Durevall, D.
There is a widespread belief that consumer coffee prices are high relative to bean prices and that lower consumer prices would lead to substantial increases in bean exports from Third-World countries. This issue is evaluated by analysing how retail prices, preferences and market power influence coffee demand in Sweden. A demand function is estimated for the period 1968-2002 and used, together with information on import prices of coffee beans, to simulate an oligopoly model. This approach gives estimates of the maximum average degree of market power and shows how coffee demand would react to reductions in marginal cost to its minimum level. The maximum level of market power is found to be low, but it generates large spreads between consumer and bean prices because the price elasticity has low absolute values. Moreover, the impact of a price decrease would be small because long-run coffee demand is dominated by changes in the population structure in combination with different preferences across age groups. Hence, a change to perfect competition would only have a negligible effect on bean imports.
Anon.
Specifications are provided for a reference chart which lists the 5 main categories of defects which are considered to be potenially present in green coffee, as marketed throughout the world, regardless of species, variety or after-harvest processing (wet or dry). The chart shows the influence of such defects on the loss of mass and on sensory properties by using the coefficients 0, 0.5 and 1. Each defect is given one of these values depending on how seriously it affects the above-mentioned characteristics. The final assessment can be a useful tool for trading parties and also gives a good indication to the purchaser of the quality of the green coffee concerned. The definitions can be used to specify terms of bilateral purchasing contracts or to classify coffee lots for their presentation to green coffee buyers or at a stock exchange. The specifications replace NEN-ISO 10470:2004 and are identical to ISO 10470:2004-01
Source : ISO
Piazza, L.; Gigli, J.; Bulbarello, A.
The espresso coffee beverage is a polyphasic colloidal system, in which the liquid phase is topped by a wet foam of tiny sphere-shaped gas bubbles. Each sphere is surrounded by a liquid film (lamellae) that isolates it from its neighbours and that hosts biopolymers and natural surfactants. Foaming biopolymers of coffee (total fraction and its sub-fractions: proteins/melanoidins fraction and polysaccharides fraction) were extracted from defatted and raw, commercially roasted ground coffee. In order to study the viscoelastic behaviour of the surface-adsorbed layer, all the extracted fractions were analyzed using a commercial interfacial rheometer CIR 100 operating in time sweep mode. The growth of the interfacial elasticity of the lamella implicitly contains all the information about the molecular interaction at the foam air/liquid interface. These interactions are described to be responsible for the foam stabilization. Results indicate that the kinetics of the film formation is mediated by the polysaccharide component and that the protein/melanoidin component of the coffee foaming fraction exhibits the highest viscoelastic interfacial properties. Lipids play a major role in the interfacial film formation due to their interaction with protein-like macromolecules, the melanoidins. A correlation was established between air/water interface properties of the foaming systems and the respective foam volumes evaluated by means of the image analysis. A new mathematical description of surface viscoelastic phenomena, covering the terms of transport of surfactant biopolymers to the interface and describing the coagulation of particles here taking place, is proposed. The suggested equation overcomes the Warburton model, taking into account the complexity of real food systems as in the case of the espresso coffee beverage.
Ramalakshmi, K.; Kubra, I. R.; Rao, L.-J. M.
: Defective (triage) coffee beans are beans rejected after grading according to size and colour. These coffee beans represent about 15-20% of coffee production in India but are not utilized for beverages since these affect the quality of brewed coffee. In this study, physical characteristics, such as bean density, brightness, titratable acidity, pH, moisture, as well as TSS and contents of caffeine, chlorogenic acids, lipids, sucrose, total polyphenols and proteins, were evaluated in defective and acceptable graded green coffee beans. Physical parameters such as wt., density and brightness of defective coffee beans were low compared with the graded beans, which is attributed to the presence of immature, broken, bleached and black beans. Caffeine content was low in triage beans compared with graded beans. Content of chlorogenic acid, a coffee component responsible for antioxidative activity, in defective coffee beans was similar to, or marginally higher in some cases, that of graded coffee beans. It is therefore concluded that triage coffee beans may be utilized as a source of antioxidative or radical scavenging activity in food systems.
Ramalakshmi, K.; Kubra, I. R.; Rao, L.-J. M.
: Defective (triage) coffee beans are beans rejected after grading according to size and colour. These coffee beans represent about 15-20% of coffee production in India but are not utilized for beverages since these affect the quality of brewed coffee. In this study, physical characteristics, such as bean density, brightness, titratable acidity, pH, moisture, as well as TSS and contents of caffeine, chlorogenic acids, lipids, sucrose, total polyphenols and proteins, were evaluated in defective and acceptable graded green coffee beans. Physical parameters such as wt., density and brightness of defective coffee beans were low compared with the graded beans, which is attributed to the presence of immature, broken, bleached and black beans. Caffeine content was low in triage beans compared with graded beans. Content of chlorogenic acid, a coffee component responsible for antioxidative activity, in defective coffee beans was similar to, or marginally higher in some cases, that of graded coffee beans. It is therefore concluded that triage coffee beans may be utilized as a source of antioxidative or radical scavenging activity in food systems.
Bytof, G.; Knopp, S. E.; Kramer, D.; Breitenstein, B.; Bergervoet, J. H.; Groot, S. P.; Selmar, D.
The chemical composition of green coffee and thus the final coffee quality are specifically determined by the mode of post-harvest treatment, i.e. the wet and dry processing. Recently, it was shown that metabolic processes, i.e. germination and, a slightly delayed stress-related metabolism are executed during the course of processing. The specific ambient conditions of either postharvest treatment may influence differentially the extent and time course of these metabolic reactions; therefore, the incidence and intensity of germination processes in coffee seeds were analysed during processing. METHODS: Expression of the germination-specific isocitrate lyase was monitored using competitive RT-PCRs analyses. Resumption of cell cycle activity and cell division were determined by flow cytometry, as well as by the abundance of beta-tubulin quantified by Western blot analyses. KEY RESULTS: The extent and the time courses of germination processes in coffee seeds differed significantly between wet and dry processed beans. The highest germination activity occurred 2 d after the onset of wet processing, whereas the corresponding maximum in the course of dry processing appeared about 1 week after the start of post harvest treatment.
CONCLUSIONS: As recently shown, there are specific differences in the chemical composition of differentially processed coffee beans. It is concluded that these substantial differences are the consequence of the differential expression of germination processes, i.e. they are the result of differences in the corresponding metabolic activities. The coherence of germination-related metabolism and of expression-specific coffee qualities establishes the basis for a novel approach in coffee research.
Nardi, A.E; Valença, A.M.; Nascimento, I.; Freire, R.C.; Veras, A.B; de Melo-Neto, V.L.; Lopes, F.L. King, A.L.; Soares-Filho, G.L.; Mezzasalma, M. A.: Rassi, A.; Zin, W.A.
Our aim was to observe the induction of anxiety symptoms and panic attacks by a caffeine challenge test in panic disorder (PD) patients (DSM-IV) and their healthy first-degree relatives. We randomly selected 25 PD patients, 27 healthy first-degree relatives of probands with PD, and 22 healthy volunteers with no family history of PD. In a randomized double-blind experiment performed over two occasions 7 days apart, 480 mg caffeine and a caffeine-free solution were administered in a coffee form. Using specific panic attack criteria, 52.0% (n=13) PD patients, 40.7% (n=11) first-degree relatives (2=1.81, df=1, P=0.179), and none of the control subjects had a panic attack after the test (2=51.7, df=2, P<0.001). In this caffeine challenge test, PD patients and their first-degree relatives were more sensitive than healthy volunteers to the panic attack symptoms but less sensitive to headache, increase in blood pressure, and insomnia. Our data suggest that there is an association between panic attacks after the intake of 480 mg of caffeine in PD patients and their first-degree relatives. There is a clear differentiation of PD patients and their first-degree relatives by a caffeine test from the healthy group.
