Bioactive profile and microbiological safety of Coffea arabica and Coffea canephora beverages obtained by innovative cold extraction methods (cold brews).

Coffee cold brews have been gaining prominence and popularity among consumers worldwide. However, only a few studies have systematically analyzed their chemical composition or evaluated microbiological safety aspects. This study aimed to evaluate the survival of Bacillus cereus and Escherichia coli in cold brews prepared from roasted and ground Coffea arabica and C. canephora seeds using the following preparation methods: immersion without filter (INF), immersion in a cotton filter bag (ICF), vacuum (Vac.) and cold dripping (Drip.). Traditional hot dripping methods using filter paper (HDFP) and cotton filter (HDCF) were also tested for comparison. Water at 4 °C or 25 °C was intentionally contaminated (105 CFU/mL) with cells of Escherichia coli ATCC 25922 (EC) and Bacillus cereus F4433 (BC) before coffee extraction and refrigeration at 4 °C. Coffee concentrations of 5, 10, and 15% were tested. Analyses of pH, soluble solids, nine chlorogenic acids and two lactones (CGA), caffeine, trigonelline, and melanoidins were performed. Results were compared by ANOVA, followed by the Fisher's test, Pearson correlation, Variable Importance in Projection (VIP), and Cluster analyses, with a significance level of 5%. EC and BC were not detected (<10 CFU/mL and < 1 CFU/mL, respectively) after preparing C. arabica and C. canephora hot brews. In cold brews, the higher the extraction of soluble solids and bioactive compounds (with the highest occurring at 25 °C), the lower the counts of inoculated microorganisms during 24 h of storage. BC was not detected after 24 h of extraction and/or storage in the drinks obtained by ICF and Drip. at 5%, 10%, and 15% and INF and Vac. at 15%. EC was not detected in ICF and Drip. at 10 and 15%, and in INF at 15%. C. canephora brews exhibited higher levels of soluble solids, CGA, caffeine, and melanoidins than C. arabica brews. Based on these results, it can be concluded that in the absence of thermal processing as in hot brews, more concentrated cold brews, such as 15%, produced at 25 °C by dripping and immersion methods, are preferable for later dilution due to the higher content of soluble solids and bioactive compounds that contribute reducing the number of microorganisms in the beverage.

Volatile fingerprinting, sensory characterization, and consumer acceptance of pure and blended arabica coffee leaf teas.

Coffee leaves contain several bioactive compounds and have been traditionally consumed as a medicinal infusion in the East for centuries. Coffee production generates large amounts of leaves as by-products, which are often wasted in most producing countries because of the low acceptability in the West. Nevertheless, processing and blending coffee leaves may increase aroma and flavor complexity. This study evaluated the volatile and sensory profiles and consumer acceptance of coffee leaf teas compared to two among the most consumed teas (black and maté teas) in Rio de Janeiro. Infusions were made with one experimental and one commercial coffee leaf tea (CLT), two black teas (BT), and one toasted maté tea (TMT) for volatile (GC-MS/MS) and sensory profiles. As an attempt to improve coffee leaf tea acceptance, CLT were also blended (50%) with BT or TMT. Acceptance, Check All That Apply (CATA), and Projective Mapping sensory tests were performed with untrained assessors aged 18-49 (n = 100). Volatile data were standardized by centering and normalization. Sensory data were treated by ANOVA/Fisher test, PCA, and AHCMFA, considering differences at p < 0.05. Ninety-two volatile compounds distributed in 12 classes were identified in different samples. CLT, BT, and TMT infusions shared 19 compounds, including 9 potential impact compounds for aroma and flavor: α-ionone, ß-ionone, hexanal, nonanal, decanal, benzaldehyde, trans-linalool oxide, linalool, and dihydroactinidiolide. The most cited flavor attributes for CLT infusions were herbs/green leaf, woody and refreshing. For TMT and BT, herbs/green leaf, woody, burnt, and fermented were the most cited. These attributes agreed with the volatile profiles. CLT shared 22 compounds with TMT and 28 with BT. Considering pure infusions, TMT presented the highest mean acceptance scores (6.7), followed by Com. and Exp. CLT (6.1 and 5.8, on a 9-point-hedonic scale, respectively). Blending with TMT increased mean acceptance of Exp. CLT (6.4), while blending with BT, downgraded the mean acceptance of Com. CLT (5.3). In Projective Mapping, CLT was considered to have a higher sensory resemblance with TMT than BT. If produced adequately, CLT was shown to have good market potential to support sustainable coffee production and promote health.

