Coffee Components Research Articles

Multiple Beneficial effects Associated with Coffee Consumption on Human Liver

Coffee is widely consumed beverage in the world. Incidence of chronic liver disease decreases with intake of coffee.The main objective of this study is to elucidate the hepatoprotective as well as chemo protective effect of coffee consumption in relation to previous published data. Prospective cohort studies based on relationship between coffee intake and ultimate effects on liver cancer have drawn various conclusions. Coffee’s beneficial effects in various disease states have been demonstrated in variety of studies. Studies have provided data regarding effects of coffee in hot as well as in cold state. Level of blood cholesterol, following filtration, is affected by the coffee components. Among the components of coffee, caffeine played the significant role in reducing the level of ALT in coffee consumers as compared with non-coffee consumers. Coffee intake is associated with cardiovascular events and hypertension risks. However, intake of coffee has been found to be inversely related to the level of serum enzymes like gamma-glutamyltransferase, and alanine aminotransferase when studies relating to coffee effect on liver were performed in different countries. Moreover, the data based on epidemiological analysis, clearly suggested that liver cirrhosis had inverse relationship with coffee consumption; however, the results obtained were not sufficient to demonstrate that coffee may have hepatoprotective effect in liver injury. There is emerging evidence revealing that consumption of coffee has been associated with reduction of risks of various types of cancers. The emerging data on coffee consumption has revealed that it has beneficial effects in colorectal, pancreatic, and pharyngeal as well as in liver cancer. A systematic review was performed regarding association of coffee consumption and effect of coffee intake on liver diseases like hepatocellular carcinoma (HCC), viral hepatitis, cirrhosis and nonalcoholic fatty liver disease (NAFLD). Coffee consumption, in dose dependent manner, was found to improve the level of serum gamma-glutamyltransferase, alanine aminotransferase and aspartate aminotransferase in individuals which were found to be at risk of liver diseases. Anticancer effect of coffee on liver is achieved by induction as well as inhibition of specific enzymes. The patients with history of chronic liver disease who consume coffee, were reported to be at a reduced risk of liver to be cirrhotic, and a decreased mortality rate was observed in cirrhosis patients, as well as a decreased rate of development of Hepatocellular carcinoma was observed. In individuals with history of chronic hepatitis C, coffee intake was found to be associated with enhanced virologic reaction to antiviral drug therapy. Furthermore, coffee intake was reported to be inversely associated with the severeness of steatohepatitis in individuals with non-alcoholic fatty liver disorder. Therefore, in patients with chronic liver disease, coffee consumption on daily basis should be persuaded.

Identification and chromatographic determination of bioactive components in the instant coffee samples

This work is devoted to the identification of chlorogenic acids and their lactones as well as to the determination of the main isomers of these acids and caffeine in the instant coffee samples by HPLC-UV-MS. The features of HPLC determination of bioactive components (alkaloids and phenolic compounds) in coffee are discussed. The conditions for chromatographic separation of the main phenolic compounds - isomers of chlorogenic acids (CGA) and their derivatives, as well as for the caffeine in instant coffee, are selected. As a result of these studies the major components corresponding to the main isomers of caffeoylquinic acids (CQA) - 5-caffeoylquinic acid (5-CQA), 3-caffeoylquinic acid (3-CQA) and caffeine were identified. Using the literature data and the results of HPLC-UV-MS analysis the isomers of caffeoylquinic acids, feruloylquinic acids (FQA) and dicaffeoylquinic acids (diCQA) and some of their lactones were identified in the test samples of instant coffee. The components with m/z values of their deprotonated ions, which correspond to the coumaroylquinic, caffeoylferuloylquinic acids (CFQA) and some conjugates of cinnamic acid and tryptophan derivatives, were found. The content of 5-CQA, 3-CQA and caffeine in thirteen analyzed samples of instant coffee was determined and varied in the ranges of 3.4-11.6, 5.3-23.0 and 23.5-42.4 mg/g respectively. It was shown that the content of CGA in instant coffee can be an effective indicator of the quality of the product. Keywords : HPLC-UV-MS, isomers of chlorogenic acids, lactones of chlorogenic acids, caffeine, instant coffee DOI: http://dx.doi.org/10.15826/analitika.2017.21.3.008 E.A. Tishchenko, T.G. Tsiupko, V.V. Milevskaia, А .Z. Temerdashev Kuban State University, Stavropolskaia ul., 149, Krasnodar, 350040, Russia Federation

Characterization of Anti-Ice Nucleation Activity of the Extract from Coffee Refuse.

