Fermentation Of Coffee Beans Research Articles

Optimization of robusta green coffee fermentation by Bifidobacterium bifidum and Lactobacillus plantarum using response surface methodology

In vitro fermented robusta coffee is fermented coffee beans using lactic acid bacteria (LAB) isolated from the stomachs of civets. In vitro fermented robusta coffee was obtained by optimizing three variables, namely inoculum concentration, use of microorganisms Bifidobacterium bifidum and Lactobacillus plantarum and in vitro fermentation time using response surface methodology (RSM). This study aimed to produce fermented robusta coffee in vitro with optimal cupping test results using three variables that affect fermentation. The results of the RSM showed that the optimum cupping test results were 72.62, inoculum concentrations of 5% (w/v), in vitro fermentation time of 8 hrs and the ratio of B. bifidum/L. plantarum at a ratio of 1:0.

Fermentation of coffee fruit with sequential inoculation of Lactiplantibacillus plantarum and Saccharomyces cerevisiae: effect on sensory attributes and chemical composition of the beans

This study has innovative aspects related to the use of sequential inoculation technique in the coffee bean fermentation process: the inoculation of Lactiplantibacillus plantarum followed by Saccharomyces cerevisiae, in the fermentation of coffee fruit for the production of specialty natural coffees. The objective was to evaluate the effect of this technique and of the total fermentation time on the sensory attributes of the coffee beverage and on the organic acid profile, bioactive compounds, and fatty acid profile of the beans. The fermentation of coffee fruit with sequential inoculation resulted in greater acidity of the beverage and contributed to increases of up to 2 points in coffee fermented. The total fermentation time was directly related to the organic acid content, and the longer the total fermentation time was, the greater the organic acid content. The fatty acid content and bioactive compound content showed little variation among treatments.

Evaluation of Arabica Coffee Fermentation Using Machine Learning

This study explores the variances in the organic, chemical, and sensory attributes of fermented coffee beans, specifically examining how post-harvest processes influence cup quality. Coffee fruits from the Catuaí IAC-144 variety were processed using both natural coffee (NC) and pulped coffee (PC) methods. The fruits were then subjected to self-induced anaerobic fermentation (SIAF) using one of the following fermentation methods: solid-state fermentation (SSF) or submerged fermentation (SMF). Within these methods, either spontaneous fermentation (SPF) or starter culture fermentation (SCF) was applied. Each method was conducted over periods of 24, 48, and 72 h. For this purpose, two-hundred-liter bioreactors were used, along with two control treatments. Numerous parameters were monitored throughout the fermentation process. A comprehensive chemical profiling and sensory analysis, adhering to the guidelines of the Specialty Coffee Association, were conducted to evaluate the influence of these fermentation processes on the flavor, aroma, and body characteristics of the coffee beverage across multiple dimensions. Data analysis and predictive modeling were performed using machine learning techniques. This study found that NC exhibited a higher production of acids (citric, malic, succinic, and lactic) compared to PC, resulting in distinct chemical and sensory profiles. The decision tree showed that fructose and malic and succinic acids were identified as the main factors enhancing sensory notes during cupping. SMF promoted higher concentrations of lactic acid, while SSF led to increased ethanol content. Consequently, the SIAF process enhances the sensory quality of coffee, adding value to the product by generating diverse sensory profiles.

The Authentication of Gayo Arabica Green Coffee Beans with Different Cherry Processing Methods Using Portable LED-Based Fluorescence Spectroscopy and Chemometrics Analysis.

