Influence of Fermentation Time and Inoculation of Starter Culture on the Chemical Composition of Fermented Natural Coffee Followed by Depulping.

Fermentation using starter cultures has been considered an alternative and economically viable technology for the production of specialty coffees. This type of technology promotes several benefits, such as increased sensory quality, control over the fermentation process, predictability of the final product and added value. Coffee (Coffea arabica L.) samples for this study were collected in Presidente Olegário - MG (2018/19 crop year) in the Cerrado region of Minas Gerais. The effects of natural fermentation and inoculation of the yeast Torulaspora delbrueckii and duration of fermentation (0, 24, 48, 72 and 96 hours) on the sensory and chemical quality (analysis of bioactive, volatile, and organic compounds and fatty acids) of coffee were evaluated. The objective of this study was to determine the effect of fermentation time and starter culture inoculation on the chemical composition of fermented coffees. Fermentation time significantly influenced the sensory description of the coffee beverage, with notes of honey, brown sugar and almond predominating up to 48 hours, for coffees fermented for 72 and 96 hours the notes described were and fruity, winey notes. The chemical composition was primarily influenced by fermentation time.

Microbiota of arabica coffee: insights from soil to fruit.

Studies have shown that a diverse and metabolically active microbiota exists throughout different stages of coffee processing, from pre- to post-harvest. This microbiota originates from both the cultivation and processing environments. Additionally, microorganisms from the soil can be found on the fruit due to the transfer between them. This study reviews the microbiota present in Arabica coffee fruits and the soils where the plants are grown. It examines how microbial profiles are related to coffee variety, altitude, cultivation region, and processing method, and establishes a connection between the microbiota in soil and fruit. A diverse microbiota was observed in both coffee fruits and soils, with similar microorganisms identified across different growing regions, processing methods, and coffee varieties. However, exclusive detections of some microorganisms were also observed. These differences highlight the influence of terroir on coffee's microbial composition, confirming that environmental conditions, genetic factors, and processing methods shape coffee microbiota. Since microbial development during coffee fermentation can affect the beverage's quality, the data presented in this review offer valuable insights for researchers and producers. Understanding the influence of processing methods, coffee varieties, and cultivation regions on coffee microbiota enables the selection of specific fermentation conditions or starter cultures to enhance terroir characteristics or adjust microbial populations to favor or introduce microorganisms beneficial for coffee quality.

Inhibition of Aspergillus spp. growth and ochratoxin A production in Conilon and Arabica coffees based-medium by Saccharomyces cerevisiae.

Saccharomyces cerevisiae CCMA 0159 is reported as a promising biocontrol agent against ochratoxin A (OTA)-producing fungi in coffee. Coffea arabica and Coffea canephora (var. Conilon or Robusta) are the most widely consumed coffee species around the world, cultivated in tropical and subtropical regions, each exhibiting distinct physicochemical and sensory characteristics. The objective of this study was to compare the growth and OTA production by Aspergillus carbonarius, A. ochraceus, and A. westerdijkiae in C. arabica and C. canephora, along with assessing the efficiency of S. cerevisiae CCMA 0159 in biocontrolling ochratoxigenic fungi in both coffee varieties. A. carbonarius exhibited a higher growth rate and OTA production in both coffee varieties, with C. canephora showing particular susceptibility. Conversely, A. ochraceus and A. westerdijkiae demonstrated lower growth and OTA production. S. cerevisiae was effective in biocontrolling the fungal isolates, inhibiting over 80 % of A. carbonarius growth in both coffee varieties. Among the mechanisms of action of the biological control agent, the production of volatile organic compounds stands out. The results of this study confirm the significant potential of S. cerevisiae CCMA 0159 as a biocontrol agent against Aspergillus for application in coffee-producing areas.

Impact of different fermentation times on the microbiological, chemical, and sensorial profile of coffees processed by self-induced anaerobiosis fermentation.