Source : Depression and Anxiety 2007
Kendrick, S. F.; Day, C. P.
A minority of persons at risk develop liver cirrhosis, but knowledge of risk modulators is sparse. Several reports suggest that coffee drinking is associated with lower cirrhosis risk.
Murosaki, S.; Lee, T. R.; Muroyama, K.; Shin, E. S.; Cho, S. Y.; Yamamoto, Y.; Lee, S. J.
To develop an anti-obesity agent containing dietary components, we focused on the mechanisms that enhance both lipolysis and fatty acid oxidation. Caffeine and arginine (CA), a nonselective adenosinereceptor antagonist and an inducer of lipolytic hormone, respectively, were used to stimulate lipolysis. Soy isoflavones and l-carnitine (SL), stimulators of carnitine palmitoyl transferase 1A and a cofactor for betaoxidation of fatty acids, respectively, were used to enhance fatty acid oxidation. Effects of a combination of CA and SL (CASL) on lipid metabolism were studied in vitro and in vivo. During 3T3-L1 differentiation, lipid accumulation was significantly lower in cells treated with CASL (50 mumol/L, 1 mmol/L, 1 mumol/L, and 1 mmol/L, respectively) compared with each alone. Lipolysis was also significantly greater in 3T3-L1 adipocytes treated with CASL (50 mumol/L, 1 mmol/L, 10 mumol/L and 0.5 mmol/L, respectively) compared with each alone. In addition, treatment with higher concentrations of CASL (2 mmol/L, 1 mmol/L, 10 mumol/L, and 1 mmol/L, respectively) significantly enhanced beta-oxidation in HepG2 cells. The effects of CASL-containing diets (250 mg, 6 g, 200 mg, and 1.5 g/kg diet, respectively) were studied in vivo. When KK mice were food deprived for 48 h and subsequently refed a fat-free diet for 72 h, hepatic triglyceride (TG) accumulation was significantly lower in mice fed CASL compared with the control mice. In addition, after obese KK mice were fed a low-fat diet for 2 wk, adipose tissue weights were significantly lower in those fed CASL, but not CA or SL alone, compared with the control mice. Plasma and liver TG levels were also lower in mice fed CASL than in the control mice. These results suggest that CASL is effective for controlling obesity.
Nehad, E. A.; Farag, M. M.; Kawther, M. S.; Abdel-Samad, A.-K. M.; Naguib, K.
Ochratoxin A (OTA) is a hepatonephrotoxic and carcinogenic mycotoxin. OTA has been known as intermittent contaminant of coffee beans and other stored cereals. Analysis of OTA in 30 locally roasted ground (R) and 45 green (G) coffee bean samples imported from 7 coffee producing countries was carried out. Of the green coffee samples 60% were contaminated with OTA at levels reaching 5.66 mug kg-1 with an average of 1.55 mug kg-1 while 66.67% of the roasted ground samples showed levels ranging from <5 to 8.35 and average 6.1 mug kg-1. 5 media were used for the determination of the total fungal counts and/or the percentages of fungal infection on green and ground roasted coffee beans. 8 fungi genera were found, Aspergillus predominated followed by Penicillium, Fusarium and Alternaria but in much lower percentages in both (G) and (R) coffee beans. 5 species of Aspergillus were detected. A. niger predominated followed by A. flavus, A. ochraceus in both green and roasted coffee beans. The 75 isolates of A. ochraceus from both G and R coffee beans 47 isolates were potential producers of OTA on both YES and SM media. The average yield of OTA elaborated in the latter medium was significantly higher than that in the former one.
Dew, T. P.; Day, A. J.; Morgan, M.-R. A.
Several studies have shown beneficial associations between tea consumption and bone mineral density (BMD) and fracture risk. Current investigations into potential mechanisms of benefit are focused upon the F and polyphenol components of tea. However, previous studies have pointed towards caffeine consumption as a potential risk factor for low BMD and high fracture risk. Tea, therefore, represents an interesting paradox as a mildly caffeinated beverage that may enhance bone health. Fruit and vegetable intake has also been associated with BMD, and it is now apparent that several fruit and vegetable components, including polyphenols, may contribute positively to bone health. This review covers evidence of dietary mediation in positive and negative aspects of bone health, in particular the roles of tea, fruit and vegetables, and of caffeine, flavonoids and polyphenols as components of these foods. Aspects considered include: tea and bone health (epidemiological studies, putative mechanisms relating tea to BMD (F and positive bone health, fluorosis, flavonoids), caffeine and bone health (epidemiological studies, putative mechanisms for the effects of caffeine upon BMD, the significance of caffeine to BMD conclusions)); and fruits, vegetables and bone health (epidemiological studies, putative mechanisms of the effects of fruits and vegetables upon BMD, role for polyphenols, phytoestrogens and BMD, role for other compounds). Since the deleterious effects of caffeine appear to have been overstated, especially in respect of the positive effects of flavonoids, it is concluded that a reassessment of the role of caffeinated beverages may be necessary.
Pardo-Lozano, R.; Alvarez-Garcia, Y.; Barral-Tafalla, D.; Farre-Albaladejo, M.
Coffee, tea, chocolate and caffeinated drinks are the main sources of caffeine, which is consumed in almost all ages and socioeconomic levels. Caffeine acts as a non-selective adenosine receptor antagonist in the central nervous system. Its main effects are as psychostimulant, acting in addition on the respiratory, muscular and cardiovascular systems. Basically, caffeine is metabolized by the hepatic cytochrome P-450 1A2 enzymes (CYP1A2). Several drugs can interact with its metabolism. The observed interindividual differences of its effects can be explained by variations in its metabolism. The main therapeutic use of caffeine is bronchodilator in respiratory diseases. Other possible uses are under investigation. Acute or chronic consumption of caffeine can induce several adverse effects, including intoxication that can be lethal. Finally, caffeine can be considered a drug of abuse. It has positive reinforcing actions, produces tolerance, and a withdrawal syndrome after stopping its consumption. Caffeine can cause different mental disorders such as dependence, which is not included in the DSM-IVR, withdrawal syndrome and intoxication. Depending on its use, caffeine can be considered a nutrient, a drug or a drug of abuse.
Source : Adicciones 2007 vol.19 (3), pp 225 - 238 (not available on line)
De Luca, M. A.; Bassareo, V.; Bauer, A.; Di Chiara, G.
It has been reported that caffeine (1.5-30 mg/kg i.p.) as well as specific A1 (DPCPX, 8-cyclopentyl-1,3- dipropylxanthine) receptor antagonists fail to increase extracellular dopamine (DA) in the shell of the nucleus accumbens (NAc). However, it has also been reported that caffeine (10 and 30 mg/kg i.p.) and the A1 antagonist 8-cyclopentyl-1,3-dimethylxanthine (CPT) increases NAc shell DA. To clarify this issue rats were implanted with microdialysis probes at different sites in the NAc shell, in the medial prefrontal cortex (PFCX, infralimbic cortex), and at the border between those areas. Irrespective of probe placement within the NAc shell and of the use of different surgical anesthetics (chloral hydrate and ketamine), we failed to observe changes in dialysate DA after 10 and 30 mg/kg i.p. of caffeine. Similarly negative results were obtained with DPCPX and CPFPX, two potent and selective A1 receptor antagonists. A significant increase of DA was obtained after caffeine when probes were located at the border between the NAc shell and the PFCX (10 and 30 mg/kg) or in the PFCX (10 mg/kg). In view of this and of our previous report that caffeine increases dialysate DA in the medial PFCX, we conclude that the increase in dialysate DA by caffeine observed by others arises from the medial PFCX rather than from the NAc shell as a result of placement of microdialysis probes at the border between the NAc shell and the PFCX.