Aceh is an important region for the production of high-quality Gayo arabica coffee in Indonesia. In this area, several coffee cherry processing methods are well implemented including the honey process (HP), wine process (WP), and natural process (NP). The most significant difference between the three coffee cherry processing methods is the fermentation process: HP is a process of pulped coffee bean fermentation, WP is coffee cherry fermentation, and NP is no fermentation. It is well known that the WP green coffee beans are better in quality and are sold at higher prices compared with the HP and NP green coffee beans. In this present study, we evaluated the utilization of fluorescence information to discriminate Gayo arabica green coffee beans from different cherry processing methods using portable fluorescence spectroscopy and chemometrics analysis. A total of 300 samples were used (n = 100 for HP, WP, and NP, respectively). Each sample consisted of three selected non-defective green coffee beans. Fluorescence spectral data from 348.5 nm to 866.5 nm were obtained by exciting the intact green coffee beans using a portable spectrometer equipped with four 365 nm LED lamps. The result showed that the fermented green coffee beans (HP and WP) were closely mapped and mostly clustered on the left side of PC1, with negative scores. The non-fermented (NP) green coffee beans were clustered mostly on the right of PC1 with positive scores. The results of the classification using partial least squares-discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and principal component analysis-linear discriminant analysis (PCA-LDA) are acceptable, with an accuracy of more than 80% reported. The highest accuracy of prediction of 96.67% was obtained by using the PCA-LDA model. Our recent results show the potential application of portable fluorescence spectroscopy using LED lamps to classify and authenticate the Gayo arabica green coffee beans according to their different cherry processing methods. This innovative method is more affordable and could be easy to implement (in terms of both affordability and practicability) in the coffee industry in Indonesia.

Impacts of Fermentation on the Phenolic Composition, Antioxidant Potential, and Volatile Compounds Profile of Commercially Roasted Coffee Beans

Fermented coffee beans are believed to have significantly different compositions of phenolic and volatile compounds and physicochemical properties compared to unfermented coffee beans. This study evaluated the effects of fermentation on coffee beans at a commercially roasted level by characterizing their phenolic compounds and semi-quantifying their volatile compounds using liquid chromatography–electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and headspace/gas chromatography–mass spectrometry (HS-SPME-GC-MS). Coffee beans from two varieties of Coffea arabica, Geisha (G) and Bourbon (B), both fermented beans had higher contents of total phenolic compounds (G: 33.52 mg/g; B: 29.95 mg/g), total flavonoid (G: 0.42 mg/g; B: 0.35 mg/g), total tannins (G: 3.49 mg/g; B: 3.18 mg/g), and higher antioxidant potential in all assays. In total, 131 phenolic compounds were tentatively characterized via LC-ESI-QTOF-MS/MS, where 73 and 65 phenolic compounds were characterized from fermented Geisha and Bourbon, respectively. Regarding GC-MS, the fermented coffee beans had higher levels of phenols, pyrazines, furan, and furanic compounds. These findings substantiated that fermented coffee beans exhibit elevated levels of phenolic and volatile compounds and greater antioxidant activity, which could contribute to relatively higher nutritional values and organoleptic properties.

Application of Ohmic Heating for Green Coffee Bean Fermentation: Effect of Voltage Gradient on the Heating Performance, Energy, EC, pH, and Fermentation Index

Application of Ohmic Heating for Green Coffee Bean Fermentation: Effect of Voltage Gradient on the Heating Performance, Energy, EC, pH, and Fermentation Index

Microbial Diversity of Anaerobic-Fermented Coffee and Potential for Inhibiting Ochratoxin-Produced Aspergillus niger.

Coffee flavor considerably depends on the fermentation process, with contributing factors including fermentation temperature, oxygen concentration, and microbial diversity. Efficient controlling of the fermentation can improve the quality of coffee beverages. Therefore, several studies on coffee fermentation processes have been conducted in various regions. The objective of this study was to assess the microbial diversity of coffee beans undergoing anaerobic fermentation at various temperatures (4 °C or 37 °C) and fermentation durations (12 h or 36 h) using full-length 16S rRNA sequencing. This analysis aimed to evaluate the inhibitory effects of the fermented metabolites against ochratoxin-producing Aspergillus niger. From our results, Acetobacter was identified as the dominant microbial community at higher fermentation temperatures, whereas Leuconostoc and Gluconobacter were the dominant genera at lower temperatures. However, at lower temperatures, changes in microbial communities were relatively slow. This study expands our knowledge of the microbial diversity involved in the anaerobic fermentation of coffee beans in Taiwan. The findings of this study can be used in future research to cultivate microorganisms linked to the quality and improve the quality of coffee beverages through fermentation.

In-fiber Mach-Zehnder interferometer as a promising tool for optical nose and odor prediction during the fermentation process.