Variation in fermentation time may be an essential alternative to provide coffee beverages with different and unique sensory profiles. This work investigated the microbiological, chemical, and sensory changes in coffees submitted to different fermentation durations (0, 24, 48, 72, and 96 h). Self-induced anaerobiosis fermentation (SIAF) was used, and two treatments were performed: spontaneous fermentation and inoculation with S. cerevisiae CCMA0543. Microbiological analyses were performed, and the permanence of the inoculum was monitored. Chromatography (sugars, organic acids, and volatile compounds) was analyzed, and sensory analysis (temporal dominance of sensations - TDS) was performed. A total of 228 isolates were identified during spontaneous fermentation. The dominant bacteria and yeasts were Leuconostoc mesenteroides, Lactiplantibacillus plantarum, Staphylococcus warneri, Bacillus sp., Torulaspora delbrueckii, Hanseniaspora uvarum, and Meyerozyma caribbica. High concentrations of citric (18.67 mg.g- 1) and succinic (5.04 mg.g- 1) acids were detected at 96 h in SIAF fermentation. One hundred twenty-one volatile compounds were detected, but 22 were detected only in inoculated coffees. In spontaneous fermentation, 48 h of fermentation showed woody notes, while 72 h showed chestnuts. However, in the inoculated coffee, 72 h of fermentation showed high fruity dominance, and 96 h of fermentation was the only one with herbaceous notes. In addition, yeast inoculation increased the intensity of caramel notes in the first 48 h and increased the fruity flavor after 72 h of fermentation. Therefore, the type of fermentation (with or without inoculation) and the chosen fermentation time will depend on the sensorial profile the producer intends to obtain.

Isolation, identification, and tolerance analysis of yeast during the natural fermentation process of Sidamo coffee beans.

Yeast, which plays a pivotal role in the brewing, food, and medical industries, exhibits a close relationship with human beings. In this study, we isolated and purified 60 yeast strains from the natural fermentation broth of Sidamo coffee beans to screen for indigenous beneficial yeasts. Among them, 25 strains were obtained through morphological characterization on nutritional agar medium from Wallerstein Laboratory (WL), with molecular biology identifying Saccharomyces cerevisiae strain YBB-47 and the remaining 24 yeast strains identified as Pichia kudriavzevii. We investigated the fermentation performance, alcohol tolerance, SO2 tolerance, pH tolerance, sugar tolerance, temperature tolerance, ester production capacity, ethanol production capacity, H2S production capacity, and other brewing characteristics of YBB-33 and YBB-47. The results demonstrated that both strains could tolerate up to 3% alcohol by volume at a high sucrose mass concentration (400 g/L) under elevated temperature conditions (40 ℃), while also exhibiting a remarkable ability to withstand an SO2 mass concentration of 300 g/L at pH 3.2. Moreover, S. cerevisiae YBB-47 displayed a rapid gas production rate and strong ethanol productivity. whereas P. kudriavzevii YBB-33 exhibited excellent alcohol tolerance. Furthermore, this systematic classification and characterization of coffee bean yeast strains from the Sidamo region can potentially uncover additional yeasts that offer high-quality resources for industrial-scale coffee bean production.

Genetic diversity and structure of the coffee leaf rust fungus Hemileia vastatrix across different coffee management systems in Ethiopia / Diversidad genética y estructura del hongo de la roya del café Hemileia vastatrix en diferentes sistemas de manejo del café en Etiopía

Although coffee leaf rust (CLR), caused by Hemileia vastatrix, poses an increasing threat to coffee production in Ethiopia, little is known regarding its genetic diversity and structure and how these are affected by coffee management. Here, we used genetic fingerprinting based on sequence-related amplified polymorphism (SRAP) markers to genotype H. vastatrix samples from different coffee shrubs, across 40 sites, covering four coffee production systems (forest coffee, semi plantation coffee, home garden coffee, and plantation coffee) and different altitudes in Ethiopia. In total, 96 H. vastatrix samples were successfully genotyped with three primer combinations, producing a total of 79 scorable bands. We found 35.44% of amplified bands to be polymorphic, and the polymorphic information content (PIC) was 0.45, suggesting high genetic diversity among our CLR isolates. We also found significant isolation-by-distance across the samples investigated and detected significant differences in fungal genetic composition among plantation coffee and home garden coffee and a marginally significant difference among plantation coffee and forest coffee. Furthermore, we found a significant effect of altitude on CLR genetic composition in the forest coffee and plantation systems. Our results suggest that both spore dispersal and different selection pressures in the different coffee management systems are likely responsible for the observed high genetic diversity and genetic structure of CLR isolates in Ethiopia. When selecting Ethiopian coffee genotypes for crop improvement, it is important that these genotypes carry some resistance against CLR. Because our study shows large variation in genetic composition across relatively short geographical distances, a broad selection of rust isolates must be used for coffee resistance screening.(AU)

Microbiological attributes as indicators of soil quality in coffee growing systems in Southwest Bahia, Brazil.

