Coffee growing altitude influences the microbiota, chemical compounds and the quality of fermented coffees

Comprehensive chemical profiling of wild Coffea racemosa, C. Zanguebariae, C. arabica, and C. canephora: A Metabolomic approach using LC-MSn and multivariate analysis

Besides the need to adapt coffee cultivation to climate change, the growing demand for high-quality and exotic coffee has increased interest in species such as Coffea racemosa and C. zanguebariae. These species offer drought and pest resistance, fast maturation, and distinct sensory profiles. However, there is a lack of information regarding their chemical profile. Therefore, this study employed a metabolomic approach using LC-MS, ESI(±)MS, and multivariate analysis to assess the chemical profiles of these species and compare them with C. arabica and C. canephora cv. Conilon. Sixty-four compounds were identified, including chlorogenic acids, lipids, carbohydrates, amino acids, and glycosylated diterpenes. The results indicate that C. racemosa shares chemical similarities with C. arabica, particularly in their trigonelline and amino acid abundance, while C. zanguebariae is characterized by a high phospholipid content, which may influence mouthfeel. Additionally, LC-MS allows isomer separation, whereas ESI(±)MS emerged as a fast alternative for chemometric modeling.

Insight into how fermentation might contribute to the distinctiveness of Australian coffee

With a view to modulating the flavour profiles of Australian coffee, this investigation focused on three estates in New South Wales. Coffee cherries were processed into beans with wet fermented and non-fermented methods to evaluate the effects of fermentation and terroir on microbial population dynamics, volatile composition, and sensory properties. Thirty-three volatiles were quantified in green and roasted coffee beans - 12 esters, 9 alcohols, 6 acids, 3 monoterpenes, 2 norisoprenoids, 1 aldehyde - and 5 thiols were quantified in roasted coffee brews. Sensory descriptive analysis defined appearance, aroma, and flavour attributes to describe the coffee brews. Fermented coffees were characterised by increased intensity of 'black tea leaves' and 'dark chocolate' aromas and 'burnt toast' flavour. Results suggested that wet fermentation of Australian coffee cherries could enhance the content of some volatile compounds known to convey "floral" and "fruity" aromas commonly ascribed to premium coffees from traditional producing regions.

rIDIMS: A novel tool for processing direct-infusion mass spectrometry data

Metabolomics using mass spectrometry-only (MS) analysis either by continuous or intermittent direct infusion (DIMS) and ambient ionization techniques (AMS) has grown in popularity due to their rapid, high-throughput nature and the advantage of performing fast analysis with minimal or no sample pretreatments. But currently, end-users without programming knowledge do not find applications with Graphical User Interface (GUI) specialized in processing DIMS or AMS data. Specifically, there is a lack of standardized workflow for processing data from limited sample sizes and scans from different total ion chronograms (TIC).To address this gap, we present rIDIMS, a browser-based application that offers a straightforward and fast workflow focusing on high-quality scan selection, grouping of isotopologues and adducts, data alignment, binning, and filtering. We also introduce a novel function for selecting TIC scans that is reproducible and statistically reliable, which is a feature particularly useful for studies with limited sample sizes. After processing in rIDIMS, the result is exported in an HTML report document that presents publication-quality figures, statistical data and tables, ready to be customized and exported. We demonstrate rIDIMS functionality in three cases: (i) Classification of coffee bean species through the chemical profile obtained with Mass Spec Pen; (ii) Public repository DIMS data from lipid profiling in monogenic insulin resistance syndromes, and (iii) Lipids for lung cancer classification. We show that our implementation facilitates the processing of AMS and DIMS data through an easy and intuitive interface, contributing to reproducible and reliable metabolomic investigations. Indeed, rIDIMS function asa user-friendly GUI based Shiny web application for intuitive use by end-users (available at https://github.com/BioinovarLab/rIDIMS).

Coffee and Cardiovascular Health: A Review of Literature

Cardiovascular disease is the leading cause of death worldwide and is on the rise. Diet is considered to be a key modifiable risk factor for reducing the incidence of cardiovascular disease. Dietary approaches have proved advantageous for preventing disease morbidity and mortality but tend to focus on fruit, vegetables, fiber, lean protein and healthy fats. Coffee is one of the most popular beverages worldwide but is often surrounded by controversy with regard to its impact on health. This review aims to explore the relationship between coffee consumption and cardiovascular disease. The evidence from observational trials as well as randomized controlled trials is discussed. By focusing on specific bioactive compounds in coffee, potential mechanisms are explored, and future directions of research in the field are considered.

