Search Results (14)

The genetic variability of Coffea canephora is essential for the identification of genotypes with enhanced nutritional traits. This study aimed to characterize C. canephora genotypes based on nutrient accumulation in fruits, evaluated over two consecutive harvests. The experiment followed a randomized block design with four replications, comprising 42 genotypes. To assess nutrient accumulation, fruit samples were collected from each genotype and oven-dried. In a plant tissue analysis laboratory, the concentrations of N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, and B were determined. Nutrient accumulation in the fruits was calculated as dry mass × nutrient concentration, and the data were converted to kg or g of nutrients accumulated per ton of coffee beans at 12% moisture content. The results revealed significant variability among genotypes in nutrient accumulation, with the general accumulation order being N > K > Ca > Mg > S > P > Mn > Fe > B > Cu > Zn. Multivariate analysis identified seven groups, with Verdim R, Clementino, and Pirata forming distinct clusters due to their unique characteristics. Clementino exhibited the highest nutrient accumulation, while LB1 had the lowest. The study demonstrated high heritability for all traits, indicating strong genetic control, along with significant positive correlations among nutrients. These findings highlight the potential of selecting nutrient-efficient genotypes to enhance the sustainability of coffee cultivation. The nutritional data obtained can support the development of more nutritionally efficient cultivars, ensuring long-term sustainability in coffee production. Full article

This study aimed to investigate the content of major bioactive compounds and characterize the volatile and sensory profiles of Coffea canephora flowers and their infusions. Dried flowers from six selected genotypes of C. canephora trees and their infusions were analyzed for bioactive compounds using HPLC–DAD, while volatile organic compounds (VOC) were analyzed using GC–MS. Eight chlorogenic acids (CGA), seven phenolic acids, and the alkaloids caffeine and trigonelline were quantified in all methanolic flower extracts. Total CGA, phenolic acids, caffeine, and trigonelline contents in the methanolic extracts ranged between 342.8 and 1079.4 mg/100 g, 27.1 and 41.0 mg/100 g, 515.6 and 745.9 mg/100 g, and 453.8 and 645.2 mg/100 g, respectively. CGA, caffeine, and trigonelline were well extracted (84%, 91%, and 74%, respectively) when the flowers were infused in hot water. No free phenolic acids were identified in the infusions. Eighty-five VOC were identified in the flowers. Aldehydes, monoterpenes, esters, alcohols, monoterpene alcohols, acids, and ketones prevailed in order of the number of compounds. In the infusions, 38 VOC were accurately identified. Monoterpenes and monoterpene alcohols prevailed. In general, floral, jasmine and orange blossom, herbal, green coffee, woody, and sweet were the most cited sensory attributes for fragrance, aroma, and flavor. Considering the typically weak aroma of C. canephora seeds, the aroma and flavor of the flower’s infusions were surprisingly strong and pleasant, showing great marketing potential. Full article

Coffee ranks as the second most consumed beverage globally, and its popularity is associated with the growing accumulation of spent coffee grounds (SCG), a by-product that, if not managed properly, constitutes a serious ecological problem. Analyses of SCG have repeatedly shown that they are a source of substances with antioxidant and antimicrobial properties. In this study, we assessed SCG as a substrate for the production of edible/biodegradable films. The κ-carrageenan was utilized as a base polymer and the emulsified SCG oil as a filler. The oil pressed from a blend of Robusta and Arabica coffee had the best quality and the highest antioxidant properties; therefore, it was used for film production. The film-forming solution was prepared by dissolving κ-carrageenan in distilled water at 50 °C, adding the emulsified SCG oil, and homogenizing. This solution was cast onto Petri dishes and dried at room temperature. Chemical characterization showed that SCG increased the level of polyphenols in the films and the antioxidant properties, according to the CUPRAC assay (CC1 23.90 ± 1.23 µmol/g). SCG performed as a good plasticizer for κ-carrageenan and enhanced the elongation at the break of the films, compared with the control samples. The solubility of all SCG films reached 100%, indicating their biodegradability and edibility. Our results support the application of SCG as an active and easily accessible compound for the food packaging industry. Full article

