Total Chlorogenic Acid Research Articles

Effect of polygalacturonase and feruloyl esterase from Aspergillus tubingensis on demucilage and quality of coffee beans

To explore the potential for the application of Aspergillus tubingensis enzyme extract in coffee processing, the effects of crude enzymes on coffee beans were studied. Yields of polygalacturonase and feruloyl esterases obtained from solid-state fermentation using A. tubingensis, with pectin and de-starched wheat bran as carbon sources, were 15.9U/mL and 2.44U/mL, respectively. Crude enzyme extracts removed the mucilage of coffee cherries within 3h, which is substantially more efficient than traditional fermentation. Additionally, the viscosity of coffee mucilage was reduced to 80% by a 3-h treatment with the crude enzyme extract at 50°C. The titratable acidity and organic acids in coffee beverages were also decreased to half the amounts of those in the traditionally fermented group. The total chlorogenic acid in the green beans decreased to 67.3%; however, a decline of only 14.3% was observed in the traditionally fermented group. On the other hand, chlorogenic acid lactones in the roasted beans were reduced to 63.9%, and a 37.2% decline in the chlorogenic acid content was detected.

Efficacy of a novel green coffee bean extract (GCB‐70) in weight management (1107.2)

Green coffee beans (GCB) are the unroasted beans or raw seeds from the Coffee fruits, which are novel, natural source of a powerful antioxidant, chlorogenic acids, as well as caffeine, caffeic acid, vanillic acid, quinides, lignans and trigonelline. Chlorogenic acids enhance the taste and caffeine solubility. Chlorogenic acid has been demonstrated to reduce the absorption of fat from food intake and improves glucose metabolism, and promotes anti‐aging pathophysiology. Our laboratories have developed a novel, patented GCB extract GCB‐70 enriched with 70% total chlorogenic acids (tCGA) which includes 35% of 5‐caffeoylquinic acid (5‐CQA). The presently available GCB extracts contain only 45% tCGA including 15% 5‐CQA. Studies demonstrated that GCB‐70 is safe, potent, which potentiates antioxidant efficacy against oxidative stress, regulates blood pressure and improve cognitive functions. Furthermore, GCB‐70 accelerates glucose and fat metabolism, and may be an effective and inexpensive means for weight management. These results are very encouraging. Further research studies are in progress.Grant Funding Source: Company

Biochemical Composition Within Coffea arabica cv. Ruiru 11 and Its Relationship With Cup Quality

<p>Biochemical composition appears to be influenced by both genetic factors and plant growth conditions. The main objective of this study was to evaluate the biochemical composition of selected Ruiru 11 sibs and its relationship with cup quality. Thirty four (34) Ruiru 11 sibs grown in three different locations in Kenya were used in this study. The experiment was laid out in a Randomized Complete Block Design with three replications. Coffee cherries were picked during the peak harvesting period between 2009 and 2011. The cherries were wet processed and graded into different grades based on size, shape and density. Fifty (50) grams of the dry coffee beans per sib per replication were frozen at -80 ºC before grinding (< 0.5 mm particle size) in liquid nitrogen as specified by the Association of Official Analytical Chemists (AOAC). The samples were packed in small plastic bottles and stored at -80 ºC awaiting extraction of biochemical components. Caffeine, trigonelline and total chlorogenic acids were extracted and purified using classical methods and analysed using High Pressure Liquid Chromatography (HPLC). For the lipids, the sample was subjected to Soxhlet extraction using n-hexane. The study demonstrated the existence of high variation in biochemical composition among Ruiru 11 sibs. Significant correlations were observed between biochemical and cup quality traits indicating that biochemical composition plays a major role in determining the sensory quality of coffee. The growing environment was also found to have an effect on biochemical composition as portrayed by high locational variations.</p>

Phenolic composition, caffeine content and antioxidant capacity of coffee silverskin