Three centuries on the science of coffee authenticity control.

Food authenticity relies on genuineness and reliability according to the information displayed on the package. Since the 18th century, when coffee became popularized in the West, adulteration began. Several methods have been developed to detect different kinds of frauds and they have evolved as demands increased and new technologies were introduced. The evolution of the science of coffee authenticity control in the past three centuries is reviewed, focusing on the discrimination between coffee and other foods or between coffee and its by-products. The earliest chemical and physical methods are presented followed by methods developed in the 20th and 21st centuries using microscopy, chromatography and spectroscopy associated with advanced statistical tools, and DNA-based methods. In addition to non-food material, before the 20th century, chicory was the most studied food-adulterant. From the 20th century on, corn, coffee by-products, and barley were the most studied, followed by chicory, rice and other food items. Matrix effects seem to be among the most challenging problems in these approaches, associated with variations in roast degree, particle size (particularly in spectroscopy-based methods), and lack of control over reference samples regarding species and purity. Limits of detection vary considerably within each category, with most limits being too high for commercial use. DNA-based methods appear to be promising to assess coffee authenticity, given that the limits of detection and quantification are low, and specificity is higher than in other methods. Nevertheless, as roast intensity increases, the sensitivity of the method decreases. So far, most reported methods have not been validated and only a few have been tested on commercial brands, except for those involving microscopy which has been highly used for monitoring coffee authenticity although not always efficiently enough.

Effect of roasting speed on the volatile composition of coffees with different cup quality.

This study investigated the volatile composition of coffee blends of different cup quality, roasted in an industrial-scale semi-fluidized bed roaster (SFBR) and in a lab-scale fluidized bed roaster (FBR), at three roasting speeds/profiles, to reach medium roast degree. Thirty volatile compounds were selectively investigated. Roasting the specialty coffee blend in both roasters produced lower concentrations of total volatile compounds, compared to the low cup quality blends. Higher concentrations of pyrazines and phenols were observed in low cup quality blends. In SFBR, quality and roasting speed affected all groups of compounds, including impact compounds such as 2,5-dimethylpyrazine, 2-ethylpyrazine, 2,3-dimethylpyrazine, 2-methoxyphenol and 4-ethyl-2-methoxyphenol. In FBR, only phenols were affected. The present results help explain why different roast profiles should be used for coffees with different cup quality for better sensory outcome and why blending should be performed after roasting of green seeds. They also show that results obtained in lab scale roasters are not necessarily reproduced in industry under the same settings.

Contents of key bioactive and detrimental compounds in health performance coffees compared to conventional types of coffees sold in the United States market.

The United States is the largest coffee consuming country worldwide. Recently, in addition to cup quality, the focus on health promotion has increased significantly in the country, with launching of many brands with health claims, mainly highlighting the antioxidative and stimulating properties of the beverage. On the other hand, mycotoxins and, to a lesser extent, acrylamide, have raised concerns among consumers and health authorities. This study investigated the contents of the main bioactive compounds (caffeine, chlorogenic acids and their 1,5-γ-quinolactones, and trigonelline) in health performance coffees and compared them to those of conventional roasted coffees available on the U.S. market. The following categories were compared by ANOVA at p ≤ 0.05, followed by Fisher's test: 1 - health performance, 2 - gourmet and 3 - traditional, totaling 127 samples. As complementary results, the contents of acrylamide and ochratoxin A were evaluated in part of the samples (n = 58). The mean contents (g per 100 g) of bioactive compounds for categories 1 to 3, respectively, were 1.09, 1.11 and 1.07 for caffeine; 1.75, 1.88 and 1.34 for chlorogenic acids/lactones, and 0.63, 0.64 and 0.56 for trigonelline. The mean contents (µg kg-1) of acrylamide for categories 1 to 3, respectively, were 82, 71 and 85. Only about 7% of the evaluated samples presented quantifiable amounts of OTA and all of them were within the maximum limits established by health authorities. In general, the contents of bioactive and potentially harmful compounds were not consistently different among categories, with high and low individual amounts in all of them. Most health claims on labels related to the amount of bioactive compounds in health performance coffees were unjustified, suggesting the need for improvement in coffee labeling regulation in the U.S.