In this paper, we present an in-fiber Mach-Zehnder interferometer (MZI) applied to coffee bean fermentation monitoring. Two MZIs, based on a combination of a fiber taper cascaded by a micro-tapered long-period fiber grating, were installed in a fermentation barrel to monitor the liquids and gases released during the fermentation process. During this process, a variety of odors arise due to the yeast activity and their classification is important to decide when to stop the fermentation process. In this work, we show that the in-fiber MZIs are good candidates for optical noses in this scenario.

Phenolic bioaccessibility, antioxidant, and antidiabetic effects of indigenous fermented coffee beans after simulated gastrointestinal digestion and colonic fermentation

Postharvest fermentation could bring significant changes in the chemical profile of coffee beans so that the nutritional aspects. This study comprehensively evaluated the effects of indigenous fermentation on coffee beans in green and roasted status by quantifying the phenolic compounds and estimating their bioaccessibility, crude absorbability, antioxidant, enzyme inhibitory activity, and SCFA production during in vitro digestion and colonic fermentation. Compared to the unfermented (UF) beans, in both phenolic extract and absorbable fraction during digestion, fermented (F) coffee beans in roasted status showed similar or lower phenolic content and antioxidant activities. Only light-roasted FK showed significantly higher TPC (50.9 mg GAE/g) and TFC (1.21 mg QE/g) than the UFK (35.8 mg GAE/g, 1.06 mg QE/g) in the gastric absorbable fraction. However, medium-roasted FK performed significantly outstanding α-amylase (9.67%) and α-glucosidase (21.86%) inhibition activities than that of UFK (7.41%, 18.31%). The bioaccessibility and crude absorption rate of total phenolics and chlorogenic acid were relatively higher during the in vitro digestion and colonic fermentation of fermented green coffee beans. The differences were eventually eliminated along with the intensification of roasting due to the thermal degradation. The total SCFAs produced from fermented beans was only up to 2.185 mM after 16 h fecal reaction, which is significantly lower than that of the unfermented (<3.216 mM) because of the hydrolyzation of polysaccharides during the postharvest fermentation. Therefore, in the long term, fermented coffee beans could perform higher nutritional values with higher phenolic absorption efficiency, especially chlorogenic acids, and antidiabetic potential.

Water Content, Total Dissolved Solids and Antioxidant Activity of Robusta Coffee Powder Produced by Fermenting Beans in Whey Kefir

Coffee is one of the plantation commodities that is usually processed into beverage products. The most widely cultivated coffee in Indonesia is Robusta coffee. However, Robusta coffee has a lower quality compared to other types of coffee. Fermentation of coffee beans during wet processing can improve coffee quality. The purpose of this study was to determine the best fermentation time for robusta coffee beans in whey kefir so that quality robusta coffee powder was obtained from the water content, total dissolved solids (TDS) and antioxidant activity. This study used a completely randomized design (CRD) with different fermentation time treatments. Parametric data were analysed by ANOVA and followed by DMRT test. Antioxidant activity data were analysed descriptively. Longer fermentation times reduced the total dissolved solids (TDS) of the coffee beans. However, prolonged fermentation can also increase the water content and reduce antioxidant activity. The best treatment was found to be a fermentation time of 18 hours, which resulted in a coffee bean with a good balance of TDS (3.25°Brix), water content (4.67%), and antioxidant activity (16.09 ppm).

Characterization of the Rhizosphere Bacterial Microbiome and Coffee Bean Fermentation in the Castillo-Tambo and Bourbon Varieties in the Popayán-Colombia Plateau