The coffee fruit is preferably harvested at the cherry stage, with high moisture and metabolic activity, and must then undergo a drying process for better preservation of the bean and its sensory attributes. In this context, this study aimed to characterize the final quality of the Arara cultivar Arabica coffee processed using the wet method and subjected to six drying methods: three conducted at the agro-industrial establishment (fixed-bed dryer, rotary drum dryer, and combined drying) and three laboratory-scale methods (convective oven, cast-tape drying, and suspended terrace). Drying was carried out to reduce the coffee’s moisture content from an initial value of 46.2% on a wet basis (w.b.) to a final average value of 11.35% (w.b.). The fruits of in natura demucilaged coffee and the processed dry coffee beans were characterized for moisture, ash content, nitrogen compounds, lipids, total titratable acidity, organic acids, sugars, and the instrumental color of the beans. The sensory profile of the Arabica coffee was evaluated by five coffee specialists using the methodology proposed by the Specialty Coffee Association (SCA), and all the coffees were classified as a specialty. Full article

Genetic characteristics and their interaction with environmental conditions, including nutritional management, determine coffee productivity and quality. The objective of this study was to evaluate fruit traits and nutrient accumulation in the fruit, husk, and bean, as well as in the leaves of different Coffea arabica cultivars cropped in the Gorongosa National Park, Mozambique. The experiment evaluated nine coffee cultivars in a randomized block design, with four replicates. Fruit and leaf samples were collected over two months (June and July 2021), in the fruit maturation phase, oven-dried and analyzed, namely, through a clustering unweighted pair group method with arithmetic mean (UPGMA). The characterization of ripe and dried coffee bean indicated differences in the performance of the cultivars. The accumulation of the macronutrients N, K, and Ca and micronutrients Fe, Mn, and B was highest in the bean, husk, fruit, and leaves of the evaluated cultivars. Nutrient concentrations and accumulation in the different evaluated organs have a direct influence on the nutritional crop management. This is crucial for a nutritional diagnosis that ensures high yields, but such mineral levels are also a result of the existing genetic diversity among cultivars, which must be taken into account for management and breeding purposes. Full article

The use of the flowers (blossoms) of the coffee plant (genus Coffea) has been neglected over the years, as the focus has primarily been on the cost-efficient production of coffee beans. Because of societal changes and economic pressures, there is an increasing demand for sustainability, so the focus has also widened towards the various by-products of the coffee production. The coffee flower is a by-product because it can be harvested following pollination without any risk to the bean production. The coffee flower can be used as a whole or as floral water in some food and cosmetic products. The flower can also be prepared as a tea-like beverage with hot water infusion. Another side-chain product in coffee plantations is the so-called coffee flower honey, which is rarely monofloral due to the short flowering period. To date, there have been few studies on coffee flowers and their sensory characterization. In this work, various compounds in Coffea arabica, C. canephora, and C. liberica flowers were identified and quantified by high-performance liquid chromatography (HPLC) with diode array detection (DAD), nuclear magnetic resonance spectroscopy (NMR), and near-infrared (NIR) spectroscopy. Caffeine, chlorogenic acids, organic acids, trigonelline, and sugars were quantified. Additionally, the sensory testing of coffee flower infusions according to the German norm DIN 10 809 was performed. With the acquired data, a principal component analysis (PCA) was performed in which hay, hops, sage, dried apricot, and honey were identified as major flavor descriptors in addition to the floral coffee flower flavors. The coffee flower is judged as a promising ingredient, which needs to be further assessed regarding its possible approval within the novel food regulations of the European Union. Full article

