Species,roasting degree and decaffeination influence the antibacterial activity of coffee against Streptococcus mutans

Coffee beverage has been associated with antibacterial activity against Streptococcus mutans, a cariogenic bacterium. This study aimed at identifying natural compounds in coffee that contribute to such activity and investigate the influence of species, roasting and decaffeination on it. Coffee chemical compounds and aqueous extracts of green and roasted regular and decaffeinated Coffea arabica and Coffea canephora beans were tested. MIC, biofilm inhibition and biofilm reduction results were correlated with the concentration of coffee compounds in the extracts. 5-Caffeoylquinic acid, trigonelline and caffeic acid solutions showed bacteriostatic activity (MIC = 0.8 mg/mL). Lighter and regular extracts showed higher inhibitory activity than darker and decaffeinated extracts, with an inverse correlation between bacterial colony-forming units and roasting degree. Only regular C. canephora extracts showed biofilm formation inhibition. The joint effect of chlorogenic acids, trigonelline and caffeine or other compounds removed by decaffeination seems to be one of the causes for coffee antibacterial activity against S. mutans.     

Caffeine,trigonelline, chlorogenic acids and sucrose diversity in wild Coffea arabica L. and C. canephora P. accessions

Numerous aroma precursor evaluations have been undertaken with green coffee beans of both species of worldwide economic importance: Coffea arabica L. and Coffea canephora P. Efforts have been made to characterise cultivars of these two species. The originality of this study is to present the biochemical diversity of wild accessions originating from Ethiopia and Kenya for C. arabica (38 genotypes) and from five African countries (Côte d'Ivoire, Guinea, Congo, Cameroon and Central African Republik) for C. canephora (38 genotypes). The biochemical aroma parameters assessed by HPLC analysis were: (1) the two alkaloids, caffeine and trigonelline, (2) chlorogenic acids and (3) sucrose. Results reveal that the two species showed significant accession differences for all compounds. Between-species-average-content comparison confirms that C. arabica showed more trigonelline and sucrose and that C. canephora presented more CGA and caffeine. C. canephora diversity was higher than that of C. arabica, except for trigonelline and sucrose. For C. canephora, results showed that: (1) no differences were highlighted between accessions for countries of origin for the alkaloids and sucrose, and (2) the 3-CQA content allowed to accessions to be pooled into two groups.     

Metagenomics and metabolomic profiles of Coffea canephora processed by honey/pulped natural technique

Post-harvest processing of coffee is the dominant factor affecting the metabolite composition and quality of the final brew. This study proposes a novel coffee processing method based on an established semi-dry process. Honey/pulped natural coffee (HC) process combines fermentation and drying excluding the washing stage thus conserving water, unlike wet method. Robusta coffee (Coffee canephora) mucilage was monitored for the evolution of bacterial and fungal diversity along with metabolites produced. Lactic acid bacteria (LAB) (48%) and the major fungal community of Wallemia (31%), a selective marker of Robusta coffee fermentation, were predominant throughout the processing. The process modulates volatiles without significantly affecting the total polyphenols (4.66%), chlorogenic acid (2.07%), caffeine (1.66%), trigonelline (0.53%) and theophylline (0.16%). HC contained compounds like 2-methoxy-4-vinyl phenol, 2-furancarboxaldehyde, 5-methyl-, acetic acid, pyrazine, methyl-, 2-propanone, 1-hydroxy-, and furfural that promotes sweet, caramelly, nutty, pungent and hazelnut taste to coffee.     

Correlation between cup quality and chemical attributes of Brazilian coffee

Brazilian arabica coffee is classified for trading according to the quality of the beverage obtained after roasting and brewing. In the present study, Brazilian green and roasted coffee beans were investigated for possible correlations between cup quality and the levels of sucrose, caffeine, trigonelline and chlorogenic acids, determined by HPLC analysis. Trigonelline and 3,4-dicaffeoylquinic acid levels in green and roasted coffee correlated strongly with high quality. To a lesser extent, caffeine levels were also associated with good quality. On the other hand, the amount of defective beans, the levels of caffeoylquinic acids (predominantly 5-caffeoyilquinic acid), feruloylquinic acids, and their oxidation products were associated with poor cup quality and with the Rio-off-flavor. The fact that similar correlations between cup quality and chemical attributes were observed in green and light roasted samples – the latter used for coffee cup classification – indicates that chemical analysis of green beans may be used as an additional tool for coffee quality evaluation.     

