AGRONOMY

Comparison of five allopatric fruit fly parasitoid populations (Psyttalia species) (Hymenoptera: Braconidae) from coffee fields using morphometric and molecular methods

Billah, M. K.; Kimani-Njogu, S. W.; Wharton, R. A.; Woolley, J. B.; Masiga, D.

Morphometric studies of five allopatric parasitoid populations (genus Psyttalia Walker) from coffee plantations in Cameroon (Nkolbisson), Ghana (Tafo) and Kenya (Rurima, Ruiru and Shimba Hills) and one non-coffee population (from Muhaka, Kenya) were compared with individuals of Psyttalia concolor (Szepligeti), a species released in several biological control programmes in the Mediterranean Region since the 20th Century. Analyses of wing vein measurements showed the second submarginal cell of the fore wing and its adjoining veins had the heaviest principal component weights and served as the main contributing variables in the diagnostic differentiation of the populations. Two populations (Rurima and Ruiru) were found to be the closest to each other and with the strongest phenetic affinity toward P. concolor (and forming one cluster). Populations from Shimba Hills (of unknown identity), Nkolbisson (P. perproximus (Silvestri)) and Tafo formed a second cluster and were separated from P. concolor. Comparison using amplified fragment length polymorphism (AFLP) also showed the Shimba, Nkolbisson and Tafo populations forming a cluster in a dendrogram generated from their genetic distances, with the Shimba and Tafo populations placed as the most closely related species. Based on consistent morphological similarities, morphometric and ecological data coupled with the genetic evidence from AFLP data, the Shimba population is suggested as belonging to the P. perproximus group and, thus, represents a new occurrence record in Kenya. Our results also support earlier conclusion from cross mating data that populations from Rurima and Ruiru belong to the Psyttalia concolor species-group.

Source :  Bull.Entomol.Res. 2008 vol.98 (1), pp 63 - 75

Epicarp characterization of coffee fruits by atomic force microscopy

Cardona, Y. P.; Oliveros, C. E.; Arias, D. F.; Alvarez, F.; Devia, A.

The superficial characterization of epicarp of the coffee fruits was made in two states of development: mature and green. The roughness of the area, and also the line for the parameters of roughness average (Ra) and quadratic root average of the roughness (Rq), were found by means of atomic force microscopy (AFM). In addition, the densities and dimensions of the coffee cells were found. The Ra range of the
mature fruit was found to be between 0.03 and 0.19mum, and for the green fruit it was between 0.23 and 0.38mum. The Rq range of the mature fruit was found to be between 0.05 and 0.24mum, and for the green fruit it was between 0.29 and 0.49mum. These values delimit ranges of roughness for each state of development analyzed, and there is a difference among them without appearing interpolation of the data. It was determined that the cells have ellipsoidal form with an average area of 194.62mum2, and the density average is 4.206cell/mm2.

Source : J Food Eng 2008 vol.86 (2), pp 167 - 171

Morphological and physiological responses of two coffee progenies to soil water availability

Dias, P. C.; Araujo, W. L.; Moraes, G. A.; Barros, R. S.; DaMatta, F. M.

Drought is a major environmental constraint affecting growth and production of coffee. The effects of water supply on growth, biomass allocation, water relations, and gas exchange in two coffee progenies representing drought-tolerant (Siriema) and drought-sensitive (Catucai) genotypes were compared. They were grown in 12-L pots until 4-months old, when they were submitted to two watering treatments for 60 d: plants receiving either 100% transpired water (control plants) or a fraction (about 40%) of the amount of water transpired by control plants (drought-stressed plants). Under control conditions, Siriema grew faster than Catucai. Regardless of the watering regimes and progenies, relative growth rate (RGR) was positively correlated both with net assimilation rate (NAR) and long-term water-use efficiency (WUE), but not with differences in biomass allocation. Both progenies responded to drought stress through (i) similar decreases in both RGR and NAR with marginal, if any, changes in allocation; (ii) decreases in leaf water potential, which occurred to a greater extent in Catucai than in Siriema, even though they have showed similar abilities to adjust osmotically and elastically; (iii) similar reductions in net photosynthesis due mainly to nonstomatal factors; and (iv) decreases in transpiration rate coupled with increased long-term WUE. However, the lower transpiration rate and the higher long-term WUE as found in Siriema relative to Catucai under control conditions persisted under drought conditions. Overall, the major differences between these progenies were largely associated with differences in plant water use, which was likely related to the improved water status of Siriema. The possible implications of selecting coffee genotypes for high WUE are discussed.