Altimari, L. R.; Cordeiro-de-Melo, J.; Costa-Trindade, M.-C. de; Serpeloni-Cyrino, E.; Tirapegui, J.
Caffeine is present in several commercial products consumed daily, such coffee, chocolate, teas and soft drinks containing guarana. This article reviews the use of this substance among athletes, in relation to: impact on exercise performance; types of athletes most likely to use caffeine; diuretic effects of caffeine; and the potential impact of removal of caffeine from the list of substances prohibited by the World Anti Doping Agency (WADA).
Source : Nutrire.2006 vol.31(1), pp 79 - 96
Molema, M. M.; Dekker, M. C.; Voermans, N. C.; van Engelen, B. G.; Aarnoutse, R. E.
No abstract available
Source : Am J Med 2007 vol.120 (8), pp e1 -s2
Armstrong, L. E.; Casa, D. J.; Maresh, C. M.; Ganio, M. S.
Dietitians, exercise physiologists, athletic trainers, and other sports medicine personnel commonly recommend that exercising adults and athletes refrain from caffeine use because it is a diuretic, and it may exacerbate dehydration and hyperthermia. This review, contrary to popular beliefs, proposes that caffeine consumption does not result in the following: (a) water-electrolyte imbalances or hyperthermia and (b) reduced exercise-heat tolerance.
Bichler, J.; Cavin, C.; Simic, T.; Chakraborty, A.; Ferk, F.; Hoelzl, C.; Schulte-Hermann, R.; Kundi, M.; Haidinger, G.; Angelis, K.; Knasmuller, S.
Aim of the study was to investigate the impact of coffee on DNA-stability in humans. DNA-damage was monitored in lymphocytes of eight individuals with single cell gel electrophoresis assays before and after consumption of 600 ml coffee (400 ml paper filtered and 200 ml metal filtered/d) for five days. Under standard conditions, no alteration of DNA-migration was seen, but a strong reduction of DNA-migration attributable to endogenous formation of oxidised purines and pyrimidines was detected with restriction enzymes; furthermore DNA-damage caused by reactive oxygen radicals (H2O2 treatment) and by the heterocyclic aromatic amine 3-amino-1-methyl-5H-pyrido[4,3-b]indole-acetate was significantly reduced after coffee consumption by 17% and 35%, respectively. Also in in vitro experiments, inhibition of H2O2 induced DNA-damage was observed with coffee at low concentrations (<or= 25 microl/ml) whereas the diterpenoids cafestol and kahweol caused only marginal effects indicating that the effects of coffee are due to scavenging effects of other constituents. Enzyme measurements showed that additionally induction of antioxidant enzymes may play a role: while the activity of glutathione peroxidase was only marginally increased after coffee consumption, a significant (38%) increase of superoxide dismutase activity was detected. Comparisons with results of earlier studies suggest that coffee consumption may prevent oxidative DNA-damage to a higher extent as diets enriched in fruits and vegetables.
Bravi, F.; Bosetti, C.; Tavani, A.; Bagnardi, V.; Gallus, S.; Negri, E.; Franceschi, S.; La Vecchia, C.
Several studies suggest an inverse relation between coffee drinking and risk of hepatocellular carcinoma (HCC). We conducted a meta-analysis of published studies on HCC that included quantitative information on coffee consumption. Ten studies were retrieved (2,260 HCC cases), including 6 case-control studies from southern Europe and Japan (1551 cases) and 4 cohort studies from Japan (709 cases). The summary relative risk (RR) for coffee drinkers versus non-drinkers was 0.54 (95% confidence interval [CI] 0.38-0.76) for case-control studies and 0.64 (95% CI 0.56-0.74) for cohort studies. The overall RR was 0.59 (95% CI 0.49-0.72), with significant heterogeneity between studies. The overall summary RR for low or moderate coffee drinkers was 0.70 (95% CI 0.57-0.85), and that for high drinkers was 0.45 (95% CI 0.38-0.53). The summary RR for an increase of 1 cup of coffee per day was 0.77 (95% CI 0.72-0.83) from case-control studies, 0.75 (95% CI 0.65-0.85) from cohort studies, and 0.77 (95% CI 0.72-0.82) overall. The consistency of an inverse relation between coffee drinking and HCC across study design and geographic areas weighs against a major role of bias or confounding. Coffee drinking has also been related to reduced risk of other liver diseases, thus suggesting a continuum of the favorable effect of coffee on liver function. However, subjects with liver conditions may selectively reduce their coffee consumption. CONCLUSION: The present analysis provides evidence that the inverse relation between coffee and HCC is real, though inference on causality remains open to discussion.
Source : Hepatology 2007 vol.46 (2), pp 430 - 435 (see also Science Daily)
Natella, F.; Nardini, M.; Belelli, F.; Scaccini, C.
Epidemiologic and intervention studies indicate that both diet as a whole and single dietary components are involved in the risk of atherosclerosis. The resistance of LDL to oxidative modification is an ex vivo indicator of risk, which is modulated by dietary components. Coffee contains phenolic compounds with antioxidant activity. These molecules are found in plasma after the consumption of coffee, and it has been shown that, in vitro, they are able to decrease the susceptibility of LDL to oxidation. OBJECTIVE: The aim of this study was to evaluate the effect of coffee consumption on the redox status of LDL as modulated by the possible incorporation of phenolic acids into LDL. DESIGN: Ten healthy volunteers, after an overnight fast, drank 200 mL filtered coffee. Blood was drawn before and and 60 min after drinking. Changes in LDL redox status were evaluated by the measure of LDL resistance to oxidative modification and the concentration of LDL(-), a mildly modified, electronegative LDL subfraction. Chlorogenic and phenolic acids concentration in LDL were measured by electrochemical HPLC. RESULTS: The resistance of LDL to oxidative modification increased significantly after coffee drinking, but the LDL(-) concentration did not increase. The concentration into LDL of conjugated forms of caffeic, p-coumaric, and ferulic acids increased significantly after coffee drinking.
CONCLUSION: Drinking 200 mL (1 cup) coffee induces an increase in the resistance of LDL to oxidative modification, probably as a result of the incorporation of coffee\'s phenolic acids into LDL.
Kroon, L. A.
The mechanisms for drug interactions with smoking and clinically significant pharmacokinetic ad pharmacodynamic drug interactions with smoking are reviewed. SUMMARY: Polycyclic aromatic hydrocarbons (PAHs) are some of the major lung carcinogens found in tobacco smoke. PAHs are potent inducers of the hepatic cytochrome P-450 (CYP) isoenzymes 1A1, 1A2, and, possibly, 2E1. After a person quits smoking, an important consideration is how quickly the induction of CYP1A2 dissipates. The primary pharmacokinetic interactions with smoking occur with drugs that are CYP1A2 substrates, such as caffeine, clozapine, fluvoxamine, olanzapine, tacrine, and theophylline. Inhaled insulin\'s pharmacokinetic profile is significantly affected, peaking faster and reaching higher concentrations in smokers compared with nonsmokers, achieving significantly faster onset and higher insulin levels. The primary pharmacodynamic drug interactions with smoking are hormonal contraceptives and inhaled corticosteroids. The most clinically significant interaction occurs with combined hormonal contraceptives. The use of hormonal contraceptives of any kind in women who are 35 years or older and smoke 15 or more cigarettes daily is considered contraindicated because of the increased risk of serious cardiovascular adverse effects. The efficacy of inhaled corticosteroids may be reduced in patients with asthma who smoke. CONCLUSION: Numerous drug interactions exist with smoking. Therefore, smokers taking a medication that interacts with smoking may require higher dosages than nonsmokers. Conversely, upon smoking cessation, smokers may require a reduction in the dosage of an interacting medication.