Challenges in coffee fermentation technologies: bibliometric analysis and critical review

Advancements in coffee processing technologies have led to improved efficiency in field operations, but challenges still exist in their practical implementation. Various alternatives and solutions have been proposed to enhance processing efficiency and address issues related to safety, standardization, and quality improvement in coffee production. A literature review using SciMAT and ScientoPy software highlighted advancements in fermentation tanks and the emergence of novel fermentation methodologies. However, these innovations lack sufficient scientific evidence. Researchers are now focusing on systematic approaches, such as controlled fermentations and evaluating the influence of microorganisms and process conditions on sensory attributes and coffee composition. Brazil is the leader in coffee bean fermentation research, but the number of published papers in the field has recently decreased. Despite this, efforts continue to improve process control and optimize product quality. The study emphasizes the need for further innovation in coffee fermentation technologies to increase efficiency, sustainability, and profitability while minimizing environmental impact. Implementing these advancements promises a more sustainable and quality-driven future for the coffee industry.

The Growing Altitude Influences the Flavor Precursors, Sensory Characteristics and Cupping Quality of the Pu'er Coffee Bean

The growing altitude is an important factor affecting the quality of coffee. We explored the flavor precursors, sensory characteristics, and cupping qualities of coffee growing at different altitudes and discussed their associated relationships. The altitude at which coffee is grown has different effects on its chemical composition. Fatty acid contents increased with increasing altitudes, whereas alkaloid and chlorogenic acids contents decreased with increasing elevation. There was no obvious trend in either organic acids or monosaccharides. Eleven of the 112 detected volatile components were significantly affected by the growing altitude. The contents of pyrazines and alcohols tended to decrease, whereas those of aldehydes tended to increase. A significantly altered composition reduces the nutty and roasted flavors of coffee, while increasing the sweet sugar and caramel aromas. The aroma and flavor tended to increase with increasing altitudes during cupping, whereas the other indicators did not change significantly. The results provide a theoretical reference for the sales and promotion of Pu'er coffee.

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.

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.

The Relationship between Microbial Communities in Coffee Fermentation and Aroma with Metabolite Attributes of Finished Products

Coffee is a critical agricultural commodity and is used to produce premium beverages enjoyed by people worldwide. The microbiome of coffee beans has proven to be an essential tool that improves the flavor profile of coffee by creating aromatic flavor compounds through natural fermentation. This study investigated the natural microbial consortium during the wet process fermentation of coffee onsite in Thailand in order to identify the correlation between microbial diversity and biochemical characteristics including flavor, aroma, and metabolic attributes. Our study found 64 genera of bacteria and 59 genera of yeast/fungi present during the fermentation process. Group of microbes, mainly yeast and lactic acid bacteria, that predominated in the process were significantly correlated with preferable flavor and aroma compounds, including linalyl formate, linalool, cis-isoeugenol, trans-geraniol, and (-)-isopulegol. Some of the detected metabolites were found to be active compounds which could play a role in health.

Biocontrol activities of yeasts or lactic acid bacteria isolated from Robusta coffee against Aspergillus carbonarius growth and ochratoxin A production in vitro

Biocontrol Agents (BCAs) can be an eco-friendly alternative to fungicides to reduce the contamination with mycotoxigenic fungi on coffee. In the present study, different strains of bacteria and yeasts were isolated from Ivorian Robusta coffee. Their ability to reduce fungal growth and Ochratoxin A (OTA) production during their confrontation against Aspergillus carbonarius was screened on solid media. Some strains were able to reduce growth and OTA production by 85 % and 90 % and were molecularly identified as two yeasts, Rhodosporidiobolus ruineniae and Meyerozyma caribbica. Subsequent tests on liquid media with A. carbonarius or solely with OTA revealed adhesion of R. ruineniae to the mycelium of A. carbonarius through Scanning Electron Microscopy, and an OTA adsorption efficiency of 50 %. For M. caribbica potential degradation of OTA after 24 h incubation was observed. Both yeasts could be potential BCAs good candidates for Ivorian Robusta coffee protection against A. carbonarius and OTA contamination.

Effect of the aggregated protein dye YAT2150 on Leishmania parasite viability

The problems associated with the drugs currently used to treat leishmaniasis, including resistance, toxicity, and the high cost of some formulations, call for the urgent identification of new therapeutic agents with novel modes of action. The aggregated protein dye YAT2150 has been found to be a potent antileishmanial compound, with a half-maximal inhibitory concentration (IC50) of approximately 0.5 µM against promastigote and amastigote stages of Leishmania infantum. The encapsulation in liposomes of YAT2150 significantly improved its in vitro IC50 to 0.37 and 0.19 µM in promastigotes and amastigotes, respectively, and increased the half-maximal cytotoxic concentration in human umbilical vein endothelial cells to >50 µM. YAT2150 became strongly fluorescent when binding intracellular protein deposits in Leishmania cells. This fluorescence pattern aligns with the proposed mode of action of this drug in the malaria parasite Plasmodium falciparum, the inhibition of protein aggregation. In Leishmania major, YAT2150 rapidly reduced ATP levels, suggesting an alternative antileishmanial mechanism. To the best of our knowledge, this first-in-class compound is the only one described so far having significant activity against both Plasmodium and Leishmania, thus being a potential drug for the treatment of co-infections of both parasites.

