Auxiliadora Santos, M.; Chalfoun, S. M.; Pimenta, C. J.
Influence of wet processing of husked coffee cherry (with or without mucilage removed) combined with different drying methods on physicochemical properties of arabica coffee was studied. Data are presented for effects of the different treatments on K leaching, electrical conductivity, polyphenol oxidase (PPO; catechol oxidase), pH, total solids and sugars. Both coffee cherry preparation and drying method influenced studied characteristics. Wet peeling of coffee cherry with mucilage intact followed by drying in the open air resulted in superior quality. Reduction in electrical conductivity and K leaching was observed as well as increase in PPO activity.
Source : Ciencia e Agrotecnologia 2009 vol.33 (1), pp 213-218 (full text)
Robinson, L. E.; Spafford, C.; Graham, T. E.; Smith, G. N.
Recent work showing that caffeine impairs glucose tolerance may be of particular concern in pregnancy because of a possible negative effect on fetal outcome. The current study sought to assess the effect of acute caffeine ingestion on glucose tolerance in women with or without gestational diabetes mellitus (GDM). Methods: Nineteen women whose routine GDM test was negative (control) and eight women with an initial positive GDM screen completed two trials one week apart in a double-blind randomized crossover study. Following an overnight fast, subjects ingested caffeine (3 mg/kg pre-pregnancy body weight) or an identical-appearing placebo (gelatin) capsule and one hour later began a 75 g 2-hour oral glucose tolerance test. Results: In the control group, caffeine did not significantly affect blood glucose, insulin, or C-peptide. In the GDM group, glucose area under the curve (AUC) was greater (P < 0.01), C-peptide AUC was greater (P < 0.05), and insulin sensitivity index was lower (18%, P < 0.05) after caffeine than after placebo.
Conclusion: Caffeine impaired insulin sensitivity in women with GDM. Additional research regarding more specific dietary caffeine recommendations for women with GDM is warranted.
Ferrazzano, G. F.; Amato, I.; Ingenito, A.; De Natale, A.; Pollio, A.
Polyphenols occurring in cocoa, coffee and tea can have a role in the prevention of cariogenic processes, due to their antibacterial action. Cocoa polyphenol pentamers significantly reduce biofilm formation and acid production by Streptococcus mutans and S. sanguinis. In the same way, trigonelline, caffeine and chlorogenic acid occurring in green and roasted coffee interfere with S. mutans adsorption to saliva-coated hydroxyapatite beads. Studies carried out on green, oolong and black tea indicate that tea polyphenols exert an anti-caries effect via an anti-microbial mode-of-action, and galloyl esters of (-)-epicatechin, (-)-epigallocatechin and (-)-gallocatechin show increasing antibacterial activities. The anti-cariogenic effects against alpha-haemolytic streptococci showed by polyphenols from cocoa, coffee, and tea suggest further studies to a possible application of these beverages in the prevention of pathogenesis of dental caries.
Hsu, C. W.; Chen, C. Y.; Wang, C. S.; Chiu, T. H.
Caffeine, an antagonist of adenosine A(1) and A(2A) receptor, is the most widely used psychoactive substance in the world. Evidence indicates that caffeine interacts with the neuronal systems involved in drug reinforcing. Although adenosine A(1) and/or A(2A) receptor have been found to play important roles in the locomotor stimulation and probably reinforcing effect of caffeine, the relative contribution of the A(1) and/or A(2A) receptors to the acute and chronic motor activation and reinforcing effects of caffeine has not been completely investigated. OBJECTIVE: The roles of adenosine A(1) and/or A(2A) receptor and the association of phospho-Thr75-dopamine- and cAMP-regulated phosphoprotein of molecular weight 32 kDa (DARPP-32) in the motor activation and reinforcing effects of caffeine, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective A(1) antagonist, and 5-amino-7-(beta-phenylethyl)-2-(8-furyl) pyrazolol [4,3-e]-1,2,4-triazolol [1,5-c] pyrimidine (SCH58261), a selective A(2A) receptor antagonist were examined. METHODS: Locomotor stimulation and behavioral sensitization of caffeine, DPCPX, and SCH58261 were studied in C57BL/6 male mice following acute and chronic administration. Conditioned place preference (CPP) paradigm was used to evaluate the drug-seeking potential of these compounds. Furthermore, the expression of phospho-Thr75-DARPP-32 in striatal membrane from behaviorally sensitized mice was analyzed by Western blot. RESULTS: Caffeine and SCH58261 but not DPCPX induced CPP and locomotor sensitization in C57BL/6 mice. The locomotor sensitization after chronic treatment was associated with increased DARPP-32 phosphorylation at Thr75 in the striatum.