Source : Am J Health Syst Pharm 2007 vol.64 (18), pp 1917 - 1921
Bassini-Cameron, A.; Sweet, E.; Bottino, A.; Bittar, C.; Veiga, C.; Cameron, L. C.
OBJECTIVE: To evaluate the effect of caffeine on white cell distribution and muscle injury markers in professional soccer players during exercise. METHODS: 22 male athletes completed a placebo controlled double blind test protocol to simulate a soccer match, followed by a Yo-Yo intermittent recovery test. RESULTS: Exercise caused an increase in packed cell volume that was enhanced by caffeine. Caffeine and exercise had a synergistic effect on the blood lymphocyte count, which increased by about 38% after exercise, and by an additional 35% when combined with caffeine. Caffeine promoted an exercise independent rise in circulating monocytes, and a synergistic action of exercise and caffeine was observed on segmented neutrophils. Caffeine promoted thrombocytosis. Plasma adenosine deaminase, aspartate aminotransferase, and lactate dehydrogenase concentrations were enhanced by exercise, and alanine transaminase concentration was enhanced in both groups, with a synergistic effect of caffeine.
CONCLUSIONS: The pronounced increase in the white cell count in the group receiving caffeine appeared to be caused by greater muscle stress and consequently more intense endothelial and muscle cell injury. The use of caffeine may augment the risk of muscle damage in athletes.
Cornelis, M. C.; El Sohemy, A.; Campos, H.
Caffeine is the most widely consumed stimulant in the world, and individual differences in response to its stimulating effects may explain some of the variability in caffeine consumption within a population. OBJECTIVE: We examined whether genetic variability in caffeine metabolism [cytochrome P450 1A2 (CYP1A2) -163A<right arrow> C] or the main target of caffeine action in the nervous system [adenosine A2A receptor (ADORA2A) 1083C<right arrow> T] is associated with habitual caffeine consumption. DESIGN: Subjects (n = 2735) were participants from a study of gene-diet interactions and risk of myocardial infarction who did not have a history of hypertension. Genotype frequencies were examined among persons who were categorized according to their self-reported daily caffeine intake, as assessed with a validated food-frequency questionnaire. RESULTS: The ADORA2A, but not the CYP1A2, genotype was associated with different amounts of caffeine intake. Compared with persons consuming <100 mg caffeine/d, the odds ratios for having the ADORA2A TT genotype were 0.74 (95% CI: 0.53, 1.03), 0.63 (95% CI: 0.48, 0.83), and 0.57 (95% CI: 0.42, 0.77) for those consuming 100-200, >200-400, and >400 mg caffeine/d, respectively. The association was more pronounced among current smokers than among nonsmokers (P for interaction = 0.07). Persons with the ADORA2A TT genotype also were significantly more likely to consume less caffeine (ie, <100 mg/d) than were carriers of the C allele [P = 0.011 (nonsmokers), P = 0.008 (smokers)]. CONCLUSION: Our findings show that the probability of having the ADORA2A 1083TT genotype decreases as habitual caffeine consumption increases. This observation provides a biologic basis for caffeine consumption behavior and suggests that persons with this genotype may be less vulnerable to caffeine dependence.
Walker, G. J.; Finlay, O.; Griffiths, H.; Sylvester, J.; Williams, M.; Bishop, N. C.
This study investigated the effect of caffeine consumed with and without carbohydrate (CHO) on immunoendocrine responses after exercise. METHODS:: On four occasions, 12 recreational male cyclists cycled for 2 h at 65% V O2max. Sixty minutes before exercise, participants ingested 6 mg.kg body mass of caffeine (CAF) or placebo (PLA), then during exercise they consumed a 6% CHO or placebo (PLA) drink, providing CAF/CHO, PLA/CHO, CAF/PLA, and PLA/PLA conditions. RESULTS:: f-MLP-stimulated neutrophil oxidative burst responses were significantly higher after exercise on CAF/CHO and PLA/CHO (both P < 0.05) than PLA/PLA when expressed as a percentage of baseline value. The response on CAF/PLA tended to be higher than PLA/PLA at this point (P = 0.056). No significant differences between CAF/CHO, PLA/CHO, and CAF/PLA were observed after exercise; however, only PLA/CHO showed no significant postexercise decline. Coingestion of CAF/CHO significantly attenuated epinephrine (P < 0.05) and IL-6 (P < 0.05) responses that occurred after ingestion of CAF alone (CAF/PLA) and significantly attenuated the transient alterations in circulating leukocyte (P < 0.05) and neutrophil (P < 0.01) counts. Plasma cortisol concentration was significantly lower on PLA/CHO than CAF/PLA and PLA/PLA after exercise (P < 0.05). Perceived exertion during exercise was significantly lower on CAF/CHO than the other three trials (P < 0.05).
CONCLUSION:: Taken together, this suggests that coingestion of caffeine and CHO has greater influence on immunoendocrine responses than neutrophil functional responses to prolonged exercise.
Ulanowska, K.; Piosik, J.; Gwizdek-Wisniewska, A.; Wegrzyn, G.
MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is a neurotoxin causing symptoms that resemble those observed in patients suffering from Parkinson\'s disease. However, in animal or human organisms, MPTP is converted to MPDP(+) (1-methyl-4-phenyl-2,3-dihydropyridinium) and further to MPP(+) (1-methyl-4-phenylpyridinium); the latter compound is the actual neurotoxin. In this report, we demonstrate that MPDP(+) and MPP(+) can form stacking complexes with methylxanthines (caffeine and penthoxifylline), which leads to significant impairment of the biological activity of these toxins (as measured by their mutagenicity).
Silvera, S. A.; Jain, M.; Howe, G. R.; Miller, A. B.; Rohan, T. E.
There is some evidence from case-control studies that coffee consumption might be positively associated with ovarian cancer risk, whereas the epidemiologic evidence regarding tea consumption and ovarian cancer is inconsistent. To date, there have been few prospective studies of these associations. Therefore, we examined ovarian cancer risk in association with both coffee and tea intake in a prospective cohort study of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 and 1985. Linkages to national mortality and cancer databases yielded data on deaths and cancer incidence, with follow-up ending between 1998 and 2000. Data from the food frequency questionnaire were used to estimate daily intake of coffee and tea. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between categories of coffee and tea intake and ovarian cancer risk. During a mean 16.4 years of follow-up, we observed 264 incident ovarian cancer cases. Tea intake was not associated with ovarian cancer risk in our study population. In contrast, a borderline positive association was observed among women who drank > 4 cups coffee/day compared to women who did not drink coffee (HR = 1.62, 95% CI = 0.95-2.75, P(trend) = 0.06). Given the pervasive use of these beverages, the associations between coffee and tea consumption and ovarian cancer risk warrant investigation in further prospective studies.
Panagiotakos, D. B.; Lionis, C.; Zeimbekis, A.; Makri, K.; Bountziouka, V.; Economou, M.; Vlachou, I.; Micheli, M.; Tsakountakis, N.; Metallinos, G.; Polychronopoulos, E.
