Search Results (154)

Premium coffee depends on high-quality beans, influenced by a combination of genetic, environmental, and postharvest factors. This review summarizes the mechanisms underlying coffee bean quality, with an emphasis on the genetic differences between Coffea arabica and Coffea canephora, as well as the integrated roles of environmental conditions, agronomic practices, including nutrient and shade management, and postharvest processing technologies. The allotetraploid genome of C. arabica is influenced by homoeologous exchanges and subgenome-biased expression (such as decreased DXMT activity that reduces caffeine), which contribute to its complex flavor profile. Key lipid metabolism genes, particularly FADS2, play a critical role in regulating lipid metabolism. The effects of altitude (1600–2000 m) and shade influence various metabolic pathways. Cooler temperatures promote sugar accumulation, while excessive shading hinders carbon assimilation and the development of flavor precursors. Postharvest processing significantly influences flavor, where microbial or enzymatic treatments enhance sensory attributes. In addition, methods like natural, washed, or honey processing modulate various nonvolatile compounds, impacting lipid emulsification and aroma retention. Multi-omics analyses suggest that MYB proteins play a key role in regulating pathways involved in caffeine, chlorogenic acids, and terpenes. Effective hermetic packaging prevents oxidation, thereby preserving freshness. Overall, superior coffee quality stems from synergistic interactions across genetic, ecological, agronomic, and processing factors, highlighting the need for the development of an integrated strategy to support the sustainable production of premium coffee. Full article

Coffea canephora cultivation areas in Brazil are frequently exposed to successive cycles of water deficit, triggering plant stress responses. In addition to water deficit, increased air temperature can act as a second stress factor. The recurrence of these stress factors may induce plant tolerance mechanisms, potentially mitigating future stress responses even of a different stress nature. We hypothesized that repeated cycles of water deficit can trigger tolerance mechanisms that make C. canephora leaves more resilient to supra-optimal temperatures. To test this hypothesis, young C. canephora plants were grown under non-limited water conditions for seven months (Ψ_mSoil > −20 kPa), after which they were subjected to two consecutive cycles of water deficit (Ψ_mSoil < −300 kPa), followed by rehydration. Two clones were used, ‘A1’ and ‘3V’, previously classified as drought sensitive and tolerant, respectively, considering the dynamics of physiological and architectural responses. After the second cycle, leaf discs were collected from completely expanded leaves formed during the two stress cycles and exposed to heat treatments (35 °C, 40 °C, 45 °C, 50 °C, and 55 °C) for 15 min in a water bath. Chlorophyll a fluorescence emission was then monitored, and the results were analyzed using OJIP transient kinetics and the JIP_Test. High temperatures induced negative changes in both OJIP kinetics and JIP_Test-derived parameters. A significant increase in F₀ and a reduction in F_M were observed mainly at 50 °C and 55 °C, due to changes in the stages of the OJIP curve. These changes impacted the “energy connectivity” and consequently the electron transport along the electron transfer chain (ETC), increasing energy dissipation, as confirmed by the JIP_Test variables. Despite the high temperature impacts, previous water deficit induced heat tolerance in clone ‘A1’, while it increased sensitivity in clone ‘3V’. This study suggests that selecting drought-resistant varieties should consider their subsequent response to short high-temperature stress to avoid cross-sensitivity caused by selecting for a single environmental factor. Full article

Coffea canephora is economically and socially important for small-scale agriculture in Northern Brazil. To identify genotypes adapted to Amazonian edaphoclimatic conditions, clones of the species have been evaluated across multiple locations in Amazonas. Introducing genetically selected materials into comparable environments may promote consistent productivity gains in the short and medium term. In this context, the aim of this study was to assess the genetic diversity of different C. canephora genotypes using microsatellite markers, which will support the development of superior genotypes adapted to Amazon conditions. A total of 43 C. canephora genotypes were analyzed. Leaves were collected for genomic DNA extraction and were standardized and amplified by PCR using microsatellite primers. Genotyping was performed via capillary electrophoresis, allowing for the determination of allele sizes. Genetic structure was inferred, and genetic diversity parameters were estimated. The average observed heterozygosity (H_O = 0.64) exceeded the expected heterozygosity (H_E = 0.53), and the average inbreeding coefficient (f = −0.19) indicated an excess of heterozygotes. The results revealed high genetic variability among the evaluated genotypes. These findings highlight the broad genetic diversity of C. canephora, reinforcing its potential as a genetic basis for selection and the development of cultivars adapted to the environmental conditions of the Amazon. Full article

