The Aromatic Scents of Four Plants in Learning and Memory of Drosophila melanogaster.

Introduction: Folkloric claims have surrounded essential oils, including their enhancement of learning and memory through inhalational exposure. Few studies in humans have shown a benefit in cognition, albeit incremental. However, this benefit may not be entirely attributable to the essential oil aroma but may be confounded by psychological associations. We investigated rosemary, peppermint, lemon, and coffee aromas in a learning and memory model of Drosophila melanogaster to eliminate this confounder. Methods: We screened for concentrations of the four treatments that are non-stimulatory for altered locomotory behavior in the flies. At these concentrations, we determined if they were chemoneutral (i.e., neither chemoattractant nor chemorepellent) to the flies. Learning and memory of the flies exposed to these aromas were determined using an Aversive Phototaxis Suppression (APS) assay. Results: The aromas of rosemary, peppermint, and lemon that did not elicit altered mobility in the flies were from dilute essential oil solutions that ranged from 0.2 to 0.5% v/v; whereas for the aroma in coffee, it was at a higher concentration of 7.5% m/v. At these concentrations, the aromas used were found to be chemoneutral towards the flies. We observed no improvement in both learning and memory in the four aromas tested. While a significant reduction (p < 0.05) in learning was observed when flies were treated with the aromas of rosemary, peppermint, and coffee, a significant reduction (p < 0.05) in memory was only observed in the peppermint aroma treatment. Conclusion: This study demonstrated that in the absence of psychological association, the four aromas do not enhance learning and memory.

Chitosan-coated paper packaging for specialty coffee beans: Coating characterization, bean and beverage analysis.

Cellulose-based packaging has received great attention due to its characteristics of biodegradability, sustainability, and recyclability. Natural polymer coatings are usually applied to the paper surface to enhance the barriers to water vapour and improve the mechanical properties. A chitosan-based coating for paper packaging was developed in this work to store specialty roasted coffee beans, evaluating two samples of chitosan (Sigma® and molasses chitosan), and following the physico-chemical and microbiological characteristics of coffee beans along a period of 60 days. Sensory tests (Ranking Descriptive Analysis and Preference Test) were applied to the beverage prepared with the roasted and ground coffee beans stored in each packaging. Thin chitosan films provided good coverage and adhesion on the paper. Improved mechanical properties and lower water permeability were observed in the chitosan-coated papers. The physicochemical and microbiological characteristics of the coffee beans were not influenced by the packaging along 60 days of storage. The molasses chitosan coating resulted in slightly darker roasted beans. In sensory evaluation, there is a clear difference between the chitosan samples, so that molasses chitosan-coated packaging had higher scores compared to Sigma® chitosan treatment for flavor and global impression in the preference analysis of the beverage. The molasses chitosan-coated packaging had three to four more consumers attributing the highest scores for the beverage prepared with the roasted beans stored in this type of packaging.

Literature Review of Proteomics Approach Associated with Coffee.

As a significant crop growing all across the world, coffee is mostly produced in the bean belt of our global atlas. Worldwide variations in environmental conditions are causing a decline in the yield and quality of coffee varieties. Coffee production is the main emphasis of several traditional breeding techniques. But conventional breeding methods are not sufficient to tackle the problems related to coffee. The field of genomics, which includes transcriptomics, proteomics, and metabolomics, has made great paces in the last ten years. Proteomics is a well-known technique used to enhance the growth, yield, breeding, and quality of different plants under stable and shifting environments. The regulation of specific enzymes, genes, protein expression, modification, translation, and other features played an important role in the enhancement of important plants. However, relatively less research on the proteomics approach for coffee has been published in the last few years. For this reason, some of the most important aspects of proteome profiling for coffee plants have been covered in this review, including growth, the somatic embryo technique, altitude, environmental adoption, drought, and the role that proteins and important enzymes play in the flavor and taste of coffee. This review can aid in the breeding of new cultivars and improve coffee attributes. Furthermore, the present literature can pave the way for proteomics research on coffee.