CONCLUSION: Caffeine-induced reinforcing effect and behavioral sensitization are mediated by antagonism at adenosine A(2A) receptor. These effects are associated with phosphorylation of DARPP-32 at Thr75 in the striatum.
Share, B.; Sanders, N.; Kemp, J.
Controversy surrounds the influence that caffeine has on accuracy and cognitive performance in precision activities such as shooting and archery. The aim of this study was to assess the effects of two doses of caffeine on shooting performance, reaction time, and target tracking times in the sport of clay target shooting. A randomized, double-blind, placebo-controlled design was undertaken by seven elite male shooters from the double-trap discipline. Three intervention trials (2 mg caffeine . kg(-1) body mass (BM); 4 mg caffeine . kg(-1) BM; placebo) were undertaken, in which shooters completed four rounds per trial of 50 targets per round. Performance accuracy (score) and digital video footage (for determination of reaction time and target tracking times) were gathered during competition. Data were analysed using repeated-measures analysis of variance. No differences in shooting accuracy, reaction time or target tracking times among the three intervention trials or across the four rounds within each intervention were observed (P > 0.05). The results indicate that ingestion of < or =4 mg caffeine . kg(-1) BM does not provide performance benefits to elite performers of clay target shooting in the double-trap discipline.
Namdar, M.; Schepis, T.; Koepfli, P.; Gaemperli, O.; Siegrist, P. T.; Grathwohl, R.; Valenta, I.; Delaloye, R.; Klainguti, M.; Wyss, C. A.; Luscher, T. F.; Kaufmann, P. A.
Caffeine is one of the most widely consumed pharmacologically active substances. Its acute effect on myocardial blood flow is widely unknown. Our aim was to assess the acute effect of caffeine in a dose corresponding to two cups of coffee on myocardial blood flow (MBF) in coronary artery disease (CAD). METHODOLOGY/PRINCIPAL FINDINGS: MBF was measured with (15)O-labelled H2O and Positron Emission Tomography (PET) at rest and after supine bicycle exercise in controls (n = 15, mean age 58+/-13 years) and in CAD patients (n = 15, mean age 61+/-9 years). In the latter, regional MBF was assessed in segments subtended by stenotic and remote coronary arteries. All measurements were repeated fifty minutes after oral caffeine ingestion (200 mg). Myocardial perfusion reserve (MPR) was calculated as ratio of MBF during bicycle stress divided by MBF at rest. Resting MBF was not affected by caffeine in both groups. Exercise-induced MBF response decreased significantly after caffeine in controls (2.26+/-0.56 vs. 2.02+/-0.56, P<0.005), remote (2.40+/-0.70 vs. 1.78+/-0.46, P<0.001) and in stenotic segments (1.90+/-0.41 vs. 1.38+/-0.30, P<0.001). Caffeine decreased MPR significantly by 14% in controls (P<0.05 vs. baseline). In CAD patients MPR decreased by 18% (P<0.05 vs. baseline) in remote and by 25% in stenotic segments (P<0.01 vs. baseline).
CONCLUSIONS: We conclude that caffeine impairs exercise-induced hyperaemic MBF response in patients with CAD to a greater degree than age-matched controls.
Source : PLoS ONE [Electronic Resource]. 2009 vol.4 (5), pp e5665
Fuhrman, B. J.; Smit, E.; Crespo, C. J.; Garcia-Palmieri, M. R.