We evaluated the association between coffee drinking and the prevalence of type 2 diabetes mellitus in elderly people from the Mediterranean islands. METHODS: During 2005-2007, 500 men and 437 women (aged 65 to 100 years) from the islands of Cyprus (n = 300), Mitilini (n = 142), Samothraki (n = 100), Cephalonia (n = 104), Corfu (n = 160) and Crete (n = 131) participated in the survey. Cardiovascular disease (CVD) risk factors (i.e. hypertension, diabetes, hypercholesterolemia and obesity), as well as behavioral, lifestyle and dietary characteristics were assessed using face-to-face interviews and standard procedures. Among various factors, fasting blood glucose was measured and prevalence of type 2 diabetes mellitus was estimated, according to the established American Diabetes Association (ADA) criteria, while all participants were asked about the frequency of any type of coffee consumption over the last year. RESULTS: Coffee drinking was reported by 84% of the participants, the majority of whom drank boiled coffee. The participants reported that they had consumed coffee for at least 30 years of their life. Data analysis adjusted for various potential confounders, revealed that, compared to non-consumption, the multi-adjusted odds ratio for having diabetes was 0.47 (95%, CI 0.32 to 0.69) for 1-2 cups/day, while it was 1.05 (95%, CI 0.70 to 1.55) for >3 cups/day, after adjusting for various potential confounders. The association of coffee drinking with diabetes was significant only among non-tea drinkers. Increased coffee intake was not associated with diabetes prevalence. CONCLUSION: The data presented suggest that moderate coffee drinking is associated with a lower likelihood of having diabetes, after adjusting for various potential confounders.
Mikkila, V.; Rasanen, L.; Raitakari, O. T.; Marniemi, J.; Pietinen, P.; Ronnemaa, T.; Viikari, J.
The Cardiovascular Risk in Young Finns Study is an ongoing, prospective cohort study assessing the effects of two major dietary patterns and several risk factors on cardiovascular disease. The main dietary patterns are, firstly, a diet characterised by a high consumption of rye, potatoes, butter, sausages, milk and coffee, and, secondly, a diet characterised by a high consumption of vegetables, legumes, nuts, rye, cheese, and other dairy products. The former diet was found to be associated with cardiovascular risk factors whilst the second, more health-conscious diet, was found to be inversely, but less strongly, associated with cardiovascular risk factors.
Source : Brit J Nutr 2007 vol.98 (1), pp 218-225 (not available on line)
Gurpegui, M.; Jurado, D.; Luna, J. D.; Fernandez-Molina, C.; Moreno-Abril, O.; Galvez, R.
Some studies find a relationship between certain personality traits, as impulsivity or sensation seeking, and caffeine consumption, but these studies do not consider the potential confounding effect of smoking on caffeine intake, a co-occurrence that has been well demonstrated in epidemiological and clinical studies. The main objective of this cross-sectional study was to analyze the association of personality with caffeine intake controlling for the effects of smoking; a secondary objective was to explore the effect of caffeine intake on the previously known relationship between personality and smoking. METHODS: A sample of 498 adults answered a self-questionnaire including socio-demographic variables, and items regarding consumption of tobacco and caffeine. Personality was measured by the Temperament and Character Inventory (TCI-125). We analyzed the association of personality traits with both caffeine intake and smoking, controlling the possible confounding effects of sex, age and each substance with the other one. RESULTS: Logistic regression analyses showed that the temperamental dimension of novelty seeking was associated with heavy caffeine consumption (>200 mg/day) (adjusted OR=2.0; 95% CI: 1.1-3.9), controlling for the effect of smoking. Moreover, novelty seeking was associated with both smoking (adjusted OR=1.8; 95% CI: 1.1-2.9) and heavy smoking (>20 cigarettes/day) (adjusted OR=1.8; 95% CI: 1.0-3.7), after controlling for the effect of caffeine intake.
ONCLUSION: Our study offers an epidemiological evidence of the relationship of novelty seeking, considered to be associated with low basal dopaminergic activity, with both nicotine consumption and heavy caffeine intake, two substances that enhance dopaminergic neurotransmission.
Source : Prog Neuropsychopharmacol Biol Psychiatry 2007 vol.31 (5), pp 997 - 1005
Koo, S. W.; Hirakawa, S.; Fujii, S.; Kawasumi, M.; Nghiem, P.
Characterization of mechanisms that can reverse residual damage from prior skin exposure to ultraviolet (UV) would be of considerable biological and therapeutic interest. Topical caffeine application to mouse skin that had previously been treated with UV has been shown to inhibit the subsequent development of squamous cell carcinomas. OBJECTIVES: We used an established mouse photodamage model to investigate other possible effects of topical caffeine application after UV. METHODS: SKH-1 hairless mice were treated with ultraviolet B (UVB) followed immediately by topical application of caffeine or vehicle three times weekly for 11 weeks. RESULTS: Caffeine applied topically after UV treatment resulted in a significant decrease in UV-induced skin roughness/transverse rhytides as assessed by treatment-blinded examiners. Histologically, topical caffeine application after a single dose of UVB more than doubled the number of apoptotic keratinocytes as evaluated by sunburn cell formation, caspase 3 cleavage and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) staining. A trend towards decreased solar elastosis was noted in the caffeine-treated group although this was not statistically significant. Other histological parameters including epidermal hyperplasia, solar elastosis and angiogenesis were increased in mice treated with UV but topical application of caffeine did not alter these particular UV effects. CONCLUSIONS: These findings support the concept that topical application of caffeine to mouse skin after UV irradiation promotes the deletion of DNA-damaged keratinocytes and may partially diminish photodamage as well as photocarcinogenesis.
Rengelshausen, J.; Goggelmann, C.; Burhenne, J.; Riedel, K. D.; Mikus, G.; Walter-Sack, I.; Haefeli, W. E.
: Urinary caffeine metabolic ratios used to quantify the activity of numerous drug-metabolizing enzymes are an established component of cocktail approaches for metabolic phenotyping. Because in vitro evidence suggests that 1-methylxanthine (1-MX), a major caffeine metabolite, is actively secreted into urine by organic anion transporters (hOATs), coadministration of renal hOAT inhibitors like probenecid may impair these procedures. METHODS: In a randomized, placebo-controlled, double-blind crossover design, single oral doses of 300 mg caffeine with oral coadministration of placebo or 500 mg probenecid 3 times daily for 2 days were administered to 7 healthy men. The plasma and urine concentrations of caffeine and its major metabolites 1,7-dimethylxanthine (1,7-DMX) and 1-MX were determined by high-performance liquid chromatography. RESULTS: Coadministration of probenecid resulted in a 34% reduction of the renal clearance of 1-MX (mean +/- SD 190 +/- 42 versus 290 +/- 83 ml min(-1), 95% CI on difference 0.2, 200, p = 0.04) with a 41% reduction in its estimated non-glomerular clearance. The renal clearances of caffeine and 1,7-DMX and the area under the plasma concentrationtime curves of all substances were not significantly changed.
CONCLUSIONS: 1-MX undergoes renal tubular secretion which is substantially reduced by probenecid, possibly due to inhibition of renal hOATs. This inhibition may explain the influence of probenecid on urinary caffeine metabolic ratios and, thus, its impact on the assessment of enzyme activities. It also suggests that 1-MX might serve as a model substrate for the renal tubular transport of organic anions.
Source : Int J Clin Pharmacol Ther 2007 vol.45 (8), pp 431 - 437
Clyman, R. I.; Roman, C.