Source : J Plant Physiol 2007 vol.164 (12), pp 1639 - 1647

Field-testing ecological and economic benefits of coffee certification programs

Philpott, S. M.; Bichier, P.; Rice, R.; Greenberg, R.

Coffee agroecosystems are critical to the success of conservation efforts in Latin America because of their ecological and economic importance. Coffee certification programs may offer one way to protect

biodiversity and maintain farmer livelihoods. Established coffee certification programs fall into three distinct, but not mutually exclusive categories: organic, fair trade, and shade. The results of previous studies demonstrate that shade certification can benefit biodiversity, but it remains unclear whether a farmer's participation in any certification program can provide both ecological and economic benefits. To assess the value of coffee certification for conservation efforts in the region, we examined economic and ecological aspects of coffee production for eight coffee cooperatives in Chiapas, Mexico, that were certified organic, certified organic and fair trade, or uncertified. We compared vegetation and ant and bird diversity in coffee farms and forests, and interviewed farmers to determine coffee yield, gross revenue from coffee production, and area in coffee production. Although there are no shade-certified farms in the study region, we used vegetation data to determine whether cooperatives would qualify for shade certification. We found no differences in vegetation characteristics, ant or bird species richness, or fraction of forest fauna in farms based on certification. Farmers with organic and organic and fair-trade certification had more land under cultivation and in some cases higher revenue than uncertified farmers. Coffee production area did not vary among farm types. No cooperative passed shade-coffee certification standards because the plantations lacked vertical stratification, yet vegetation variables for shade certification significantly correlated with ant and bird diversity. Although farmers in the Chiapas highlands with organic and/or fair-trade certification may reap some economic benefits from their certification status, their farms may not protect as much biodiversity as shade-certified farms. Working toward triple certification (organic, fair trade, and shade) at the farm level may enhance biodiversity protection, increase benefits to farmers, and lead to more successful conservation strategies in coffee-growing regions.

Source : Conserv. Biol. 2007 vol.21 (4), pp 975 - 985 

BIOCHEMISTRY / BIOTECHNOLOGY

The storage of green coffee (Coffea arabica): decrease of viability and changes of potential aroma precursors

Selmar, D.; Bytof, G.; Knopp, S. E.

When green coffee is stored for a prolonged time the coffee quality decreases distinctively. Apart from well-known 'off-notes' that arise from undesired oxidations of lipids, a typical 'flattening' of the cup quality is detectable. In order to elucidate the biological causes for this phenomenon, differentially processed coffees (wet, dry, semi-dry processing), were stored under standard conditions for 2 years and analysed comprehensively. METHODS: Wet-processed coffee was stored either as parchment coffee, where the endocarp remained around the beans or as hulled beans. Viability of coffee seeds was estimated using the tetrazolium-test of seed viability. Changes in concentration of free amino acids and soluble carbohydrates were analysed by HPLC. KEY RESULTS: Whereas all other coffees lost viability within the first 6 months of storage, coffee beans stored within the parchment remained viable for >1 year. Glucose and fructose decreased slightly in the course of storage and glutamine content declined significantly. However, the changes observed in sugar and amino acid content were not correlated with the viability of the coffee beans. Consequently, neither typical metabolic reactions occurring within living cells nor characteristic post-mortem reactions could be responsible for the observed changes. As a result of post-mortem reactions in re-imbibed seeds, a characteristic bluish-green colour developed, putatively due to the oxidation of chlorogenic acids and subsequent reactions with primary amino compounds. This coloration might be an appropriate marker to substantiate if coffee seeds had been stored for an expanded time and putative quality losses were not relevant so far.

CONCLUSIONS: It is suggested that loss of viability is relevant for the aroma flattening. As neither metabolic nor post-mortem reactions were responsible for the observed changes, it is concluded that Maillard reactions that occur during storage might be the cause of the decrease in potential aroma precursors.