Exploring the microbiome of coffee plants: Implications for coffee quality and production

Coffee stands as one of the world's most popular beverages, and its quality undergoes the influence of numerous pre- and post-harvest procedures. These encompass genetic variety, cultivation environment, management practices, harvesting methods, and post-harvest processing. Notably, microbial communities active during fermentation hold substantial sway over the ultimate quality and sensory characteristics of the final product. The interaction between plants and microorganisms assumes critical significance, with specific microbes assuming pivotal roles in coffee plant growth, fruit development, and, subsequently, the fruit's quality. Microbial activities can synthesize or degrade compounds that influence the sensory profile of the beverage. However, studies on the metabolic products generated by various coffee-related microorganisms and their chemical functionality, especially in building sensory profiles, remain scarce. The primary aim of this study was to conduct a literature review, based on a narrative methodology, on the current understanding of the plant-microorganism interaction in coffee production. Additionally, it aimed to explore the impacts of microorganisms on plant growth, fruit production, and the fermentation processes, directly influencing the ultimate quality of the coffee beverage. Articles were sourced from ScienceDirect, Scopus, Web of Science, and Google Scholar using specific search terms such as "coffee microorganisms", "microorganisms-coffee interactions", "coffee fermentation", "coffee quality", and 'coffee post-harvest processing". The articles used were published in English between 2000 and 2023. Selection criteria involved thoroughly examining articles to ensure their inclusion was based on results about the contribution of microorganisms to both the production and quality of the coffee beverage. The exploration of microorganisms associated with the coffee plant and its fruit presents opportunities for bioprospecting, potentially leading to targeted fermentations via starter cultures, consequently generating new profiles. This study synthesizes existing data on the current understanding of the coffee-associated microbiome, its functionalities within ecosystems, the metabolic products generated by microorganisms, and their impacts on fermentation processes and grain and beverage quality. It highlights the importance of plant-microorganism interactions in the coffee production chain.

Enhancing Sensory Quality of Coffee: The Impact of Fermentation Techniques on Coffea arabica cv. Catiguá MG2

Fermentation, a critical post-harvest process, can be strategically manipulated to augment coffee quality. This enhancement is achieved through the activity of microorganisms, which generate metabolites instrumental in the formation of distinct sensory profiles. This study investigated the impact of different fermentation methods on the quality of coffee beverages, specifically utilizing the Catiguá MG2 variety. The experimental setup involved fermenting the coffee in 200 L bioreactors, employing both natural and pulped coffee beans. The fermentation process utilized was self-induced anaerobic fermentation (SIAF), conducted in either a solid-state or submerged medium over a 96 h period. Analytical sampling was conducted initially and at 24 h intervals thereafter to quantify the concentration of sugars, alcohols, and organic acids. Sensory evaluation was performed using the established protocols of the Specialty Coffee Association (SCA). The outcomes of this investigation reveal that fermentation substantially enhances the quality of coffee, with each treatment protocol yielding divergent profiles of acids and alcohols, thereby influencing the sensory characteristics of the resulting beverage. Notably, superior quality beverages were produced from naturally processed coffee subjected to solid-state fermentation for durations exceeding 24 h. These findings underscore the significant influence of fermentation techniques and duration on the sensory attributes and overall quality of coffee.

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.

Multi-attribute temporal descriptive methods in sensory analysis applied in food science: A systematic scoping review

Among descriptive sensory evaluation methods, temporal methods have a wide audience in food science because they make it possible to follow perception as close as possible to the moment when sensations are perceived. The aim of this work was to describe 30 years of research involving temporal methods by mapping the scientific literature using a systematic scoping review. Thus, 363 research articles found from a search in Scopus and Web of Science from 1991 to 2022 were included. The extracted data included information on the implementation of studies referring to the use of temporal methods (details related to subjects, products, descriptors, research design, data analysis, etc.), reasons why they were used and the conclusions they allowed to be drawn. Metadata analysis and critical appraisal were also carried out. A quantitative and qualitative synthesis of the results allowed the identification of trends in the way in which the methods were developed, refined, and disseminated. Overall, a large heterogeneity was noted in the way in which the temporal measurements were carried out and the results presented. Some critical research gaps in establishing the validity and reliability of temporal methods have also been identified. They were mostly related to the details of implementation of the methods (e.g., almost no justification for the number of consumers included in the studies, absence of report on panel repeatability) and data analysis (e.g., prevalence of use of exploratory data analysis, only 20% of studies using confirmatory analyses considering the dynamic nature of the data). These results suggest the need for general guidelines on how to implement the method, analyze and interpret data, and report the results. Thus, a template and checklist for reporting data and results were proposed to help increase the quality of future research.

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.

