa beans obtained from Banjaroya, Kulonprogo. First, cocoa beans were roasted and grinded. Then, 200 g cocoa liquor were extracted for 20, 30 and 45 minutes at 70, 100 and 110°C. Cocoa powder characteristics e.g: moisture content, fat content, the weight of cocoa bungkil, and colour level were evaluated. The result showed that cocoa powder which was extracted in 70°C for 30 minutes had a lowest moisture content (3,12 %). The fat content is about 40-47% for all treatment. The color intensity is similiar, with the most brightest are cocoa powder which was extracted in 70°C. The temperature treatment in 70°C were accordance with the quality standards of cocoa butter determined by SNI 3747:2009.

Analysis of cumulative oxygen uptake in cocoa beans (Theobroma cacao L.) fermentation using a packed bed reactor

The research aims to determine cumulative oxygen uptake in cocoa beans fermentation using packed bed reactor. Observed variables were including: length times of cocoa fruit ripening before fermentation (X1) i.e., 1; 5; 9 days, aeration rate (X2) i.e. 0.2; 0.3; 0.4 liters/minute, and aeration mode (X3) is intermittent 1; intermittent 2; continuous. The response surface methodology was used to figure out and to describe the relationship between cumulative oxygen uptake to the variables. The research results showed that the highest oxygen consumption occurred on day 2 and day 3 of the fermentation process, where the average peak oxygen demand occurred at the hour 25-72 fermentation, then continue to decline until end of the fermentation process (at fermentation time to 120 hours). The value of cumulative oxygen uptake during the fermentation process using a response surface methodology was obtained at 7.291 – 25.350 g O2/kg vs on various treatments. The results of response surface methodology also showed that the highest oxygen consumption during the cocoa beans fermentation was obtained on cocoa fruit ripening of 1-3 days, aeration rate of 0.3-0.4 litres/minute and continuous aeration mode. While the lowest oxygen consumption was obtained on cocoa beans ripening of 1 day, aeration rate of 0.2 to 0.3 litres/minute and aeration mode of intermittent 1.

A Study of Bread Yeast and Sucrose to the Successful Process of Cocoa Beans Fermentation

This research aims to know the effect of the concentration of sucrose and bread yeast to the successful process of cocoa beans fermentation. The research was conducted in the form of Completely Random Design of Factorial Pattern, two Factors. The first factor is sucrose consisted of 0% (control), 1%, 2%, and 3% sucrose. The second factor was the bread yeast consists of two (2) concentrations: 0,5% and 1 %, and each repeated twice to obtain 16 experimental units. The observed parameters were fermentation index, slaty beans and the pH of cocoa beans. The result of the research showed that there was an interaction between sucrose and bread yeast in the successful process of cocoa beans fermentation in small scale. The treatment without sucrose and adding 1% of bread yeast had a better effect to the fermentations index value of 1,72; salty beans were 1,56 and pH beans was 5,30.

The Usage of Dried Starter for Re-Fermentation of Unfermented Cocoa Beans

In order to improve the quality of cocoa beans, it has been made by re-fermentation of unfermented beans using dried starter. The methodology used in the fermentation process using a dry starter with the concentration of 1, 2 and 3% towards the quality of cocoa beans produced. The design of experiments was used completely randomized design (RAL) with two replications. Observations during the fermentation of cocoa beans were temperature, pH, alcohol and acid contents, whereas for the quality of dry beans were determined moisture content, ash, protein, fat, free fatty acid (FFA), fermentation index (IF). The flavor was also detected by GCMS. The results showed that during fermentation, the temperature was increased on the first day, then decreasing until day 6. Afterward, the pH tended to increase until day 7. Furthermore, alcohol and acid content (acetic and lactic acids) tends to decrease. The quality of dry beans gave moisture content, ash, protein, fat and FFA ranges from 8.12 to 9.21; 4.07 to 4.16; 21.28 to 22.06; 31.52 to 34.90 and 0.44 to 0.51, respectively. Index fermentation of 2% starter concentration gave the best value. Flavor compounds were detected on the re-fermented cocoa beans, namely the group of compounds pyrazines, ketones, aldehyde, alcohol, acid and pyron groups.