Rapid detection of markers in green coffee beans with different primary processing treatments of Coffea arabica L. from Yunnan.

The characteristic flavor of Coffea arabica from Yunnan is largely attributed to the primary processing treatments through affecting the VOCs accumulation. Therefore, a rapid and comprehensive detection technique is needed to accurately recognize VOCs in green coffee beans with different pretreatment methods. Hence, we conducted volatile profiles and identified nine markers of three different primary processed green coffee beans from the major production areas in Yunnan with the combined of HS-SPME-GC-MS and PTR-TOF-MS. The relationships between the chemical composition and the content of VOCs in green coffee beans were elucidated. Among the markers, palmitic acid (F3), linoleic acid (F6), α-ethylidene phenylacetaldehyde (T4), and phytane (T8) contributed to the antioxidant activity of sun-exposed green coffee beans. In conclusion, the analytical technology presented here provided a general tool for an overall and rapid understanding of a detailed volatile profiles of green coffee beans in Yunnan.

Coffee Extract as a Natural Antioxidant in Fresh Pork Sausage-A Model Approach.

Consumers are increasingly looking for healthy foods without the addition of synthetic additives. The aim of this study was to evaluate the efficiency of coffee extracts as a natural antioxidant in fresh pork sausage. Firstly, the conditions for obtaining coffee green extracts were optimized (Central Composite Rotatable Design 23, variables: extraction time, ethanol-water ratio, and sample-solvent ratio) in an ultrasound bath (70 °C). The response variables were the bioactive compounds levels and antioxidant activity. Valid models were obtained (p ≤ 0.05, R2 > 0.751), with higher bioactive content and antioxidant activity in the central point region. Extracts of Robusta and Arabica coffee green (RG and AG) and medium roast (RR and AR) obtained, and central point (10 min, an ethanol concentration of 30%, and a sample-solvent ratio of 10 g/100 mL) and optimized (14.2 min, 34.2%, and 5.8 g/100 mL) parameters were characterized. The RG presented a significantly (p ≤ 0.05) higher content of caffeine (3114.8 ± 50.0 and 3148.1 ± 13.5 mg/100 g) and 5-CQA (6417.1 ± 22.0 and 6706.4 ± 23.5 mg/100 g) in both extraction conditions, respectively. The RG and RR coffee presented the highest antioxidant activity. Two concentrations of RG and RR coffee extracts were tested in fresh pork sausage. The Robusta coffee extract presented the highest antioxidant activity in both roasted and green states. However, when applied to a meat product, the extract prepared with RG coffee showed better results, with efficiency in replacing synthetic antioxidants (content of malonaldehyde/kg of sample below 0.696 ± 0.059 in 20 days of storage), without altering the sensory attributes of the product (average scores above 7.16 ± 1.43 for all attributes evaluated). Therefore, the RG coffee extract was a suitable alternative as a natural antioxidant applied to fresh pork sausage.

Synthesis and toxicity assessment of Coffea arabica extract-derived gold nanoparticles loaded with doxorubicin in lung cancer cell cultures.

Cancer is the second leading cause of death worldwide, despite the many treatments available, cancer patients face side effects that reduce their quality of life. Therefore, there is a need to develop novel strategies to increase the efficacy of treatments. In this study, gold nanoparticles obtained by green synthesis with Coffea arabica green bean extract were loaded with Doxorubicin, (a highly effective but non-specific drug) by direct interaction and using commercial organic ligands that allow colloidal dispersion at physiological and tumor pH. Conjugation of these components resulted in stable nanohybrids at physiological pH and a tumor pH release dependent, with a particle size less than 40 nm despite having the ligands and Doxorubicin loaded on their surface, which gave them greater specificity and cytotoxicity in H69 tumor cells.