Expanding Coffea canephora cultivation to transitional altitudes offers a promising strategy to sustain coffee production under climate change. This study evaluated 27 genotypes cultivated under two water management regimes (fully and minimally irrigated) at 650 m altitude in Espírito Santo, Brazil, over eight harvests (2018–2025). A split-plot design was analyzed using a three-way mixed model (REML/BLUP) to estimate genetic parameters and predicted genotypic values. Adaptability and stability were assessed using the harmonic mean of relative performance of genotypic values (HMRPGV) and weighted average of absolute scores (WAASB) and integrated into a multi-trait selection index. Significant genotypic and temporal effects were detected, while the interaction between genotypes and water management regimes was non-significant, indicating consistent performance under different water regimes. Broad-sense heritability was moderate, with high selective accuracy. Genotypes 108 and 203 achieved the highest predicted yields (91.4 and 86.8 bags ha⁻¹) and superior adaptability. The multi-trait index identified six outstanding genotypes—108, 203, 201, 306, 303, and 302—combining high yield, broad adaptability, and temporal stability, resulting in an expected genetic gain of 8.17% in relation to the original population. These findings demonstrate that selected C. canephora genotypes are well adapted to transitional altitudes, supporting breeding programs for climate-resilient and high-yielding crops. Full article

The main characteristics of the large number of coffee species are differences in aroma and caffeine content. Labeled blends of Coffea arabica (C. arabica) and Coffea canephora (C. canephora) are common to broaden the flavor profile or enhance the stimulating effect of the beverage. New emerging species such as Coffea liberica (C. liberica) further increase the variability in blends. However, significant price differences between coffee species increase the risk of unlabeled blends and thus influence food quality and safety for consumers. In this study, a prototypic hyphenation of trapped headspace-gas chromatography-ion mobility spectrometry-quadrupole mass spectrometry (THS-GC-IMS-QMS) was used for the detection of characteristic compounds of C. arabica, C. canephora, and C. liberica in green and roasted coffee samples. For the discrimination of coffee species with IMS data, multivariate resolution with multivariate curve resolution–alternating least squares (MCR-ALS) prior to partial least squares–discriminant analysis (PLS-DA) was evaluated. With this approach, the classification accuracy, as well as sensitivity and specificity, of the PLS-DA model was significantly improved from an overall accuracy of 87% without prior feature selection to 92%. As MCR-ALS preserves the physical and chemical properties of the original data, characteristic features were determined for subsequent substance identification. The simultaneously generated QMS data allowed for partial annotation of the characteristic volatile organic compounds (VOC) of roasted coffee. Full article

Coffee silverskin is generated in large quantities as a co-product during the roasting process of coffee beans. This co-product is rich in bioactive compounds that offer potential health benefits, justifying its consideration as a functional ingredient in food. In this study, silverskin from the species Coffea arabica and Coffea canephora from six different countries was characterized to highlight its potential and applicability as a safe ingredient in new food formulations. The results revealed a dietary fiber content ranging from 71.81 to 76.86 g/100 g, with a high portion of insoluble fiber ranging from 54.02 to 60.58 g/100 g. The mineral content showed that, in all samples, potassium and calcium were the main elements with values ranging from 6.66 to 17.57 mg/g and from 9.25 to 16.44 mg/g, respectively. The caffeine content was quantified with levels ranging from 0.81 to 7.32 mg/g. In addition, high levels of phenolic compounds were identified in free and bound forms, with 5-caffeoylquinic, 3-caffeoylquinic, 4,5-dicaffeoylquinic, and ferulic acids being the main components in both fractions. All samples analyzed showed a good antioxidant capacity in the four different methods used, with values ranging from 8.12 to 10.85 mg Trolox Equivalents (mgTE/g) in the DPPH assay; from 9.69 to 19.68 mgTE/g in the FRAP assay; from 5.96 to 11.05 mgTE/g in the FRAP assay; and from 0.21 to 1.11 and 4.69 mg EDTA/g sample in the FIC assay. In conclusion, coffee silverskin has the potential to play a beneficial role as an ingredient in new food formulations, thus contributing to the development of a circular economy in the food industry. Full article