Coffea arabica silverskin (CSS), the inner fruit layer surrounding coffee beans, was analyzed for its (poly)phenolic and caffeine content by means of liquid chromatography–tandem mass spectrometry and evaluated for its antioxidant properties by means of the Folin–Ciocalteu and FRAP methods. The most abundant quantified phenolics were caffeoylquinic acids, with the 5- and 3-isomers being the most relevant (199mg/100g and 148mg/100g, respectively). The three caffeoylquinic acid isomers reached a total concentration of 432mg/100g, corresponding to 74% of the total chlorogenic acids detected in CSS. The level of the three feruloylquinic acids detected was 143mg/100g, corresponding to 23%, and the two identified coumaroylquinic acids plus the two caffeoylquinic acid lactones were only marginally contributing to the final figure (only 3% of total hydroxycinnamates). No unconjugated phenolic acid was detected. Caffeine content in CSS was equal to 10mg/g of product, 3.5 times lower than most coffee brews. The total antioxidant capacity (TAC) of CSS was 139mmol Fe2+/kg, a value similar to those of valuable sources of food antioxidants like dark chocolate, herbs and spices. Besides its potential as a food supplement, CSS may represent an innovative functional ingredient exploitable to increase the TAC of a wide range of food products.

The effect of processing on chlorogenic acid content of commercially available coffee

Chlorogenic acids (CGA) are a class of polyphenols noted for their health benefits. These compounds were identified and quantified, using LC–MS and HPLC, in commercially available coffees which varied in processing conditions. Analysis of ground and instant coffees indicated the presence of caffeoylquinic acids (CQA), feruloylquinic acids (FQA) and dicaffeoylquinic acids (diCQA) in all 18 samples tested. 5-CQA was present at the highest levels, between 25 and 30% of total CGA; subsequent relative quantities were: 4-CQA>3-CQA>5-FQA>4-FQA>diCQA (sum of 3,4, 3,5 and 4,5-diCQA). CGA content varied greatly (27.33–121.25mg/200ml coffee brew), driven primarily by the degree of coffee bean roasting (a high amount of roasting had a detrimental effect on CGA content). These results highlight the broad range of CGA quantity in commercial coffee and demonstrate that coffee choice is important in delivering optimum CGA intake to consumers.

Importance of Espresso Coffee Machine Parameters on the Extraction of Chlorogenic Acids in a Certified Italian Espresso by Using SPE-HPLC-DAD

<p>Chlorogenic acids (CGA) are a group of phenolic acid derivatives, which are commonly found in coffee at concentrations reaching 0.1-0.2%. A method based on high performance liquid chromatography-diode array detector (HPLC-DAD) is proposed for the simultaneous determination of three chlorogenic acids, i.e. 3-<em>O</em>-caffeoylquinic acid (3-CQA), 5-<em>O</em>-caffeoylquinic acid (5-CQA) and 3,5-di-O-caffeoylquinic acid (3,5-diCQA), in time portions of espresso coffee. Two different espresso coffee machines working with different pressure and temperature curves, and two different blends (i.e. Arabica and Robusta) were used. The method presents good linearities (correlation coefficient greater than 0.99) and recoveries (in the range 67-99%) for the 3 chlorogenic acids. The concentration of total CGAs in a cup of Certified Italian Espresso ranged from 1522.5 to 2223.4 mg kg<sup>-1</sup> and CGA isomer contents were, in decreasing order, 5-CQA > 3-CQA > 3,5-diCQA.</p> <p>The concentration of total chlorogenic acids was higher in Espresso coffee (EC) prepared with Aurelia machine rather than with Leva; Arabica blend possessed higher level ot total chlorogenic acids than Robusta samples. <strong></strong></p>

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.

Biochemical indices of hop resistance to Verticillium albo-atrum and Fusarium sambucinum

The contents of total phenolic compounds, chlorogenic acid and peroxidase activity as well as monophenols to polyphenols ratio were studies in the suckers of the hops as indices of resistance to <i>Verticillium albo-atrum</i> and <i>Fusarium sambucinum</i>. The suckers of hop taken in the early spring from the healthy and infected plots were used in the experiments. As a research material were included cv. 'Northern Brewer' - a wilt tolerant variety, two wild susceptible varieties - cv. 'Lubelski' and cv. 'Brewers Gold', four breeding clones and one male plant. It was found that, 'Northern Brewer' contains more total phenolic compounds, rnonophenols and chlorogenic acid, and in particular considerably higher peroxidase activity as compared to cv. 'Lubelski'. Taking into consideration the contents of these compounds, in the majority of cases, the new breeding clones were similar to the mother variety 'Northern Brewer'. It seems resonable to assume, that the new clones should be more wilt tolerant than varieties and populations cultivated in our country.