This study investigates the possibility of valorizing coffee silverskin through the recovery of its bioactive compounds using a sustainable extraction method that could be industrially applied. For that, aqueous extracts were prepared using ultrasonic-assisted extraction (laboratorial scale) and, for comparison, a scale-up of the process was developed using the Multi-frequency Multimode Modulated technology. A concentration procedure at the pilot scale was also tested. The three types of extracts obtained were characterized regarding caffeine and chlorogenic acids contents, and the effects on intestinal glucose and fructose uptake (including sugar transporters expression) in human intestinal epithelial (Caco-2) cells were ascertained. The phytochemical contents of the extracts prepared at the laboratory and pilot scale were comparable (caffeine: 27.7 vs. 29.6 mg/g freeze-dried extract; 3-, 4-, and 5-caffeoylquinic acids: 0.19 vs. 0.31, 0.15 vs. 0.42, and 1.04 vs. 1.98 mg/g, respectively; 4- and 5- feruloylquinic acids: 0.39 vs. 0.43 and 1.05 vs. 1.32 mg/g, respectively). Slight differences were noticed according to the extracts preparation steps, but in general, all the extracts promoted significant inhibitions of [1,2-³H(N)]-deoxy-D-glucose and ¹⁴C-D-fructose uptake, which resulted mainly from a decrease on the facilitative glucose transporter 2 (GLUT2) and sodium-glucose linked transporter 1 (SGLT1) genes expression but not on the expression of the facilitative glucose transporter 5 (GLUT5) gene. Moreover, a synergistic effect of caffeine and 5-caffeoylquinic acid on sugars uptake was found. The results clearly show that the Multi-frequency Multimode Modulated technology is a viable option to be applied at an industrial level to recover bioactive components from silverskin and obtain extracts with antidiabetic potential that could be used to develop functional food products or dietary supplements. Full article

The morphological analysis of patterns in dried droplets has allowed the generation of efficient techniques for the detection of molecules of medical interest. However, the effectiveness of this method to reveal the coexistence of macromolecules of the same species, but different conformational states, is still unknown. To address this problem, we present an experimental study on pattern formation in dried droplets of bovine serum albumin (BSA), in folded and unfolded conformational states, in saline solution (NaCl). Folded proteins produce a well-defined coffee ring and crystal patterns all over the dry droplet. Depending on the NaCl concentration, the crystals can be small, large, elongated, entangled, or dense. Optical microscopy reveals that the relative concentration of unfolded proteins determines the morphological characteristics of deposits. At a low relative concentration of unfolded proteins (above 2%), small amorphous aggregates emerge in the deposits, while at high concentrations (above 16%), the “eye-like pattern”, a large aggregate surrounded by a uniform coating, is produced. The radial intensity profile, the mean pixel intensity, and the entropy make it possible to characterize the patterns in dried droplets. We prove that it is possible to achieve 100% accuracy in identifying 4% of unfolded BSA contained in a protein solution. Full article

Coffee silverskin (CS) is the major by-product of coffee roasting and a source of caffeine and chlorogenic acids (CGA), recognized modulators of sugar metabolism. In this work, the effect of a CS extract on glucose and fructose uptake by human intestinal epithelial (Caco-2) cells was ascertained. Freeze-dried aqueous extracts were prepared using an ultrasound probe. The obtained powder was characterized regarding its caffeine content and CGA profile by RP-HPLC-DAD. Caco-2 cells were incubated (at 37 °C for 24 h) with 1 mg/mL of extract, and then glucose and fructose uptake were measured by incubating the cells (at 37 °C for 6 min) with 10 nM ³H-deoxy-D-glucose (³H-DG) or 100 nM ¹⁴C-fructose (¹⁴C-FRU), respectively. The effects of the major compounds identified were similarly assessed using standards, individually and combined. Furthermore, the mRNA levels of the intestinal transporters of these sugars (SGLT1, GLUT2, and GLUT5) were quantified by RT-qPCR after cell treatment (for 24 h) with the CS extract. Caffeine was the main component of the extract and 5-caffeoylquinic acid (5-CQA) was the major CGA, followed by 5-feruloylquinic acid (5-FQA). Other isomers were found in minor amounts (3-CQA, 4-CQA, and 4-FQA). CS was able to significantly reduce ³H-DG and ¹⁴C-FRU uptake (~17% and ~19%, respectively). These effects were not related to cytotoxicity, as confirmed by the lactate dehydrogenase assay. When testing individual compounds at the concentrations present in the extract, neither caffeine nor 5-CQA influenced ³H-DG and ¹⁴C-FRU uptake, but significant inhibitions were found when the compounds were combined together (~16% and ~18%, for ³H-DG and ¹⁴C-FRU uptake, respectively). This synergistic activity suggests their major role in CS effects. The extract also decreased (in 71%) the expression levels of the GLUT2 transporter, without any influence on the SGLT1 and GLUT5 transporters, thus evidencing the importance of GLUT2 on sugar uptake results. Overall, these findings highlight the beneficial effects that CS might have on type 2 diabetes and other metabolic disorders. Full article