Coffee fermentation process: A review

In recent years, the importance of controlling coffee fermentation in the final quality of the beverage has been recognized. The literature review was conducted in the Science Direct and Springer databases, considering studies published in the last ten years, 74 references were selected. Several studies have been developed to evaluate and propose fermentation conditions that result in sensory improvements in coffee. So, this review aims to describe detailed the different protocols for conducting the coffee fermentation step and how they could influence the sensory quality of coffee based on the Specialty Coffee Association protocol. We propose a new way to identify coffee post-harvest processing not based on the already known wet, dry and semi-dry processing. The new identification is focused on considering fermentation as a step influenced by the coffee fruit treatment, availability of oxygen, water addition, and starter culture utilization. The findings of this survey showed that each type of coffee fermentation protocol can influence the microbiota development and consequently the coffee beverage. There is a migration from the use of processes in open environments to closed environments with controlled anaerobic conditions. However, it is not possible yet to define a single process capable of increasing coffee quality or developing a specific sensory pattern in any environmental condition. The use of starter cultures plays an important role in the sensory differentiation of coffee and can be influenced by the fermentation protocol applied. The application of fermentation protocols well defined is essential in order to have a good product also in terms of food safety. More research is needed to develop and implement environmental control conditions, such as temperature and aeration, to guarantee the reproducibility of the results.

Coffee bean processing: Emerging methods and their effects on chemical, biological and sensory properties

Emerging processing methods have been applied in coffee bean processing for improved sensory quality. The processes focus on optimizing the fermentation process of the coffee cherries and beans. This involves various pathways, including the formation of volatiles, flavor precursors and organic acids and the reduction in the concentrations of bioactive compounds. Comprehensive information regarding the effect of these emerging processes on the chemical, biological and sensory properties of the coffee beans is summarized. Emerging processes affected the coffee bean to various degrees depending on the raw material and the method used. The emerging methods promoted the reduction of bioactives such as caffeine and phenolics in coffee beans. Substantial improvement of these processes is needed to obtain coffee beans with improved biological activities. Effort to simplify the methods and optimize the post-fermentation process is crucial for the methods to be easily accessible by the producers and to produce defect-free coffee beans.

Comparative studies of fermented coffee fruits post-treatments on chemical and sensory properties of roasted beans in Yunnan, China

In this study, medium roasted coffee with four different fermented coffee fruits post-treatments (dry, wet, semi-dry and hot air dry) was used as the material. Chemical profile and sensorial analysis were used to comprehensively analyze the effects of post-treatments on coffee flavor characteristics from multiple dimensions. A total of 31 water-soluble chemical components and 39 volatile compounds were identified in roasted coffee, and distinct post-treatments based on chemical orientation make coffee highly differentiated. In addition, the principal component analysis (PCA) of the chemical composition integrated data set showed that the first two principal components could explain 54.9% of the sample variability. All four post-treatments can be classified as "specialty coffees" according to the Specialty Coffee Association (SCA) protocol, with various organoleptic characteristics and flavor attributes. As a result, the fermented coffee fruits post-treatment method further determines the quality characteristics of coffee, thus meeting the needs of different niche markets.

Molecular, Chemical, and Sensory Attributes Fingerprinting of Self-Induced Anaerobic Fermented Coffees from Different Altitudes and Processing Methods

Coffee quality is achieved by performing good practices. This study aimed to evaluate coffees from different altitudes fermented with the self-induced anaerobic method (SIAF) and processed via natural (N) and pulped natural (PN). Molecular (PCR-DGGE), chemical (HPLC, ABTS, DPPH, ATR-FTIR, and GC-MS), and sensory analyses were performed. Leuconostoc predominated both processes and all altitudes. Hanseniaspora and Pichia predominated both processes at 800 and 1200 m. Acids were higher in N coffees for all altitudes. Acetic, malic acid and alcohols were the most abundant. Higher sensory scores were obtained in N (mainly at 1400 m-88.13). Floral and spices were perceived in all samples. ABTS capacity in roasted coffee increased with altitude in PN (2685.71, 2724.03, and 3847.14 µM trolox/g); meanwhile, the opposite was observed in N. High sensory scores were obtained in high altitudes. Alcohols and acids in roasted beans increase with altitude. Leuconostoc and Pichia showed potential as future coffee starters.

Influence of pre-and post-harvest factors on the organoleptic and physicochemical quality of coffee: a short review

The coffee quality is affected by 40% pre-harvest, 40% post-harvest, and 20% export handling. Besides, future risks for the coffee industry are related with climate change and increased pathogens. Considering the importance of the aroma profile and unique flavor of Arabica coffee, most literature focuses on this variety because of the high market share; however, nowadays, Robusta coffee stands out for its increasing industrial value and resistance to drought. In this review, both species are emphasized, highlighting sensory aspects of possible new products mixed with a higher proportion of Robusta given market trends for bitter beverages. In the present work, a systematic search of peer-reviewed literature evaluates how the coffee cup quality and physicochemical characteristics of Robusta and Arabica are influenced by environmental, agronomic, and further processing factors.