Study on Antioxidant Mechanism of Yin-Huang Buccal Tablet

Aim: As an over-the-counter medicine (OTC) in traditional Chinese medicine (TCM), Yin-Huang buccal tablet has been used to eliminate toxic heat which may be related to oxidative stress. However, its antioxidant ability in vitro has not been explored so far. The aim of the study was to evaluate its antioxidant activity, and further discuss the possible mechanism. Methods: Yin-Huang tablet was firstly determined by various antioxidant assays in vitro, including DPPH• scavenging, ABTS• scavenging, Fe reducing, Cu reducing, and Cu chelating assays. Subsequently, its total phenolic and chlorogenic acid contents were respectively determined by Folin-Ciocalteu assay and HPLC analysis. Results: Antioxidant assays indicated a dose-dependent effect of Yin-Huang. Its half maximal inhibitory concentration (IC50) values were 144.67±2.27, 41.39±2.44, 358.65±11.75, 127.91±5.19, and 1158.05±37.39 μg/mL, respectively for DPPH• scavenging, ABTS• scavenging, Fe reducing, Cu reducing, and Cu chelating assays. Chemical determination revealed that its total phenolic content was 21.56±3.52 mg Pyr./g, and chlorogenic acid content was 7.99±0.55 mg/g. Conclusion: Based on the mechanistic analysis, it can be concluded that: (i) Yin-Huang buccal tablet presents effective antioxidant ability and its antioxidant ability may be partly responsible for the pharmacological effects in TCM; (ii)It exerts its antioxidant ability possibly through metal-chelating, and free radical-scavenging which is mediated via donating hydrogen atom (H•) and electron (e); (iii) Its antioxidant ability may arise from the phenolic compounds, especially chlorogenic acid.

Dose‐dependent absorption of chlorogenic acids in the small intestine assessed by coffee consumption in ileostomists

Until now, the question of how the ingested doses of chlorogenic acids (CGA) from coffee influence their absorption and metabolism remains unresolved. To assess absorption in the small intestine, we performed a dose-response study with a randomized, double-blinded, crossover design with ileostomist subjects. After a polyphenol-free diet, the volunteers consumed, on three separate occasions, coffee with different total CGA contents (high 4525 μmol; medium 2219 μmol; low 1053 μmol). CGA concentrations in plasma, ileal effluent, and urine were subsequently determined by HPLC-DAD-ESI-MS and -ESI-MS/MS. The results show that the consumption of higher CGA concentrations leads to a faster ileal excretion. This corresponds to a renal excretion of 8.0 ± 4.9% (high), 12.1 ± 6.7% (medium), and 14.6 ± 6.8% (low) of total CGA and metabolites. Glucuronidation of CGA became slightly greater with increasing dose. After enzyme treatment, the area under the curve (AUC)(0-8h) for CGA metabolites in plasma was 4412 ± 751 nM × h(0-8) (-1) (high), 2394 ± 637 nM × h(0-8) (-1) (medium), 1782 ± 731 nM × h(0-8) (-1) (low), respectively. Additionally, we were able to identify new metabolites of CGA in urine and ileal fluid. We conclude that the consumption of high CGA concentrations via coffee might influence the gastrointestinal transit time and consequently affect CGA absorption and metabolism.

Espresso Coffee Residues: A Valuable Source of Unextracted Compounds

Espresso spent coffee grounds were chemically characterized to predict their potential, as a source of bioactive compounds, by comparison with the ones from the soluble coffee industry. Sampling included a total of 50 samples from 14 trademarks, collected in several coffee shops and prepared with distinct coffee machines. A high compositional variability was verified, particularly with regard to such water-soluble components as caffeine, total chlorogenic acids (CGA), and minerals, supported by strong positive correlations with total soluble solids retained. This is a direct consequence of the reduced extraction efficiency during espresso coffee preparation, leaving a significant pool of bioactivity retained in the extracted grounds. Besides the lipid (12.5%) and nitrogen (2.3%) contents, similar to those of industrial coffee residues, the CGA content (478.9 mg/100 g), for its antioxidant capacity, and its caffeine content (452.6 mg/100 g), due to its extensive use in the food and pharmaceutical industries, justify the selective assembly of this residue for subsequent use.