In recent decades, vibrational spectroscopic methods such as Raman and FT-IR spectroscopy are widely applied to investigate plasma and serum samples. These methods are combined with drop coating deposition techniques to pre-concentrate the biomolecules in the dried droplet to improve the detected vibrational signal. However, most often encountered challenge is the inhomogeneous redistribution of biomolecules due to the coffee-ring effect. In this study, the variation in biomolecule distribution within the dried-sample droplet has been investigated using Raman and FT-IR spectroscopy and fluorescence lifetime imaging method. The plasma-sample from healthy donors were investigated to show the spectral differences between the inner and outer-ring region of the dried-sample droplet. Further, the preferred location of deposition of the most abundant protein albumin in the blood during the drying process of the plasma has been illustrated by using deuterated albumin. Subsequently, two patients with different cardiac-related diseases were investigated exemplarily to illustrate the variation in the pattern of plasma and serum biomolecule distribution during the drying process and its impact on patient-stratification. The study shows that a uniform sampling position of the droplet, both at the inner and the outer ring, is necessary for thorough clinical characterization of the patient’s plasma and serum sample using vibrational spectroscopy. Full article

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. Full article

Our research aimed to evaluate the formation of Maillard reaction products in sun-dried coffee cascara and their impact on the safety and health promoting properties of a novel beverage called “Instant Cascara” (IC) derived from this coffee by-product. Maillard reaction products in sun-dried coffee cascara have never been reported. “Instant Cascara” (IC) extract was obtained by aqueous extraction and freeze-drying. Proteins, amino acids, lipids, fatty acid profile, sugars, fiber, minerals, and vitamins were analyzed for its nutritional characterization. Acrylamide and caffeine were used as chemical indicators of safety. Colored compounds, also called melanoidins, their stability under 40 °C and in light, and their in vitro antioxidant capacity were also studied. A safe instant beverage with antioxidant properties was obtained to which the following nutritional claims can be assigned: “low fat”, “low sugar” “high fiber” and “source of potassium, magnesium and vitamin C”. For the first time, cascara beverage color was attributed to the presence of antioxidant melanoidins (>10 kDa). IC is a potential sustainable alternative for instant coffee, with low caffeine and acrylamide levels and a healthy composition of nutrients and antioxidants. Full article

The aim of this study is to investigate the effect of microwave vacuum drying (MVD) on the drying characteristics and quality attributes of green coffee beans. We specifically focused on the effective moisture diffusion coefficient (D_eff), surface temperature, glass transition temperature (T_g), water state, and microstructure. The kinetics of color changes during drying, total phenolic content (TPC), and antioxidant activity (DPPH, FRAP, and ABTS) were also characterized. Microwave power during MVD affected the porosity of coffee beans, their color, TPC, and antioxidant activity. The Allometric 1 model was the most suitable for simulating surface temperature rise kinetics. Thermal processing of green coffee beans resulted in increased b*, L*, ΔE, and TPC values, and greater antioxidant capacity. These findings may provide a theoretical reference for the technical improvement, mechanisms of flavor compound formation, and quality control of dried green coffee beans. Full article

Ochratoxin A (OTA) is secondary metabolite naturally produced in food and feed by toxigenic fungi, especially some Aspergillus species and Penicillium verucosum. OTA is one of the most studied mycotoxins and is of great interest due to its toxic effects on human and animals. OTA is produced in different food and feed matrices and contaminates a large range of base foods including cereals and derivatives, spices, dried fruits, wine and coffee, etc. Morocco, a North African country, has a climate characterized by high humidity and temperature, which probably favors the growth of molds. This contribution gives an overview of principal investigations about the presence of OTA in foods available in Morocco. Due to its toxicity, OTA presence is increasingly regulated worldwide, especially in countries of the European Union. However, up until now, no regulation limits were in force in Morocco, probably due to the ignorance of the health and economic problems resulting from OTA contamination. Finally, recommendations and future research directions are given required to assess the situation completely. Full article