Antiproliferative effect of guava fruit extracts in MDA-MB-435 and MCF-7 human breast cancer cell lines.

Breast cancer is the most frequent and lethal neoplastic disease among women worldwide. Psidium Guajava is a promising functional food against cancer, owing to a variety of bioactive compounds. This study aimed to evaluate the anticarcinogenic potential of Pedro Sato (PS), Hitigio (HI) and Tsumori (TS) guava cultivars fruit pulp extracts in MDA-MB-435 and MCF-7 human breast cancer cells. The antioxidant capacity of the extracts and their effect on cell viability, cell cycle and apoptosis were assessed. Additionally, the concentration of carotenoids, total phenolics, ascorbic acid and other physicochemical parameters were evaluated. PS pulp extract showed the highest in vitro antioxidative activity by all tested methods, as well as the highest content of lycopene and total phenolics, while TS pulp extract presented the highest concentration of ß-carotene. After 48 hours treatment, all guava cultivars' extracts caused reduction of MDA-MB-435 and MCF-7 cells viability, with PS and HI being the most effective extracts. All guava extracts caused MDA-MB-435 and MCF-7 cell count reduction in G0/G1 and G2/M phases and increased apoptosis. The present results strongly suggest that guava pulp exerts antiproliferative effect on breast adenocarcinoma cells.

Therapeutic Potential of Bauhinia forficata Link in Dental Biofilm Treatment.

The oral cytotoxicity, antimicrobial and anti-demineralizing effects of a tincture from Bauhinia forficata Link tincture (BFLT) were evaluated in vitro and ex vivo. Susceptibility tests (minimum inhibitory and microbicidal concentrations-MIC and time-kill assay-MMC) were performed against planktonic oral microorganisms. The contents of phenolic compounds were investigated. Cytotoxic potential was evaluated on oral fibroblasts after 1-5 min exposure to BFLT. Blocks of sound bovine enamel (N = 60) were inoculated with a saliva pool and sustained in a multiple plaque growth system for 48 h to form a biofilm. Biofilm blocks were randomly divided into groups-G (n = 10): G1-Baseline (48 h maturation biofilm), G2-BFLT 23.2 mg/mL, G3-Ethanol 81.20 g/mL, G4-Chlorhexidine 0.12%, G5-Growth control, and G6-Blank control. Treatments (50 µL/1 min) were performed once a day for a week. Streptococcus spp. (S) and total microorganism (TM) counts were expressed as Log10 CFU/mL. Biofilm height was evaluated by confocal microscopy analyses (CMA). Final surface hardness was assessed and percentage of microhardness loss (% MHL) was calculated. Results were significant when P < .05. BFLT inhibited all tested microorganisms (MIC = 1.3-23.2 mg/mL) and promoted optical reduction (0.05-0.22 nm) of all microorganisms after 48-h treatment compared with controls. After 5-min treatment, BFLT showed low values of cell death (3.20%). G2-BFLT reduced S (6.61 ± 0.20) and TM (7.14 ± 0.38) compared with G1-Baseline (S = 7.82 ± 0.28; TM = 8.81 ± 0.67) and G5-Growth control (S = 7.48 ± 0.39; TM = 7.89 ± 0.68); but G4-chlororexidine (S = 6.11 ± 0.48; TM = 6.45 ± 0.16) showed the highest antibiofilm activity. CMA was not different among treatment groups. G2 showed lower % MHL compared with G5, although G4 presented the lowest. Results suggest BFLT is beneficial against dental caries, showing antimicrobial effects against a mature dental biofilm and no cytotoxicity.

Effects of regular and decaffeinated roasted coffee (Coffea arabica and Coffea canephora) extracts and bioactive compounds on in vitro probiotic bacterial growth.