Polyphenol distribution in plant organs of tomato introgression lines

The content of total polyphenols, chlorogenic, caffeic (CaA) and ferulic acids, and rutin, was investigated in plant organs of three introgression lines (IL7-3, IL10-1 and IL12-4) of Solanum pennellii in Solanum lycopersicum cv M82 and compared with that of cropped parental. Such study aims to evidence factors associated to the introgressions that can affect polyphenol distribution in plant. Among genotypes few differences in polyphenols were recorded on fresh weight basis. IL7-3 showed higher total polyphenols in fruits and lower rutin in leaves than the other genotypes. IL12-4 showed an increasing trend of total polyphenol concentration in fresh vegetative organs; however, this seems to depend on the lower water content rather than on a higher polyphenol biosynthesis in the genotype. IL10-1 sowed higher CaA and lignin contents in leaves. Such differences agree with the morphological and physiological traits of the genotypes.

Variability on urinary excretion of chlorogenic acid compounds and metabolites in humans after overnight fasting and under controlled diets

Large intra‐ and inter‐individual variabilities have been observed in previous studies evaluating polyphenols bioavailability in humans. The present study evaluated the intra‐ and inter‐individual variations on the urinary excretion of chlorogenic acids (CGA) and metabolites in adults (n=12), in 5 separate days, after 10h fasting and a 48h controlled phenolic free‐diet. A total of 22 compounds (359.74 ± 197.90 μmol) were identified in urine by HPLC/MS, including 6 CGA and 16 phenolic acids, varying from 1 to 10 fold for the same subject intra‐day. Only 0.36 ± 0.35 μmol of total CGA were excreted in urine, varying from 1 to 7 fold for the same subject intra‐day. A large inter‐individual variation was also observed for all compounds. The largest variation was observed for p‐coumaric acid, followed by 4‐caffeoylquinic and 3‐(4’‐hydroxyphenyl) propionic acids, whereas benzoic, hippuric and 2,4‐dihydroxybenzoic acids showed the lowest variation. The patterns of CGA and metabolites excretion were also remarkably different among subjects, but remained similar in different days for the same subjects. Concluding, the inter‐individual variability on CGA metabolism seems to be more expressive when compared to intra‐individual variability. Our results also suggest the need for long washout periods for CGA and that their metabolization routs may vary according to individuals, which should be thoroughly investigated. Financial Support: CNPQ and FAPERJ.

Chlorogenic acids in Brazilian Coffea arabica cultivars from various consecutive crops

Abstract The present work evaluated the chlorogenic acids (CGA) content and profile in economically important Brazilian cultivars of Coffea arabica from four to five consecutive crops. The contents of three caffeoylquinic acids (CQA), two feruloylquinic acids (FQA) and three dicaffeoylquinic acids (diCQA) were evaluated in semi-dry processed green seeds of Red Catuai, Yellow Catuai, Bourbon and Mundo Novo cultivars by HPLC and LC–MS. Average CGA contents in all cultivars and crops ranged from 6.1 ± 0.7 to 6.6 ± 1.1 g 100 g−1 (dry weight). The distribution of CGA classes was similar in all evaluated cultivars and crops, being CQA the major class, followed by diCQA and FQA. Total and individual CGA content did not vary significantly among cultivars when all crops were considered, but differed among crops. Our results indicate that in order to compare the CGA composition of different cultivars for selection of a CGA-rich cultivar or for other reason one should evaluate more than three crops.

Effect of foliar calcium chloride treatment on the level of chlorogenic acid, β-carotene, lutein and tocopherols in lettuce (Lactuca sativa L.)