Caffeine and other methyl xanthines are widely used in the neonatal period. A recent, randomized, placebo-controlled, multicenter trial found that infants who were randomly assigned to caffeine treatment had less need for pharmacologic and/or surgical closure of a patent ductus arteriosus (PDA). We hypothesized that the decreased need for pharmacologic and surgical closure of the PDA after caffeine treatment might be due to a direct effect of caffeine on ductus contractility. We examined preterm fetal lamb ductus arteriosus (from 24 fetuses, 105 +/- 4 d of gestation, term = 147 d), in vitro to determine the direct effects of caffeine on the isometric tension of the ductus arteriosus. Caffeine (0.003-0.3 mM) had no direct effect on ductus arteriosus tension, nor did it affect the contractile response of the ductus arteriosus to increasing oxygen concentrations. Caffeine\'s lack of effect was observed in both the presence and absence of indomethacin and NG-nitro-L-arginine methyl ester (L-NAME) (inhibitors of prostaglandin and nitric oxide production). In conclusion, we found no evidence of a direct effect of therapeutic caffeine concentrations on ductus contractility.
Ritchie, K.; Carriere, I.; de Mendonca, A.; Portet, F.; Dartigues, J. F.; Rouaud, O.; Barberger-Gateau, P.; Ancelin, M. L.
OBJECTIVE: To examine the association between caffeine intake, cognitive decline, and incident dementia in a community-based sample of subjects aged 65 years and over. METHODS: Participants were 4,197 women and 2,820 men from a population-based cohort recruited from three French cities. Cognitive performance, clinical diagnosis of dementia, and caffeine consumption were evaluated at baseline and at 2 and 4 year follow-up. RESULTS: Caffeine consumption is associated with a wide range of sociodemographic, lifestyle, and clinical variables which may also affect cognitive decline. Multivariate mixed models and multivariate adjusted logistic regression indicated that women with high rates of caffeine consumption (over three cups per day) showed less decline in verbal retrieval (OR = 0.67, CI = 0.53, 0.85), and to a lesser extent in visuospatial memory (OR = 0.82, CI = 0.65, 1.03) over 4 years than women consuming one cup or less. The protective effect of caffeine was observed to increase with age (OR = 0.73, CI = 0.53, 1.02 in the age range 65 to 74; OR = 0.3, CI = 0.14, 0.63 in the range 80+). No relation was found between caffeine intake and cognitive decline in men. Caffeine consumption did not reduce dementia risk over 4 years.
CONCLUSIONS: The psychostimulant properties of caffeine appear to reduce cognitive decline in women without dementia, especially at higher ages. Although no impact is observed on dementia incidence, further studies are required to ascertain whether caffeine may nonetheless be of potential use in prolonging the period of mild cognitive impairment in women prior to a diagnosis of dementia.
Lu, Y. P.; Nolan, B.; Lou, Y. R.; Peng, Q. Y.; Wagner, G. C.; Conney, A. H.
Treatment of SKH-1 mice orally with caffeine (0.1 mg/ml in the drinking water), voluntary running wheel exercise, or a combination of caffeine and exercise for 2 weeks (i) decreased the weight of the parametrial fat pads by 35, 62, and 77%, respectively; (ii) decreased the thickness of the dermal fat layer by 38, 42, and 68%, respectively; (iii) stimulated the formation of UVB-induced apoptotic sunburn cells in the epidermis by 96, 120, and 376%, respectively; and (iv) stimulated the formation of UVB-induced caspase 3 (active form)-positive cells in the epidermis by 92, 120, and 389%, respectively (average of two experiments). Oral administration of caffeine (0.4 mg/ml in the drinking water) in combination with voluntary exercise was less effective than administration of the low dose of caffeine in combination with exercise in stimulating UVB-induced apoptosis. Although orally administrated caffeine (0.1 mg/ml in the drinking water) or voluntary exercise for 2 weeks caused only a small nonsignificant stimulation of UVB induced increase in the percentage of phospho-p53 (Ser-15)-positive cells in the epidermis (27 or 18%, respectively), the combination of the two treatments enhanced the UVB-induced increase in phospho-p53 (Ser-15)-positive cells by 99%. The plasma concentration of caffeine in mice ingesting caffeine (0.1-0.4 mg/ml drinking water) is similar to that in the plasma of most coffee drinkers (one to four cups per day). Our studies indicate a greater than additive stimulatory effect of combined voluntary exercise and oral administration of a low dose of caffeine on UVB-induced apoptosis.
Source : Proc Natl Acad Sci U S A 2007 vol.104 (31), pp 12936 - 12941
Robin, L. P.
Acrylamide and furan are both potential human carcinogens that occur in food as a result of cooking or heat processing. A review of studies by the FDA on acrylamide and furan is described, together with international research findings. Acrylamide has been found mainly in plant-based foods, particularly potato products, cereal foods and coffee. Research has focused on ways to reduce formation of acrylamide in foods. A broad range of activities regarding acrylamide initiated by the FDA is summarised. The FDA has developed a large database of acrylamide levels in foods, and has studied Acrylamide toxicology. The EU has established an Acrylamide Information Base to summarise EU activities, and held several meetings to share information on acrylamide risk and potential reduction strategies. Californian state food safety law Proposition 65 may force food manufacturers and restaurant chains to provide labelling warning of possible acrylamide content. FDA and international toxicological research relating to furan is detailed.
So, Hyun Kim; Ko, Woon Yoon; Mi, Kyo Kim; Se, Hee Paek; Dongmi, Choi; Sangsuk, Oh; Jin, Byung Park
Acrylamide contents of foods were analysed by LC-MS after degradation of food matrix components by digestive enzymes (pepsin and pancreatin) and extraction with water. Quantities of Acrylamide detected in samples of cereals, potato chips, peanuts and coffee were 62 ± 5.1, 970, 106 ± 20 and 890 ppb, respectively. No acrylamide was detected in tofu, fish cakes or ham. Digestive enzyme treatment led to approx. 2x increases in amounts of acrylamide detected in cereal and peanut samples, but had no impact on amounts detected in other food types. Results suggest that enzymic digestion increases the accuracy of acrylamide analysis by LC-MS after aqueous extraction.
Source : Food Sci Biotech 2007 vol.16(3), pp 493 - 495 (not available on line)
Chambers, L.; Mobini, S.; Yeomans, M. R.
Previous studies found that caffeine consumers acquired a liking for the flavour of novel caffeinated drinks when these drinks were consumed repeatedly in a caffeine-deprived, but not nondeprived, state. Expression of this acquired liking appeared acutely sensitive to current caffeine deprivation state, but the use of between-subjects designs confounded interpretation of those studies. The present study evaluated these findings further using a within-subject design, with one flavour paired with caffeine (CS + ) and the second with the absence of caffeine (CS-). During four CS + and four CS- training days, 32 moderate caffeine consumers alternatively consumed a novel flavoured drink a CS + paired with caffeine and a CSflavour paired with placebo. Participants evaluated both drinks before and after training in two motivational states: caffeine deprived and nondeprived. As predicted, pleasantness ratings for the caffeine-paired flavour increased overall. However, this acquired liking was only significant when tested in a caffeinedeprived state. These data are consistent with a conditioned-flavour preference model and imply that expression of acquired liking for a novel caffeinated flavour depends on the need for the effects of caffeine at the time when the drink is evaluated.
Source : Q.J Exp Psychol (Colchester.) 2007 vol.60 (10), pp 1356 - 1366
Wunnecke, H.; Bonnlander, B.; Winterhalter, P.
These two items highlight research into coffee analysis methods. The first looks at the characterisation of different dichlorogenic acids in roasted coffee, while the second looks at a rapid and sensitive detection method for Robusta traces in blends of raw and roasted coffees.