The aim of this study was to investigate the effects of coffee species, roast degree and decaffeination on in vitro probiotic bacterial growth, and to identify the major coffee compounds responsible for such effects. Six C. arabica and C. canephora extracts (regular medium and dark roasted and decaffeinated medium roasted), and five bioactive compounds (chlorogenic acid, galactomannan, type 2 arabinogalactan, caffeine and trigonelline) were individually incorporated into a modified low-carbon broth medium-(mMRS), at different concentrations (0.5 to 1.5% soluble coffee and 0.05 to 0.8 mg mL-1 standard solutions). Inulin and fructooligosaccharides (FOS) were used as prebiotic references. MRS and mMRS were used as rich and poor medium controls, respectively. The growth of Lactobacillus rhamnosus GG ATCC 53103-(GG), L. acidophilus LA-5-(LA), Bifidobacterium animalis DN-173010-(BA) and B. animalis subsp. lactis BB12-(BB12), as well as the growth inhibition of non-probiotic Escherichia coli ATCC 25922 were evaluated. Differences in growth between mMRS and treatments (Δlog CFU mL-1) were compared by ANOVA and Tukey's test, and considered when p ≤ 0.05. Overall, after 48 h incubation, the medium roasted arabica coffee extract increased the growth of GG, LA and BA (range: Δlog CFU mL-1 = 0.5 to 1.8), while the dark roasted arabica coffee extract increased BB12 growth (range: Δlog CFU mL-1 = 0.9 to 1.7), in a dose dependent manner. Improved performances of GG, LA and BA were promoted by higher polysaccharides and CGA concentrations, with better performance for Lactobacillus sp. The tested coffee bioactive compounds promoted the poor growth of BB12. Plain caffeine did not promote Bifidobacterium sp. growth and limited the growth of Lactobacillus sp. Regular C. arabica and C. canephora extracts inhibited the growth of E. coli, while the decaffeinated extracts promoted its growth. The present results show that coffee consumption can selectively improve the growth of probiotic strains, thus exerting a prebiotic effect, and show that coffee roasting and decaffeination affect this property and that different strains utilize different coffee components to grow.

Homeopathic medicine of Melissa officinalis combined or not with Phytolacca decandra in the treatment of possible sleep bruxism in children: A crossover randomized triple-blinded controlled clinical trial.

PURPOSE: The present randomized controlled clinical trial evaluated the efficacy of homeopathic medicines of Melissa officinalis (MO), Phytolacca decandra (PD), and the combination of both in the treatment of possible sleep bruxism (SB) in children. STUDY DESIGN: Patients (n = 52) (6.62 ± 1.79 years old) were selected based on the parents report of SB. The study comprised a crossover design that included 4 phases of 30-day treatment (Placebo; MO 12c; PD 12c; and MO 12c + PD 12c), with a wash-out period of 15 days between treatments. METHODS: At baseline and after each phase, the Visual Analogic Scale (VAS) was used as the primary outcome measure to evaluate the influence of treatments on the reduction of SB. The following additional outcome measures were used: a children's sleep diary with parent's/guardian's perceptions of their children's sleep quality, the trait of anxiety scale (TAS) to identify changes in children's anxiety profile, and side effects reports. Data were analyzed by ANOVA with repeated measures followed by Post Hoc LSD test. RESULTS: Significant reduction of SB was observed in VAS after the use of Placebo (-1.72 ± 0.29), MO (-2.36 ± 0.36), PD (-1.44 ± 0.28) and MO + PD (-2.21 ± 0.30) compared to baseline (4.91 ± 1.87). MO showed better results compared to PD (p = 0.018) and Placebo (p = 0.050), and similar result compared to MO+PD (p = 0.724). The sleep diary results and TAS results were not influenced by any of the treatments. No side effects were observed after treatments. CONCLUSION: MO showed promising results in the treatment of possible sleep bruxism in children, while the association of PD did not improve MO results.