Source : Ann Bot (Lond) 2008 vol.101 (1), pp 31 - 38

A novel caffeine dehydrogenase in Pseudomonas sp. strain CBB1 oxidizes caffeine to trimethyluric acid

Yu, C. L.; Kale, Y.; Gopishetty, S.; Louie, T. M.; Subramanian, M.

A unique heterotrimeric caffeine dehydrogenase was purified from Pseudomonas sp. strain CBB1. This enzyme oxidized caffeine to trimethyluric acid stoichiometrically and hydrolytically, without producing hydrogen peroxide. The enzyme was not NAD(P)(+) dependent; coenzyme Q(0) was the preferred electron acceptor. The enzyme was specific for caffeine and theobromine and showed no activity with xanthine.

Source : J Bacteriol 2008 vol.190 (2), pp 772 - 776

Towards a Phylogeny for Coffea (Rubiaceae): identifying well-supported lineages based on nuclear and plastid DNA sequences

Maurin, O.; Davis, A. P.; Chester, M.; Mvungi, E. F.; Jaufeerally-Fakim, Y.; Fay, M. F.

The phylogenetic relationships between species of Coffea and Psilanthus remain poorly understood, owing to low levels of sequence variation recovered in previous studies, coupled with relatively limited species sampling. In this study, the relationships between Coffea and Psilanthus species are assessed based on substantially increased molecular sequence data and greatly improved species sampling. METHODS: Phylogenetic relationships are assessed using parsimony, with sequence data from four plastid regions [trnL-F intron, trnL-F intergenic spacer (IGS), rpl16 intron and accD-psa1 IGS], and the internal transcribed spacer (ITS) region of nuclear rDNA (ITS 1/5.8S/ITS 2). Supported lineages in Coffea are discussed within the context of geographical correspondence, biogeography, morphology and systematics. KEY RESULTS: Several major lineages with geographical coherence, as identified in previous studies based on smaller data sets, are supported. Other lineages with either geographical or ecological correspondence are recognized for the first time. Coffea subgenus Baracoffea is shown to be monophyletic, but Coffea subgenus Coffea is paraphyletic. Sequence data do not substantiate the monophyly of either Coffea or Psilanthus. Low levels of sequence divergence do not allow detailed resolution of relationships within Coffea, most notably for species of Coffea subgenus Coffea occurring in Madagascar. The origin of C. arabica by recent hybridization between C. canephora and C. eugenioides is supported. Phylogenetic separation resulting from the presence of the Dahomey Gap is inferred based on sequence data from Coffea.

Source :  Ann Bot (Lond) 2007 vol.100 (7), pp 1565 - 1583

Mechanism and control of Solanum lycocarpum seed germination

Pinto, L. V.; Da Silva, E. A.; Davide, A. C.; De Jesus, V. A.; Toorop, P. E.; Hilhorst, H. W.

Solanaceae seed morphology and physiology have been widely studied but mainly in domesticated crops. The present study aimed to compare the seed morphology and the physiology of germination of Solanum lycocarpum, an important species native to the Brazilian Cerrado, with two species with endospermic seeds, tomato and coffee. METHODS: Morphological parameters of fruits and seeds were determined by microscopy. Germination was monitored for 40 d under different temperature regimes. Endosperm digestion and resistance, with endo-beta-mannanase activity and required force to puncture the endosperm cap as respective markers, were measured during germination in water and in abscisic acid. KEY RESULTS: Fruits of S. lycocarpum contain dormant seeds before natural dispersion. The best germination condition found was a 12-h alternating light/dark and high/low (20/30 degrees C) temperature cycle, which seemed to target properties of the endosperm cap. The endosperm cap contains 7-8 layers of elongated polygonal cells and is predestined to facilitate radicle protrusion. The force required to puncture the endosperm cap decreased in two stages during germination and showed a significant negative correlation with endo-beta-mannanase activity. As a result of the thick endosperm cap, the puncture force was significantly higher in S. lycocarpum than in tomato and coffee. Endo-beta-mannanase activity was detected in the endosperm cap prior to radicle protrusion. Abscisic acid inhibited germination, increase of embryo weight during imbibition, the second stage of weakening of the endosperm cap and of endo-beta-mannanase activity in the endosperm cap.

CONCLUSIONS: The germination mechanism of S. lycocarpum bears resemblance to that of tomato and coffee seeds. However, quantitative differences were observed in embryo pressure potential, endo-beta¬mannanase activity and endosperm cap resistance that were related to germination rates across the three species.