Effects of geographical origin and post-harvesting processing on the bioactive compounds and sensory quality of Brazilian specialty coffee beans.

Specialty coffee beans are those produced, processed, and characterized following the highest quality standards, toward delivering a superior final product. Environmental, climatic, genetic, and processing factors greatly influence the green beans' chemical profile, which reflects on the quality and pricing. The present study focuses on the assessment of eight major health-beneficial bioactive compounds in green coffee beans aiming to underscore the influence of the geographical origin and post-harvesting processing on the quality of the final beverage. For that, we examined the non-volatile chemical profile of specialty Coffea arabica beans from Minas Gerais state, Brazil. It included samples from Cerrado (Savannah), and Matas de Minas and Sul de Minas (Atlantic Forest) regions, produced by two post-harvesting processing practices. Trigonelline, theobromine, theophylline, chlorogenic acid derivatives, caffeine, caffeic acid, ferulic acid, and p-coumaric acid were quantified in the green beans by high-performance liquid chromatography with diode array detection. Additionally, all samples were roasted and subjected to sensory analysis for coffee grading. Principal component analysis suggested that Cerrado samples tended to set apart from the other geographical locations. Those samples also exhibited higher levels of trigonelline as confirmed by two-way ANOVA analysis. Samples subjected to de-pulping processing showed improved chemical composition and sensory score. Those pulped coffees displayed 5.8% more chlorogenic acid derivatives, with an enhancement of 1.5% in the sensory score compared to unprocessed counterparts. Multivariate logistic regression analysis pointed out altitude, ferulic acid, p-coumaric acid, sweetness, and acidity as predictors distinguishing specialty coffee beans obtained by the two post-harvest processing. These findings demonstrate the influence of regional growth conditions and post-harvest treatments on the chemical and sensory quality of coffee. In summary, the present study underscores the value of integrating target metabolite analysis with statistical tools to augment the characterization of specialty coffee beans, offering novel insights for quality assessment with a focus on their bioactive compounds.

Drought Stress Responses in Arabica Coffee Genotypes: Physiological and Metabolic Insights.

Understanding the impact of drought stress on Arabica coffee physiology and metabolism is essential in the pursuit of developing drought-resistant varieties. In this study, we explored the physiological and metabolite changes in coffee genotypes exhibiting varying degrees of tolerance to drought-namely, the relatively tolerant Ca74110 and Ca74112, and the sensitive Ca754 and CaJ-19 genotypes-under well-watered conditions and during terminal drought stress periods at two time points (0 and 60 days following the onset of stress). The metabolite profiling uncovered significant associations between the growth and the physiological characteristics of coffee genotypes with distinct drought tolerance behaviors. Initially, no marked differences were observed among the genotypes or treatments. However, at the 60-day post-drought onset time point, notably higher shoot growth, biomass, CO2 assimilation, pigments, and various physiological parameters were evident, particularly in the relatively tolerant genotypes. The metabolite profiling revealed elevations in glucose, maltose, amino acids, and organic acids, and decreases in other metabolites. These alterations were more pronounced in the drought-tolerant genotypes, indicating a correlation between enhanced compatible solutes and energy-associated metabolites crucial for drought tolerance mechanisms. This research introduces GC-MS-based metabolome profiling to the study of Ethiopian coffee, shedding light on its intricate responses to drought stress and paving the way for the potential development of drought-resistant coffee seedlings in intensified agro-ecological zones.

Combined sensory, volatilome and transcriptome analyses identify a limonene terpene synthase as a major contributor to the characteristic aroma of a Coffea arabica L. specialty coffee.