Antibacterial and Cytotoxic Potential of a Brazilian Red Propolis

Objective: To evaluate in vitro the effect of a red propolis ethanolic extract (RPE) in the prevention of growth of a cariogenic biofilm and its cytotoxic potential. Material and Methods: Minimum inhibitory and bactericidal concentrations (MIC and MBC) of RPE against Streptococcus mutans and Lactobacillus casei were determined. The cytotoxic potential of 0.4% RPE in oral fibroblasts was observed after 1, 3 and 5 min of contact. Cellulose membrane disks (13 mm, N=12) were used for biofilm formation (24 h) of S. mutans and L. casei, which were treated (1 min) with 0.4% RPE or 0.12% Chlorhexidine (CHX). The control group of biofilm formation was not submitted to any treatment. Serial dilutions were then made to evaluate microbial viability. Descriptive data analysis and, for microbial viability, Mann Whitney test were performed (p≤0.05). Results: RPE showed similar MIC and MBC (4.46 mg/mL) against S. mutans and, for L. casei, they were 8.92 mg/mL (MIC) and 17.85 mg/mL (MBC). CHX presented MIC and MBC <0.00002 mg/mL for S. mutans and 0.00047 mg/mL for L. casei. After 1, 3 and 5 min, the RPE exhibited, respectively, 69.38%, 43.91% and 40.36% of viable cells. The RPE (6.55) and CHX (6.87) presented similar efficacy to reduce the total number of viable bacteria (p>0.05). Regarding the total number of viable bacteria (Log10 CFU/mL), the RPE (6.55) and CHX (6.87) presented similar efficacy (p>0.05). Conclusion: Red propolis extract showed antibacterial activity against the tested strains, exhibited acceptable cytotoxicity and reduced the colonization of S. mutans and L. casei in a biofilm membrane model.

Treatment of dental biofilm with a tincture of Bauhinia forficata leaves: an ex-vivo study.

The inhibitory activity of a Bauhinia forficata tincture (TBF) was investigated against oral microorganism's strains and against a mature oral biofilm. The viability of planktonic cells was analyzed by Minimal Inhibitory and Microbicidal concentrations of TBF. Salivary samples from health volunteers were collected and mixed to form a saliva pool. An aliquot from this pool were seeded on membranes, which were incubated to form biofilm (48 h). The biofilm was treated according to the groups: G1-Chlorhexidine 0.12%; G2-TBF at the highest MMC; G3-Ethanol at the TBF highest MMC. G4 was the growth control. Streptococcus spp. (S) and total microorganisms (TM) from biofilm were counted. TBF was microbicidal against all oral pathogens. G2 was able to reduce the counts of S and TM from biofilm compared to G3 and G4, but less than G1 (p < 0.05). TBF is able to reduce the microbial levels from a mature oral biofilm.

Comparative oesophageal cancer risk assessment of hot beverage consumption (coffee, mate and tea): the margin of exposure of PAH vs very hot temperatures.

BACKGROUND: Consumption of very hot (> 65 °C) beverages is probably associated with increased risk of oesophageal cancer. First associations were reported for yerba mate and it was initially believed that high content of polycyclic aromatic hydrocarbons (PAH) might explain the risk. Later research on other beverage groups such as tea and coffee, which are also consumed very hot, found associations with increased risk of oesophageal cancer as well. The risk may therefore not be inherent in any compound contained in mate, but due to temperature. The aim of this study was to quantitatively assess the risk of PAH in comparison with the risk of the temperature effect using the margin of exposure (MOE) methodology. METHODS: The human dietary benzo[a]pyrene (BaP) and PAH4 (sum of benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene) exposure through consumption of coffee, mate, and tea was estimated. The oesophageal cancer risk assessment for both PAH and temperature was conducted using the MOE approach. RESULTS: Considering differences in the transfer of the PAH from the leaves of mate and tea or from the ground coffee to the infusion, and considering the different preparation methods, exposures may vary considerably. The average individual exposure in µg/kg bw/day arising from consumption of 1 cup (0.2 L) of infusion was highest for mate (2.85E-04 BaP and 7.22E-04 PAH4). The average per capita exposure in µg/kg bw/day was as follows: coffee (4.21E-04 BaP, 4.15E-03 PAH4), mate (4.26E-03 BaP, 2.45E-02 PAH4), and tea (8.03E-04 BaP, 4.98E-03 PAH4). For all individual and population-based exposure scenarios, the average MOE for BaP and PAH4 was > 100,000 independent of beverage type. MOE values in this magnitude are considered as a very low risk. On the contrary, the MOE for the temperature effect was estimated as < 1 for very hot drinking temperatures, corroborating epidemiological observations about a probable oesophageal cancer risk caused by this behaviour. CONCLUSIONS: The temperature effect but not PAH exposure may pose an oesophageal cancer risk. Consumer education on risks associated with consumption of 'very hot' beverages and policy measures to threshold serving temperatures should be discussed.