Source : Ann.Bot.(Lond)  2007 vol.100 (6), pp 1175 - 1187

Functional complementation of a yeast knockout strain by Schistosoma mansoni Rho1 GTPase in the presence of caffeine, an agent that affects mutants defective in the protein kinase C signal transduction pathway

Aguiar, P. H.; Santos, D. N.; Lobo, F. P.; Santos, T. M.; Macedo, A. M.; Pena, S. D.; Machado, C. R.; Franco, G. R.

In a previous study, the Schistosoma mansoni Rho1 protein was able to complement Rho1 null mutant Saccharomyces cerevisiae cells at restrictive temperatures and under osmotic stress (low calcium concentration) better than the human homologue (RhoA). It is known that under osmotic stress, the S. cerevisiae Rho1 triggers two distinct pathways: activation of the membrane 1,3-beta-glucan synthase enzymatic complex and activation of the protein kinase C1 signal transduction pathway, promoting the transcription of response genes. In the present work the SmRho1 protein and its mutants smrho1 E97P, smrho1 L1 01T, and smrho1 E97P, L1 01T were used to try to clarify the basis for the differential complementation of Rho1 knockout yeast strain by the human and S. mansoni genes. Experiments of functional complementation in the presence of caffeine and in the presence of the osmotic regulator sorbitol were conducted. SmRho1 and its mutants showed a differential complementation of the yeast cells in the presence of caffeine, since smrho1 E97P and smrho1 E97P, L101 T mutants showed a delay in the growth when compared to the yeast complemented with the wild type SmRho1. However, in the presence of sorbitol and caffeine the wild type SmRho1 and mutants showed a similar complementation phenotype, as they allowed yeast growth in all caffeine concentrations tested.

Source : Mem.Inst.Oswaldo Cruz  2006 vol.101 (Suppl 1),  pp 323 - 326 (full text)

MICROBIOLOGY

Water activity and temperature effects on growth of Aspergillus niger, A. awamori and A. carbonarius isolated from different substrates in Argentina

Astoreca, A.; Magnoli, C.; Ramirez, M. L.; Combina, M.; Dalcero, A.

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus and some species of Aspergillus section Nigri (formerly Aspergillus niger group and Aspergillus carbonarius). This study examined the effect of water activity, temperature and their interactions on mycelial growth rate and lag phase prior to growth of isolates of Aspergillus section Nigri isolated from peanuts, maize kernels, dried grapes and coffee cherries from Argentina. All factors alone and interactions were statistically significant in relation to growth rates and lag phase for Aspergillus niger, Aspergillus awamori and Aspergillus carbonarius isolates. The authors suggest that data could be used to predict possible fungal contamination of substrates.

Source : Intern J Food Microbiol 2007 vol.119 (3), pp 314-318

Detection and quantification of Aspergillus westerdijkiae in coffee beans based on selective amplification of beta-tubulin gene by using real-time PCR

Morello, L. G.; Sartori, D.; Oliveira- Marti nez, A. L.; Vieira, M. L. C.; Taniwaki, M. H.; Fungaro, M. H. P.

Aspergillus westerdijkiae is a new species of fungus, and most isolates of this fungus can produce large amounts of ochratoxin A (OTA), which has been found in beverages, such as coffee. The toxicity and carcinogenicity of OTA has been demonstrated in animals. Real-time PCR technologies allow precise quantification of target fungal DNA in host tissues. This study examined the nucleotide sequence variability in a region of the beta-tubulin gene from isolates obtained from Brazilian coffee bean samples, previously identified as Aspergillus ochraceus, compared with those of Aspergillus westerdijkiae. A specific method was developed for detecting and quantifying Aspergillus westerdijkiae in coffee beans using real-time PCR. The authors suggest that the method developed could be adapted for quantification of this fungus in other foods.

Source : Intern J Food Microbiol 2007 vol.119 (3), pp 270-276

PROCESSING

Development of a dryer with airflow reversal and a pneumatic system for grain movement

Sampaio, C. P.; Nogueira, R. M.; Roberto, C. D.; Silva, J. S.