The supercooling-facilitating (SCF) activities, that is, the anti-ice nucleation activity of the hot water extracts from five types of processed food refuse was examined. The extract with the highest activity among five hot water extracts was coffee refuse, showing 1.50℃ of SCF activity at a final concentration of 0.1 mg/ml. From the hot water extract of coffee refuse, the coffee refuse extract containing various polyphenols was prepared by the ultrafiltration (less than MWCO 10,000), a solvent fractionation of ethyl acetate. The yield of coffee refuse extract was 0.9% (w/w) from dried coffee refuse. The SCF activity of the coffee refuse extract at a final concentration of 1.0 mg/ml was 4.2℃. HPLC analysis of the coffee refuse extract showed that caffeine and chlorogenic acid, which are major components of coffee, could be found at 173 and 62.3 µg/ml, respectively. However, the SCF activities of both compounds (0.70 and 1.06℃) at a final concentration of 0.1 mg/ml were lower than those of ferulic acid and coumaric acid, respectively at 3.40 and 2.35℃. This is the first report to our knowledge on the SCF activity of caffeine. The SCF activity of caffeine at a final concentration of 1.0 mg/ml was 2.3℃. The specificity of caffeine against various ice nuclei containing calcium oxalate, 9-fluorenon, and ice nucleating bacteria was examined. Caffeine at a final concentration of 1.0 mg/ml could inhibit the ice nucleation activity of calcium oxalate, and Pseudomonas fluorescens KUIN-1 at the same level that of as silver iodide. From these results, it was suggested that the extract could be able to be applied to the field to control the frost damage of the vegetables and that the harvested vegetables might be stored unfrozen even at 0℃ or less.

Having a Coffee Break: The Impact of Caffeine Consumption on Microglia-Mediated Inflammation in Neurodegenerative Diseases.

Caffeine is the major component of coffee and the most consumed psychostimulant in the world and at nontoxic doses acts as a nonselective adenosine receptor antagonist. Epidemiological evidence suggests that caffeine consumption reduces the risk of several neurological and neurodegenerative diseases. However, despite the beneficial effects of caffeine consumption in human health and behaviour, the mechanisms by which it impacts the pathophysiology of neurodegenerative diseases still remain to be clarified. A promising hypothesis is that caffeine controls microglia-mediated neuroinflammatory response associated with the majority of neurodegenerative conditions. Accordingly, it has been already described that the modulation of adenosine receptors, namely, the A2A receptor, affords neuroprotection through the control of microglia reactivity and neuroinflammation. In this review, we will summarize the main effects of caffeine in the modulation of neuroinflammation in neurodegenerative diseases.

Biochemical Components of Shaded Coffee under Different Management Levels

This study was conducted to evaluate the effect of management and shade levels on some biochemical components of coffee. The study was carried out at the Kenya Agricultural and Livestock Research Organization, Coffee Research Institute (KALRO-CRI) coffee farm in Bungoma County and two farmers’ fields in Bungoma County, representing high, medium and low management levels. The coffee management levels were categorized depending on field operations and application of inputs. The different shade levels were based on the distances from the shade tree trunk: 0-1.5, 1.5-3, 3-4.5, 4.5-6 m, respectively and coffee trees under full sun. The shading level was estimated by measuring the Photosynthetic Photon Flux Density in μmol m-2/s using a Line Quantum Sensor and expressing it as a percentage of that obtained under full sun. Fully ripe cherries were harvested, wet processed and the wet parchment dried to final moisture content of 10.5 to 11%. Caffeine, trigonelline, total chlorogenic acids, oil and sucrose were determined using specific methodologies and quantified on dry weight basis. The results showed that biochemical components were affected significantly due to shade and management levels. Most of the biochemical components were positively correlated with shade and management levels. This showed the possibility of manipulating the two parameters to enhance the quality of coffee.