Distinct breeding populations of Coffea canephora often exhibit genetic divergence, yet the biological pathways underlying yield and leaf rust resistance in contrasting populations remain poorly understood. Here, we performed a comparative genomic analysis of two populations (Premature and Intermediate) to dissect the genetic architecture of coffee bean production, green bean yield, and leaf rust incidence. By integrating single-SNP association, machine learning (Bootstrap Forest), and Gene Ontology (GO) pathway analysis, we found that the Premature population’s traits were linked to specialized metabolic pathways, particularly lipid modification and organelle lumen–associated processes. In contrast, the Intermediate population was governed by core cellular machinery, with significant enrichment for actin cytoskeleton regulation and salicylic acid signaling. These findings demonstrate that distinct breeding populations achieve agronomic success through fundamentally different biological strategies and provide a reusable resource of ranked SNP lists for targeted, population-aware breeding. Full article

Grafting is a strategy to mitigate biotic and abiotic stresses in coffee systems. However, initial compatibility indicators between Coffea arabica scions and C. canephora rootstocks under controlled conditions remain insufficiently documented. We evaluated the physiological and morphological compatibility of four C. arabica cultivars (Bourbon, Geisha, Catuai, and Villa Sarchí) grafted onto C. canephora (Robusta) rootstock in a tropical highland nursery in the Peruvian Amazon. Seven physiological and six morphological variables were measured. Statistical analyses included one-way ANOVA and Kruskal–Wallis tests with Bonferroni post hoc comparisons. Two physiological parameters were significantly higher in Villa Sarchí grafts than in Robusta: PSII quantum yield (+0.044 units; p < 0.05) and electron transport rate (+14.702 µmol e⁻ m⁻² s⁻¹; p < 0.05); by contrast, net photosynthesis, stomatal conductance, intercellular CO₂ concentration, and transpiration did not differ, and maximum PSII efficiency was similar among treatments (p = 0.509). Conversely, no morphological trait showed significant differences, and graft-take was high across all combinations. The results support the use of Coffea robusta as a rootstock for these four cultivated varieties, thereby offering the possibility of improving their resilience in tropical highland regions. Full article

Plant growth-promoting bacteria (PGPB) associated with Coffea arabica L. and Coffea canephora Pierre ex Froehner offer a viable strategy to reduce synthetic inputs and enhance resilience in coffee agroecosystems. This review synthesizes evidence from the past decade on rhizosphere-associated and endophytic taxa, their plant growth-promotion and biocontrol mechanisms and the resulting agronomic outcomes. A compartment-specific core microbiome is reported, in the rhizosphere of both hosts, in which Bacillus and Pseudomonas consistently dominate. Within endophytic communities, Bacillus predominates across tissues (roots, leaves and seeds), whereas accompanying genera are host- and tissue-specific. In C. arabica, endophytes frequently include Pseudomonas in roots and leaves. In C. canephora, root endophytes recurrently include Burkholderia, Kitasatospora and Rahnella, while seed endophytes are enriched for Curtobacterium. Functionally, coffee-associated PGPB solubilize phosphate; fix atmospheric nitrogen via biological nitrogen fixation; produce auxins; synthesize siderophores; and express 1-aminocyclopropane-1-carboxylate deaminase. Indirect benefits include the production of antifungal and nematicidal metabolites, secretion of hydrolytic enzymes and elicitation of induced systemic resistance. Under greenhouse conditions, inoculation with PGPB commonly improves germination, shoot and root biomass, nutrient uptake and tolerance to drought or nutrient limitation. Notable biocontrol activity against fungal phytopathogens and plant-parasitic nematodes has also been documented. Key priorities for translation to practice should include (i) multi-site, multi-season field trials to quantify performance, persistence and economic returns; (ii) strain-resolved omics to link taxa to functions expressed within the plant host; (iii) improved bioformulations compatible with farm management and (iv) rationally designed consortia aligned with production goals and biosafety frameworks. Full article