Performance and construction of a coffee drier with airflow reversal and a pneumatic system for grain movement is described. Coffee with different moisture contents was used to assess drier performance. Natural coffee (initial moisture content = 24.6 ± 1.8% w.b.) had drying times of 11.5, 10.3 and 9.6 h (moisture content at storage = 11.9 ± 1.3% w.b.), whereas drying times for parchment coffee (initial moisture content = 33.9 ± 2.1%) were 14.0, 12.5 and 12.2 h (moisture content at storage = 12.0 ± 1.5% w.b.). Parchment and natural coffees dried using the new drier were classified as type 4 and 6, respectively, with high cup quality.

Source : Biosystems Engineering 2007 vol.98 (1), pp 33 - 38

CHEMISTRY / SENSORICS

Determination of caffeine and sympathomimetic alkaloids in weight loss supplements by high-performance liquid chromatography

Evans, R. L.; Siitonen, P. H.

Reversed-phase high-performance liquid chromatography utilizing photodiode array detection is used for the simultaneous determination of caffeine and nine alkaloids from Citrus aurantium (CA) and ephedra (EA) contained in dietary weight loss products. Since the Food and Drug Administration (FDA) ban of EA, manufacturers have substituted CA in their weight loss formulations, usually combined with high levels of caffeine. The alkaloids contained in CA have some physiological effects similar to those of the EA alkaloids and are, therefore, cause for concern. Caffeine has been shown to potentiate the toxicity of the EA alkaloids. Recently, a federal judge overturned the absolute ban and allowed marketing of low levels (< 10 mg/day) of total EA alkaloids. To support an absolute ban, the FDA is now compelled to perform dose-dependent toxicology studies to determine the toxic dose(s) of EA. The toxicity of the CA compounds is largely unknown, especially in combination with caffeine. The described method enables quantitation over a wide range of product formulations. Recoveries range from 91 % to 100% from a variety of fortified plant matrices.

Source :  J Chromatogr Sci  2008 vol.46 (1), pp 61 - 67

Calorimetric and spatial characterization of polymorphic transitions in caffeine using quasi-isothermal MTDSC and localized thermomechanical analysis

Manduva, R.; Kett, V. L.; Banks, S. R.; Wood, J.; Reading, M.; Craig, D. Q.

We describe a novel integrated approach to the study of polymorphic transformation that includes quasi-isothermal modulated temperature differential scanning calorimetry (QI-MTDSC) and microthermal analysis (MTA), with a view to studying the thermal, kinetic and spatial characteristics of the process. Form II and I caffeine was prepared and conventional DSC and hot stage microscopy performed. The Form II to I transition at circa 413 K was associated with a change in crystal habit to needle shaped crystals. QI-MTDSC was used to measure the heat capacity of the system as a function of temperature, while MTA was able to spatially differentiate between the two polymorphs in compressed systems. We present a novel extension of the reduced temperature method whereby we apply it for the first time to linear rising temperature data corresponding to the transition; the analysis suggests a close approximation to Arrhenius behavior. We also describe a heat transfer model that allows calculation of the thermal gradients within a hermetically sealed pan for the first time. The combined approach has therefore allowed the characterization of the thermodynamics and kinetics of the transformation process as well as spatial identification of the distribution of the transformation in compressed systems.

Source :  J Pharm Sci 2008 vol.97 (3), pp 1285 - 1300

Comparison of high performance TLC and HPLC for separation and quantification of chlorogenic acid in green coffee bean extracts

Urakova, I. N.; Pozharitskaya, O. N.; Shikov, A. N.; Kosman, V. M.; Makarov, V. G.

Two chromatographic methods, high-performance TLC (HPTLC) and HPLC, were developed and used for separation and quantitative determination of chlorogenic acid in green coffee bean extracts. For HPTLC silica gel Kieselgel 60 F 254 plates with ethyl acetate/dichlormethane/formic acid/acetic acid/water (100:25:10:10:11, v/v/v/v/v) as mobile phase were used. Densitometric determination of chlorogenic acid by HPTLC was performed at 330 nm. A gradient RP HPLC method was carried out at 330 nm. All necessary validation tests for both methods were developed for their comparison. There were no statistically significant differences between HPLC and HPTLC for quantitative determination of chlorogenic acid according to the test of equality of the means.