BACKGROUND: The fruity aromatic bouquet of coffee has attracted recent interest to differentiate high value market produce as specialty coffee. Although the volatile compounds present in green and roasted coffee beans have been extensively described, no study has yet linked varietal molecular differences to the greater abundance of specific substances and support the aroma specificity of specialty coffees. RESULTS: This study compared four Arabica genotypes including one, Geisha Especial, suggested to generate specialty coffee. Formal sensory evaluations of coffee beverages stressed the importance of coffee genotype in aroma perception and that Geisha Especial-made coffee stood out by having fine fruity, and floral, aromas and a more balanced acidity. Comparative SPME-GC-MS analyses of green and roasted bean volatile compounds indicated that those of Geisha Especial differed by having greater amounts of limonene and 3-methylbutanoic acid in agreement with the coffee cup aroma perception. A search for gene ontology differences of ripening beans transcriptomes of the four varieties revealed that they differed by metabolic processes linked to terpene biosynthesis due to the greater gene expression of prenyl-pyrophosphate biosynthetic genes and terpene synthases. Only one terpene synthase (CaTPS10-like) had an expression pattern that paralleled limonene loss during the final stage of berry ripening and limonene content in the studied four varieties beans. Its functional expression in tobacco leaves confirmed its functioning as a limonene synthase. CONCLUSIONS: Taken together, these data indicate that coffee variety genotypic specificities may influence ripe berry chemotype and final coffee aroma unicity. For the specialty coffee variety Geisha Especial, greater expression of terpene biosynthetic genes including CaTPS10-like, a limonene synthase, resulted in the greater abundance of limonene in green beans, roasted beans and a unique citrus note of the coffee drink.

Transcriptomic Analysis of Alternative Splicing Events during Different Fruit Ripening Stages of Coffea arabica L.

To date, genomic and transcriptomic data on Coffea arabica L. in public databases are very limited, and there has been no comprehensive integrated investigation conducted on alternative splicing (AS). Previously, we have constructed and sequenced eighteen RNA-seq libraries of C. arabica at different ripening stages of fruit development. From this dataset, a total of 3824, 2445, 2564, 2990, and 3162 DSGs were identified in a comparison of different fruit ripening stages. The largest proportion of DSGs, approximately 65%, were of the skipped exon (SE) type. Biologically, 9 and 29 differentially expressed DSGs in the spliceosome pathway and carbon metabolism pathway, respectively, were identified. These DSGs exhibited significant variations, primarily in S1 vs. S2 and S5 vs. S6, and they involve many aspects of organ development, hormone transduction, and the synthesis of flavor components. Through the examination of research findings regarding the biological functions and biochemical pathways associated with DSGs and DEGs, it was observed that six DSGs significantly enriched in ABC transporters, namely, LOC113712394, LOC113726618, LOC113739972, LOC113725240, LOC113730214, and LOC113707447, were continually down-regulated at the fruit ripening stage. In contrast, a total of four genes, which were LOC113732777, LOC113727880, LOC113690566, and LOC113711936, including those enriched in the cysteine and methionine metabolism, were continually up-regulated. Collectively, our findings may contribute to the exploration of alternative splicing mechanisms for focused investigations of potential genes associated with the ripening of fruits in C. arabica.

Perceptions of Deficiencies in the Basic Conditions for Farm Management and Quality of Life in Coffee-Growing Households: A Panel Analysis of a Rural Community in Eastern Uganda.

In the present study, information collected from 360 coffee-cultivating households (HHs) is used to investigate perceptions of deficiencies in three sub-counties in Eastern Uganda and to study changes in these perceptions between two survey rounds. The results of an explorative principal components analysis identify five factors affecting farmers' perceptions. Whereas perceptions of deficiencies in the preconditions for farm management activities differ significantly between the three sub-counties investigated, indicators of deficiencies in general life quality are distributed more equally. Deteriorations are explained mainly by perceived changes in weather conditions. On the one hand, it can be assumed that the high constraint level will continue to increase in the future due to climate change and its impacts on life quality and the basic conditions required for farm management. On the other hand, access to resources such as water taps but also increased competition between buyers, have improved the situation. Results further indicate that if activities such as the expansion of information access and improvement of road conditions (after land registration) are implemented on a larger scale, these negative trends can be partly counteracted to help farmers maintain the conditions for effective farm management and improve their quality of life in the future.