Microorganisms are important indicators of soil quality due to their sensitivity to changes, reflecting the impacts caused by different land uses. The objective of this study was to evaluate the microbiological and physical-chemical attributes of the soil in areas cultivated with coffee under three different management systems (shaded coffee and full sun coffee with two spacings), as well as in adjacent areas under pasture and native forest, in Bahia, Brazil. The microbiological and physicochemical indicators evaluated were basal soil respiration (MBR), soil total organic carbon (TOC), microbial biomass carbon (MBC), metabolic quotient (qCO2), microbial quotient (qMic), enzyme activities (urease, acid phosphatase and fluorescein diacetate hydrolysis (FDA)). Physical and chemical indicators (particle size, texture, pH, P, K+, Ca2+, Mg2+, Al3+, and sum of bases) were also evaluated. Biological and chemical attributes were much more discriminative of study areas in the dry season. Microbial quotient (qMic) and metabolic quotient (qCO2) in the dry season showed that pasture is the most degraded land use. Conversely, nature forest and coffee with Grevillea were similar and were the best ones. In general, soil quality indicators were more sensitive to discriminate pasture and native forest from coffee systems, which, in turn, were not well discriminated among themselves.

Parallel host shifts in a bacterial plant pathogen suggest independent genetic solutions.

While there are documented host shifts in many bacterial plant pathogens, the genetic foundation of host shifts is largely unknown. Xylella fastidiosa is a bacterial pathogen found in over 600 host plant species. Two parallel host shifts occurred-in Brazil and Italy-in which X. fastidiosa adapted to infect olive trees, whereas related strains infected coffee. Using 10 novel whole-genome sequences from an olive-infecting population in Brazil, we investigated whether these olive-infecting strains diverged from closely related coffee-infecting strains. Several single-nucleotide polymorphisms, many derived from recombination events, and gene gain and loss events separated olive-infecting strains from coffee-infecting strains in this clade. The olive-specific variation suggests that this event was a host jump with genetic isolation between coffee- and olive-infecting X. fastidiosa populations. Next, we investigated the hypothesis of genetic convergence in the host shift from coffee to olive in both populations (Brazil and Italy). Each clade had multiple mutations and gene gain and loss events unique to olive, yet no overlap between clades. Using a genome-wide association study technique, we did not find any plausible candidates for convergence. Overall, this work suggests that the two populations adapted to infect olive trees through independent genetic solutions.

The essential role of spontaneous and starter yeasts in cocoa and coffee fermentation.

Yeasts are important microorganisms used in different fermentation processes. The cocoa beans must go through a correct fermentation process to obtain good-quality chocolate, which involves the action of yeasts and bacteria, and yeasts play a crucial role since they act in the first days of fermentation. In coffee, several studies have shown that the microbiota in the fruits is also a relevant factor. The fermentation process (regardless of the processing type) improves the beverage's quality. In this sense, studies using starter cultures in these two raw materials are important for better control of the process, and optimization of fermentation time, in addition to the improvement and diversification of volatile and non-volatile compounds produced by yeasts. Thus, this review discusses the importance and role of yeasts during fermentation, their metabolism, the produced compounds, and how yeast and the different chemical reactions help increase the quality of chocolate and coffee.

Inoculation of yeast and bacterium in wet-processed Coffea canephora.

This study evaluated the inoculation of Meyerozyma guilliermondii and Bacillus licheniformis, separately or in co-culture, in wet-processed conilon coffee. Wet fermentation was conducted for 48 h. Mesophilic bacteria, lactic acid bacteria, yeasts, and filamentous fungi were counted during fermentation. The inoculation of B. licheniformis and M. guilliermondii stimulated the multiplication of lactic acid bacteria. Acetic, citric, lactic, oxalic, malic, succinic, tartaric acids, glucose, and fructose were identified in all treatments at different concentrations. Methyl salicylate, 2-heptanol, 2-nonanol, and heptanone were found during fermentation. Methylpyrazine, 2,6-dimethylpyrazine, 2,5-dimethylpyrazine, and 3-ethyl-2,5-dimethylpyrazine identified after roasting assigned notes of "almond" and "chocolate" to the beverages. All treatments were classified as "premium," with the B. licheniformis treatment receiving the highest score. Bacillus licheniformis obtained better performance in fermentation, increasing coffee score and producing volatile compounds that provided positive sensory notes to the beverage.

Mathematical modelling and analysis of coffee berry disease dynamics on a coffee farm.