The aim of the presented study was to determine the effect of foliar application of CaCl<sub>2</sub> on the level of β-carotene, lutein, tocopherols and phenolic compounds in the leaves of lettuce cv. Omega (<i>Lactuca sativa</i> L.). The experiments were conducted in the greenhouse of the Faculty of Cultivation and Fertilisation of Horticultural Plants, University of Life Sciences in Lublin. During the growing period, 7 and 14 days before harvest, the plants were treated with a solution of CaCl<sub>2</sub> with concentrations of 0.1 M and 0.2 M. Plants sprayed with water were the control treatment in the experiment. Analyses were performed on whole leaves and the blade without midrib. The obtained results indicate that the leaves of lettuce cv. Omega are a good source of phenolic compounds, carotenoids and tocopherols. The dominant carotenoid in lettuce cv. Omega was β-carotene. Foliar application of CaCl<sub>2</sub> on the plants did not have any significant effect on the level of β-carotene and lutein in the whole leaves. The contents of tocopherols, total phenolic compounds and chlorogenic acid were dependent on the concentration of CaCl<sub>2</sub>. The application of 0.1 M CaCl<sub>2</sub> solution in the plants resulted in a decrease in the level of total phenolic compounds and chlorogenic acid, and an increase in tocopherol content. However, the treatment of the plants with 0.2M CaCl<sub>2</sub> solution caused a lowering of the concentration of tocopherols and an increase in the content of chlorogenic acid and total phenolic compounds.

Impact of different colored shade polyethylene and maturation on development of flavonoids and phenolic acids in flowers of Chrysanthemum indicum L.

Chrysanthemum indicum L. is a significant medicinal plant, which flowers (capitula) are usually used as Chinese medicine. The phytochemical test analyzed the regularity of biosynthesis and degradation of flavonoids and phenolic acids in flowers which grown under colored polyethylene and harvested from five flowering stages. Dry weight of one thousand buds or flower heads from different maturation stages and total number of flowers from individual plant were evaluated as biomass yield. The results indicated that the total number of buds and flower heads of individual plant grown under red polyethylene film was substantially higher than other treatments (P<0.01), as well as accumulated more quercetin, apigenin and chlorogenic acid, but gave poor content of luteolin and caffeic acid. Comparing with plants grown in open condition, blue polyethylene has the lowest mean weight of one thousand buds or flower heads from different harvesting stages, but it has potentials to increase the total number of buds and flower heads from individual plant and the yield ofbioactive compounds total flavonoids, quercetin, apigenin, acacetin, linarin, chlorogenic acid and caffeic acid, except luteolin. Key word: Chrysanthemum indicum L., colored polyethylene, maturation, flavonoids, phenolic acids.

Chlorogenic acid levels in leaves of coffee plants supplied with silicon and infected by Hemileia vastatrix

Rust, caused by Hemileia vastatrix, is the main disease that decreases coffee production in Brazil. New and enhanced methods to reduce rust intensity that can be integrated with modern genetic and chemical approaches need to be investigated. Considering that many plant species supplied with silicon (Si) show increased resistance to several pathogens, this study examined the possible effect of this element in increasing chlorogenic acid (CA) concentrations in coffee leaves and, consequently, increasing the level of resistance to rust. Plants (cv. "Catuai Vermelho IAC 44") were inoculated with H. vastatrix after growing for 35 days in a hydroponic culture amended with 0 (-Si) or 2 (+Si) mM Si. Concentration of Si in leaf tissues was of 0.36 and 0.42 dag/kg for -Si and +Si treatments, respectively, but without a statistically significant difference. The area under rust progress curve was 154.5 and 119.4 for -Si and +Si treatments, respectively, but without significant statistical difference. For non-inoculated plants, the concentrations of total CA and caffeoyl-quinic acid (CQA) compounds (diCQA) were similar between -Si and +Si treatments. Even though there was an increase of 236.4 and 257.1%, respectively, for total CA and diCQA for +Si when compared to -Si treatment at 30 days after inoculation with H. vastatrix, reduction on rust severity was not obtained once the fungus had already colonized the leaf tissues. Therefore, regardless of the increase in the concentrations of chlorogenic acid on leaves, coffee resistance to H. vastatrix infection was not potentialized by Si.