The floral development of the allotetraploid Coffea arabica L. correlates with a small RNA dynamic reprogramming.

Noncoding and coding RNAs are key regulators of plant growth, development, and stress responses. To investigate the types of transcripts accumulated during the vegetative to reproductive transition and floral development in the Coffea arabica L., we sequenced small RNA libraries from eight developmental stages, up to anthesis. We combined these data with messenger RNA and PARE sequencing of two important development stages that marks the transition of an apparent latent to a rapid growth stage. In addition, we took advantage of multiple in silico tools to characterize genomic loci producing small RNAs such as phasiRNAs, miRNAs, and tRFs. Our differential and co-expression analysis showed that some types of small RNAs such as tRNAs, snoRNAs, snRNAs, and phasiRNAs preferentially accumulate in a stage-specific manner. Members of the miR482/miR2118 superfamily and their 21-nucleotide phasiRNAs originating from resistance genes show a robust co-expression pattern that is maintained across all the evaluated developmental stages. Finally, the majority of miRNAs accumulate in a family stage-specific manner, related to modulated hormonal responses and transcription factor expression.

A semi-quantitative histochemical method for assessment of biochemical responses to osmotic stress in Coffea arabica leaf disks.

A simple method set for assessing biochemical changes associated with osmotic stress responses was developed using coffee (Coffea arabica L.) leaf disks. Stress was induced by polyethylene glycol (PEG) exposure. Quantitative evaluation of tissue physiological stress parameters was carried out using analytical methods to validate the conversion of classic qualitative histochemical tests for localizing lipid peroxidation, hydrogen peroxide, and total xanthine alkaloids into semi-quantitative assays. Relative electrolyte leakage (EL%) and chlorophyll content (SPAD index) were also recorded. EL% levels of treated disks were higher than those of control ones, whereas SPAD indexes were comparable. Histochemical localization indicated that levels of lipid peroxidation, H2O2, and total xanthines were also higher under osmotic stress than in control conditions. Semi-quantitative data obtained by image processing of histochemical staining consistently matched quantitative evaluations. Chromatographic analyses revealed that theophylline and caffeine concentrations increased in the presence of PEG, whereas theobromine remained constant in relation to the control. The methods herein described can be useful to rapidly acquire initial data regarding biochemical osmotic stress responses in coffee tissues based on simple staining and imaging steps. Moreover, it is likely that the same method may be applicable to other types of stresses and plant species upon minor adjustments.

Taxonomic and Functional Diversity of Flower-Visiting Insects in Coffee Crops.

Despite the important role that flower-visiting insects play in agricultural production, none of the previous studies of coffee pollinators in Colombia have incorporated functional diversity into their analysis. Therefore, this study aimed to quantify the abundance, richness, and functional diversity of insects that visit flowers in coffee crops. Twenty-eight plots were selected among five sites in the north, center, and south of Colombia. In each plot, coffee flower insect visitors were collected and recorded on 90 trees at eight-minute intervals per tree, at three different times over three days. All sampling was carried out during two flowering events per year, over three years, resulting in a total of 1240 h of observations. Subsequently, the insects were taxonomically identified, and the number of individuals and species, as well as the diversity of the order q, were estimated. Functional diversity was also characterized in the bee community. The results: (a) 23,735 individuals belonging to 566 species were recorded; of them, 90 were bees, with the native species being the most abundant during 10:30 and 13:00 h; (b) bees formed five functional groups, with corbiculate and long-tongued non-corbiculate bees being the most abundant and occupying the largest regions of functional space; (c) potential pollinators in coffee crops are Apis mellifera, Nannotrigona gaboi, Tetragonisca angustula, Geotrigona cf. tellurica, and Partamona cf. peckolti. Coffee crops host a wide diversity of flower visitors, especially bees, which could be beneficial for productivity and contribute to the maintenance of plant species that accompany coffee cultivation.