This paper focuses on a mathematical model for coffee berry disease infestation dynamics. This model considers coffee berry and vector populations with the interaction of fungal pathogens. In order to gain an insight into the global dynamics of coffee berry disease transmission and eradication on any given coffee farm, the assumption of logistic growth with a carrying capacity reflects the fact that the amount of coffee plants depends on the limited size of the coffee farm. First, we show that all solutions of the chosen model are bounded and non-negative with positive initial data in a feasible region. Subsequently, endemic and disease-free equilibrium points are calculated. The basic reproduction number with respect to the coffee berry disease-free equilibrium point is derived using a next generation matrix approach. Furthermore, the local stability of the equilibria is established based on the Jacobian matrix and Routh Hurwitz criteria. The global stability of the equilibria is also proved by using the Lyapunov function. Moreover, bifurcation analysis is proved by the center manifold theory. The sensitivity indices for the basic reproduction number with respect to the main parameters are determined. Finally, the numerical simulations show the agreement with the analytical results of the model analysis.

Coinoculation of lactic acid bacteria and yeasts increases the quality of wet fermented Arabica coffee.

Wet coffee fermentation is widely used in coffee-producing regions such as Colombia and Hawaii, but it is not widespread in Brazil. This study aimed to evaluate inoculating the lactic acid bacteria Leuconostoc mesenteroides CCMA1105 and Lactiplantibacillus plantarum CCMA 1065 and the yeasts Saccharomyces cerevisiae CCMA0543 and Torulaspora delbrueckii CCMA0684 as starter cultures on wet coffee fermentation using the SIAF method (self-induced anaerobiosis fermentation). The microbial activity resulted in high consumption of the carbohydrates glucose (98.6%), fructose (97.6%), and sucrose (100%), in addition to the production of lactic and acetic acids, impacting the final quality of the beverage. A total of 108 volatile compounds belonging to 17 classes were identified in the green and roasted coffee samples, including 2,3-butanediol produced by lactic acid bacteria, contributing to coffee's aromatic profile. The final scores for the coffees from the different fermentations ranged from 79.0 to 83.25. The inoculated fermentations were classified as specialty according to the Specialty Coffee Association. Therefore, whole coffee fruit processed via wet using SIAF method and yeast and lactic acid bacteria starter is an alternative for improving wet fermented coffee quality and obtaining coffee beverages with a different sensory profile.

Constitutive Defense Strategy of Coffee Under Field Conditions: A Comparative Assessment of Resistant and Susceptible Cultivars to Rust.

Coffea arabica is the most economically important coffee species worldwide. However, its production is severely limited by diseases such as rust. The mechanisms underlying constitutive defense responses in coffee are still poorly understood, compared with induced defense mechanisms. We aimed to characterize constitutive defense responses of thirteen cultivars of C. arabica. Cultivars were classified under field conditions according to the level of resistance to rust: resistant (R), moderately resistant (MR), and susceptible (S). Based on this classification, the stability of eight reference genes (RGs) was evaluated. The most stable RGs were EF1α, APT1, and 24S. We also evaluated the expression of CaWRKY1, CaPAL1, CaCAD1, and CaPOX1, and activities of PAL, CAD, and POX, which are involved in lignin biosynthesis, and leaf content of total phenolic compounds and lignin. Gene expression and enzymatic activity were not correlated with defense metabolites in the R cultivar group but showed a negative correlation with phenolic compounds in MR cultivars. Cultivar S showed positive correlations of gene expression and enzyme activity with phenolic compounds. These results may assist coffee breeding programs regarding selection of genotypes and in optimization of rust resistance.

Evaluation of fungal contamination and ochratoxin A detection in different types of coffee by HPLC-based method.

BACKGROUND: Mycotoxins are secondary fungal metabolites that are produced by some toxigenic fungi on foodstuffs which are poisoning and potentiate for human's health hazards. In coffee samples, ochratoxin A and fungal contamination were examined. METHODS: Immunoaffinity columns were used for treating of all 50 samples from four types of coffee, after that high-performance liquid chromatography was used for determining the amount of ochratoxin. For the identification of fungi, all coffee samples were cultured in appropriated media. RESULTS: The results showed that all samples were contaminated by ochratoxin A but only up to 50% of them had toxins higher than acceptable level as detected in black beans (47%), green beans (33.3%), torch (33.3%), and espresso (25%). Black coffee had a higher mean concentration of ochratoxin A than green coffee. CONCLUSION: Predominant fungi isolated from coffee samples were Aspergillus species. Finally, careful monitoring of mycotoxins in coffee samples is essential to improve the quality of this favorable beverage in future.

Epidemics and the future of coffee production.