The influence of coffee bean maturity on the content of chlorogenic acids,caffeine and trigonelline

This paper reports changes, with coffee fruit maturity, in the coffee bean content of chlorogenic acids, caffeine and trigonelline. The major change was a sigmoidal increase in total caffeoylquinic acid essentially in parallel with the total dry matter gain, and representing between 5% and 12% thereof. The corresponding changes in the contents of several other chlorogenic acids, caffeine and trigonelline were slight on a mass per 100 beans basis.     

Comparative study of polyphenols and caffeine in different coffee varieties affected by the degree of roasting

The bioactive composition of coffee, as one of the most popular beverages in the world, has attracted interest as a potential source of beneficial bioactive compounds, especially polyphenols and caffeine. Since the content of these compounds is affected by the processing conditions, the objective of this study was to determine the content of polyphenolic compounds and caffeine in four different coffee varieties: Minas and Cioccolatato (Coffea arabica), and Cherry and Vietnam (Coffea canephora syn. Coffea robusta), roasted by three varying degrees (light, medium and dark). The content of the polyphenolic compounds and the antioxidant capacity of coffees were determined using UV/Vis spectrophotometric methods, while the content of chlorogenic acid derivatives was determined using HPLC analysis. The caffeine content was determined by means of two spectrophotometric methods, as well as HPLC analysis. Additionally, raw caffeine was also obtained by an isolation procedure with chloroform. Cherry coffee, a variety of C. canephora exhibited the highest overall content of total phenols (42.37 mg GAE/g), followed by Minas coffee, while Cioccolatato contained the lowest TPC (33.12 mg GAE/g). Cherry coffee also exhibited the highest content of individual classes of polyphenols (flavan-3-ols, procyanidins and tannins), while the highest content of chlorogenic acid (CQA) derivatives was determined in Minas and Cioccolatato coffees (C. arabica). The highest content of total and individual polyphenolic compounds was determined in coffees roasted in both light and medium roasting conditions, which was also observed for the content of CQA derivatives and antioxidant capacity of roasted coffees. The highest caffeine content in the coffee samples was determined by employing the HPLC analysis (0.06–2.55%). Light roasted Cherry coffee contained the highest overall content of caffeine among all coffees, which exhibited a decrease with intensified roasting.     

Chlorogenic acid and caffeine contents in various commercial brewed coffees

Twelve commercial brewed coffees (seven regular and five decaffeinated) were analyzed for chlorogenic acids (CGA) and caffeine by HPLC. Their pH and UV–Vis absorbances were also measured. The CGAs identified were three caffeolylquinic acids (3-CQA, 4-CQA, and 5-CQA), three feruloylquinic acids (3-FQA, 4-FQA, and 5-FQA), and three dicaffeoylquinic acids (3,4-diCQA, 3,5-diCQA, and 4,5-diCQA). The total CGAs ranged from 5.26 mg/g to 17.1 mg/g in regular coffees and from 2.10 mg/g to 16.1 mg/g in decaffeinated coffees. Among CGA, 5-CQA was present at the highest level, ranging from 2.13 mg/g to 7.06 mg/g coffee, and comprising 36–42% and 37–39% of the total CGA in the regular and decaffeinated coffees, respectively. CGA isomer contents were, in decreasing order, 5-CQA > 4-CQA > 3-CQA > 5-FQA > 4-FQA > 3-FQA > 3,4-diCQA > 4,5-diCQA, 3,5-diCQA. The caffeine content in regular and decaffeinated coffees ranged from 10.9 mg/g to 16.5 mg/g and from 0.34 mg/g to 0.47 mg/g, respectively. The pH of regular and decaffeinated coffees ranged from 4.95 to 5.99 and from 5.14 to 5.80, respectively. The relationship between the pH and the UV–Vis absorbance at 325 nm was moderately correlated (R² = 0.7829, p < 0.001, n = 12).     