Interactive effect of post-harvest processing method, roasting degree, and brewing method on coffee metabolite profiles

Our study aims to characterize metabolite profiles, varying by major determinants in brewed coffee as follows: three post-harvest processing, three roasting degrees, and two brewing methods for C. arabicacv. Geisha. The major discriminant factor was the roasting degree, explaining 58.84% of the total variance of metabolite profiles. Despite a lesser degree of influence, specific metabolite profiles were retained in temperature-based brewing (Light, 11.11%; Medium, 12.01%; Dark, 22.15%) and post-harvest processing (Light, 35.29%; Medium, 29.64%; Dark, 22.03%), respectively. The effect of pressure application on the coffee metabolome was significant only for the light roasted beans (9.88%). Of note, the post-harvest processing method was featured by norharman (anaerobic), pimelic acid (natural), and xanthine (washed). In addition, our study proposed novel compounds, DiHOMEs, associated with potential health benefits, which will step-up the coffee values and suggest future direction of the development of coffee processing.

Does Coffee Have Terroir and How Should It Be Assessed?

The terroir of coffee is defined as the unique sensory experience derived from a single origin roasted coffee that embodies its source. Environmental conditions such as temperature, altitude, shade cover, rainfall, and agronomy are considered the major parameters that define coffee terroir. However, many other parameters such as post-harvest processing, roasting, grinding, and brewing can combine to influence the perception of terroir. In this review, we discuss the contribution of these parameters and their influence on coffee terroir. Assessment of terroir requires defined sensory descriptors, as provided by the World Coffee Research Lexicon, and standardized roast level, grind size, and brew method. The choice of the post-harvest processing method is often environmentally dependent, suggesting that an inclusion into the coffee terroir definition is warranted. Coffee terroir is often not intentionally created but results from the contributions of the Coffea species and variety planted, environmental and agricultural parameters, and both the harvest and post-harvest method used. The unique combination of these parameters gives the consumer a unique cup of coffee, reminiscent of the place the coffee was produced.

Traditional Fermented Foods from Ecuador: A Review with a Focus on Microbial Diversity

The development of early civilizations was greatly associated with populations’ ability to exploit natural resources. The development of methods for food preservation was one of the pillars for the economy of early societies. In Ecuador, food fermentation significantly contributed to social advances and fermented foods were considered exclusive to the elite or for religious ceremonies. With the advancement of the scientific research on bioprocesses, together with the implementation of novel sequencing tools for the accurate identification of microorganisms, potential health benefits and the formation of flavor and aroma compounds in fermented foods are progressively being described. This review focuses on describing traditional fermented foods from Ecuador, including cacao and coffee as well as less popular fermented foods. It is important to provide new knowledge associated with nutritional and health benefits of the traditional fermented foods.

Interactions between Geomorphology and Production Chain of High-Quality Coffee in Costa Rica

High-altitude coffee has an international reputation due to its high quality, especially in countries with a long production history, such as Costa Rica. Specific geographical characteristics determine the regions where high-altitude coffee can be cultivated. Over the last two decades, new production conditions have promoted the growth of smallholder coffee farms in the Upper Buenavista Catchment (UBC) in the South of Costa Rica. To understand this phenomenon’s process, we initially performed a detailed geomorphological mapping of the high-elevation production sites in the UBC. Then, we used remote sensing to determine the coffee land cover (2005, 2012, and 2018) to compare their landforms. Furthermore, we analyzed the production–processing–market chain that has promoted coffee plantations since 2005. Our results show that coffee farmers chose more unstable and erosive areas with short-term production prospects to cultivate premium-priced coffee. Moreover, farmers have changed their role in the coffee sector, evolving from small producers to entrepreneurs with specialized knowledge. These actions may reduce economic risks and improve the household incomes of smallholder coffee producers. However, limited research has been conducted along the tropics about the relationships between landforms, socioeconomic drivers, and high-altitude coffee yield. Therefore, our results are essential to present geomorphology and applied geography as baselines in land-use planning for agricultural landscapes.

Application of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for the Rapid Identification of Yeast Species From Polar Regions

Protein profiling based on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) has proved to be a powerful tool for yeast identification. However, it is rarely used in the identification of yeast isolates from polar regions, which may be due to the limited data available for the differentiation of polar yeast species. The present study constructed a supplementary database of MALDI-TOF MS, including 33 yeast species from the Arctic and Antarctica. These yeast species were used to assess the accuracy and practicality of MALDI-TOF MS-based identification compared to the ribosomal DNA [internal transcribed spacer (ITS) and large subunit (LSU) gene regions] sequencing identification. Their dendrogram based on main spectra profiles (MSPs) in the supplementary database was somewhat consistent with their phylogenetic tree. The accuracy of MALDI-TOF MS identification was also compared by the ethanol-formic acid extraction method and the on-plate extraction method. In addition, peptide markers of some yeast species (e.g., Glaciozyma, Phenoliferia, Mrakia, and Vishniacozyma) were identified. It is concluded that the MALDI-TOF MS method can differentiate some closely related yeast species from polar regions, thus is suitable for the identification of polar yeasts.