Breakfast consumption induces retarded release of chlorogenic acid metabolites in humans

Coffee is the main source of chlorogenic acids (CGAs) in human nutrition. In this study, one main point of interest was whether the simultaneous consumption of coffee and food affects the absorption and bioavailability of CGAs. Fourteen healthy participants consumed pure instant coffee (T1), or coffee with either a high-carbohydrate (T2) or a high-fat meal (T3). All volunteers consumed the same quantity of CGAs (3.1 mg CGA/kg bw), and blood and urine samples were collected at various time points for up to 15 h and 24 h after consumption, respectively. Existing CGAs, and their respective metabolite concentrations, were determined using HPLC–ESI-MS/MS. The area under the curve (AUC) was the measure of CGA quantity in plasma samples collected after each treatment. We observed significantly greater CGA bioavailability after pure instant coffee consumption (T1) than with an additional consumption of a high-fat meal (T3). However, the difference in CGA bioavailability between pure coffee (T1) and coffee plus high-carbohydrate meal (T2) was not statistically significant. The latter observation held true when T3-samples were compared with T2-samples. When the metabolites were split into their respective classes, significant differences in the sums of AUC were observed only for some classes, and not among the treatments. Data did not show differences in the total bioavailability, but revealed differences in the kinetic of release. The co-ingestion of breakfast favored a slow and continuous release of colonic metabolites in contrast to the non-metabolized coffee components appearing in the first hour after coffee consumption. Urine samples collected over 24 h did not show any statistically significant differences among the treatments. Only samples collected within the first 6 h post-coffee consumption showed that the CGA quantities in urine samples collected after T1 and T3 were significantly greater than quantities with an additional consumption of carbohydrates (T2). Breakfast had no significant effect on CGA absorption from coffee. However, a shift in gastrointestinal transit time and in the plasma metabolite composition was observed. So breakfast consumption induces retarded release of chlorogenic acid metabolites in humans.

Investigation of CO2 precursors in roasted coffee.

Two CO2 formation pathways (chlorogenic acid (CGA) degradation and Maillard reaction) during coffee roasting were investigated. CGA is shown not a major contributor to CO2 formation, as heating of this compound under typical roasting conditions did not release a large quantity of CO2. However, heating of a CGA moiety, caffeic acid, resulted in high yield of CO2 (>98%), suggesting that CGA hydrolysis could be the rate limiting step for CO2 formation from CGA. A large amount of CO2 was detected from glycine-sucrose model system under coffee roasting conditions, implying the importance of Maillard reactions in CO2 formation. Further studies on the heating of various components isolated from green coffee beans showed that CO2 was generated from various green coffee components, including water insoluble proteins and polysaccharides. Around 50% of CO2 was formed from thermal reactions of lower molecular weight compounds that represent ∼25% by weight in green coffee.

A randomized placebo-controlled trial of the effect of coffee consumption on insulin sensitivity: Design and baseline characteristics of the Coffee for METabolic Health (COMETH) study.

BackgroundCoffee consumption has been consistently associated with a lower risk of type 2 diabetes mellitus in cohort studies. In addition, coffee components increased insulin sensitivity in animal models. However, data from intervention studies on the effect of coffee consumption on glucose metabolism have been limited by small sample sizes, lack of blinding, short follow-up duration and the use of surrogate indices of insulin sensitivity. We designed the Coffee for Metabolic Health (COMETH) study to evaluate the effect of coffee consumption on insulin sensitivity.MethodologyThe COMETH study is a double-blind randomized placebo-controlled 24-week trial. Participants were overweight, male and female habitual coffee consumers who were of Chinese, Malay and Asian-Indian ethnicity. We excluded smokers, persons with diabetes, and persons with low insulin resistance (HOMA-IR < 1.30). Participants were randomly assigned to receive daily 4 cups of instant regular coffee or 4 cups of a coffee-like placebo beverage. The hyperinsulinemic euglycemic clamp was performed at baseline and at the end of 24 weeks to determine changes in the bodyweight standardized M-value. Secondary outcomes included changes in fasting glucose and insulin sensitivity mediators such as adiponectin, markers of inflammation, liver function, and oxidative stress.We enrolled 128 participants, 126 (57.1% males; aged 35–67 years) of whom completed baseline assessments.DiscussionIf improvement in insulin sensitivity in the coffee group is significantly greater than that of the placebo group, this would support the hypothesis that coffee consumption reduced risk of type 2 diabetes through biological pathways involving insulin sensitivity.Trial registrationClinicalTrials.gov identifier: NCT01738399. Registered on 28 November 2012. Trial Sponsor: Nestlé Research Center, Lausanne, Switzerland. Trial Site: National University of Singapore.