OBJECTIVE: To study prospectively the association of coffee intake with incident diabetes in the Puerto Rico Heart Health Program cohort, comprising 9824 middle-aged men (aged 35-79 years). METHODS: Of 9824 men, 3869 did not provide a fasting blood sample at baseline, 1095 had prevalent diabetes and 131 were not given fasting glucose tests at any subsequent study visit. Thus, the present analysis includes 4685 participants. Diabetes was ascertained at baseline and at two study visits between 1968 and 1975 using fasting glucose tests and self-reports of physician-diagnosed diabetes or use of insulin or hypoglycaemic medication. Logistic regression analysis was used to assess the association of coffee intake with risk of incident diabetes while adjusting for covariates (age, BMI, physical activity, smoking, education, alcohol intake, family history of diabetes, intakes of milk and sugar). RESULTS: Five hundred and nineteen participants met the criteria for incident diabetes. Compared with those reporting intake of 1-2 servings of coffee/d, coffee abstainers were at reduced risk (OR = 0.64; 95 % CI 0.43, 0.94). Among coffee drinkers, there was a significant trend of decreasing risk by intake (P = 0.02); intake of >/=4 servings/d was associated with an odds ratio of 0.75 (95 % CI 0.58, 0.97).
CONCLUSIONS: Study findings support a protective effect of coffee intake on diabetes risk, while also suggesting that abstainers may be at reduced risk.
Source : Intern J Sport Nutr Exerc Metab 2009 vol.19 (2) pp 150-161
Nettleton, J. A.; Follis, J. L.; Schabath, M. B.
Coffee contains polyphenolic antioxidants and caffeine, which may favorably affect pulmonary function. Therefore, the authors studied cross-sectional associations (1987-1989) between coffee intake and pulmonary function in the Atherosclerosis Risk in Communities Study, a population-based cohort study (analytic sample = 10,658). They also conducted analyses stratified by smoking status, since smoking is a strong risk factor for respiratory disease and could influence the effects of caffeine and antioxidants. Self-reported coffee intake was categorized as rare/never, <7 cups/week, 1 cup/day, 2-3 cups/day, and >or=4 cups/day. Pulmonary function was characterized by the spirometric measures forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)). After adjustment for demographic factors, lifestyle characteristics, and dietary factors, pulmonary function values increased across increasing categories of coffee consumption in never and former smokers but not in current smokers. In never or former smokers who consumed >or=4 cups of coffee daily, FVC and FEV(1) were 2%-3% greater than in never or former smokers who rarely/never consumed coffee (P(trend) values: in never smokers, 0.04 for FVC and 0.07 for FEV(1); in former smokers, <0.001 for FVC and <0.001 for FEV(1)). These data show a possible beneficial effect of coffee (or a coffee ingredient) on pulmonary function, but it appears to be limited to nonsmokers.
Kotsopoulos, J.; Vitonis, A. F.; Terry, K. L.; De, Vivo, I; Cramer, D. W.; Hankinson, S. E.; Tworoger, S. S.
We evaluated whether genetic variability, as well as menopausal status, modify the association between coffee intake and risk of ovarian cancer. Risk factor information and biologic specimens from three large epidemiological studies, the Nurses\' Health Study (NHS), NHSII, and the New England based Case-Control Study of ovarian cancer (NECC) were pooled resulting in 1,354 ovarian cancer cases and 1,851 controls for analysis. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using conditional (NHS/NHSII) and unconditional (NECC) logistic regression. Coffee consumption was not associated with overall risk (OR = 0.99; 95% CI 0.77-1.28); however, there was a suggested increased risk of ovarian cancer among premenopausal women in the NECC only and an inverse association among postmenopausal women. Carrying one or both of the variant CYP19013 A or CYP19027 G alleles was associated with an 18% increased (P for trend = 0.02) and 15% decreased (P for trend = 0.05) risk of ovarian cancer, respectively. Variation in CYP1A1, CYP1A2, or CYP2A6 did not explain the inconsistent reports of coffee intake and risk. Furthermore, we did not observe any clear gene-environment interactions between caffeine metabolizing genes and ovarian cancer. Future studies evaluating mechanisms by which coffee mediates this relationship are warranted.
Source : Cancer Causes & Control 2009 vol.20 (3), pp 335-344
Terry, P.; Doumas, M.; Desai, R. I.; Wing, A. M.