A 4-week consumption of medium roast and dark roast coffees affects parameters of energy status in healthy subjects

ScopeThis study intended to clarify whether two coffee brews, a market blend (MB) and a study blend (SB), containing equal amounts of caffeine, but differing in their contents of N-methylpyridinium, trigonelline and chlorogenic acids, differentially affect blood lipid profiles and glucose concentrations as well as blood platelet phosphodiesterase and lymphocyte energy charge potential in healthy volunteers.Methods and resultsIn this double-blinded, randomized, controlled cross-over intervention study, 84 healthy normal-weight female and male volunteers consumed 750 mL of medium roast MB and dark roast SB coffee per day for 4 weeks. Following MB and SB coffee intervention, plasma free fatty acid concentrations equally increased (p < 0.001) by 140 ± 187 μM and 178 ± 160 μM, respectively. Plasma glucose remained largely unchanged. Lymphocyte adenosine nucleotide analysis revealed a comparable rise in the energy charge potential, as calculated from ADP/ATP concentrations, adjusted to total adenosine nucleotides. Blood platelet phosphodiesterase activity was found decreased to about the same extent (p < 0.001). Levels of HDL-cholesterol, adiponectin, leptin, insulin and osteopontin were found to some extent differentially influenced by MB, respectively SB coffee.ConclusionThe results of this intervention study indicate that MB and SB coffees, although differing in contents of N-methylpyridinium, trigonelline and chlorogenic acids, largely exert similar biological effects as monitored by the biomarkers tested.     

Fast simultaneous analysis of caffeine, trigonelline, nicotinic acid and sucrose in coffee by liquid chromatography–mass spectrometry

A rapid liquid chromatography–mass spectrometry method for the simultaneous quantification of caffeine, trigonelline, nicotinic acid and sucrose in coffee was developed and validated. The method involved extraction with hot water, clarification with basic lead acetate and membrane filtration, followed by chromatographic separation using a Spherisorb^® S5 ODS2, 5 μm chromatographic column and gradient elution with 0.3% aqueous formic acid/methanol at a flow rate of 0.2 mL/min. The electrospray ionization source was operated in the negative mode to generate sucrose ions and in the positive mode to generate caffeine, trigonelline and nicotinic acid ions. Ionization suppression of all analytes was found due to matrix effect. Calibrations curves prepared in green and roasted coffee extracts were linear with r² > 0.999. Roasted coffee was spiked and recoveries ranged from 93.0% to 105.1% for caffeine, from 85.2% to 116.2% for trigonelline, from 89.6% to 113.5% for nicotinic acid and from 94.1% to 109.7% for sucrose. Good repeatibilities (RSD < 5%) were found for all analytes in the matrix. The limit of detection (LOD), calculated on the basis of signal-to-noise ratios of 3:1, was 11.9, 36.4, 18.5 and 5.0 ng/mL for caffeine, trigonelline, nicotinic acid and sucrose, respectively. Analysis of 11 coffee samples (regular or decaffeinated green, ground roasted and instant) gave results in agreement with the literature. The method showed to be suitable for different types of coffee available in the market thus appearing as a fast and reliable alternative method to be used for routine coffee analysis.     

Can near‐infrared reflectance of green coffee be used to detect introgression in Coffea arabica cultivars?

Most new coffee cultivars disseminated over the last 15 years are derived from the Timor Hybrid (Coffea arabica × C canephora). Introgression of genes from the C canephora genome has been estimated at between 9 and 29% of the genome. It has been shown that introgression can have a negative impact on the cup quality of cultivars derived from the Timor Hybrid. Consequently, coffee buyers or roasters may wish to assess whether the coffee they are purchasing comes from introgressed varieties. The possibility of distinguishing between non‐introgressed Arabicas and genotypes carrying chromosome fragments introgressed from C canephora was investigated (i) using some classical chemical compounds (caffeine, chlorogenic acids, trigonelline, fat and sucrose) and (ii) using a new approach based on spectra acquired by near‐infrared reflectance of green coffee. Near‐infrared spectra were obtained for 129 samples from two collections (Nicaragua and Costa Rica) of introgressed and non‐introgressed coffee trees. The spectral collections were treated by principal component and factorial discrimination. When the introgressed coffee trees were compared with the non‐introgressed trees using the chemical compounds, small but significant differences were found in caffeine, trigonelline and chlorogenic acid contents. However, the small variations in those compounds are not enough to detect introgression. The spectral collections treated by principal component and factorial discrimination made it possible to class from 92.30 to 94.87% of the analysed samples correctly, while the percentages of correctly classified samples in the verification file varied from 88.23 to 94.11%. The NIRS method appears to be an efficient method for determining whether a green coffee comes from an introgressed variety. Copyright © 2005 Society of Chemical Industry     