Canephora coffee genotypes developed in other growing regions, with traits of interest such as drought tolerance and high coffee bean yield, need to be introduced and characterized in other locations to check adaptability. The aim of this study was to check the agronomic performance and determine the genetic parameters of the clonal canephora coffee cultivar Marilândia ES 8143, composed by twelve genotypes, developed by the Capixaba Institute of Research, Technical Assistance and Rural Extension (Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural—Incaper), in an irrigated system of the Central Cerrado region of Brazil. The study was conducted in the experimental areas of Embrapa Cerrados at 1050 m altitude in a center pivot irrigation system using a management system with water stress controlled for around 65 days. A randomized block experimental design was used with three replications, and each plot consisted of eight plants. The clones were planted in February 2019 and in 2021 and 2022. Phenotyping was carried out to evaluate the following traits: coffee bean yields, sieve retention percentages, plant height, canopy projection, number of pairs of plagiotropic branches, and frost damage using a scoring scale. Clone 5 stood out in mean value in the two years evaluated for bean yield. Clones 5, 6, 7, 8, and 9 had higher mean values for flat-type coffee beans in both years. Clones 1 and 5 exhibited mean values indicating good vegetative development. Clones 5 and 12 showed no visible symptoms for low air temperatures and frost effects. Highly significant differences were observed among the genotypes for all the morphoagronomic traits evaluated, and high values of heritability, genetic coefficients of variation, and selective accuracy showed conditions favorable to the selection of clones for the agronomic traits analyzed. Clones 1, 2 and 6 have values in lower groups for chlorogenic acids and caffeine, and in higher groups for protein and soluble solids, thus showing greater potential for obtaining quality beverages. Full article

This study evaluated the genetic diversity of 33 Coffea canephora genotypes through morphophysiological and molecular analyses, aiming to identify promising genotypes for pre-breeding purposes in the southern region of Espírito Santo, Brazil. Cutting-propagated seedlings were evaluated 120 days after planting, considering height, stem and crown diameter, number of leaves, fresh and dry shoot and root weight, chlorophyll content, and root characteristics. Molecular analysis was performed on 32 genotypes; one was excluded due to absent DNA, and 18 ISSR markers were used. Morphological data were analyzed by ANOVA, Scott–Knott’s mean test, principal component analysis, and cluster analysis. The results revealed significant diversity among genotypes. The first two principal components explained 75.5% of the total variability. Genotypes 2, 3, 4, 5, 6, 10, 32, and 33 stood out as those that produced the most vigorous seedlings. Molecular analysis also revealed genetic diversity among genotypes, with the formation of 16 groups, while the morphophysiological analysis revealed four groups. The Mantel test demonstrated a small but significant positive difference (r = 0.228; p = 0.018) between the genetic and morphophysiological distances of the genotypes. This diversity indicates that the genotypes evaluated are promising for use in C. canephora breeding programs. Full article

Sustainable ultraviolet (UV) filters that couple photoprotection with antioxidant activity are needed. Carbon dots (CDots) derived from agro-industrial waste have emerged as promising candidates. CDots were prepared from Coffea canephora (coffee leaf) residues by a one-pot microwave route and characterized by UV–Vis, FTIR, and TEM. Antioxidant capacity was determined by CUPRAC and DPPH-EPR. The photoprotective efficacy was assessed in vitro by diffuse reflectance spectrophotometry before and after solar-simulator exposure. Nearly spherical CDots (3.3 ± 0.7 nm) displayed a 4.16 eV optical bandgap and broad absorption from 200 to 400 nm. At 10 μg mL⁻¹, CDots exhibited 24.62 ± 0.19% antioxidant activity relative to Trolox by CUPRAC, while by DPPH-EPR, they showed 99.9 ± 12.5% of radical quenching at 240 µg mL⁻¹. Addition of 4.5% w/w (dry basis) CDots to the sunscreen system increased the in vitro SPF from 26 ± 13 to 161 ± 8 (p < 0.05) while maintaining the critical wavelength at 380 ± 0.64 nm. After 30 min of irradiation, the SPF dropped only 10%, versus 44% for the CDots-free sample (control), indicating superior photostability. Coffee leaf CDots acted as an efficient broadband UV absorber and antioxidant that markedly enhanced and stabilized a conventional sunscreen formulation. The work positions waste-derived CDots as an eco-friendly, next-generation multifunctional ingredient, aligning with circular economy principles. Full article