SPME-GC-MS untargeted metabolomics approach to identify potential volatile compounds as markers for fraud detection in roasted and ground coffee.

Roasted ground coffee has been intentionally adulterated for economic revenue. This work aims to use an untargeted strategy to process SPME-GC-MS data coupled with chemometrics to identify volatile compounds (VOCs) as possible markers to discriminate Arabica coffee and its main adulterants (corn, barley, soybean, rice, coffee husks, and Robusta coffee). Principal Component Analysis (PCA) showed the difference between roasted ground coffee and adulterants, while the Hierarchical Clustering of Principal Components (HCPC) and heat map showed a trend of adulterants separation. The partial Least-Squares Discriminant Analysis (PLS-DA) approach confirmed the PCA results. Finally, 24 VOCs were putatively identified, and 11 VOCs are candidates for potential markers to detect coffee fraud, found exclusively in one type of adulterant: coffee husks, soybean, and rice. The results for possible markers may be suitable for evaluating the authenticity of ground-roasted coffee, thus acting as a coffee fraud control and prevention tool.

First Report of Alternaria alternata Causing Leaf Spot on Coffea arabica in China.

Yunnan Province is the major region for coffee (Coffea arabica) cultivation in China, contributing to over 98% of the national yield and total production value (Ma et al. 2022). In May 2023, brown spot symptoms were observed only on the leaves of coffee plants in a field located in Baoshan City (98°52'37.988400"E, 24°58'17.673600"N), Yunnan Province. Notably, brown and irregularly shaped spots initially started on the leaf bases. The spots enlarged and developed concentric rings with dark brown margins, which are often surrounded by yellow halos. Finally, the necrotic spots spread across the entire leaf and caused the leaf to curl and fall off. The incidence of the disease was approximately 3% of the coffee plants (n = 600). The symptomatic leaves collected from 10 plants were sectioned (5 × 5 mm), subjected to surface sterilization with 70% ethanol for 40 s, rinsed with sterile distilled water, air-dried, and transferred to potato dextrose agar (PDA). Fungi with grayish-white, cotton-like aerial mycelia grew after 7 days at 28°C. The older mycelia of these isolates displayed dark gray pigmentation. Single conidia were cultivated on PDA, and 15 morphologically similar monosporic isolates were ultimately obtained. Microscopic observation revealed that these isolates produced branched, septate, transparent and amber mycelium. Brown, elliptical or pear-shaped conidia with 2 to 4 transversal septa and 0 to 3 longitudinal septa, measuring 9.6 to 33.3 long × 6.0 to 15.0 µm wide (n = 30), were observed on potato carrot agar (PCA). Molecular identification of multiple genes, such as ITS (Schoch et al. 2012), RPB2 (O'Donnell et al. 2010) and GAPDH (Berbee et al. 1999), indicated consistent 100% identity among these isolates. Sequences of the representative isolates CFSY1-CFSY5 were deposited in GenBank (acc. nos.: OR351112, PP188577, PP188578, PP294863, PP294864, OR509742, PP215341-PP215344, OR509740 and PP239378-PP239381), revealing 98.35% - 100% homology with distinct Alternaria alternata strains previously deposited in GenBank (acc. nos.: PP110780, MN649031 and OR485338). The multigene phylogenetic analysis positioned isolates CFSY1-CFSY5 within a distinct cluster, alongside diverse A. alternata isolates. Based on morphological and molecular characterizations, the pathogen was identified as A. alternata. To verify its pathogenicity, a conidial suspension (1×106 conidia/mL) of isolate CFSY1 was sprayed on six leaves of three healthy one-year-old C. arabica seedlings. Subsequently, the inoculated seedlings were covered with plastic bags and placed in a growth chamber under controlled conditions (a 14 h daylight period and a 10 h dark period at 28°C). The experiment was repeated three times. After 20 days, typical brown spot symptoms analogous to those originally observed in the field appeared on the leaves in all inoculated plants. Reisolation, morphology identification and DNA sequencing substantiated Koch's postulates. In contrast, control plants treated with sterilized water remained asymptomatic, and no pathogen was reisolated from them. Significantly, A. alternata has been previously reported as the causal agent for leaf spot disease in a diverse variety of woody plant species in China, including Prunus avium (Ahmad et al. 2020), Magnolia grandiflora (Liu et al. 2019) and citrus (Wang et al. 2010). This study represents the first report of brown leaf spot caused by A. alternata specifically on C. arabica in China, enriching the contents of fungal pathogens under Chinese coffee cultivation conditions.