The impacts of psychoactive drugs on timing have usefully informed theories of timing and its substrates. The objectives of the study are to test the effects of alcohol and caffeine on the explicit timing involved in tapping with the implicit timing observed in the coordinated picking up of an object, and with the temporal discrimination. MATERIALS AND METHODS: Participants in the "alcohol" experiment (N = 16) received placebo, "low" (0.12 g/kg or 0.14 g/kg for women/men, respectively) or "high" (0.37 g/kg or 0.42 g/kg, respectively) doses of alcohol, and those in the "caffeine" experiment (N = 16) received placebo, 200 or 400 mg caffeine. Time production variability was measured by repetitive tapping of specified intervals, and sources of variance attributable to central timer processes and peripheral motor implementation were dissociated. The explicit timing in tapping was compared with the implicit timing in the coordinated picking up of an object. Time perception was measured as discrimination thresholds for intervals of similar duration. Drug effects on reaction time were also measured. RESULTS: For tapping, alcohol significantly increased timer variability, but not motor variability; it did not affect coordination timing in the grip-lift task. Conversely, for time perception, the low dose of alcohol improved temporal discrimination. Caffeine produced no effects on any of the timing tasks, despite significantly reducing reaction times.
CONCLUSIONS: The effects of alcohol argue against a common clock process underlying time interval perception and production in the range below 1 s. In contrast to reaction time measures, time perception and time production appear relatively insensitive to caffeine.
Rosser, J. I.; Walsh, B.; Hogan, M. C.
The purpose of the present study was to determine whether exposure to exogenous physiological concentrations of caffeine influence contractility, Ca(2+) handling, and fatigue development in isolated single Xenopus laevis skeletal muscle fibers. After isolation, two identical contractile periods (separated by 60-min rest) were conducted in each single myofiber (n = 8) at 20 degrees C. During the first contractile period, four fibers were perfused with a noncaffeinated Ringer solution, while the other four fibers were perfused with a caffeinated (70 microM) Ringer solution. The order was reversed for the second contractile period. The single myofibers were stimulated during each contractile period at increasing frequencies (0.16, 0.20, 0.25, 0.33, 0.50, and 1.0 tetanic contractions/s), with each stimulation frequency lasting 2 min until fatigue ensued, defined in this study as a fall in tension development to 66% of maximum. Tension development and free cytosolic [Ca(2+)] (fura-2 fluorescence spectroscopy) were simultaneously measured. There was no significant difference in the peak force generation, time to fatigue, cytosolic Ca(2+) levels, or relaxation times between the noncaffeinated and caffeinated trials. These results demonstrate that physiological levels of caffeine have no significant effect on Xenopus single myofiber contractility, Ca(2+) handling, and fatigue development, and suggest that any ergogenic effects of physiological levels of caffeine on muscle performance during contractions of moderate to high intensity are likely related to factors extraneous to the muscle fiber.
Source : Am J Physiol - Regul Integ Comp Physiol 2009 vol.296 (5), pp R1512-1517
Justinova, Z.; Ferre, S.; Barnes, C.; Wertheim, C. E.; Pappas, L. A.; Goldberg, S. R.; Le Foll, B.
Adenosine receptors are involved in cocaine and methamphetamine discrimination and exposure to caffeine can affect behavioral effects of nicotine in rats. OBJECTIVES: Here we investigated the relative involvement of adenosine A(1) and A(2A) receptors in nicotine, cocaine, and methamphetamine discrimination, before and/or during chronic caffeine exposure. MATERIALS AND METHODS: The nonselective adenosine receptor antagonist caffeine, the A(1)-receptor antagonist cyclopentyltheophylline (CPT), and the A(2A)-receptor antagonist MSX-3 were evaluated in rats trained to discriminate 0.4 mg/kg nicotine from saline under a fixed-ratio schedule of food delivery. Effects of adenosine receptor antagonists were then compared in rats discriminating nicotine, methamphetamine, or cocaine from saline during chronic caffeine exposure in their drinking water. RESULTS: Caffeine, CPT, and MSX-3 partially generalized to nicotine and shifted nicotine dose-response curves leftwards. During chronic caffeine exposure, however, all three ligands failed to generalize to nicotine and failed to shift nicotine dose-response curves. In previous experiments, CPT and MSX-3 partially generalized to methamphetamine and cocaine and shifted dose-response curves leftwards. In the present experiments, CPT neither generalized nor shifted dose-response curves for methamphetamine or cocaine during chronic caffeine exposure. However, MSX-3 partially generalized to both psychostimulants and shifted their dose-response curves leftwards. Caffeine partially generalized to cocaine, but not methamphetamine, and shifted both dose-response curves leftwards.