Effects of harvesting stage on functional constituents of four kinds of Hangbaiju

To reveal the effects of harvesting stage on the functional constituents of four kinds of Hangbaiju and determine the best harvesting stage. Sixteen samples of Hualei, Taiju, Youju, Quanju were collected from Zhejiang Tongxiang. The content of total flavonoids were determined by UV spectrophotometry. Chlorogenic acid, lutelin-7-O-beta-D-glucoside and 3,5-O-discaffeoylquinc acid were analyzed by HPLC. The results showed that the effect of harvesting stage on the functional constituents of four kinds of Hangbaiju was significant. The contents of total flavonoids and chlorogenic acid reached maximum at the Hualei stage, and next was Taiju. The highest content of lutelin-7-O-beta-D-glucoside and 3,5-O-discaffeoylquinc acid was found in samples of Taiju. The yield of the four kinds of Hangbaiju increased obviously as the collection time deferred. Considering the functional constituents, yield and harvesting stage, the stage of Taiju is the best harvesting time.

Investigation of Optimum Roasting Conditions to Obtain Possible Health Benefit Supplement, Antioxidants from Coffee Beans

ABSTRACTIn order to investigate the role of roasting conditions in antioxidant formation, methanol and hot water extracts from Robusta coffee beans roasted for various lengths of time and at various temperatures were analyzed for total phenolic acid, chlorogenic acid, and caffeine content, as well as for their antioxidant activities using 1,1-diphenyl-2-picryhydrazyl (DPPH), thiobarbituric acid (TBA), and malonaldehyde/gas chromatography (MA/GC) assays. The amount of total phenolics in methanol extracts decreased linearly over the roasting temperature from 63.51 ± 0.77 mg chlorogenic acid equivalent (CAE)/g coffee beans (roasted at 200°C) to 42.56 ± 0.33 mg CAE/g coffee beans (roasted at 240°C). The total chlorogenic acid content decreased when the roasting time was increased from 78.33 ± 1.41 mg/g (green coffee beans) to 4.31 ± 0.23 mg/g (roasted for 16 min at 250°C). All methanol extracts from roasted coffee beans possessed over 90% antioxidant activities in the DPPH assay. The antioxidant activity of methanol extracts ranged from 41.38 ± 1.77% (roasted at 250°C for 10 min) to 98.20 ± 1.49% (roasted at 230°C for 16 min) as tested by the TBA assay. The antioxidant activity of methanol extracts of green coffee beans and roasted coffee beans ranged from 93.01% (green coffee beans) to 98.62 ± 1.32% (roasted at 250°C for 14 min) in the MA/GC assays. All hot water extracts exhibited moderate pro-oxidant activities in TBA and MA/GC assays. The results indicated that roasting conditions of coffee beans play an important role in the formation of antioxidants in brewed coffee, which can be dietary supplements having beneficial effect to human health.

Flavanols from green tea and phenolic acids from coffee: Critical quantitative evaluation of the pharmacokinetic data in humans after consumption of single doses of beverages

Coffee contains a complex mixture of chlorogenic acids, which are mainly ferulic and caffeic acids ester-linked to quinic acid. Green tea contains flavanols, mainly (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC) and (-)-epicatechin (EC). For healthy humans, we identified seven studies on green tea in liquid form and five on coffee beverage reporting single-dose plasma pharmacokinetics. Weighted averages, based on the number of subjects, and elimination of outliers, allowed estimation of some pharmacokinetic parameters. After consumption of an "average" cup of green tea containing 112 mg of (-)-epigallocatechin gallate, 51 mg of EGC and 15 mg of EC in 200 mL, the predicted C(max) values (total free and sulfate/glucuronide conjugates) in plasma are 125, 181 and 76 nM, respectively, together with 94 nM methyl-EGC and 51 nM methyl-EC (standard deviation <20%). After consumption of an "average" cup of coffee (160 mg total chlorogenic acids (0.46 mmol)/200 mL), predicted C(max) values of caffeic, ferulic, isoferulic, dihydrocaffeic and dihydroferulic acids are 114, 96, 50, 384 and 594 nM, respectively (too few studies to calculate standard deviation). Most studies report a very low amount of intact chlorogenic acids in plasma, with one exception. More studies on absorption of chlorogenic acids from coffee are required, including dose-response studies.