Acids in coffee: A review of sensory measurements and meta-analysis of chemical composition

Coffee contains a variety of organic acids (OAs) and chlorogenic acids (CGAs) that contribute to overall sensory properties. Large variations in preparation and measurement methodology across the literature complicate interpretation of general trends. Here, we perform a systematic review and meta-analysis of the published literature to elucidate the concentrations of OAs and CGAs in both Coffea arabica (arabica) and Coffea canephora (robusta), for both green coffee and roasted coffee at multiple roast levels. A total of 129 publications were found to report acid concentration measurements, yielding 8,634 distinct data points. Analysis of the full data set reveals several trends. First, roasted robusta has considerably more acidic compounds than arabica with 2 to 5 times as much total OAs, and much larger amounts of formic and acetic acid. As for CGAs, in both arabica and robusta 5-CQA is the major component, and progressive roasting decreases the concentration of all CGAs. The total amount of CGA present was more dependent on roast level than the type of coffee (arabica vs. robusta). Overall, this meta-analysis suggests that the increases in certain OAs with roast level might play more of a role in the sensory profile of dark roast coffees than previously suspected.

Ochratoxin a levels in fermented specialty coffees from Caparaó, Brazil: Is it a cause of concern for coffee drinkers?

Although postharvest coffee fruit fermentation can improve coffee flavour and quality, the mycotoxin ochratoxin A (OTA) can also be a result of microbiological activity, albeit in the later drying step of coffee processing. To evaluate the possible occurrence of OTA contamination in postharvest fruit fermentation, fourteen coffees that entailed two different postharvest fruit fermentation times were evaluated. These coffees originated in the surroundings of the village of Pedra Menina in the qualified Denomination of Origin and coffee producer region of Caparaó on the border between Minas Gerais and Espírito Santo states in Brazil. All coffees were classified according to the Specialty Coffee Association (SCA) protocol and 12 achieved specialty level. OTA was determined in all 14 coffees using immunoaffinity for sample clean-up and high-performance liquid chromatography with fluorescence detection for quantification. One sample presented an OTA concentration of 0.75 µg kg^-1 and two samples showed OTA concentrations of 0.87 µg kg^-1. The other samples had concentrations of OTA below the limit of quantification obtained in this work (0.64 µg kg^-1). Thus, all samples showed OTA concentrations far below the most stringent maximum residue limit (MRL) of 5 µg kg^-1 established for roasted coffees by European legislation. These low levels were similar to most of the previous results for Brazilian coffees listed and tabled in this work. This comparison showed that OTA contamination due to this kind of postharvest process - fruit fermentation - should not be a concern for producers and consumers of these fermented coffees.

Microbial diversity associated with spontaneous coffee bean fermentation process and specialty coffee production in northern Colombia

Coffee fermentation involves the action of microorganisms, whose metabolism has a significant influence on the composition of the beans and, consequently, on the beverage's sensory characteristics. In this study, the microbial diversity during the wet fermentation of Coffea arabica L. in the Sierra Nevada of Santa Marta (SNSM) in Colombia was explored by high-throughput sequencing and the resulting cup quality through the standards of the Specialty Coffee Association. The taxonomic assignment of sequence reads showed a high microbial diversity comprised of 695 bacterial and 156 fungal genera. The microbial community was dominated by the Lactic Acid Bacteria (LAB) Leuconostoc, the yeast Kazachstania, and the Acetic Acid Bacteria (AAB) Acetobacter. Co-occurrence relationships suggested synergistic patterns between populations of LAB-AAB, yeasts-AAB, Leuconostoc-Prevotella, LAB-ABB-Selenomonas, and yeasts-fungi-nonLAB-nonAAB, which may result in the production of metabolites that positively impact the sensory attributes of coffee. The beverages produced were classified as specialty coffees, and their score was positively influenced by the fungal richness and the abundance of unclassified Lactobacillales, Pichia, and Pseudomonas. The findings show the richness and microbial diversity of the SNSM and serve as input for future research such as the analysis of microbial-derived metabolites and the establishment of starter cultures in coffee processing that guarantee the generation of high-quality beverages, the standardization of processes, the reduction of economic losses, and the production of value-added products that allow taking advantage of specialty coffee market.

The Altitude of Coffee Cultivation Causes Shifts in the Microbial Community Assembly and Biochemical Compounds in Natural Induced Anaerobic Fermentations

Coffee harvested in the Caparaó region (Minas Gerais, Brazil) is associated with high-quality coffee beans resulting in high-quality beverages. We characterize, microbiologically and chemically, fermented coffees from different altitudes through target NGS, chromatography, and conventional chemical assays. The genera Gluconobacter and Weissella were dominant in coffee’s fruits from altitudes 800 and 1,000 m. Among the Eukaryotic community, yeasts were the most dominant in all altitudes. The most dominant fungal genus was Cystofilobasidium, which inhabits cold environments and resists low temperatures. The content of acetic acid was higher at altitudes 1,200 and 1,400 m. Lactic acid and the genus Leuconostoc (Pearson: 0.93) were positively correlated. The relative concentration of volatile alcohols, especially of 2-heptanol, was high at all altitudes. Bacteria population was higher in coffees from 800 m, while at 1,000 m, fungi richness was favored. The altitude is an important variable that caused shifts in the microbial community and biochemical compounds content, even in coffees belonging to the same variety and cultivated in the same region under SIAF (self-induced anaerobic fermentation) conditions. Coffee from lower altitudes has higher volatile alcohols content, while high altitudes have esters, aldehydes, and total phenolics contents.