Source : J Sep Sci  2008 vol.31 (2), pp 237 - 241 

Evaluation of methods used to determine ochratoxin A in coffee beans

Ahmed, N. E.; Farag, M. M.; Soliman, K. M.; Abdel-Samed, A. K. M.; Naguib, K. M.

Ochratoxin A (OTA) is a toxic mould metabolite produced by Aspergillus ochraceus and Penicillium verrucosum that is a contaminant of cereals and coffee beans. This study evaluated existing methods for OTA determination involving TLC, HPLC and an immunoaffinity column clean-up procedure, with the aim of selecting an accurate, sensitive and less expensive method for detecting OTA in green and roasted coffee beans. Results indicated that the AOAC official method for the extraction of OTA in green coffee and determination by HPLC is an efficient method for routine analyses of OTA in green and ground roasted coffee beans. The immunoaffinity column/HPLC procedure tested is recommended for use in processed coffee beans where low concentrations of OTA are expected.

Source : J Agric Food Chem 2007 vol.55 (23), pp 76-9580

Analysis of the headspace volatiles of freshly brewed arabica coffee using solid-phase microextraction

Akiyama, M.; Murakami, K.; Ikeda, M.; Iwatsuki, K.; Wada, A.; Tokuno, K.; Onishi, M.; Iwabuchi, H.

Headspace volatiles of freshly brewed drip coffee were investigated by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/olfactometry (GC/O, CharmAnalysis) analyses. For this purpose, a solid-phase microextraction (SPME) sampling method for the headspace volatiles of freshly brewed drip coffee was developed. SPME fiber coated with divinylbenzene (DVB)/carboxen/polydimethylsiloxane (PDMS) was selected from 6 types, and sampling time was determined at 2 min. The headspace coffee volatiles stayed constant in proportion for the first 2 min to keep the freshness of the brewed coffee aroma. Using this sampling method, the headspace volatiles of freshly brewed drip coffee (Ethiopian arabica coffee, roast degree: L value; 23) were examined by GC/MS and GC/O analyses. From the GC/O results, 1-(3,4-dihydro-2H-pyrrol-2-yl)-ethanone (nutty-roast odor) and 4-(4'-hydroxyphenyl)-2-butanone (raspberry ketone, sweet-fruity odor) were newly detected as components in the aroma of coffee.

Source :  J. Food Sci. 2007 vol.72 (7), pp C388 - C396

Isolation, identification, and quantification of roasted coffee antibacterial compounds

Daglia, M.; Papetti, A.; Grisoli, P.; Aceti, C.; Spini, V.; Dacarro, C.; Gazzani, G.

Coffee brew is a widely consumed beverage with multiple biological activities due both to naturally occurring components and to the hundreds of chemicals that are formed during the roasting process. Roasted coffee extract possesses antibacterial activity against a wide range of microorganisms, including Staphylococcus aureus and Streptococcus mutans, whereas green coffee extract exhibits no such activity. The naturally occurring coffee compounds, such as chlorogenic acids and caffeine, cannot therefore be responsible for the significant antibacterial activity exerted by coffee beverages against both bacteria. The very low minimum inhibitory concentration (MIC) found for standard glyoxal, methylglyoxal, and diacetyl compounds formed during the roasting process points to these alpha-dicarbonyl compounds as the main agents responsible for the antibacterial activity of brewed coffee against Sa. aureus and St. mutans. However, their low concentrations determined in the beverage account for only 50% of its antibacterial activity. The addition of caffeine, which has weak intrinsic antibacterial activity, to a mixture of alpha-dicarbonyl compounds at the concentrations found in coffee demonstrated that caffeine synergistically enhances the antibacterial activity of alpha-dicarbonyl compounds and that glyoxal, methylglyoxal, and diacetyl in the presence of caffeine account for the whole antibacterial activity of roasted coffee.

Source : J Agric Food Chem 2007. vol.55 (25), pp 10208 - 10213 

Isolation and determination of alpha-dicarbonyl compounds by RP-HPLC-DAD in green and roasted coffee

Daglia, M.; Papetti, A.; Aceti, C.; Sordelli, B.; Spini, V.; Gazzani, G.