Quercetin, not caffeine, is a major neuroprotective component in coffee

Epidemiologic studies indicate that coffee consumption reduces the risk of Parkinson's disease and Alzheimer's disease. To determine the factors involved, we examined the protective effects of coffee components. The test involved prevention of neurotoxicity to SH-SY5Y cells that was induced by lipopolysaccharide plus interferon-γ or interferon-γ released from activated microglia and astrocytes. We found that quercetin, flavones, chlorogenic acid, and caffeine protected SH-SY5Y cells from these toxins. They also reduced the release of tumor necrosis factor-α and interleukin-6 from the activated microglia and astrocytes and attenuated the activation of proteins from P38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa light chain enhancer of activated B cells (NFκB). After exposure to toxin containing glial-stimulated conditioned medium, we also found that quercetin reduced oxidative/nitrative damage to DNA, as well as to the lipids and proteins of SH-SY5Y cells. There was a resultant increase in [GSH]i in SH-SY5Y cells. The data indicate that quercetin is the major neuroprotective component in coffee against Parkinson's disease and Alzheimer's disease.

Neuroprotective Properties of the Coffee Component EHT

Coffee is a complex mixture of more than eight hundred compounds with a variety of health benefits including reducing the risk of neurodegenerative diseases such as Alzheimer's and Parkinson's disease. A coffee compound, unrelated to caffeine, called eicosanoyl‐5‐hydroxytryptamide (EHT) has been identified as a regulator of the major serine/threonine phosphatase in the brain, protein phosphatase 2A (PP2A). In diseased tissue, PP2A exhibits reduced activity and methylation of its carboxy‐terminal tail. Previous reports indicate EHT is able to protect PP2A's methylation state and activity in vitro in addition to improving cognitive and motor function in animal models. In order to further understand the role of EHT in neuroprotection we sought to evaluate its ability to combat oxidative injury, structural damage and chemical toxicity in neuronal cell cultures. Utilizing lipid peroxidation as a marker for oxidative injury, we directly measured the formation of lipid hydroperoxides in the presence and absence of EHT. This colorimetric assay reports on the redox reaction between iron and hydroperoxides. Our results indicate that EHT is able to significantly reduce the production of the ferric ion suggesting EHT possesses antioxidant activity that may aid in maintaining membrane integrity. Next we studied the potential of EHT to reinforce the structural integrity of neurons, specifically analyzing their neuronal processes. Differentiated SH‐SY5Y neuroblastoma cells were treated with lysophosphatidic acid (LPA) to induce neurite retraction. Upon treatment with EHT, an increase in neurite length was observed suggesting protection from LPA. Lastly, the neuroprotection of SH‐SY5Y neuroblastoma cells against the chemical neurotoxin MPTP was evaluated. Dose‐dependent treatments with EHT resulted in maximal neuroprotection at a concentration of 100 nM. These data further support EHT as a component from coffee with neuroprotective activity.

Coffee and tea consumption in relation with non-alcoholic fatty liver and metabolic syndrome: A systematic review and meta-analysis of observational studies

Diet plays a role in the onset and progression of metabolic disorders, including non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS). We aimed to systematically review and perform quantitative analyses of results from observational studies on coffee/tea consumption and NAFLD or MetS. A Medline and Embase search was performed to retrieve articles published up to March 2015. We used a combination of the keywords "coffee", "caffeine", "tea", "non-alcoholic fatty liver disease", "non-alcoholic steatohepatitis", "metabolic syndrome". Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by random-effects model. Seven studies assessed coffee consumption in NAFLD patients. Fibrosis scores were reported in four out of seven; all four studies revealed an inverse association of coffee intake with fibrosis severity, although the lack of comparable exposure and outcomes did not allow to perform pooled analysis. Seven studies met the inclusion criteria to be included in the meta-analysis on coffee consumption and MetS. Individuals consuming higher quantities of coffee were less like to have MetS (RR=0.87, 95% CI: 0.79-0.96). However, the association of coffee and individual components of MetS was not consistent across the studies. Pooled analysis of six studies exploring the association between tea consumption and MetS resulted in decreased odds of MetS for individuals consuming more tea (RR=0.83, 95% CI: 0.73-0.95). Studies on coffee and NAFLD suggest that coffee consumption could have a protective role on fibrosis. Both coffee and tea consumption are associated with less likelihood of having MetS but further research with better designed studies is needed.