Coffee, maté, açaí and beans are the main contributors to the antioxidant capacity of Brazilian's diet.

PURPOSE: The aim of the present study was to evaluate the relative contribution of the most commonly consumed plant foods in Brazil to the total antioxidant capacity (AC) of Brazilian's diet. The importance of regional consuming habits and income for dietary AC was also approached. METHODS: The annual per capita consumption database from the Brazilian Institute of Geography and Statistics (IBGE) was used for identification of the most consumed plant foods in Brazil. Out of 124 key plant foods, 42 top AC contributing candidates were selected for AC determination based on both the frequency of consumption, and AC results reported in the literature, and in our preliminary assays. The selected food products were prepared according to the Brazilian Food Guide, and their AC was measured by TEAC and FRAP assays. Dietary AC was determined by combining these AC results with IBGE consumption data, and the relative contribution of each plant food was calculated. RESULTS: Among all evaluated food products, coffee and green maté tea presented the highest AC, followed by toasted maté tea, red wine, açaí-a native Amazonian fruit-and beans. Associating AC with the annual consumption database from IBGE, coffee alone contributed, on average, to 66 % of dietary AC; other beverages, including maté and wine, contributed altogether to 13 % of dietary AC; beans contributed to 9 %, cereals and derivatives contributed to 4 %; and in natura fruits and vegetables contributed to only 3 and 2 %, respectively. In the North region, fruits were important contributors to AC-mostly because of high açaí consumption, while in the South maté and wine also gained importance, with wine contribution being specially associated with high household income. CONCLUSIONS: Coffee is the main contributor to the total dietary AC in Brazil, regardless of household income. Maté tea, açaí and beans are other major dietary AC contributors.

Using Real-Time PCR as a tool for monitoring the authenticity of commercial coffees.

Coffee is one of the main food products commercialized in the world. Its considerable market value among food products makes it susceptible to adulteration, especially with cereals. Therefore, the objective of this study was to develop a method based on Real-Time Polymerase Chain Reaction (PCR) for detection of cereals in commercial ground roast and soluble coffees. After comparison with standard curves obtained by serial dilution of DNA extracted from barley, corn and rice, the method was sensitive and specific to quantify down to 0.6 pg, 14 pg and 16 pg of barley, corn and rice DNA, respectively. To verify the applicability of the method, 30 commercial samples obtained in different countries were evaluated and those classified as gourmets or superior did not present the tested cereals DNA. However, barley was detected in various traditional (cheaper) samples from South America. In addition, corn and rice were also detected in different samples. Real-Time PCR showed to be suitable for detection of food adulterants in commercial ground roast and soluble coffees.

Coffee Adulteration: More than Two Decades of Research.

Coffee is a ubiquitous food product of considerable economic importance to the countries that produce and export it. The adulteration of roasted coffee is a strategy used to reduce costs. Conventional methods employed to identify adulteration in roasted and ground coffee involve optical and electron microscopy, which require pretreatment of samples and are time-consuming and subjective. Other analytical techniques have been studied that might be more reliable, reproducible, and widely applicable. The present review provides an overview of three analytical approaches (physical, chemical, and biological) to the identification of coffee adulteration. A total of 30 published articles are considered. It is concluded that despite the existence of a number of excellent studies in this area, there still remains a lack of a suitably sensitive and widely applicable methodology able to take into account the various different aspects of adulteration, considering coffee varieties, defective beans, and external agents.

Volatile fingerprint of Brazilian defective coffee seeds: corroboration of potential marker compounds and identification of new low quality indicators.

In the present work, the volatile profiles of green and roasted Brazilian defective coffee seeds and their controls were characterised, totalling 159 compounds. Overall, defective seeds showed higher number and concentration of volatile compounds compared to those of control seeds, especially pyrazines, pyrroles and phenols. Corroborating our previous results, butyrolactone and hexanoic acid, previously considered as potential defective seeds' markers, were observed only in raw and roasted defective seeds, respectively, and not in control seeds. New compounds were suggested as potential defective seeds' markers: hexanoic acid (for raw and roasted defective seeds in general), butyrolactone (for raw defective seeds in general), and 3-ethyl-2-methyl-1,3-hexadiene (for raw black seeds); ß-linalool and 2-butyl-3,5-dimethylpyrazine (for roasted defective seeds in general), and 2-pentylfuran (for roasted black seeds). Additional compounds suggested as low quality indicators were 2,3,5,6-tetramethylpyrazine,2,3-butanediol and 4-ethylguaiacol, ß-linalool, 2-,3-dimethylbutyl butanoate, 2-phenylethyl acetate, 2,3-butanedione, hexanedioic acid, guaiacol, 2,3-dihydro-2-methyl-1H-benzopyrrol, 3-methylpiperidine, 2-pentylpiperidine, 3-octen-2-one, 2-octenal, 2-pentylfuran and 2-butyl-3-methylpyrazine.