CONCLUSIONS: Both adenosine A(1) and A(2A) receptors are capable of modulating the discriminative-stimulus effects of nicotine. Chronic caffeine exposure produces complete tolerance to both A(1)- and A(2A)-mediated effects in nicotine-trained rats. In contrast, chronic caffeine exposure produces tolerance to adenosine A(1)-mediated, but not A(2A)-mediated, effects in methamphetamine- and cocaine-trained rats.
Jahanfar, S.; Sharifah, H.
Maternal caffeine consumption during pregnancy may have adverse effects on fetal, neonatal and maternal outcomes. OBJECTIVES: This review investigates the effects of restricting caffeine intake by mothers on fetal, neonatal and pregnancy outcomes. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group\'s Trials Register (December 2008), scanned bibliographies of published studies and corresponded with investigators. SELECTION CRITERIA: Randomised controlled trials including quasi-randomised controlled trials (RCTs) investigating the effect of caffeine and/or supplementary caffeine versus restricted caffeine intake or placebo on pregnancy outcome. DATA COLLECTION AND ANALYSIS: The two review authors independently assessed trial quality and extracted data. MAIN RESULTS: One study met the inclusion criteria. Caffeinated instant coffee (568 women) was compared with decaffeinated instant coffee (629 women) and it was found that reducing the caffeine intake of regular coffee drinkers (3+ cups/day) during the second and third trimester by an average of 182 mg/day did not affect birthweight or length of gestation.
AUTHORS\' CONCLUSIONS: There is insufficient evidence to confirm or refute the effectiveness of caffeine avoidance on birthweight or other pregnancy outcomes. There is a need to conduct high-quality, double-blinded RCTs to determine whether caffeine has any effect on pregnancy outcome.
Source : Cochrane Database of Systematic Reviews 2009 (2), CD006965
Lee, T. H.
Whether it\'s a basic Mr. Coffee or a gadget that sports a snazzy device for grinding beans on demand, the office coffee machine offers a place for serendipitous encounters that can improve the social aspect of work and generate new ideas. What\'s more, a steaming cup of joe may be as good for your health as it is for the bottom line, says Lee, a professor of medicine at Harvard Medical School and the CEO of Partners Community HealthCare. Fears of coffee\'s carcinogenic effects now appear to be unfounded, and, in fact, the brew might even protect against some types of cancer. What\'s more, coffee may guard against Alzheimer\'s disease and other forms of dementia and somehow soften the blow of a heart attack. Of course, its role as a pick-me-up is well known. So there\'s no need to take your coffee with a dollop of guilt, especially if you ease up on the sugar, cream, double chocolate, and whipped-cream topping.
Hayashi, K.; Tsuchiya, H.; Yamamoto, N.; Shirai, T.; Yamauchi, K.; Takeuchi, A.; Kawahara, M.; Miyamoto, K.; Tomita, K.
Caffeine can safely enhance the cytocidal effects of anticancer drugs through its DNA repair-inhibiting effect. We have demonstrated in several studies that caffeine-potentiated chemotherapy induces a high complete response rate in patients with osteosarcoma. The present study focused on monitoring and adjusting serum caffeine levels during caffeine-potentiated chemotherapy to reduce adverse effects. METHODS: We utilized a method for rapidly determining caffeine concentration by high-performance liquid chromatography. The maximum caffeine concentration was predicted from the measured concentrations at 24 and 48 h after the beginning of caffeine administration. The caffeine infusion rate was then modified accordingly to prevent the expected final concentration from exceeding 80 microg/ml. The study involved 22 American Joint Committee on Cancer (AJCC) stage IIB high-grade osteosarcoma patients treated with caffeine-potentiated chemotherapy. Nine patients underwent monitoring of their serum caffeine levels (monitoring group), and the remaining 13 patients were not monitored (nonmonitoring group). Toxicities were graded according to the Japan Clinical Oncology Group Toxicity Criteria. RESULTS: Hematological toxic events were well tolerated in both groups. Grade 4 leukocyte toxicity events occurred in both groups. In the nonmonitoring group grade 2 or higher toxicities included 5 elevated aspartate aminotransferase / alanine aminotransferase level events and 17 hyponatremia events versus 1 hyponatremia event in the monitoring group. Histological examination of excised tumor samples after preoperative chemotherapy revealed that chemotherapeutic efficacy in the monitoring group was as good as in the nonmonitoring group. The median follow-up period in all patients was 72 months. Event-free survival was 76%, and overall survival was 100%.