Identification of Chemical Clusters Discriminators of Arabica and Robusta Green Coffee

The chemical parameters pH, soluble solids, caffeine, trigonelline, total chlorogenic acids, total caffeoylquinic acids, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, total dicaffeoylquinic acids, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid, total feruloylquinic acids, 3-O-feruloylquinic acid, and 5-O-feruloylquinic acid were measured in Arabica (C. arabica) and Robusta (C. canephora) green coffees in order to determine discrimination parameters. In general, Robusta green coffee showed higher values for pH, soluble solids, caffeine, total caffeoylquinic acids, total dicaffeoylquinic acid, and total feruloylquinic acid, but the content of soluble solids was not significantly different in both species of green coffee. Through application of a multivariate analysis, it was concluded that these chemicals form three clusters, being the group of caffeine, trigonelline, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 3-O-feruloylquinic acid, 5-O-feruloylquinic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, and 4,5-O-dicaffeoylquinic acid highly discriminating for Arabica and Robusta green coffees.     

Bioactivities of low-grade green coffee and spent coffee in different in vitro model systems

Methanolic extracts of low-grade green coffee beans (LCB) and spent coffee were analysed for radical-scavenging activity (α,α-diphenyl-β-picrylhydrazyl radical) and oxygen radical absorbance capacity (ORAC). The extracts were also evaluated for anti-tumour (P388 cell assay), anti-inflammatory (J774A.1 cell assay) and anti-allergenic (RBL-2H3 cell line) activities in vitro. LCB extract was found to exhibit a radical-scavenging activity of 92.0% followed by spent Arabica (86.9%) and spent Robusta (82.0%) at a concentration of 50 ppm. The antioxidant activity of LCB extract, measured as Trolox equivalents (4416 μM/g) was significantly (p < 0.05) higher than that of the spent coffee extracts. However, extracts of spent coffee exhibited significantly (p < 0.05) more anti-tumour activity than the LCB extract in terms of cell viability. This could be due to the possible role of brown pigments (melanoidins and phenolic polymers), formed during roasting, which may protect cells from oxidative damage in the biological system. However, both the extracts of LCB and spent coffee showed limited anti-inflammatory and anti-allergic activities. The presence of phenolics and chlorogenic acids in appreciable quantities along with brown pigments makes these coffee by-products a source for natural antioxidants.     

Inhibitory effects of chlorogenic acids from green coffee beans and cinnamate derivatives on the activity of porcine pancreas α-amylase isozyme I

Nine kinds of chlorogenic acids (CGAs) account for 80% of the total CGA content in green coffee beans. They consist of three subgroups of caffeoylquinic acids (CQAs), feruloylquinic acids (FQAs), and dicaffeoylquinic acids (diCQAs). We previously reported the inhibitory effects of 5-CQA on porcine pancreas α-amylase (PPA) isozymes, PPA-I and PPA-II. In this paper, we investigated the PPA-I inhibition by eight kinds of CGAs. The IC₅₀ values of CQAs, FQAs, and diCQAs against the PPA-I-catalysed hydrolysis of p-nitrophenyl-α-D-maltoside were 0.08–0.23 mM, 1.09–2.55 mM, and 0.02–0.03 mM, respectively. All CQAs and FQAs and 3,5-diCQA showed mixed-type inhibition with binding to the enzyme–substrate complex (ES) being stronger than to the enzyme (E). 3,4-DiCQA and 4,5-diCQA showed mixed-type inhibition, but, conversely are suggested to bind to E stronger than ES.     