BackgroundThe microbial biodiversity and the role of microorganisms in the fermentation of washed coffee in Colombia were investigated using the Bourbon and Castillo coffee varieties. DNA sequencing was used to evaluate the soil microbial biota and their contribution to fermentation. The potential benefits of these microorganisms were analyzed, including increased productivity and the need to understand the rhizospheric bacterial species to optimize these benefits.MethodsThis study used coffee beans for DNA extraction and 16 S rRNA sequencing. The beans were pulped, samples were stored at 4ºC, and the fermentation process was at 19.5ºC and 24ºC. The fermented mucilage and root-soil samples were collected in duplicate at 0, 12, and 24 h. DNA was extracted from the samples at a concentration of 20 ng/µl per sample, and the data obtained were analyzed using the Mothur platform.ResultsThe study demonstrates that the coffee rhizosphere is a diverse ecosystem composed primarily of microorganisms that cannot be cultured in the laboratory. This suggests that the microbial community may vary depending on the coffee variety and play an essential role in fermentation and overall coffee quality.ConclusionsThe study highlights the importance of understanding and optimizing the microbial diversity in coffee production, which could have implications for the sustainability and success of coffee production. DNA sequencing techniques can help characterize the structure of the soil microbial biota and evaluate its contribution to coffee fermentation. Finally, further research is needed to fully understand the biodiversity of coffee rhizospheric bacteria and their role.

효소 및 미생물 복합체를 사용한 인비트로 루왁 커피의 품질 특성

In vitro luwak coffee was produced using enzyme-microbial complexes. The coffee quality of non-fermented coffee beans (NFC) and fermented coffee beans (FC) was compared. The total free amino acid content was higher in FC than in NFC. The levels of glutamic acid and γ-amino-n-butyric acid in NFC were higher than those in FC; however, the contents of essential amino acids, such as lysine, leucine, and valine, in FC were higher than in NFC. During fermentation, the sucrose content decreased, whereas the fructose and glucose contents increased (p&lt;0.001). The chromaticity of the coffee extract showed higher lightness (L), redness (a), and yellowness (b) values in FC than those in NFC. The caffeine content was significantly lower in FC (696.94±0.04 μg/mL) compared to that in NFC (1,130.22±1.55 μg/mL) (p&lt;0.001). Conversely, the polyphenol and chlorogenic acid contents were significantly higher ​​in NFC than in FC (p&lt;0.001). Electronic nose analysis indicated considerable differences between the volatile aromatic components in NFC and FC. Sensory scores were significantly higher for FC than those for NFC. Therefore, the fermentation of coffee beans using enzyme-microbial complexes altered the chemical components, which promoted the Maillard reaction during the coffee bean roasting process. These results suggest the possibility of producing in vitro luwak coffee with better flavor and lower caffeine content.

효소 및 미생물 복합체를 사용한 인비트로 루왁 커피의 품질 특성

In vitro luwak coffee was produced using enzyme-microbial complexes. The coffee quality of non-fermented coffee beans (NFC) and fermented coffee beans (FC) was compared. The total free amino acid content was higher in FC than in NFC. The levels of glutamic acid and γ-amino-n-butyric acid in NFC were higher than those in FC; however, the contents of essential amino acids, such as lysine, leucine, and valine, in FC were higher than in NFC. During fermentation, the sucrose content decreased, whereas the fructose and glucose contents increased (p&lt;0.001). The chromaticity of the coffee extract showed higher lightness (L), redness (a), and yellowness (b) values in FC than those in NFC. The caffeine content was significantly lower in FC (696.94±0.04 μg/mL) compared to that in NFC (1,130.22±1.55 μg/mL) (p&lt;0.001). Conversely, the polyphenol and chlorogenic acid contents were significantly higher ​​in NFC than in FC (p&lt;0.001). Electronic nose analysis indicated considerable differences between the volatile aromatic components in NFC and FC. Sensory scores were significantly higher for FC than those for NFC. Therefore, the fermentation of coffee beans using enzyme-microbial complexes altered the chemical components, which promoted the Maillard reaction during the coffee bean roasting process. These results suggest the possibility of producing in vitro luwak coffee with better flavor and lower caffeine content.