CONCLUSIONS: Monitoring and adjusting caffeine levels were achieved without apparent loss of chemotherapeutic efficacy.
Johansen, A. M.; Wilcox, A. J.; Lie, R. T.; Andersen, L. F.; Drevon, C. A.
A large, population-based case-control study of facial clefts was carried out in Norway between 1996 and 2001. The study included 573 cases -- 377 with cleft lip with or without cleft palate and 196 with cleft palate only -- and 763 randomly selected controls. Maternal consumption of coffee and other caffeine-containing beverages in early pregnancy was recorded shortly after birth. Compared with that for no coffee consumption, the adjusted odds ratios for cleft lip with or without cleft palate were 1.39 (95% confidence interval: 1.01, 1.92) for less than 3 cups a day and 1.59 (95% confidence interval: 1.05, 2.39) for 3 cups or more. Coffee consumption was not associated with risk of cleft palate only (for > or = 3 cups vs. none, adjusted odds ratio = 0.96, 95% confidence interval: 0.55, 1.67). Tea consumption was associated with a reduced odds ratio of both cleft lip with or without cleft palate and cleft palate only. There was little evidence of an association between caffeine exposure and clefts when all sources of caffeine were considered. Adjustment for known confounding factors in general had minor effects on risk estimates. Still, the authors could not rule out the possibility of uncontrolled confounding by factors associated with the habit of drinking coffee.
Addicott, M. A.; Yang, L. L.; Peiffer, A. M.; Laurienti, P. J.
The field of research regarding the effects of habitual caffeine use is immense and frequently utilizes self-report measures of caffeine use. However, various self-report measures have different methodologies, and the accuracy of these different methods has not been compared. MATERIALS AND METHODS: Self-reported caffeine use was estimated from two methods (a retrospective interview of weekly caffeine use and a 7-day prospective diary; n = 79). These estimates were then tested against salivary caffeine concentrations in a subset of participants (n = 55). RESULTS: The estimates of caffeine use (mg/day) from the interview- and diary-based methods correlated with one another (r = 0.77) and with salivary caffeine concentrations (r = 0.61 and 0.68, respectively). However, almost half of the subjects who reported more than 600 mg/day in the interview reported significantly less caffeine use in the diary.
CONCLUSIONS: Self-report measures of caffeine use are a valid method of predicting actual caffeine levels. Estimates of high caffeine use levels may need to be corroborated by more than one method.
Kotsopoulos, J.; Eliassen, A. H.; Missmer, S. A.; Hankinson, S. E.; Tworoger, S. S.
Circulating estrogens and androgens are important factors in the development of various female cancers. Caffeine intake may decrease risk of breast and ovarian cancer, although the data are not entirely consistent. Whether or not caffeine affects cancer risk by altering sex hormone levels is currently unknown. METHODS:: We examined the relationship of caffeine, coffee, decaffeinated coffee, and tea with plasma concentrations of estrogens, androgens, progesterone, prolactin, and sex hormone-binding globulin (SHBG) in 524 premenopausal and 713 postmenopausal women from the Nurses\' Health Study (NHS) and NHSII. RESULTS:: In premenopausal women, caffeine intake was inversely associated with luteal total and free estradiol, and positively associated with luteal progesterone levels (P-trend = .02, .01, .03, respectively). Coffee intake was significantly associated with lower luteal total and free estradiol levels, but not luteal progesterone levels (P-trend = .007, .004, .20, respectively). Among the postmenopausal women, there was a positive association between caffeine and coffee intake and SHBG levels (P-trend = .03 and .06, respectively). No significant associations were detected with the other hormones.
