Search Results (76)

Fermentation with various microorganisms modifies the quality of coffee. In animal-digested coffee, enzymatic activity also affects coffee characteristics. However, limited information is available on in vitro coffee modification employing both mechanisms simultaneously in controlled conditions. In this study, robusta green beans were modified with selected bacterial species (Bacillus subtilis, Gluconobacter sp., Lactiplantibacillus plantarum) and pepsin, which was introduced at the soaking or fermentation stage. The characteristics of green and roasted coffee were analyzed, including the amount of basic aroma precursors, antioxidant activity, acrylamide concentration and volatile organic compound (VOC) content. The number of bacterial cells increased by 1.95–2.64 logCFU/mL during the modification process; pepsin addition did not affect their growth significantly. The use of acid-producing bacteria (APB) resulted in higher consumption of sucrose but also in greater retention of bioactive compounds and higher antioxidant activity. The acrylamide content in fermented and roasted beans was below 10 μg/100 g dry matter; the lowest values were reported after modification with L. plantarum. The combination of tested bacterial and enzymatic processes changed the content and composition of VOCs. Further research should focus on sensory attributes as the result of the combined modification process. Full article

Caffeine is one of the most well-known biologically active compounds in coffee beans, and its content largely determines the taste and stimulating properties of the drink. However, the amount of caffeine in beans can vary significantly depending on growing conditions, even within the same coffee variety. The growing global demand for coffee and the current market dynamics emphasize the necessity to investigate how the origin of coffee beans influences beverage quality. Arabica beans, particularly the Red Bourbon variety, are known to exhibit variations in chemical composition, sensory characteristics, and technological behavior depending on their cultivation environment. The study aimed to evaluate the physicochemical and sensory properties of Arabica Red Bourbon beans sourced from distinct geographic regions, considering factors such as altitude and local environmental conditions. The sensory characteristics of the resulting beverages were evaluated using the capping method, and water activity, density, moisture content, color, pH, extractivity and caffeine content were determined. Roasted bean color ranged from 61.4 to 62.5, while ground coffee color was 72.5–75.4. Moisture content was highest in Col and R (3.4%) and lowest in Con (3.1%). The greatest moisture loss during roasting occurred in S and R (13.4%). Water activity decreased from 0.50–0.56 in green beans to 0.18–0.30 post-roasting. Extraction yield ranged from 20.03 to 21.21%, and total dissolved solids (TDS) varied at 1.23–1.30%. The least acidic sample was S (pH 5.04). Colombian beans contained unusually high caffeine. The conducted research confirmed that the geographical origin of Arabica Red Bourbon beans significantly impacts their physicochemical and sensory attributes. Variations in moisture, acidity, and caffeine content were observed among the samples, despite a consistent roasting profile. Full article

The Coffee Cuality Method provides a comprehensive assessment of the sensory quality of coffee that includes an overall quality rating, just-about-right (JAR) scaling of select attributes, check-all-that-apply (CATA) selections from a list of sensory and holistic attributes and open comments. We validated the method with 56 expert coffee tasters by comparing Coffee Cuality with their customary method (i.e., SCA’s, Q-grading or company’s own) for the evaluation of the sensory quality of 12 specialty coffees and commercial blends brewed with their preferred method (cupping, drip, pour over or espresso). A subset of 18 experts then participated in focus groups on the method. Quality mapping (principal component and cluster analyses of the quality ratings) showed consistency among the experts’ overall quality ratings regardless of brewing method, with the dark roasts rated systematically lower than the light- and medium-roasted coffees. Penalty analysis relating JAR ratings to quality scores showed that too dark of a roast or a beverage color and too low of an acidity had the largest (negative) impact on quality. The map of sensory and holistic attributes derived from CATA selections by correspondence analysis, and the word clouds of those selections showed which attributes drove quality ratings, positively or negatively. Focus groups with a subset of the experts suggested improvements to the evaluation protocol and scorecard. By deconstructing, documenting and justifying coffee quality ratings, Coffee Cuality offers a valuable alternative to conventional evaluation protocols. Full article