Multivariate data analysis of GC‐MS/IMS data of coffee powder and brewed coffee from fermented coffee beans

LebensmittelchemieVolume 77, Issue S1 p. S1-137-S1-137 Aritlce Multivariate data analysis of GC-MS/IMS data of coffee powder and brewed coffee from fermented coffee beans Catherine Kiefer, Corresponding Author Catherine Kiefer [email protected] Hochschule Mannheim, Institut für Instrumentelle Analytik/Competency Center for Chemometrics CHARISMA, Mannheim, GermanySearch for more papers by this authorSascha Rohn, Sascha Rohn TU Berlin, Institut für Lebensmittelchemie, Berlin, GermanySearch for more papers by this authorPhilipp Weller, Philipp Weller Hochschule Mannheim, Institut für Instrumentelle Analytik/Competency Center for Chemometrics CHARISMA, Mannheim, GermanySearch for more papers by this author Catherine Kiefer, Corresponding Author Catherine Kiefer [email protected] Hochschule Mannheim, Institut für Instrumentelle Analytik/Competency Center for Chemometrics CHARISMA, Mannheim, GermanySearch for more papers by this authorSascha Rohn, Sascha Rohn TU Berlin, Institut für Lebensmittelchemie, Berlin, GermanySearch for more papers by this authorPhilipp Weller, Philipp Weller Hochschule Mannheim, Institut für Instrumentelle Analytik/Competency Center for Chemometrics CHARISMA, Mannheim, GermanySearch for more papers by this author First published: 01 March 2023 https://doi.org/10.1002/lemi.202352107AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume77, IssueS1Supplement: Abstracts der Vorträge der Regionalverbände und die der Posterflashtalks der AG JLCMarch 2023Pages S1-137-S1-137 RelatedInformation

Understanding the Effects of Self-Induced Anaerobic Fermentation on Coffee Beans Quality: Microbiological, Metabolic, and Sensory Studies.

In this study, an investigation of the microbial community structure and chemical changes in different layers of a static coffee beans fermentation tank (named self-induced anaerobic fermentation-SIAF) was conducted at different times (24, 48, and 72 h). The microbial taxonomic composition comprised a high prevalence of Enterobacteriaceae and Nectriaceae and low prevalence of lactic acid bacteria and yeast, which greatly differs from the traditional process performed in open tanks. No major variation in bacterial and fungal diversity was observed between the bottom, middle, and top layers of the fermentation tank. On the other hand, the metabolism of these microorganisms varied significantly, showing a higher consumption of pulp sugar and production of metabolites in the bottom and middle layers compared to the top part of the fermentation tank. Extended processes (48 and 72 h) allowed a higher production of key-metabolites during fermentation (e.g., 3-octanol, ethyl acetate, and amyl acetate), accumulation in roasted coffee beans (acetic acid, pyrazine, methyl, 2-propanone, 1-hydroxy), and diversification of sensory profiles of coffee beverages compared to 24 h of fermentation process. In summary, this study demonstrated that SIAF harbored radically different dominant microbial groups compared to traditional coffee processing, and diversification of fermentation time could be an important tool to provide coffee beverages with novel and desirable flavor profiles.

Performance of Mixed-Microbial Culture from Civet Fecal Suspensions on Physicochemical Composition of Wet Fermented Arabica Coffee

This study aimed to evaluate the effects of mixed microbial culture from civet fecal suspension used as the inoculum for the fermentation of Arabica coffee. The type of Arabica coffee used for the research was the unpeeled coffee or the Arabica coffee cherries. Different proportion of inoculum introduced was thoroughly evaluated to assess the appropriate concentration of inoculum (0-40% inoculums represented in treatment 0-4 or T0 to T4) that would be applied to the fermentation of Arabica coffee cherries. Results revealed that treatment 4 (T4) containing 40% of the inoculum could degrade the sugar of the coffee beans faster than that of the other treatments in which within 24 hours of the incubation approximately 84% of the sugar was converted. T4 also reached the lowest caffeine content (1.8%) of the fermented coffee beans among other that of other treatments while the control had higher caffeine content (2.2%).This was substantially significant as the Arabica coffee cherries fermented with mixed microbial civet fecal suspensions can remarkably reduce the sugar and caffeine content of the Arabica coffee beans.