High consumption of coffee is associated with decreased multiple sclerosis risk; results from two independent studies

ObjectivePrevious studies on consumption of caffeine and risk of multiple sclerosis (MS) have yielded inconclusive results. We aimed to investigate whether consumption of coffee is associated with risk of MS.MethodsUsing...

Coffee induces vascular endothelial growth factor (VEGF) expression in human neuroblastama SH-SY5Y cells

Recent evidence indicates that hypoxia-inducible vascular endothelial growth factor (VEGF) has neurotrophic and neuroprotective effects on neuronal and glial cells. On the other hand, recent epidemiological studies showed that daily coffee consumption has been associated with a lower risk of several neuronal disorders. Therefore, we investigated the effect of coffee on VEGF expression in human neuroblastoma SH-SY5Y cells. We found that even low concentration of coffee (<2%) strongly induced VEGF expression via an activation of HIF-1α. The activation of HIF-1α by coffee was attributed to the coffee-dependent inhibition of prolyl hydroxylation of HIF1α, which is essential for proteolytic degradation of HIF-1α. However, no inhibition was observed at the catalytic activity in vitro. Coffee component(s) responsible for the activation of HIF-1α was not major constituents such as caffeine, caffeic acid, chlorogenic acid, and trigonelline, but was found to emerge during roasting process. The active component(s) was extractable with ethyl acetate. Our results suggest that daily consumption of coffee may induce VEGF expression in neuronal cells. This might be related to protective effect of coffee on neural disorders such as Alzheimer's disease and Parkinson's disease.

Caffeine may enhance orthodontic tooth movement through increasing osteoclastogenesis induced by periodontal ligament cells under compression

ObjectiveCaffeine is the kernel component of coffee and has multiple effects on bone metabolism. Here we aimed to investigate the effects of caffeine intake on orthodontic tooth movement (OTM). Design(1) In the in vivo study, two groups comprising 15 randomly assigned rats each underwent orthodontic treatment. One group ingested caffeine at 25mg/kg body weight per day and the other, plain water. After 3 weeks, the degree of tooth movement and effect on the periodontium were assessed. (2) In the in vitro study, we established a model mimicking the essential bioprocess of OTM, which contained a periodontal ligament tissue model (PDLtm), and a co-culture system of osteoblasts (OBs) and osteoclast precursors (pre-OCs). After being subjected to static compressive force with or without caffeine administration, the conditioned media from the PDLtm were used for the OB/pre-OC co-cultures to induce osteoclastogenesis. Results(1) In vivo, the caffeine group displayed a significantly greater rate of tooth movement than the control. The alveolar bone mineral density and bone volume fraction were similar between the two groups; however, immunohistochemical staining showed that the caffeine group had significantly more TRAP+ osteoclasts and higher RANKL expression in the compressed periodontium. (2) In vitro, caffeine at 0.01mM significantly enhanced the compression-induced expression of RANKL and COX-2, as well as prostaglandin E2 production in the PDLtm. Furthermore, the “caffeine+compression”-conditioned media induced significantly more TRAP+ OC formation when compared with compression alone. ConclusionsDaily intake of caffeine, at least at some specific dosage, may enhance OTM through increasing osteoclastogenesis.