Source : Lebensmittelchemie; 2007.61 (4), 79-80 (not available on line)
Lopez-Galilea, I.; Paz-de-Pena, M.; Cid, C.
Relationships between volatile and nonvolatile compounds and the antioxidant capacity of coffee brews prepared from commercial conventional and torrefacto roasted coffees, employing commonly used doses and prepared by 4 brewing procedures (filter, plunger, mocha and espresso machine) were assessed. Significant correlations between volatile Maillard reaction products and antioxidant capacity (measured by both 2,2-diphenyl-1-picrylhydrazyl radical and redox potential methods) were not observed. Highly positive correlations between browned compounds and caffeine with both antioxidant capacity parameters were reported. Principal component analysis allowed coffee brews separation according to coffee roasting processes (PC1) and brewing procedures (PC2), showing that in all cases coffee brews from torrefacto roasted coffee were more antioxidant that those extracted from conventional ones; also, coffee brews extracted by an espresso machine were more antioxidant than those extracted by mocha, plunger and filter machines.
Thomas, J. B.; Sharpless, K. E.; Mitvalsky, S.; Roman, M.; Yen, J.; Satterfield, M. B.
The concentrations of caffeine and caffeine-related compounds in 2 ephedra-containing reference materials have been determined by 3 independent methods with measurements performed by the National Institute of Standards and Technology (NIST) and a collaborating laboratory. Results from the 3 methods were used for value assignment of caffeine, theobromine, and theophylline in these Standard Reference Materials (SRMs). The methods used at NIST to determine the concentration levels of caffeine, theobromine, and theophylline in SRM 3243 Ephedra-Containing Solid Oral Dosage Form and SRM 3244 Ephedra-Containing Protein Powder used reversed-phase liquid chromatography with absorbance detection and tandem mass spectrometry. These reference materials are part of the first suite in a series of NIST SRMs that provide concentration values for multiple components in dietary supplements. These SRMs are primarily intended for method validation and for use as control materials to support the analysis of dietary supplements and similar materials.
Mancha-Agresti, P.-D. C.; Franca, A. S.; Oliveira, L. S.; Augusti, R.
The coffee roasted in Brazil is considered to be of low quality, due to the presence of defective coffee beans that depreciate the beverage quality. In view of the fact that coffee flavour is directly related to the volatile compounds produced during roasting, the objective of the present study was to perform a comparative evaluation of the volatile fraction of defective (black, immature, sour) and healthy coffee beans, in order to find possible chemical markers for detection of defective coffee beans in roasted coffee. Volatiles extraction and concentration was performed by solid phase micro-extraction (SPME) of the roasted coffee headspace, using a triple phase (divinylbenzene/carboxen/polydimethylsiloxane) fiber. Analysis of the volatile profiles was performed by GC-MS. The results obtained showed that the proposed methodology was adequate for extraction, concentration and analysis of the coffees volatile profile. Several substances were identified as possible markers for differentiating black, sour and immature beans from healthy coffee beans. Statistical analysis of the data by principal components (PCA) demonstrated that the volatile profile enables the differentiation of healthy and defective coffees. The data were separated into two major groups, one represented by immature and black beans and the other by healthy and sour coffee beans. Such results indicated that black and sour beans can be associated to fermentation of immature and of healthy beans, respectively.
Jham, G. N.; Winkler, J. K.; Berhow, M. A.; Vaughn, S. F.
Adulteration of coffee with cereals, coffee twigs etc. is apparently widespread in Brazil with corn being considered the most widely used contaminant. No adequate methods are available to detect such contamination in commercial coffee. A new method, based on HPLC tocopherol determination was developed to detect coffee adulteration by corn. Percentages of alpha-, beta-, gamma-, and deltatocopherol determined using HPLC in 6 coffee varieties were 29.0, 61.7, 3.3 and 6.0, respectively. Similar values were obtained in 6 popular coffee brands. Percentages of alpha-, gamma- and delta-tocopherol in 6 corn samples were 3.6, 91.3 and 5.1, respectively. These differences could be applied to detect corn in a pure coffee sample intentionally contaminated with corn with the best result obtained with gammatocopherol. Using this methodology, 1 coffee brand was apparently adulterated (8.9%), most likely with corn. Tocopherol fingerprinting offers the potential to detect adulteration.
Muscat, S.; Munch, G.; Pischetsrieder, M.; Kolling, Speer, I; Kurzrock, T.; Speer, K.; Dunger, H.; Hilal, Y.; Engelhardt, U. H.; Geschwantner, U.; Haupt, N.; Glomb, M. A.
This series of short items summarise analytical and other research done into coffee and tea. Subject areas include the immune modulating effect of coffee and melanoidins; the methylcafestol and caffeine content of selected commercial instant coffees; HPLC analysis of coffee diterpenes; a rapid method for the determination of the amino acid theanine in tea and tea extracts; the properties of white tea; and the antioxidant capacity of the phenolic compounds in rooibos (redbush) tea.
Source : Lebensmittelchemie 2007 vol.61 (4), pp 74 - 76 (not available on line)
Yamauchi, Y.; Nakamura, A.; Kitai, M.; Hatanaka, K.; Kohno, I.; Tanimoto, T.
We have improved sample pre-treatment for the effective removal of polyphenols and simple analysis of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (PVPP). Nearly 100% of catechins were removed from the green tea sample and caffeine was completely recovered in the range of 98.2-101.3% by sample pre-treatment with a PVPP cartridge. Reproducibility of preparing PVPP pre-treatment cartridges was sufficient for quantitative analysis, because RSDs of analytical values for caffeine obtained by using three individual pre-treatment cartridges filled with 10-200 mg PVPP were 0.60-2.8%. The PVPP pre-treatment cartridge also removed polyphenols perfectly and recovered caffeine faultlessly from oolong and black tea samples. Comparison with the conventional method without sample pre-treatment indicated that the present pre-treatment method with a PVPP cartridge was useful for the simple and precise analysis of caffeine in green, oolong and black tea samples.
Source : Chem Pharm Bull (Tokyo) 2007 vol.55 (9), pp 1393 - 1396
Clifford, M. N.; Kirkpatrick, J.; Kuhnert, N.; Roozendaal, H.; Salgado, P. R.
The behaviour of cis isomers of selected mono- and di-acyl chlorogenic acids produced by UVirradiation has been investigated by LC-MSn. cis Isomers fragment identically to the more common trans isomers. cis-5-Acyl chlorogenic acids are more hydrophobic and elute later than their mono- or di-trans counterparts whereas the reverse is true for cis-3-acyl and cis-4-acyl chlorogenic acids. The cis isomers of 1,3-dicaffeoylquinic acid, the only 1-acyl chlorogenic acid investigated, are also more hydrophobic than the di-trans isomer. Coffee leaves had a proportionately greater content of cis isomers relative to trans isomers compared with coffee beans suggesting that UV-irradiation in vivo may also cause geometric isomerisation.
Ucun, F.; Saglam, A.; Guclu, V.
The molecular structures, vibrational frequencies and corresponding vibrational assignments of xanthine and its methyl derivatives (caffeine and theobromine) have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-31G(d, p) basis set level. The calculations were utilized to the C(S) symmetries of the molecules. The obtained vibrational frequencies and optimised geometric parameters (bond lengths and bond angles) were seen to be well agreement with the experimental data. The used scale factors which have been obtained the ratio of the frequency values of the strongest peaks in the calculated and experimental spectra seem to cause the gained vibrations well corresponding to the experimental ones. Theoretical infrared intensities and Raman activities are also reported.
Source : Spectrochim Acta A Mol Biomol Spectrosc 2007 vol.67 (2), pp 342 - 349
Leong, S. L.; Hien, L. T.; An, T. V.; Trang, N. T.; Hocking, A. D.; Scott, E. S.