CONCLUSIONS:: Data from this cross-sectional study suggest that caffeine may alter circulating levels of luteal estrogens and SHBG, representing possible mechanisms by which coffee or caffeine may be associated with pre- and postmenopausal malignancies, respectively. Future studies evaluating how caffeine-mediated alterations in sex hormones and binding protein levels affect the risk of female cancers are warranted.
Yu, L.; Coelho, J. E.; Zhang, X.; Fu, Y.; Tillman, A.; Karaoz, U.; Fredholm, B. B.; Weng, Z.; Chen, J. F.
Caffeine is the most widely consumed psychoactive substance and has complex pharmacological actions in brain. In this study, we employed a novel drug target validation strategy to uncover the multiple molecular targets of caffeine using combined A(2A) receptor (A(2A)R) knockouts (KO) and microarray profiling. Caffeine (10 mg/kg) elicited a distinct profile of striatal gene expression in WT mice compared with that by A(2A)R gene deletion or by administering caffeine into A(2A)R KO mice. Thus, A(2A)Rs are required but not sufficient to elicit the striatal gene expression by caffeine (10 mg/kg). Caffeine (50 mg/kg) induced complex expression patterns with three distinct sets of striatal genes: 1) one subset overlapped with those elicited by genetic deletion of A(2A)Rs; 2) the second subset elicited by caffeine in WT as well as A(2A)R KO mice; and 3) the third subset elicited by caffeine only in A(2A)R KO mice. Furthermore, striatal gene sets elicited by the phosphodiesterase (PDE) inhibitor rolipram and the GABA(A) receptor antagonist bicucullin, overlapped with the distinct subsets of striatal genes elicited by caffeine (50 mg/kg) administered to A(2A)R KO mice. Finally, Gene Set Enrichment Analysis reveals that adipocyte differentiation/insulin signaling is highly enriched in the striatal gene sets elicited by both low and high doses of caffeine. The identification of these distinct striatal gene populations and their corresponding multiple molecular targets, including A(2A)R, non-A(2A)R (possibly A(1)Rs and pathways associated with PDE and GABA(A)R) and their interactions, and the cellular pathways affected by low and high doses of caffeine, provides molecular insights into the acute pharmacological effects of caffeine in the brain.
Orecchio, S.; Ciotti, V. P.; Culotta, L.
Roasting is a crucial step for the production of coffee, as it enables the development of color, aroma, and flavor, which are essential for the characterization of the coffee quality. At the same time, roasting may lead to the formation of not desirable compounds, such as polycyclic aromatic hydrocarbons (PAHs). In this paper, we report a method for PAHs determination in coffee brew, based on saponification and liquid-liquid extraction with small volumes of hexane, with exclusion of further processes of purification since we analyze the extract by gas chromatography with mass spectrometric detectors in the single ion monitoring mode (SIM). The total concentration of the 28 compounds investigated, expressed as the sum of concentrations (SigmaPAH), in coffee brew varies from 0.52 to 1.8 microg/l. Carcinogenic PAHs, expressed as B[a]Peq ranged from 0.008 to 0.060 microg/l. The results indicate that coffee contributes with very insignificant quantities to the daily human intake of carcinogenic PAHs. The values of calculated isomeric ratios confirm that the PAHs identified in most of the coffee samples originate from high temperature processes.
Lopes de Oliveira, A.; Cabral, F. A.; Nogueira Eberlin, M.; Bolini Cordello, H. M. A.
The oil obtained from Brazilian roasted coffee by supercritical CO2 extraction shows considerable aromatic properties, and is mainly composed of 5 aroma compounds: 2-methylpyrazine; 2-furfurylalcohol; 2,5-dimethylpyrazine; gamma-butyrolactone; and 2-furfurylacetate. Sensory analyses were used to verify the influence of a mixture of these classes of aromatic coffee compounds (pyrazines, furans and lactones) and of the roasted coffee aromatic oil on the coffee aroma and flavour of black instant freeze- and spray-dried coffee beverages. In the acceptance evaluation of the aroma, the samples prepared with freeze-dried instant coffee without the mixture of volatile compounds (sample 4) were not significantly different from the freeze-dried instant coffee in which the aromatic coffee oil was added (sample 5) and from the sample prepared with freeze-dried coffee in which the mixture of the 5 volatiles was added (sample 3). Sample (3) did not differ from samples prepared with spray dried instant coffee without (sample 1) and with (sample 2) the mixture of volatiles added. Therefore, with respect to this attribute, the addition of the mixture did not interfere with beverage acceptance. Taking into consideration the flavour, samples (5), (3) and (4) did not differ significantly, and sample (4) did not differ from samples (1) and (2). The addition of the aromatic oil of roasted coffee or a mixture of volatile in samples of freeze-dried instant coffee gave better acceptance than in samples of spray dried coffee (samples 1 and 2). Thus, the enrichment of beverages with the aromatic oil of roasted coffee, or even with the mixture of the 5 components did not influence consumer acceptance with respect to aroma, but exerted effects with respect to flavour.