In this perspective, we draw on recent scientific research on the coffee leaf rust (CLR) epidemic that severely impacted several countries across Latin America and the Caribbean over the last decade, to explore how the socioeconomic impacts from COVID-19 could lead to the reemergence of another rust epidemic. We describe how past CLR outbreaks have been linked to reduced crop care and investment in coffee farms, as evidenced in the years following the 2008 global financial crisis. We discuss relationships between CLR incidence, farmer-scale agricultural practices, and economic signals transferred through global and local effects. We contextualize how current COVID-19 impacts on labor, unemployment, stay-at-home orders, and international border policies could affect farmer investments in coffee plants and in turn create conditions favorable for future shocks. We conclude by arguing that COVID-19's socioeconomic disruptions are likely to drive the coffee industry into another severe production crisis. While this argument illustrates the vulnerabilities that come from a globalized coffee system, it also highlights the necessity of ensuring the well-being of all. By increasing investments in coffee institutions and paying smallholders more, we can create a fairer and healthier system that is more resilient to future social-ecological shocks.

Growth, survival, and metabolic activities of probiotics Lactobacillus rhamnosus GG and Saccharomyces cerevisiae var. boulardii CNCM-I745 in fermented coffee brews.

Amidst rising demand for non-dairy probiotic foods, and growing interest in coffees with added functionalities, it would be opportune to ferment coffee brews with probiotics. However, challenges exist in maintaining probiotic viability in high-moisture food products. Here, we aimed to enhance the viability of the probiotic bacteria, Lactobacillus rhamnosus GG, in coffee brews by co-culturing with the probiotic yeast, Saccharomyces cerevisiae var. boulardii CNCM-I745. The yeast significantly enhanced the viability of L. rhamnosus GG, as bacterial populations beyond 7 Log CFU/mL were maintained throughout 14 weeks of storage at 4 and 25 °C. In contrast, the single culture of L. rhamnosus GG suffered viability losses below 6 Log CFU/mL within 10 weeks at 4 °C, and 3 weeks at 25 °C. Growth and survival of S. boulardii CNCM-I745 remained unaffected by the presence of L. rhamnosus GG. Volatile profiles of coffee brews were altered by probiotic metabolic activities, but co-culturing led to suppressed generation of diacetyl and ethanol compared to single cultures. Probiotic fermentation did not alter principal coffee bioactive compounds and antioxidant capacities; however, declines in peroxyl radical scavenging capacities were observed after ambient storage. Overall, we illustrate that yeasts are effective in enhancing probiotic bacterial viability in coffee brews, which may be useful in developing shelf stable probiotic food products.

Microbial diversity and chemical characteristics of Coffea canephora grown in different environments and processed by dry method.

This study aimed to assess the microbial diversity in Coffea canephora grown in four different environments of Espirito Santo state, Brazil. Coffee cherries of two different altitudes (300 and 600 m) and two terrain aspects (Southeast-facing and Northwest-facing slopes) were processed by the dry method. Samples were collected during the drying/fermentation process. Microorganisms were counted, isolated, and identified by MALDI-TOF, followed by sequencing of the ribosomal region. Sugars and organic acids were quantified by HPLC and volatile compounds of the roasted coffees were evaluated by GC-MS. Bacteria population presented a significant number of isolates as well as higher counts during the drying/fermentation process with respect to the population of yeasts. The principal genera of microorganisms found were Bacillus, Pichia, Candida, and Meyerozyma. Meyerozyma guilliermondii was the most frequent yeast in all environments. On the other hand, Pichia kluyveri was found only in coffee cherries from the 600 m altitude. The highest concentration of acetic and succinic acids observed was 6.06 mg/g and 0.84 mg/g, respectively. Sucrose concentrations ranged from 0.68 to 5.30 mg/g, fructose from 1.30 to 4.60 mg/g, and glucose from 0.24 to 1.25 mg/g. Thirty-six volatile compounds, belonging to the groups of pyrazines, alcohols, aldehydes, ketones, and furans were identified in roasted coffee, with differences between altitude and terrain aspects. Information about microbial diversity is crucial to better understand the coffee quality and distinct characteristics of coffee produced in different environments.

Isolation of microorganisms from the feces of ring-tailed coati related to the production of "misha coffee" in the central forest of Peru and evaluation of some features of technological importance.