Mineral composition modulates plant health, agro-morphological attributes, and functional quality in coffee, yet large-scale evaluations remain limited. In 150 Coffea arabica L. accessions, we quantified grain minerals (Ca, K, Mg, Na, P, Zn, Cu, Fe, Mn); resistance to coffee leaf miner (CLM), coffee berry borer (CBB), and coffee leaf rust (CLR); agro-morphological traits; bioactive compounds (phenolics, flavonoids, chlorogenic acid, trigonelline, caffeine); and antioxidant capacity (ABTS, DPPH, FRAP). Mn and Zn were associated with greater resistance to CBB and CLM, whereas P and Ca related with lower susceptibility to CLR; a P–Zn antagonism emerged as a critical nutritional axis. Phosphorus was linked to larger size and higher 100-bean mass; Ca and Mg to greater fruit number and fruit mass per plant; and Fe to improved filling and higher 100-bean mass in parchment coffee. For bioactive compounds, P and K were positively associated with total phenolics, total flavonoids, caffeine, and ABTS/FRAP antioxidant activity, while trigonelline and chlorogenic acid correlated positively with the micronutrients Zn, Cu, and Fe. Cluster analysis resolved groups associated with resistance, Zn/Fe biofortification, productivity, and functional quality. PER1002287, PER1002216, PER1002207, and PER1002197 emerged as promising accessions balancing plant health, yield, and phytochemical quality. Overall, grain mineral composition is linked to plant health, productivity, and functional quality in coffee, providing a foundation for precision nutrient management and breeding programs aimed at resilient and high–value-added coffee. Full article

This study reports the development and characterization of novel active edible films based on apple pectin and honey (80:20, w/w), incorporating raw propolis powder at 0.1%, 0.2%, and 0.3% (w/w, relative to honey) as a natural source of bioactive compounds for sustainable packaging of soluble coffee and matcha powders. The study aims to provide sustainable and functional packaging solutions capable of maintaining the stability and quality of these powdered beverages. The effects of honey and propolis incorporation on the physicochemical, mechanical, optical, and microbiological properties of the films were systematically evaluated. Propolis addition resulted in decreased tensile strength, elastic modulus, and elongation at break, but did not significantly alter the thermal stability of the films, as evidenced by differential scanning calorimetry and thermogravimetric analysis. Increasing propolis concentrations led to higher total phenolic content and significantly improved antioxidant activity, with the 0.3% formulation exhibiting the most pronounced effect. Application tests demonstrated that the honey–propolis-enriched pectin films effectively preserved the sensory attributes and physicochemical quality of soluble coffee and matcha powders. Overall, these results highlight the potential of pectin–honey–propolis films as bioactive carriers and functional materials for active packaging of powdered beverages. Full article

Coffee (Coffea sp.) bean variety and harvesting periods are factors that directly affect its overall quality. In this study, we investigated the effects of four different harvesting periods (December, January, February and March) on the physicochemical and sensory properties of two coffee bean Catimor varieties (7963 and T8667) planted in the same orchard. Physiological characteristics were significantly affected by the delay in harvest periods, specifically the physicochemical properties of each coffee bean variety between the periods. For the green 7963 variety, the defect rate decreased from 11.08% to 4.19% while chlorogenic acid content increased from 3.78% to 4.99% as the harvest period was delayed. The 7963 variety harvested in February and March and T8667 variety harvested in February had the best quality performance, and their cupping scores were significantly higher than those harvested in other periods. Furthermore, a high correlation was found between physical attributes (defect rate, thousand-grain weight, and green bean size), chemical components (lipids, proteins, chlorogenic acid, caffeine, and trigonelline) and cupping scores. Full article