The Determination of Caffeine Level of Wolaita Zone, Ethiopia Coffee Using UV-visible Spectrophotometer

Coffee is an important commodity culturally, commercially and economically in the world. Because of its consumption in most countries in the world, it is important to investigate the exact amounts of its chemical constituents. Caffeine is one of the main components of coffee that affect the quality of coffee. In this research, rapid, simple, accurate, reproducible and cheap UV-Vis spectrometer was used for the quantification of caffeine in coffee and dichloromethane was used as a solvent for the coffee samples taken from Wolaita zone of five woredas. The results of this research show that the amount of caffeine of the coffee samples ranged from (450.13 to 579.60 (mg/L). The amounts of caffeine in Bolso Bomba coffee is the greatest, of all the other coffee samples studied in Wolaita Zone. On the other hand, Kindo Koisha and that of Bolso sore coffee has the least caffeine content compared to the other coffee samples measured. The caffeine content of Sodo Zuria coffee and Humbo coffee samples has an average amounts of caffeine.

Caffeine reduces hepatic lipid accumulation through regulation of lipogenesis and ER stress in zebrafish larvae.

BackgroundCaffeine, the main component of coffee, has showed its protective effect on non-alcoholic fatty liver disease (NAFLD) in many studies. However, the hepatoprotection of caffeine and its mechanisms in zebrafish were unexplored. Thus, this study’s intentions are to establish a NAFLD model of zebrafish larvae and to examine the role of caffeine on fatty liver with the model.ResultsGrowth and the incidence of fatty liver of zebrafish larvae increased with the increased amount of feeding in a dose-dependent manner. The degree of hepatic steatosis of larvae also gradually aggravated with the increased quantity and duration of feeding. Triglyceride contents of zebrafish fed for 20 days significantly increased in model group (180 mg/d) compared with control group (30 mg/d) (P < 0.001). Significant decreases in body weight and hepatic steatosis rate were observed in 2.5, 5, 8 % caffeine treatment group compared with model group (P < 0.05). Hepatic lipid accumulation was also significantly reduced in caffeine treatment larvae. Moreover, caffeine treatment was associated with upregulation of lipid β-oxidation gene ACO and downregulation of lipogenesis-associated genes (SREBP1, ACC1, CD36 and UCP2), ER stress-associated genes (PERK, IRE1, ATF6 and BIP), the inflammatory cytokine genes (IL-1beta and TNF-alpha) and autophagy associated genes (ATG12 and Beclin-1). Protein expression of CHOP, BIP and IL-1beta remarkably reduced in caffeine treatment group compared with model group.ConclusionsWe induced hepatoteatosis in zebrafish by overfeeding regimen and demonstrated caffeine have a role in suppression of hepatosteatosis by downregulation of genes associated with lipogenesis, ER stress, inflammatory response and enhancement of lipid oxidation, indicating zebrafish model may be used to identify putative pharmacological targets and to test novel drugs for human NAFLD treatment.

Coffee, tea, and melanoma risk among postmenopausal women.

Laboratory research suggests that components in coffee and tea may have anticarcinogenic effects. Some epidemiologic studies have reported that women who consume coffee and tea have a lower risk for melanoma. We assessed coffee, tea, and melanoma risk prospectively in the Women's Health Initiative - Observational Study cohort of 66,484 postmenopausal women, followed for an average of 7.7 years. Coffee and tea intakes were measured through self-administered questionnaires at baseline and at year 3 of follow-up. Self-reported incident melanomas were adjudicated using medical records. Cox proportional hazard models were used to estimate risk, adjusting for covariates, with person-time accumulation until melanoma diagnosis (n=398), death, loss to follow-up, or through 2005. Daily coffee [hazard ratio (HR)=0.87, 95% confidence interval (CI) 0.68-1.12] and tea (HR=1.03, 95% CI 0.81-1.31) intakes were not significantly associated with melanoma risk compared with nondaily intake of each beverage. No significant trends were observed between melanoma risk and increasing intakes of coffee (P for trend=0.38) or tea (P for trend=0.22). Women who reported daily coffee intake at both baseline and year 3 had a significantly decreased risk compared with women who reported nondaily intake at both time points (HR=0.68, 95% CI 0.48-0.97). Consistent daily tea intake was not associated with decreased melanoma risk. Overall, there is no strong evidence that increasing coffee or tea consumption can lead to a lower melanoma risk. We observed a decrease in melanoma risk among long-term coffee drinkers, but the lack of consistency in the results by dose and type cautioned against overinterpretation of the results.

The evaluation of inflammatory and oxidative stress biomarkers on coffee-diabetes association: results from the 10-year follow-up of the ATTICA Study (2002-2012).