Coffee Fruit Rot: The Previously Unrecognized Role of Fusarium and Its Interactions with the Coffee Berry Borer (Hypothenemus hampei).

Coffee fruit rot (CFR) is a well-known disease worldwide, mainly caused by Colletotrichum spp., the most important species being C. kahawae subsp. kahawae. In Puerto Rico, Colletotrichum spp. were identified as pathogens of coffee fruits. The coffee berry borer (CBB) was shown to be a dispersal agent of these fungi, and interaction of Fusarium with Colletotrichum affecting coffee fruits was suggested. In this study, we demonstrated that Fusarium spp. also cause CFR in Puerto Rico. Fusarium spp. are part of the CBB mycobiota, and this insect is responsible for spreading the pathogens in coffee fields. We identified nine Fusarium spp. (F. nirenbergiae, F. bostrycoides, F. crassum, F. hengyangense, F. solani-melongenae, F. pseudocircinatum, F. meridionale, F. concolor, and F. lateritium) belonging to six Fusarium species complexes isolated from CBBs and from rotten coffee fruits. Pathogenicity tests showed that F. bostrycoides, F. lateritium, F. nirenbergiae, F. solani-melongenae, and F. pseudocircinatum were pathogens causing CFR on green coffee fruits. F. bostrycoides was the predominant species isolated from the CBB mycobiota and coffee fruits with symptoms of CFR, suggesting a close relationship between F. bostrycoides and the CBB. To our knowledge, this is the first report of F. bostrycoides, F. solani-melongenae, F. pseudocircinatum, and F. nirenbergiae causing CFR worldwide and the first report of F. lateritium causing CFR in Puerto Rico. Understanding the CFR disease complex and how the CBB contributes to dispersing different Fusarium spp. on coffee farms is important to implement disease management practices in Puerto Rico and in other coffee-producing countries.

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.

Impact of roasting conditions on physicochemical, taste, volatile, and odor-active compound profiles of Coffea arabica L. (cv. Yellow Bourbon) using electronic sensors and GC-MS-O using a multivariate approach.

This study investigated the effects of roasting conditions on the physicochemical, taste, and volatile and odor-active compound (OAC) profiles of Coffea arabica L. At 150 ℃, roasting increased chlorogenic acid, total flavonoids, and caffeine concentrations. However, umami and sourness sensor decreased during the roasting process. At 210 ℃ roasting, total flavonoid and caffeine concentrations increased during the roasting process. Aldehydes, ketones, and sulfur-containing compounds dramatically increased during the roasting at 210 ℃ for 20 and 30 min in E-nose analysis. Pyrazines were mainly generated during the roasting at 210 ℃ for 20 and 30 min, and pyrazines showed the highest concentrations among all OACs in GC-olfactometry (GC-O) analysis. E-tongue data showed the separation of beans by roasting temperature. However, the E-nose and GC-O data showed the separation of beans by both roasting temperature and time via multivariate analysis. We identified similar results and patterns in the E-nose and GC-O analyses.

Genetic diversity and structure of the coffee leaf rust fungus Hemileia vastatrix across different coffee management systems in Ethiopia.

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.