Dicarbonyl compounds are intermediates formed during the heating of food, and caramelisation and the Maillard reaction are the main types of reactions in heated foods. The toxicology of alpha-dicarbonyl compounds is unclear, and methods have been developed to determine alpha-dicarbonyl compounds. In this study, a method of sample preparation allowing simultaneous and accurate determination of glyoxal, methylglyoxal and diacetyl in coffee brew was developed using reverse-phase HPLC with a diode array detector, and the kinetics of their formation during roasting were investigated. Light- and medium-roasted coffees had the highest glyoxal and methylglyoxal content; dark-roasted coffee had smaller amounts of glyoxal, methylglyoxal and diacetyl. Interfering compounds were eliminated, and advantages of the proposed method are discussed.

Source : J Agric Food Chem 2007 vol.55 (22), pp 8877-8882

Natural occurrence of ochratoxin A and antioxidant activities of green and roasted coffees and corresponding byproducts

Napolitano, A.; Fogliano, V.; Tafuri, A.; Ritieni, A.

Ochratoxin A is an important mycotoxin that can enter the human food chain in cereals, wine, coffee, spices, beer, cocoa, dried fruits, and pork meats. Coffee is one of the most common beverages and, consequently, it has a potential risk factor for human health related to ochratoxin A exposure. In this study, coffee and corresponding byproducts from seven different geographic regions were investigated for ochratoxin A natural occurrence by HPLC-FLD, nutritional characterization, and antioxidant activities by spectrophotometric assay. The research focused on composition changes in coffee during the processing step "from field to cup". Costa Rica and Indian green coffees were the most contaminated samples, with 13 and 11 microg/kg, respectively, while the Ethiopian coffee was the least contaminated, with 3.8 microg/kg of ochratoxin A. The reduction of ochratoxin A contamination during the roasting step was comparable for any samples that were considered under the recommended level of 4 microg/kg. Total dietary fibers ranged from 58.7% for Vietnam and 48.6% for Ivory Coast in green coffees and ranged from 58.6% for Costa Rica to 61.2% for India in roasted coffee. Coffee silverskin byproduct obtained from Ivory Coast was the highest, with 69.2 and 64.2% of insoluble dietary fibers, respectively.

Source : J Agric Food Chem 2007 vol.55 (25), pp 10499 - 10504

Determination of caffeine in coffee products by dynamic complexation with 3,4-dimethoxycinnamate and separation by CZE

Nogueira, T.; Lucio-do-Lago, C.

A method based on the formation of PI-complexes with chlorogenate-like species is proposed for the determination of caffeine in regular (nondecaffeinated) and decaffeinated coffee. Both caffeate and 3,4- dimethoxycinnamate were able to transform caffeine, a neutral species in aqueous solutions, into an anionic species. Use of 3,4-dimethoxycinnamate in the running electrolyte is advantageous because of its greater chemical stability and improved resolution of peaks of caffeine, theobromine and theophylline. Negative peaks were registered with a capacitively coupled contactless conductivity detector when solutions of these alkylxanthines were analysed with a BGE composed of 20 mmol/l 3,4- dimethoxycinnamic acid and pH adjusted to 8.5 with Tris. This behaviour was expected as the complex is larger and should move slower than the free anion. Caffeine was determined in ground and instant coffee with precision and accuracy that meets Brazilian standards. The limit of detection was estimated as 33 mg/l, which corresponds to 0.8 and 0.3 mg of caffeine/g of dry instant coffee and ground coffee, respectively. For decaffeinated coffee, a 10x preconcentration with dichloromethane was carried out to allow the quantitation of caffeine, which should not exceed 1 mg/g in DM.

Source : Electrophoresis 2007 vol.28 (19), pp Inorganic - 3574

In-house validation of a simple headspace gas chromatography-mass spectrometry method for determination of furan levels in food

Vranova, J.; Bednarikova, A.; Ciesarova, Z.

A method for determination of furans in foods based on headspace GC-MS was validated for routine application in food control. Validation was performed in house by evaluation of method precision, trueness, recovery, limit of detection (LOD), limit of quantification (LOQ), operating range and calibration. Uncertainty statements obtained for tomato ketchup analysis showed that the method was suitable for determination of furans in this matrix (LOD, 0.9 mug/kg; LOQ, 2.9 mug/kg; recoveries, 103-115% (for spiking levels of 10-100 mug/kg) with relative s.d. of 4- 8%). The GC-MS method was also applied to determination of furans in various other processed foods including infant foods, canned meat and vegetables, liquid seasonings, sauces and coffee. Furan concn. ranged from below LOD to 920 mug/kg.