Investigation of metabolite differences in green coffee beans fermented with various microbes

In this study, green coffee beans were fermented using three yeast and three lactic acid bacteria (LAB) starters. The effects of each starter on the metabolite profiles of green coffee beans were comparatively analyzed. The principal component analysis (PCA) biplot showed a clear separation between the groups fermented with LAB (Leuconostoc mesenteroides, Lactobacillus plantarum, and Pediococcus pentosaceus) and the groups fermented with yeast (Saccharomyces cerevisiae, Candida parapsilosis, and Pichia guilliermondii). Various metabolites, including palmitic acid, stearic acid, and piperidine, were associated with the LAB strains. 2-Palmitoylglycerol, ribonic acid, and arabitol were related to C. parapsilosis and P. guilliermondii. Phenylethyl alcohol, succinic acid, shikimic acid, and methylamine contributed greatly to the separation of S. cerevisiae from the other strains in the PCA biplot. In addition, chlorogenic acid levels were higher in the LAB strains than in the yeast strains after fermentation. In particular, C. parapsilosis and P. guilliermondii showed much lower levels. The level of caffeine was highest in P. pentosaceus and lowest in C. parapsilosis after fermentation. This study provides comprehensive information on the metabolic changes after green coffee bean fermentation according to the type of microbes used.

Fermentation Method With the Help of Extremely Low Frequency (Elf) Magnetic Field Radiation to Support Luwak Coffee Superior Products In Sidomulyo Village, Silo District, Jember Regency, East Java

Coffee production in Sidomulyo Village, located at the foot of Mount Gumitir, Silo District, Jember Regency, is famous for being very abundant. This condition is very supportive of the increasing needs of coffee drink lovers. However, the taste of ready-to-brewed ground coffee produced by the Sidomulyo Koperasi WANITA is still unable to compete with coffee on the market. This activity aimed to provide training on civet coffee production through the dry coffee bean fermentation method as a primary ingredient. The fermentation process was carried out using a Magnetic Fermentation machine which was the result of research in 2020. The fermentation process training activity was attended by 15 members of the Koperasi WANITA. 50 kg of dry coffee was fermented using a Magnetic Fermenter machine. Dry coffee was soaked first in warm water (temperature around 30 - 400C) for 5 hours. Then it was drained and put in a fermenter box by adjusting the intensity of the ELF magnetic field to around 300 T for 90 minutes. The coffee beans were transferred to buckets and ripened for up to 5 days, then washed and sun-dried for three days, after drying in Roasting and continue grinding. The targeted outputs of this activity included scientific publications in the National Journal of Abdimas with ISSN. The results of this activity produced fermented coffee beans that had been roasted in the form of roasted coffee beans and ground coffee. Based on the results of the evaluation, the members of the Ketakasi Koperasi already had skills in producing artificial Luwak coffee. This had the potential to develop superior products for Sidomulyo civet coffee.

Multivariate data analysis of low and high field NMR data of brewed coffee from fermented coffee beans

Multivariate data analysis of low and high field NMR data of brewed coffee from fermented coffee beans

Isolation and Molecular Identification of Lactic Acid Bacteria from Robusta Coffee Fermentation and Antifungal Test against Penicillium sp.

Lactic acid bacteria (LAB) play an important role in robusta coffee fermentation by soaking coffee beans. Spontaneous fermentation of coffee beans can improve coffee quality by producing organic acids and volatile compounds. The ability of LAB to produce organic acids also has the potential as an antifungal compound. Penicillium is one of the predominant contaminants of coffee beans products in Indonesia. Coffee beans can become contaminated by Penicillium during various stages such as harvesting, processing, transport, and storage. To prevent contamination of coffee beans, new preservation methods involving biological agents, such as lactic acid bacteria, may be used instead of chemicals. The secondary metabolites produced by LAB can be utilized for bio preservation. Lactic acid bacteria in robusta coffee fermentation should be further explored and analyzed for antifungal activity against Penicillium sp., and molecularly identified to determine the spesies of lactic acid bacteria that have antifungal potential. The isolation method was carried out using multilevel dilution and spread plate on MRSA+CaCO3 media. Identification was conducted through macroscopic and microscopic observation of cells and their characteristics, as well as molecular identification. Antifungal testing was performed using the agar well diffusion method. The results of LAB isolation yielded 12 LAB isolates with characteristics of round colony shape, gram-positive, rod and round cell shape, with negative catalase. The test results showed that isolates BKR 4, BKR 11, BKR 12 exhibited antifungal activity. BKR11 isolate was identified as Leuconostoc mesenteroides.