Co-inoculation of yeasts starters: A strategy to improve quality of low altitude Arabica coffee

The study aimed to improve the quality of dry-processed coffee grown at low altitudes through yeast inoculation, using three species (Saccharomyces cerevisiae CCMA 0543, Torulaspora delbrueckii CCMA 0684, and Candida parapsilosis CCMA 0544) singly and with co-inoculation for fermentation. Important chemical compounds and groups were analyzed by liquid and gas chromatography and Fourier-transform infrared spectroscopy (FTIR). The inoculated coffees with yeast populations around 10⁶ cell/g obtained the highest scores, and the co-inoculation with C. parapsilosis CCMA 0544 and T. delbrueckii CCMA 0684 had the highest score in the sensory analysis (85). Different descriptors were observed in each treatment, and body, flavor, balance, and aftertaste are strongly related to C. parapsilosis CCMA 0544. The fermentation process improved the quality of low-altitude coffees, and the combination of non-Saccharomyces yeasts (C. parapsilosis CCMA 0544 and T. delbrueckii CCMA 0684) was the most indicated as starter cultures.

Fermentation of Coffea canephora inoculated with yeasts: Microbiological, chemical, and sensory characteristics

This work aimed to evaluate Coffea canephora's microbiological, chemical, and sensory characteristics at 300 and 600 m elevation plantations processed by the natural method inoculated with yeasts. The coffee was spread on suspended terraces and sprayed with approximately 10⁷ cfu/mL of Meyerozyma caribbica CCMA 1738 or Pichia kluyveri CCMA 1743, separately. Cherries containing bark and parchment were collected during fermentation for microbial groups counting, qPCR, quantification of organic acids, and sugars (HPLC). Volatile compounds (GC-MS) and sensory analyses, cupping test with expert coffee tasters and triangular test with consumers, were performed on roasted coffee beans. The inoculated yeasts persisted during the entire fermentation process. M. caribbica reduced the filamentous fungal population by 63% and 90% in the 300- and 600-m coffees, respectively. The 300-m coffee fruits showed higher concentrations of organic acids in all fermentation times when compared to the 600-m reaching out to 8 times more. Twenty-four volatile compounds were identified in the roasted coffee beans, with the predominance of pyrazines. The 600-m coffee inoculated with M. caribbica showed an increase of more than one point in the score given by certified tasters. Consumers noticed the M. caribbica inoculation in the 300- and 600-m-elevation coffees. M. caribbica is a promising starter culture for Conilon coffee with the potential to increase the beverage quality.

Novel stainless steel tanks enhances coffee fermentation quality

Fermenting in bioreactors can improve coffee quality, standardize the fermentation process, and generate specialty coffees. This work aimed to evaluate novel stainless steel bioreactors with inoculated and non-inoculated coffees processed via natural and pulped natural. Yeast and bacteria populations were evaluated and grown on Yeast Extract Peptone Glucose; De Man, Rogosa, and Sharpe; and Nutrient agar media. Volatile compounds from roasted beans were analyzed in a Gas Chromatography-Mass Spectrometry equipment, and the sensory perception was evaluated through a cup test. The mesophilic bacteria population was statistically significant in pulped natural coffee compared to yeast and lactic acid bacteria. Furans had the highest concentration among the chemical groups. Beverage inoculated with CCMA 0535 presented the highest SCA score. Prune, peach, and floral attributes were only perceived in Nat CCMA 0535. The sensory perception indicated that the inoculated yeasts modified the flavor attributes, enhanced the quality, and increase their SCA scores.

Microbial dynamics in rearing trials of Hermetia illucens larvae fed coffee silverskin and microalgae