Source : Ciencia e Tecnologia de Alimentos 2009 vol.29 (1), pp 76-80 (full text)
Murugan, N. A.; Sayeed, A.
We have studied the thermal behavior of orientationally disordered phase of caffeine molecular crystal using variable shape variable size Monte Carlo simulations in isothermal-isobaric ensemble. We have investigated the structure, especially the nature of orientational disorder of caffeine molecules as a function of temperature in the range of 400-550 K. Experimentally this system is known to undergo a phase transition at 426 K (considered to be an orientational order-disorder transition) and melt at 512 K. Our simulations reproduce these two transitions in excellent agreement with experiment. We find that the in-plane reorientational motion of molecules is restricted to small angles below 425 K, and above this temperature, molecules undergo essentially free rotations in molecular plane, and we find the melting to occur between 525 and 550 K. In the high temperature disordered phase, the disorder is mostly attributable to the in-plane orientational motion of the molecules. The potential energy profile for the in-plane reorientational rotation has six wells as a consequence of specific packing of molecules in the ab crystallographic plane. Also we find considerable out-of-plane reorientational disorder for the molecules in the high temperature disordered phase. We have also studied the structure and orientational disorder of the system that is quenched from 450 to 300 K. We find that in the quenched phase, the molecular orientational arrangement remains partially frozen.
Source : J Chem Phys 2009 vol.130 (20), 204514-204514-8 (for details)
Schramm, E.; Kurten, A.; Holzer, J.; Mitschke, S.; Muhlberger, F.; Sklorz, M.; Wieser, J.; Ulrich, A.; Putz, M.; Schulte-Ladbeck, R.; Schultze, R.; Curtius, J.; Borrmann, S.; Zimmermann, R.
An in-house-built ion trap mass spectrometer combined with a soft ionization source has been set up and tested. As ionization source, an electron beam pumped vacuum UV (VUV) excimer lamp (EBEL) was used for single-photon ionization. It was shown that soft ionization allows the reduction of fragmentation of the target analytes and the suppression of most matrix components. Therefore, the combination of photon ionization with the tandem mass spectrometry (MS/MS) capability of an ion trap yields a powerful tool for molecular ion peak detection and identification of organic trace compounds in complex matrixes. This setup was successfully tested for two different applications. The first one is the detection of security-relevant substances like explosives, narcotics, and chemical warfare agents. One test substance from each of these groups was chosen and detected successfully with single photon ionization ion trap mass spectrometry (SPI-ITMS) MS/MS measurements. Additionally, first tests were performed, demonstrating that this method is not influenced by matrix compounds. The second field of application is the detection of process gases. Here, exhaust gas from coffee roasting was analyzed in real time, and some of its compounds were identified using MS/MS studies.
Sanchez-Cach, L. A.; Ortiz-Garcia, M. M.; Minero-Garcia, Y.; Munoz-Sanchez, J. A.; Hernandez-Sotomayor, S. T.; Suarez-Solis, V. M.; Los Santos-Briones, C.
A cDNA encoding the catalytic site of a phosphatidylinositol-specific phospholipase C (PI-PLC) was isolated from Coffea arabica suspension cells. The cDNA (designated CaPLC) encodes a polypeptide of 308 amino acids, containing the catalytic X and Y domains, and has 99% identity to the soybean gene. Recombinant CaPLC protein was expressed in Escherichia coli, purified, and used to produce a polyclonal antibody. The peptide has a molecular mass of 27 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot analyses. Immunoblots revealed the presence of PLC-like proteins in the tissues of different plant species.