The purpose of this work was to investigate the association between coffee drinking and diabetes development and potential mediation by oxidative stress and inflammatory biomarkers. In 2001-2002, a random sample of 1514 men (18-87 years old) and 1528 women (18-89 years old) were selected to participate in the ATTICA study (Athens metropolitan area, Greece). A validated food-frequency questionnaire was used to assess coffee drinking (abstention, casual, habitual) and other lifestyle and dietary factors. Evaluation of oxidative stress and inflammatory markers was also performed. During 2011-2012, the 10-year follow-up of the ATTICA study was carried out. The outcome of interest in this work was incidence of type 2 diabetes, defined according to American Diabetes Association criteria. During follow-up, 191 incident cases of diabetes were documented (incidence 13.4% in men and 12.4% in women). After various adjustments, individuals who consumed ⩾250 ml of coffee (≈1.5cup) had 54% lower odds of developing diabetes (95% confidence interval: 0.24, 0.90), as compared with abstainers. A dose-response linear trend between coffee drinking and diabetes incidence was also observed (P for trend=0.017). When controlling for several oxidative stress and inflammatory biomarkers, the inverse association between habitual coffee drinking and diabetes was found to be mediated by serum amyloid-A levels. This work highlights the significance of long-term habitual coffee drinking against diabetes onset. The anti-inflammatory effect of several coffee components may be responsible for this protection.

Identification of two metallothioneins as novel inhalative coffee allergens cof a 2 and cof a 3.

BackgroundDust of green coffee beans is known to be a relevant cause for occupational allergic disorders in coffee industry workers. Recently, we described the first coffee allergen (Cof a 1) establishing an allergenic potential of green coffee dust.ObjectiveOur aim was to identify allergenic components of green coffee in order to enhance inhalative coffee allergy diagnosis.MethodsA Coffea arabica pJuFo cDNA phage display library was created and screened for IgE binding with sera from allergic coffee workers. Two further coffee allergens were identified by sequence analysis, expressed in E. coli, and evaluated by Western blots. The prevalence of sensitization to recombinant Cof a 1, Cof a 2, and Cof a 3 and to commercially available extract was investigated by ELISA (enzyme-linked immunosorbent assay) respectively CAP (capacity test) screening in 18 sera of symptomatic coffee workers.ResultsIn addition to the previously described chitinase Cof a 1, two Coffea arabica cysteine-rich metallothioneins of 9 and 7 kDa were identified and included in the IUIS Allergen Nomenclature as Cof a 2 and Cof a 3. Serum IgE antibodies to at least one of the recombinant allergens were found in 8 out of 18 symptomatic coffee workers (44%). Only 2 of the analysed sera (11%) had reacted previously to the commercial allergy test.ConclusionsIn addition to the previously described Cof a 1 we have identified two further coffee proteins to be type I coffee allergens (Cof a 2 and Cof a 3) which may have a relevant potential for the specific diagnosis and/or therapy of coffee allergy.

English

The study aimed at comparing the effects of three coffee pulping methods on the physico-chemical properties and sensory qualities of coffee. The coffee cherries were processed by disc pulper, drum pulper and eco-pulper methods which varied on mode of operations and mucilage removal methods. The coffee parchment were dried to moisture content of 10 ± 1% and green coffee beans were evaluated for parameters including moisture content, mass, volume, density, pH, titratable acidity, protein, sucrose and lipids content of green coffee beans. The parameters such as moisture, mass, volume and density were determined by actual measurements. Protein was determined by Kjeldhal method, lipids were extracted by Soxhlet method and sucrose extracted and determined by HPLC. The pH showed some significant difference (p<0.05) between the treatments. There was no significant difference on other parameters such as mass, volume, density and titratable acidity, protein, lipids and sucrose. The processing methods showed similar levels on the scores of sensory attributes analyzed by qualified panelist and the scores varied between 7.0-10. The final quality was not significantly different between the processing methods and no defects and faults noted in the samples. It was concluded that the three processing methods do not vary on the levels of physico-chemical components of coffee and gives similar characteristics on sensory attributes and final quality of coffee beverage. Key words: Coffee processing, pulping methods, fermentation, physico-chemical composition, sensory quality.