Coffee production is one of the main sources of income for products from Peru’s inter-Andean valleys. However, the rugged geographical conditions offer few growing areas with different altitudes, which could lead to variations in the quality of the beans and, consequently, of the coffee in the cup. This study aimed to evaluate the effect of altitudinal gradients on the exportable yield, and physical and cup quality of the Typica and Catimor varieties produced in the Inkawasi inter-Andean valley of Cusco, Peru. Coffee beans produced at altitudes of 1600, 1800, and 2100 m were considered, and the physical quality of parchment and green coffee was evaluated using Peruvian Technical Standards and the SCAA guidelines. Similarly, the sensory attributes of the coffee in the cup were assessed according to criteria established by the SCAA by five certified tasters. It was observed that increasing altitude considerably reduces pest attack and damage in both varieties and increases secondary damage, shrinkage, and exportable yield, which ranged from 79.12 to 81.98%. Sensory attributes ranged from “Very Good” to “Extraordinary”, allowing the Specialty Grade (>80 points) to be achieved according to SCAA standards. The PCA revealed that the Typica variety has superior sensory qualities that improve with altitude. The coffee produced in the Inkawasi valleys is well received on the international market, especially that grown above 1800 m. Its sustainable cultivation could improve the socioeconomic conditions of its inhabitants. Full article

A comprehensive overview is provided on factors and processes influencing the final quality of a cup of coffee, with an emphasis on the brewing method’s central role. Coffee quality assessment, both at the bean and cup level, combines objective parameters (color, moisture, bean defects, density) with a notable degree of subjectivity, as consumer sensory perception is ultimately decisive. The brewing technique is described as a critical determinant of the final chemical, physical, and sensory attributes. Key parameters such as aroma profile, pH, titratable acidity, total and filtered solids, lipid and fatty acid content, viscosity, foam (crema), and colorimetric indices are detailed as essential metrics in coffee quality evaluation. Roasting creates most of coffee’s key aroma compounds. The brewing method further shapes the extraction of both volatile and other bioactive compounds like caffeine, chlorogenic acids, and lipids. Brewing methods significantly affect acidity, “body,” and crema stability, while water quality, temperature, and pressure are shown to impact extraction results and sensory properties. Attention is paid to how methods such as Espresso, filter, French press, and cold brew yield distinct physicochemical and sensory profiles in the cup. Overall, the review highlights the multifaceted nature of coffee cup quality and the interplay between raw material, processing, and preparation, ultimately shaping the coffee sensory experience and market value. Full article

Background: Saudi coffee, made from Khawlani beans, is known for its sweeter, less acidic flavor and rich content of bioactive compounds. However, traditional preparation methods are time consuming and inefficient in extracting these compounds, limiting their global appeal. This study introduces an ultrasonic-assisted nanoparticle preparation technique to enhance the extraction efficiency, chemical profile, and sensory quality of Saudi coffee. The method aims to overcome limitations of traditional grinding by reducing the particle size while preserving key bioactive compounds. Methods: Finely ground coffee was subjected to ultrasonic processing at optimized parameters 450 W (60% of 750 W output), with 10 min of pulsed sonication to produce nanoparticles. These were characterized using SEM, FT-IR, XRPD, and particle size analysis. Comparative chemical analysis (caffeine, total phenols) and sensory evaluation were conducted against regular Saudi coffee. Results: Ultrasonication reduced the particle size to ~101 nm, significantly enhancing caffeine (from 0.54 to 3.21 mg/g) and phenolic content (from 426.7 to 1825.3 µg GAE/g). Solubility also increased from 40.7% to 75.9%. Sensory tests showed an improved aroma, mouthfeel, and flavor. These improvements are attributed to an enhanced extraction and surface area at the nanoscale. Conclusion: Ultrasonic-assisted nanoparticle technology significantly improves the physicochemical and sensory properties of Saudi coffee. This approach offers a fast, scalable, and eco-friendly method for quality enhancement, positioning Saudi coffee for greater global competitiveness. Full article

The growing demand for health-promoting and eco-friendly foods has driven interest in biofunctional dairy products. Goat milk yogurt, though nutritionally beneficial, faces sensory challenges, while antioxidant-rich spent coffee grounds (SCGs), a coffee by-product, offer sustainable enhancement potential. This study assessed the consumer acceptance of goat milk yogurt enriched with 2% and 3% SCG extract. A total of 137 untrained consumers evaluated six sensory attributes—appearance, aroma, taste, texture, coffee–yogurt balance, and aftertaste—on a five-point hedonic scale. Due to non-normal data, Wilcoxon rank-sum tests and Spearman correlations were applied. No significant differences emerged between formulations (p > 0.05). Taste, aftertaste, and aroma were strongly correlated (r > 0.65). All attributes significantly predicted purchase intent (p < 0.01), with taste as the strongest driver (OR = 2.24). Consumers aged 26–35, usually presenting health or environmental concerns, showed greater acceptance. The addition of SCG extract did not compromise sensory quality, supporting its viability as a sustainable functional ingredient. These findings present high acceptance of a newly developed eco-friendly and nutritionally beneficial product, responding to consumers’ current qualitative demands related to the food they consume. Full article