Identification of chemical clusters discriminators of the roast degree in Arabica and Robusta coffee beans

To identify chemical parameters that might be used as discriminators, pH, soluble solids, caffeine, trigonelline, total caffeoylquinic acids, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, total dicaffeoylquinic acids, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid, total feruloylquinic acids, 3-O-feruloylquinic acid, and 5-O-feruloylquinic acid were measured in Arabica and Robusta coffees submitted to three roasting levels. It was found that the fraction of soluble solids increased with roasting level, being slightly higher in Robusta roasted coffee. The contents of caffeine did not vary significantly between roasting degrees within the Arabica and Robusta samples, respectively, revealing a considerable stability during browning. The contents of trigonelline in Arabica and Robusta coffee decreased significantly with browning intensification. Overall, the levels of chlorogenic acids remained higher in Robusta roasted coffee beans but decreased sharply with roast increase. With roasting intensification, the ratio of total caffeoylquinic acids, total dicaffeoylquinic acids, and total feruloylquinic acids varied markedly in both species, with the proportion of total caffeoylquinic acids and total feruloylquinic acids increasing significantly, whereas the opposite occurred with dicaffeoylquinic acids. One can conclude, through the application of a multivariate analysis, that these chemicals form four clusters, constituting caffeine, trigonelline, total dicaffeoylquinic acids, and total feruloylquinic acids a relevant group for T₃ roasting level discrimination, in both coffee species. Additionally, detailing discriminators for roasting intensity in Arabica coffee might be caffeine, trigonelline, 3-O-caffeoylquinic acid, and 4-O-caffeoylquinic acid, whereas in Robusta roasted coffee are trigonelline, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-O-dicaffeoylquinic acid, 3,5-O-dicaffeoylquinic acid, 4,5-O-dicaffeoylquinic acid, 3-O-feruloylquinic acid, and 5-O-feruloylquinic acid.     

Microwave-assisted extraction of chlorogenic acids from green coffee beans

Microwave-assisted extraction (MAE) has been considered as a potential alternative to conventional solvent extraction for the isolation of phenolic compounds from plants. Aqueous and alcoholic extracts of green coffee bean obtained by MAE were quantitatively analysed for total yield of extracts, chlorogenic acids, caffeine and total polyphenol content. The extracts were also evaluated for radical-scavenging activity, using 1,1-diphenyl-β-picrylhydrazyl radical. Under optimum conditions of time (5 min), temperature (50 °C) and wattage (800 W), the maximum chlorogenic acids and caffeine could be extracted with water as solvent. The extracts contained chlorogenic acids and caffeine in the ranges of 31–62% and 22–40%, respectively. The yields of MAE under optimum conditions were higher than those from the conventional solvent extraction at 5 min and 50 °C and the extracts showed radical-scavenging activity of >75%, even at the concentration of 25 ppm. The MAE process can thus be predicted and controlled for industrial application.     

Chemical characterization and antioxidant properties of a new coffee blend with cocoa,coffee silverskin and green coffee minimally processed

The search for new technologies and ingredients with interesting characteristics and potential for incorporation into functional foods emerges in parallel with the demand for alternative sustainable and economically viable blends. Pursuing these aims, the formulation of a new coffee blend with 94% roasted coffee powder (Coffea canephora cv. Robusta and Coffea arabica, 70/30, w/w), 3% cocoa powder, 2% coffee silverskin and 1% golden coffee (green coffee minimally processed) was developed. The influence of the ingredients in the blend was compared with two other commercial coffee blends (in capsule and in a sealed package with a one-way degassing valve), being characterized the formulation, the physicochemical parameters, as its innovation. It is concluded that the developed coffee blend shows an enriched content of bioactive compounds (chlorogenic acids, trigonelline, theobromine and caffeine), displays an important antioxidant capacity and was favorably appreciated due to its sensory characteristics. Moreover, the addition of skin by-product becomes an additional valorization and the processing of green coffee and cocoa was minimized by adding innovation and an optimized extraction.     

Characterisation of polymeric skin and seed proanthocyanidins during ripening in six Vitis vinifera L. cv

The polymeric proanthocyanidin (PAs) composition of skins and seeds from Vitis vinifera L. cv during ripening was evaluated. Six grape varieties (Cabernet Sauvignon, Malvasia bianca, Moscato bianco, Nascetta, Nebbiolo and Pinot bianco) cultivated in Piedmont (vintage 2008) were collected at five different ripening stages (from 6 to 20 °Brix). Polymeric proanthocyanidins were determined both by vanillin assay and by phloroglucinolysis; these analytical methods were compared showing a significant correlation (r = 0.8321, p < 0.0001 and r = 0.7406, p < 0.0001 for grape skins and seeds, respectively). Acid-catalysed cleavage of the polymer, combined with HPLC separation, enabled quantification of individual polymer subunits, estimation of mean degree of polymerisation (mDP), and the evolution of the extractable polymeric fraction isolated during ripening. Antiradical activity was evaluated as inhibition percentage of DPPH radical. A significant positive correlation between total PAs content and antiradical activity was observed (r = 0.6410, p < 0.0001); on the contrary, the mDP appeared to be negatively correlated to the antiradical activity (r = −0.6238, p < 0.0001).     