The aim of this study was to determine the incidence and severity of infection by ochratoxin A (OA)- producing fungi in Vietnamese green coffee beans. Aspergillus carbonarius, A. niger and yellow Aspergilli (A. ochraceus and related species in section Circumdati) were isolated by direct plating of surface disinfected Robusta (65 samples) and Arabica (11 samples) coffee beans from southern and central Vietnam. Significantly, more Robusta than Arabica beans were infected by fungi. Aspergillus niger infected 89% of Robusta beans, whereas A. carbonarius and yellow Aspergilli each infected 12-14% of beans. OA was not produced by A. niger (98 isolates) or A. ochraceus (77 isolates) but was detected in 110 of 113 isolates of A. carbonarius, 10 isolates of A. westerdijkiae and one isolate of A. steynii. The maximum OA concn. observed in samples severely infected with toxigenic species was 1.8 mug kg-1; however, no relationship between extent of infection and OA contamination was observed. Vietnamese green coffee beans were more severely infected with fungi than the levels reported for beans from other parts of the world, yet OA contamination appears to be infrequent. Results suggest that Aspergillus niger is the dominant species infecting Vietnamese coffee beans, yet A. carbonarius is the likely source of OA contamination.
Source : Letters in Applied Microbiology.2007 vol.45 (3), pp 301 - 306
Kaikake, K.; Hoaki, K.; Sunada, H.; Dhakal, R. P.; Baba, Y.
The feasibility of using coffee beans after being dripped and degreased (DCB) as an adsorbent for base metals such as copper(II), zinc(II), lead(II), iron(III) and cadmium(II) were examined. The compositions of the DCB were characterized by Fourier transform infrared spectroscopy, scanning electronic micrograph and fluorescent X-ray. It was found that DCB contain sulfur and calcium from te analysis using fluorescent X-ray. The plant cell wall in DCB has the porous structure from the scanning electron microscopy (SEM) analysis, and the specific surface area was determined to be 1.2 m2/g using the specific surface area analyzer. Batch adsorption experiments on DCB were carried out at various pHs in order to elucidate the selectivity of metal ions. All metals were adsorbed at low pH region (3.0-5.0). Of particular interest was the adsorption characteristics of cadmium(II) on DCB. The adsorption isotherm for cadmium(II) at pH 8 fitted with a Langmuir equation to yield an adsorption equilibrium constant of 55.2 mmol dm(-3) and an adsorption capacity of 5.98 x 10(-2) mmol g(-1). The desorption of cadmium(II) was easily achieved over 90% by a single batchwise treatment with an aqueous solution of hydrochloric acid or nitric acid at more than 0.01 mol dm(-3). These results suggested that DCB behaves as a cation exchanger.
Source : Bioresour Technol 2007 vol.98 Issue 15 pp 2787 - 2791
Aranda, M.; Morlock, G.
This item reports on a method for detecting and determining a range of components in sports and energy drinks, improving on the several methods that have been developed to detect these separately. The high-throughput method for simultaneous detection of riboflavin (vitamin B2), pyridoxine (vitamin B6), nicotinamide, caffeine and taurine uses HPTLC-UV/VIS/FLD with mass confirmation using HPTLC/ESI/MS. The method is reported to be simple, reliable and robust and to offer a good alternative for routine analysis.
Source : Lebensmittelchemie 2007 vol.61 (4), 93 (not available on lline)
Pizarro, C.; Esteban-Diez, I.; Gonzalez-Saiz, J. M.; Forina, M.
Near-infrared spectroscopy (NIRS), combined with diverse feature selection techniques and multivariate calibration methods, has been used to develop robust and reliable reduced-spectrum regression models based on a few NIR filter sensors for determining two key parameters for the characterization of roasted coffees, which are extremely relevant from a quality assurance standpoint: roasting color and caffeine content. The application of the stepwise orthogonalization of predictors (an "old" technique recently revisited, known by the acronym SELECT) provided notably improved regression models for the two response variables modeled, with root-mean-square errors of the residuals in external prediction (RMSEP) equal to 3.68 and 1.46% for roasting color and caffeine content of roasted coffee samples, respectively. The improvement achieved by the application of the SELECT-OLS method was particularly remarkable when the very low complexities associated with the final models obtained for predicting both roasting color (only 9 selected wavelengths) and caffeine content (17 significant wavelengths) were taken into account. The simple and reliable calibration models proposed in the present study encourage the possibility of implementing them in online and routine applications to predict quality parameters of unknown coffee samples via their NIR spectra, thanks to the use of a NIR instrument equipped with a proper filter system, which would imply a considerable simplification with regard to the recording and interpretation of the spectra, as well as an important economic saving. Keywords: Multivariate calibration; NIRS; feature selection; stepwise orthogonalization; roasted coffee; quality assurance; roasting color.
Wang, Y.; Bennet, A. J.
Two isomeric bicyclo[4.1.0]heptane analogues of the glycosidase inhibitor galacto-validamine, (1R*,2S,3S,4S,5S,6S*)-5-amino-1-(hydroxymethyl)bicyclo[4.1.0]heptane-2,3,4-triol, have been synthesized in 13 steps from 2,3,4,6-tetra-O-benzyl-D-galactose. The inhibitory activities of the two conformationally restricted amines, and their corresponding acetamides, were measured against commercial alpha-galactosidase enzymes from coffee bean and E. coli. The activity of the glycosyl hydrolase family GH27 enzyme (coffee bean) was competitively inhibited by the 1R,6S-amine (7), a binding interaction that was characterized by a K(i) value of 0.541 microM. The GH36 E. coli alphagalactosidase exhibited a much weaker binding interaction with the 1R,6S-amine (IC(50)= 80 microM). The diastereomeric 1S,6R-amine (9) bound weakly to both galactosidases, (coffee bean, IC(50)= 286 microM) and (E. coli, IC(50)= 2.46 mM).
Benoit, I.; Asther, M.; Bourne, Y.; Navarro, D.; Canaan, S.; Lesage-Meessen, L.; Herweijer, M.; Coutinho, P. M.; Asther, M.; Record, E.
The full-length gene that encodes the chlorogenic acid hydrolase from Aspergillus niger CIRM BRFM 131 was cloned by PCR based on the genome of the strain A. niger CBS 513.88. The complete gene consists of 1,715 bp and codes for a deduced protein of 512 amino acids with a molecular mass of 55,264 Da and an acidic pI of 4.6. The gene was successfully cloned and overexpressed in A. niger to yield 1.25 g liter-1, i.e., 330-fold higher than the production of wild-type strain A. niger CIRM BRFM131. The histidine-tagged recombinant ChlE protein was purified to homogeneity via a single chromatography step, and its main biochemical properties were characterized. The molecular size of the protein checked by mass spectroscopy was 74,553 Da, suggesting the presence of glycosylation. ChlE is assembled in a tetrameric form with several acidic isoforms with pIs of around 4.55 and 5.2. Other characteristics, such as optimal pH and temperature, were found to be similar to those determined for the previously characterized chlorogenic acid hydrolase of A. niger CIRM BRFM 131. However, there was a significant temperature stability difference in favor of the recombinant protein. ChlE exhibits a catalytic efficiency of 12.5 x 106 M-1 s-1 toward chlorogenic acid (CGA), and its ability to release caffeic acid from CGA present in agricultural by-products such as apple marc and coffee pulp was clearly demonstrated, confirming the high potential of this enzyme.
Source : Appl Environ Microbiol 2007 vol.73 (17), pp 5624 - 5632