Coffee is one of the most widely consumed beverages worldwide, primarily due to the stimulating effects attributed to its caffeine content. However, excessive intake of caffeine results in negative effects, including palpitations, anxiety, and insomnia. Therefore, low-caffeine coffee has captivated growing consumer interest, highlighting its significant market potential. Traditional decaffeination methods often lead to non-selective extraction, resulting in a loss of desirable flavor compounds, thereby compromising coffee quality. In recent years, microbial fermentation has emerged as a promising, targeted, and safe approach for reducing caffeine content during processing. Additionally, mixed-culture fermentation further enhances coffee flavor and overcomes the drawbacks of monoculture fermentation, such as low efficiency and limited flavor profiles. Nonetheless, several challenges are yet to be resolved, including microbial tolerance to caffeine and related alkaloids, the safety of fermentation products, and elucidation of the underlying mechanisms behind microbial synergy in co-cultures. This review outlines the variety of microorganisms with the potential to degrade caffeine and the biochemical processes involved in this process. It explores how microbes tolerate caffeine, the safety of metabolites produced during fermentation, and the synergistic effects of mixed microbial cultures on the modulation of coffee flavor compounds, including esters and carbonyls. Future directions are discussed, including the screening of alkaloid-tolerant strains, constructing microbial consortia for simultaneous caffeine degradation for flavor enhancement, and developing high-quality low-caffeine coffee. Full article

With the development of various new types of instrumental aroma sensing technologies, there is a need for methodologies that help developers and users evaluate the performance of the different devices. This study introduces a simple method that uses standard coffee beverages, reproducible worldwide, thus allowing users to compare aroma sensing devices and technologies globally. Eight different variations of commercial coffee capsules were used to brew espresso coffees (40 mL), consisting of either Arabica coffee or a blend of Robusta and Arabica coffee, covering a wide range of sensory attributes. The AlphaMOS Astree electronic tongue (equipped with sensors based on chemically modified field-effect transistor technology) and the AlphaMOS Heracles NEO and the Volatile Scout3 electronic noses (both using separation technology based on gas chromatography) were used to describe the taste and odor profiles of the freshly brewed coffee samples and also to compare them to the various sensory characteristics declared on the original packaging, such as intensity, roasting, acidity, bitterness, and body. Linear discriminant analysis (LDA) results showed that these technologies were able to classify the samples similarly to the pattern of the coffees based on the human sensory characteristics. In general, the arrangement of the different coffee types in the LDA results—i.e., the similarities and dissimilarities in the types based on their taste or smell—was the same in the case of the Astree electronic tongue and the Heracles electronic nose, while slightly different arrangements were found for the Scout3 electronic nose. The results of the Astree electronic tongue and those of the Heracles electronic nose showed the taste and smell profiles of the decaffeinated coffees to be different from their caffeinated counterparts. The Heracles and Scout3 electronic noses provided high accuracies in classifying the samples based on their odor into the sensory classes presented on the coffee capsules’ packaging. Despite the technological differences in the investigated devices, the introduced coffee test could assess the similarities in the taste and odor profiling capacities of the aroma fingerprinting technologies. Since the coffee capsules used for the test can be purchased all over the world in the same quality, these coffees can be used as global standard samples during the comparison of different devices applying different measurement technologies. The test can be used to evaluate instrumentational and data analytical developments worldwide and to assess the potential of novel, cost-effective, accurate, and rapid solutions for quality assessments in the food and beverage industry. Full article