A diversity of yeasts and lactic bacteria were isolated from the feces of ring-tailed coaties bred in captivity and related to the production of "misha coffee". Isolation of yeasts was carried out using oxytetracycline-glucose-yeast extract agar containing 100 mg/L oxytetracycline and, lactic bacteria using de Man-Rogosa and Sharpe agar containing 20 mg/L of vancomicin. Then, isolates were biochemically analysed using API strips (ID 32C for yeasts and 50CHL for lactic bacteria) followed by 16S and 26S rRNA gene sequencing. Among the yeasts, Debaryomyces hansenii, Pichia kluyveri, Pichia kudriavzevii, and Candida sorboxilosa were the most frequent, whereas Weissella cibaria, Weissella paramesenteroides, Enterococcus thailandicus and Enterococcus faecalis were the most important lactic bacteria. Cultivation of the isolated yeasts under agitated conditions, showed that Pichia kluyveri LBFT.Lev3 (0.15 ± 0.01 h-1) and Pichia kudriavzevii LBTF.Lev7 (0.14 ± 0.01 h-1) had higher specific growth rates than Debaryomyces hansenii LBFT.Lev9 (0.09 ± 0.01 h-1), whereas cultivation of lactic bacteria under static fashion showed that Weisella paramesenteroides LBTF.Bal2 (0.16 ± 0.01 h-1) and Weisella cibaria LBTF.Bal3 (0.18 ± 0.01 h-1) had better growth than Enterococcus thailandicus LBTF.Bal1 (0.1 ± 0.015 h-1) and Enterococcus faecalis LBTF.Bal7 (0.14 ± 0.01 h-1). Additionally, evaluation of pectinolytic activity revealed that Pichia kudriavzevii LBTF.Lev7 and Debaryomyces hansenii LBFT.Lev9 were able to use pectin as carbon source for their growth. On the other hand, W. cibaria LBTF.Bal3, E. thailandicus LBTF.Bal1 and W. paramesenteroides LBTF.Bal2 showed inhibitory activity against S. mutans ATCC 35668, B. subtilis subsp. spizizenii ATCC 6633 and Staph. epidermidis ATCC 14990. Results of this study are useful for the search of potential application of the isolated yeasts and lactic bacteria in coffee and other food fermentations.

Facility-specific 'house' microbiome ensures the maintenance of functional microbial communities into coffee beans fermentation: implications for source tracking.

This work aimed at studying the unconfirmed hypothesis predicting the existence of a connection between coffee farm microbiome and the resulting spontaneous fermentation process. Using Illumina-based amplicon sequencing, 360 prokaryotes and 397 eukaryotes were identified from coffee fruits and leaves, over-ripe fruits, water used for coffee de-pulping, depulped coffee beans, soil, and temporal fermentation samples at an experimental farm in Honduras. Coffee fruits and leaves were mainly associated with high incidence of Enterobacteriaceae, Pseudomonas, Colletotrichum, and Cladosporium. The proportion of Enterobacteriaceae was increased when leaves and fruits were collected on the ground compared to those from the coffee tree. Coffee farm soil showed the richest microbial diversity with marked presence of Bacillus. Following the fermentation process, microorganisms present in depulped coffee beans (Leuconostoc, Gluconobater, Pichia, Hanseniaspora, and Candida) represented more than 90% of the total microbial community, which produced lactic acid, ethanol, and several volatile compounds. The community ecology connections described in this study showed that coffee fruit provides beneficial microorganisms for the fermentation process. Enterobacteria, Colletotrichum, and other microbial groups present in leaves, fruit surface, over-ripe fruits, and soil may transfer unwanted aromas to coffee beans, so they should be avoided from having access to the fermentation tank.

Microbial fermentation affects sensorial, chemical, and microbial profile of coffee under carbonic maceration.

In view of the possibility of diversifying metabolic routes promoted by fermentation, this study proposed a new processing method for coffee, which consists of adapting a technique already consolidated in winemaking, carbonic maceration. The assay occurred under anaerobic conditions with different time and temperature fermentation. The aim of this study was to determine the differences in coffee characteristics (sensorial, chemical, and microbial) after carbonic maceration and fermentation. Specialty Coffee Association protocol, nuclear magnetic resonance, and denaturing gradient gel electrophoresis were used in these analyzes. A significant functional relationship between global score and temperature (38 °C), for the fermentation time of 96 h was observed. Bacterial diversity and sensory characteristics had a positive correlation. Furthermore, trigonelline, formic acid, hydroxymethylfurfural, lipids, and γ-butyrolactone also contributed to score and sensory quality of coffee beverage. Thus, our data show consistent factors to infer on the microbiological action on the sensory quality of coffee beverage.