Effect of Coffea canephora aqueous extract on microbial counts in ex vivo oral biofilms: a case study.

In the present study, the ex vivo antimicrobial effect of brewed coffee was tested on oral biofilms. For this, unsweetened and sweetened (10 % sucrose) brewed light-roasted Coffea canephora at 20 % was used in biofilms formed by non-stimulated saliva from three volunteers. After 30 min contact with unsweetened and sweetened brews, the average microorganism count in the biofilms reduced by 15.2 % and 12.4 %, respectively, with no statistical difference among them. We also observed a drop of microorganisms in the biofilms after treatment with sucrose solution at 5 % compared to control (saline) and to sucrose at 1 % and 3 %. In conclusion, Coffea canephora extract reduces the microbial count in oral biofilm, and our data suggest that sucrose concentration in coffee brew can influence its antimicrobial property against the referred biofilm.

Effect of simultaneous consumption of milk and coffee on chlorogenic acids' bioavailability in humans.

Different studies have shown that milk may interact with polyphenols and affect their bioavailability in humans. The present study investigated the effect of the simultaneous consumption of coffee and milk on the urinary excretion of chlorogenic acids (CGA) and metabolites. Subjects were submitted to consumption of water, instant coffee (609 mmol of CGA) dissolved in water, and instant coffee dissolved in whole milk. Urine was collected for 24 h after consumption of each treatment for analysis of CGA and metabolites by HPLC/LC-MS. The amount of CGA and metabolites recovered after consumption of combined coffee-milk (40% ± 27%) was consistently lower in all subjects compared to that of coffee alone (68% ± 20%). Concluding, the simultaneous consumption of milk and coffee may impair the bioavailability of coffee CGA in humans.

Modeling weight loss and chlorogenic acids content in coffee during roasting.

Roasting is a key step in the production of a high-quality coffee. Roasting degree is directly related to coffee chemical composition and may be determined objectively by weight loss after roasting. Chlorogenic acids (CGA) are thermally labile phenolic compounds that play an important role in the final cup quality and health benefits of coffee. Considering the interest in finding a reliable method to predict weight loss and CGA content in coffee, models have been developed to estimate these parameters during roasting. Weight loss was successfully modeled (r = 0.99) independent of the instant temperature. CGA degradation followed first-order Arrhenius-compliant kinetic models with good predictability (r = 0.98), especially for light to moderately dark samples. In both cases distinct models for Coffea arabica and Coffea canephora were calculated, because of differences in chemical composition and cell wall structure between these species. The proposed models may become important predictive tools in the coffee industry.

The increase in human plasma antioxidant capacity after acute coffee intake is not associated with endogenous non-enzymatic antioxidant components.

This study evaluated the association between the main plasma endogenous non-enzymatic antioxidant components and the increase in human antioxidant capacity (AC) after acute coffee intake. Ten adults were tested before and 90 min after consumption of coffee or water, in a crossover design, with a 7-day interval between tests. AC (FRAP and TRAP), ascorbic acid, α-tocopherol and γ-tocopherol, albumin, bilirubin and uric acid were analyzed in plasma/serum. After coffee consumption FRAP and TRAP increased 2.6% and 7.6% (P<0.05), whereas after water consumption FRAP and TRAP decreased 2.5% and 1.0% (P <0.05), respectively. In general, AC assays correlated with uric acid and α-tocopherol (r >0.75; P <0.04), independently of treatment and time point. Changes in AC assays after coffee intake did not correlate with endogenous components, which remained unchanged. These results suggest that coffee components spare endogenous antioxidants or are themselves the main contributors to plasma AC increase after coffee intake.