Tropical montane cloud forests (TMCFs) are biodiversity hotspots that have been increasingly cleared to cultivate coffee under full sun exposure, replacing traditional shaded agroforestry systems. This study evaluated the impact of TMCF clearing on soil quality by analyzing 108 samples from undisturbed primary and secondary forests and deforested coffee plantations in the Dominican Republic and Haiti. Our findings indicate that forest clearing has a substantial adverse impact on soil nutrient status. Soils from undisturbed plots had total organic carbon (TOC) concentrations 4.83 units higher than those from cleared plots. Nitrogen levels were reduced by 28–61%, and available potassium declined by 23–51% in soils that had been cleared. Conversely, the available phosphorus levels exhibited a modest increase (ranging from 23% to 27%) following the clearing process, presumably attributable to diminished plant uptake and augmented mineralization in conditions characterized by diminished organic matter. However, given that phosphorus is not a limiting factor for coffee growth, this marginal gain does not compensate for the broader degradation of soil fertility. The study emphasizes that allowing TMCFs to be used for sun-grown coffee results in long-term nutrient depletion through erosion and leaching, which poses a threat to both the productivity of the soil and the ecological integrity of these valuable forest systems. Full article

The objective of this study was to obtain and evaluate a coffee aroma extract/oil with sensorial attributes close to the original brew of Greek coffee for use in an instant Greek coffee powder. The oil was obtained directly from commercial Greek coffee by solid-liquid extraction using hexane as a solvent and treated with a series of hexane-ethanol mixtures (0:10, 1:4, 1:9) to remove the intense roasted flavor of the crude coffee oil obtained by hexane; the de-oiled coffee was used for the recovery of water-soluble compounds, and the produced water extract was freeze-dried. The aromatic volatiles of the coffee oil samples were analyzed by using a purge-and-trap device coupled to GC-MS, as well as sensory analysis. The instant Greek coffee powder was produced by mixing the freeze-dried base (74.4%) with the extract derived after treatment of the crude oil with hexane-ethanol mixture 1:4 (18.2%) and foaming agent (7.4%). Two different materials were studied as bases: instant coffee (F3_Gr-D) and ground Greek coffee (reference sample, C_Gr). The shelf-life stability of the produced powders was examined at three storage temperatures (25, 45, 60 °C). Instrumental analysis (purge-and-trap GC-MS) of aroma and sensory analysis (aroma, taste, staling, total sensory quality on a 1–9 hedonic scale) was conducted. Aroma loss (furfuryl alcohol, furfural, dimethyl pyrazines, ethyl methyl pyrazines) and scores for sensory attributes during storage were modeled using 1st and 0-order reaction kinetics, respectively. The storage temperature effect was expressed by the Arrhenius model (activation energy E_a). According to the results, the developed instant coffee powder presented satisfactorily the aroma characteristics of regular Greek coffee. The shelf life for the instant Greek coffee powder was estimated as 80 days (air packed) (based on 20% retention of furfuryl alcohol that was the most abundant aromatic volatile of Greek coffee aroma, ground as well as extract oil). Full article

Brazil is the leading producer and exporter of coffee, accounting for more than one-third of global production. However, the coffee berry borer (CBB), Hypothenemus hampei, poses a significant threat to coffee yield and quality. Its control has been primarily based on the use of chemical insecticides, which entail risks to human health and the environment. We evaluated the efficacy of an ethylene synthesis inhibitor and a Bacillus subtilis-based nanobioproduct combined with entomopathogenic fungi against the CBB. The treatments included combinations of potassium phosphate-based and nanobioproduct-based bioregulators, bioinsecticide comprising Beauveria bassiana + Metarhizium anisopliae, and chemical insecticides (acetamiprid + bifenthrin). The experiment included an in vitro assay assessing the reproduction of CBB females on treated coffee berries and a field trial evaluating the impact of the treatments on coffee bean quality, beverage sensory attributes, and antioxidant enzyme activities. All insecticide treatments, except the bioregulator at 6 L ha⁻¹ + insecticides, significantly reduced larvae production. The 6 L ha⁻¹ bioregulator treatment reduced bean defects. The fungi + insecticide treatment increased superoxide dismutase activity, while ascorbate peroxidase activity was highest in the control, followed by the fungi + nanobioproduct treatment group. The nanobioproduct bioregulator combined with entomopathogenic fungi proved to be an efficient strategy for managing the CBB. Full article