Chitinases have been demonstrated to enhance plant resistance to fungi in various pathosystems. Although there is evidence of the effectiveness of these proteins in coffee–fungus interactions, no genome-wide identification or characterization of coffee chitinases has been performed. In this study, we employed phylogenetic analysis, domain architecture, gene structure analysis, and subcellular localization to identify and characterize putative genes and proteins in the genomes of Coffea arabica and its progenitors, Coffea canephora and Coffea eugenioides. A total of 113, 47, and 69 putative chitinase proteins were identified in C. arabica, C. canephora, and C. eugenioides, respectively. These chitinases were classified according to their catalytic domains, GH18 and GH19, and into Classes I, II, III, IV, and V, as determined through phylogenetic analysis based on the Arabidopsis thaliana classification. Furthermore, based on orthologous analysis, we identified ten, six, and seven putative chitinases associated with fungal defense responses in C. arabica, C. canephora, and C. eugenioides, respectively. These findings are valuable for future studies focusing on coffee chitinases, particularly on genetic programs involved in plant pathogen resistance. Full article

This study investigates the solubility correlation of oil extracted from Sabah green Robusta coffee (Coffea canephora) beans through supercritical carbon dioxide (SC-CO₂) extraction. Sabah, recognized as the largest coffee-producing region in Malaysia, serves as a significant source of Robusta beans for this research. The solubility of coffee bean oil was evaluated under varying pressures (10–30 MPa) and temperatures (40–80 °C). The maximum solubility, 2.681 mg/g CO₂, was recorded at 30 MPa and 40 °C, whereas the lowest solubility, approximately 0.440 mg/g CO₂, occurred at 20 MPa and 80 °C. A clear inverse relationship between solubility and temperature was observed, with solubility decreasing as temperature increased to 80 °C. Conversely, elevated pressure, particularly at 30 MPa, enhanced solubility due to the increased density and solvent power of SC-CO₂. Experimental data exhibited strong agreement with Chrastil’s equation, yielding a relatively low percentage error of 3.37%, compared with 14.57% for the del Valle-Aguilera model. These findings demonstrate the reliability of Chrastil’s model in predicting the solubility of Sabah green coffee bean oil in SC-CO₂. Overall, the research highlights the potential of SC-CO₂ extraction as a sustainable, solvent-free approach for obtaining high-quality coffee oil extracts, with promising applications in the food industry and possible extension to the recovery of other bioactive compounds in food processing. Full article

Non-destructive measurement of leaf size based on leaf length and/or width is a simple, economical, and precise methodology. Leaf morphometric indicators were measured on 55 coffee progenies obtained from intraspecific and interspecific crosses. The estimation of parameters in the models and the testing of hypotheses related to these were performed. The relationships between leaf width and length, the ellipticity index, and leaf size were subsequently analyzed with a partitioning algorithm. The groups were then compared using Hotelling’s T² test. In coffee, the Montgomery model allowed for an adequate estimation of leaf size for each progeny, hybridization type, and grouped data. An α value of 0.67000 for the Montgomery model was consistent. This finding indicates that it is a suitable model for both individual and groups of progenies. The model based on the “principle of similarity” was found to be suitable only on a per-progeny basis. Certain characteristics, such as the leaf width-to-length ratio, ellipticity index, and leaf size, modify the parameter fit to inherent values. Similarly, leaves with a higher width-to-length ratio were the most elliptical for coffee, according to the groupings found. The estimation of coffee leaf size improves if the selected model considers whether they come from specific progenies or groups of progenies. Full article