Effect of processing,fermentation, and aging treatment to content and profile of phenolic compounds in soybean seed,soy curd and soy paste

This study reports the effect of processing, fermentation, and aging treatment on the content and profile of 43 phenolic compounds in soybean seeds, soy curd (tofu), and soy paste (ChungGukJang, CGJ). Mean content of phenolic compounds was ranked as soybean seed = CGJ aged for 3 days (CGJ-3D) = CGJ aged for 6 days (CGJ-6D) > tofu (P < 0.0001). Low percent recovery (47.1%) of phenolic compounds in tofu was due to heating (boiling), leaching in water, filtering, coagulation, and whey exclusion during tofu making. Aging period did not affect the mean contents of 43 phenolic compounds in the CGJ, whereas it affected the phenolic acids contents in the CGJ (P < 0.01). Benzoic, ferulic, chlorogenic, gentisic, protocatechuic, or β-Resorculic acid was major phenolic compounds in soybean seeds, tofu, CGJ-3D, or CGJ-6D. Especially, the CGJ-3D contained large amounts of isoflavone aglucons and phenolic acids compared to soybean seeds or tofu.     

Does roasted coffee contain chlorogenic acid lactones or/and cinnamoylshikimate esters?

Coffee is one of the most popular and consumed beverages in the world with many positive health effects. In this study the chlorogenic acid lactones and cinnamoylshikimate esters, a subclass of phenolics, from seven commercial roasted Robusta coffee samples were detected and characterized by LC–MSⁿ (n = 2–4). This is the first time when cinnamoylshikimate esters are reported in roasted coffee based on their tandem MS data. We used a previously developed LC–MSⁿ method to distinguish between chlorogenic acid lactones and cinnamoylshikimate esters. Chlorogenic acid lactones and their isomeric shikimate esters have identical m/z values in their MS spectra but different tandem MS spectra and retention times. Structures of these chlorogenic acid lactones and shikimate esters were assigned on the basis of LC–MS³ patterns of fragmentation, relative hydrophobicity and fragmentation analogy to the synthetic standards of mono-acyl chlorogenic acid lactones and shikimate esters containing moieties of ferulic, caffeic, p-coumaric and dimethoxycinnamic acids. Furthermore, 7 unknown and 52 known mono and diacyl chlorogenic acids were identified and characterized to their regioisomeric level. The study is relevant for profiling chlorogenic acids and their dehydration derivatives, shikimates and lactones, in roasted coffee.     

A dark brown roast coffee blend is less effective at stimulating gastric acid secretion in healthy volunteers compared to a medium roast market blend

Coffee consumption sometimes is associated with symptoms of stomach discomfort. This work aimed to elucidate whether two coffee beverages, containing similar amounts of caffeine, but differing in their concentrations of ^βN‐alkanoyl‐5‐hydroxytryptamides (C5HTs), chlorogenic acids (CGAs), trigonelline, and N‐methylpyridinium (N‐MP) have different effects on gastric acid secretion in healthy volunteers. The intragastric pH after administration of bicarbonate with/without 200 mL of a coffee beverage prepared from a market blend or dark roast blend was analyzed in nine healthy volunteers. Coffee beverages were analyzed for their contents of C5HT, N‐MP, trigonelline, CGAs, and caffeine using HPLC‐DAD and HPLC‐MS/MS. Chemical analysis revealed higher concentrations of N‐MP for the dark brown blend (87 mg/L) compared to the market blend coffee (29 mg/L), whereas concentrations of C5HT (0.012 versus 0.343 mg/L), CGAs (323 versus 1126 mg/L), and trigonelline (119 versus 343 mg/L) were lower, and caffeine concentrations were similar (607 versus 674 mg/mL). Gastric acid secretion was less effectively stimulated after administration of the dark roast blend coffee compared to the market blend. Future studies are warranted to verify whether a high ratio of N‐MP to C5HT and CGAs is beneficial for reducing coffee‐associated gastric acid secretion.