In the present study, Hermetia illucens larvae were reared on a main rearing substrate composed of a coffee roasting byproduct (coffee silverskin, Cs) enriched with microalgae (Schizochytrium limacinum or Isochrysis galbana) at various substitution levels. The microbial diversity of the rearing substrates, larvae, and frass (excrement from the larvae mixed with the substrate residue) were studied by the combination of microbial culturing on various growth media and metataxonomic analysis (Illumina sequencing). High counts of total mesophilic aerobes, bacterial spores, presumptive lactic acid bacteria, coagulase-positive cocci, and eumycetes were detected. Enterobacteriaceae counts were low in the rearing diets, whereas higher counts of this microbial family were observed in the larvae and frass. The microbiota of the rearing substrates was characterized by the presence of lactic acid bacteria, including the genera Lactobacillus, Leuconostoc and Weissella. The microbiota of the H. illucens larvae fed Cs was characterized by the dominance of Paenibacillus. H. illucens fed diets containing I. galbana were characterized by the presence of Enterococcus, Lysinibacillus, Morganella, and Paenibacillus, depending on the algae inclusion level, while H. illucens fed diets containing S. limacinum were characterized by high relative abundances of Brevundimonas, Enterococcus, Paracoccus, and Paenibacillus, depending on the algae inclusion level. Brevundimonas and Alcaligenes dominated in the frass from larvae fed I. galbana; the predominance of Brevundimonas was also observed in the frass from larvae fed Schyzochitrium-enriched diets. Based on the results of the present study, an effect of algae nutrient bioactive substances (e.g. polysaccharides, high-unsaturated fatty acids, taurine, carotenoids) on the relative abundance of some of the bacterial taxa detected in larvae may be hypothesized, thus opening new intriguing perspectives for the control of the entomopathogenic species and foodborne human pathogens potentially occurring in edible insects. Further studies are needed to support this hypothesis. Finally, new information on the microbial diversity occurring in insect frass was also obtained.

Coffee Microbiota and Its Potential Use in Sustainable Crop Management. A Review

Intensive coffee production is accompanied by several environmental issues, including soil degradation, biodiversity loss, and pollution due to the wide use of agrochemical inputs and wastes generated by processing. In addition, climate change is expected to decrease the suitability of cultivated areas while potentially increasing the distribution and impact of pests and diseases. In this context, the coffee microbiota has been increasingly studied over the past decades in order to improve the sustainability of the coffee production. Therefore, coffee associated microorganisms have been isolated and characterized in order to highlight their useful characteristics and study their potential use as sustainable alternatives to agrochemical inputs. Indeed, several microorganisms (including bacteria and fungi) are able to display plant growth-promoting capacities and/or biocontrol abilities toward coffee pests and diseases. Despite that numerous studies emphasized the potential of coffee-associated microorganisms under controlled environments, the present review highlights the lack of confirmation of such beneficial effects under field conditions. Nowadays, next-generation sequencing technologies allow to study coffee associated microorganisms with a metabarcoding/metagenomic approach. This strategy, which does not require cultivating microorganisms, now provides a deeper insight in the coffee-associated microbial communities and their implication not only in the coffee plant fitness but also in the quality of the final product. The present review aims at (i) providing an extensive description of coffee microbiota diversity both at the farming and processing levels, (ii) identifying the “coffee core microbiota,” (iii) making an overview of microbiota ability to promote coffee plant growth and to control its pests and diseases, and (iv) highlighting the microbiota potential to improve coffee quality and waste management sustainability.

Is Coffee (Coffea arabica L.) Quality Related to a Combined Farmer–Farm Profile?

This study proposed a classification model for 125 agricultural productive units (APUs) in Tolima, Colombia, to establish whether they are related to the quality of coffee produced. The model considered two aspects related to farmer profile and farm profile. The following proposed categories resulted from the coordinate obtained in relation to the two aspects: Low-Low, High-Low, Low-High, and High-High. The variables for each aspect were prioritized using the analysis hierarchical process (AHP). The coffee’s quality, sensory profile by attribute, and specific descriptors for each category were determined employing the Specialty Coffee Association (SCA) protocol. The sensory attributes were analyzed by way of one-way analysis of variance (ANOVA), and the Bonferroni test was used to compare by category, both with a significance level of α = 0.05. The model grouped the APUs by category and cup quality, with the High-High category achieving the best scores in the sensory analysis. The variables with the greatest relative weight within the AHP model constituted farmer stance regarding the use of good agricultural practices (44.5%) and farmer attitude toward excellence (40.6%) in the farmer’s profile. As part of the farm’s profile, environmental commitment level (38.0%) and international certifications (29.1%) were the greatest relative weights. Coffee in the High-High category was characterized by its notes of cinnamon, cocoa, chocolate, and dried vegetables.

Arabica and Conilon coffee flowers: Bioactive compounds and antioxidant capacity under different processes

This study presents innovative research for comparison of the effect of the different dehydration techniques and methods of extraction on the antioxidant potential and bioactive compounds of Conilon and Arabica coffee flowers. The compounds were analyzed by high performance liquid chromatography and the antioxidant capacity evaluated by the 2,2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide assays. Among the compounds evaluated, trigonelline, gallic acid, chlorogenic acid, and caffeine were identified, with trigonelline and caffeine being those with the highest concentration. The investigated factors significantly influenced the profile of the bioactive compounds identified, and the antioxidant capacity. The 92 °C infusion of freeze-dried Conilon coffee flowers, in general, showed greater antioxidant capacity by ABTS and DPPH assays, as well as total phenolic content. Lyophilization had a positive influence on maintaining the content of phenolic compounds and antioxidant capacity of the samples. Coffee flowers proved to be a potential raw material for making tea-like drinks.