Source : J Food Nutrit Res 2007 vol.46 (3), pp 123 - 127 (full text)

COFFEE & HEALTH

Coffee consumption, serum gamma-glutamyltransferase and risk of type II diabetes

Bidel, S.; Silventoinen, K.; Hu, G.; Lee, D. H.; Kaprio, J.; Tuomilehto, J.

Objectives:To study the joint association of coffee consumption and serum gamma-glutamyltransferase (GGT) levels on the risk of developing type II diabetes. Design, setting and subjects:A total of 21 826 Finnish men and women who were 35-74 years of age and without any history of diabetes at baseline (years 1982, 1987, 1992 and 1997) were included in the present analyses. They were prospectively followed up for onset of type II diabetes (n=862 cases), death or until the end of the year 2002. Coffee consumption, serum GGT and other study parameters were determined at baseline using standardized measurements. Analyses were stratified by the serum GGT level classified into two classes using the 75th sex-specific percentiles as the cut point.Results:Coffee consumption was significantly and inversely associated with incident diabetes among both men and women. Serum GGT modified the association between coffee consumption and incident diabetes. Subjects in the high category of coffee consumption with the GGT level >/=75th percentile showed a significant inverse association for women, and for both sexes combined. The association was not significant in subjects with the GGT level </=75th percentile. There was a significant interaction effect of GGT and coffee consumption on risk of type II diabetes in data of women (P=0.05) and in both sexes combined (P=0.02). Conclusions:Habitual coffee consumption is associated with lower incidence of type II diabetes particularly in those with higher baseline serum GGT levels.

Source : Eur.J.Clin.Nutr. 2008 vol.62 (2), pp 178 - 185

Psychological effects of dietary components of tea: caffeine and L-theanine

Bryan, J.

This review summarizes the literature on the association between two dietary components of tea, caffeine and L-theanine, and the psychological outcomes of consumption; it also identifies areas for future research. The studies reviewed suggest that caffeinated tea, when ingested at regular intervals, may maintain alertness, focused attention, and accuracy and may modulate the more acute effects of higher doses of caffeine. These findings concur with the neurochemical effects of L-theanine on the brain. L-theanine may interact with caffeine to enhance performance in terms of attention switching and the ability to ignore distraction; this is likely to be reflective of higher-level cognitive activity and may be sensitive to the detrimental effects of overstimulation. Further research should investigate the interactive effects of caffeine, L-theanine, and task complexity, utilize a range of ecologically valid psychological outcomes, and assess the neuroprotective effects of L-theanine using epidemiological or longer-term intervention studies among individuals at risk of neurodegenerative disease.

Source : Nutr Rev 2008 vol.66 (2), pp 82-90

Interaction of caffeine with regadenoson-induced hyperemic myocardial blood flow as measured by positron emission tomography: a randomized, double-blind, placebo-controlled crossover trial

Gaemperli, O.; Schepis, T.; Koepfli, P.; Siegrist, P. T.; Fleischman, S.; Nguyen, P.; Olmsted, A.; Wang, W.; Lieu, H.; Kaufmann, P. A.

No abstract available

Source : J Am Coll Cardiol 2008 vol.51 (3),  pp 328 - 329

The effects of l-theanine, caffeine and their combination on cognition and mood

Haskell, C. F.; Kennedy, D. O.; Milne, A. L.; Wesnes, K. A.; Scholey, A. B.

l-Theanine is an amino acid found naturally in tea. Despite the common consumption of l-theanine, predominantly in combination with caffeine in the form of tea, only one study to date has examined the cognitive effects of this substance alone, and none have examined its effects when combined with caffeine. The present randomised, placebo-controlled, double-blind, balanced crossover study investigated the acute cognitive and mood effects of l-theanine (250mg), and caffeine (150mg), in isolation and in combination. Salivary caffeine levels were co-monitored. l-Theanine increased 'headache' ratings and decreased correct serial seven subtractions. Caffeine led to faster digit vigilance reaction time, improved Rapid Visual Information Processing (RVIP) accuracy and attenuated increases in self-reported 'mental fatigue'. In addition to improving RVIP accuracy and 'mental fatigue' ratings, the combination also led to faster simple reaction time, faster numeric working memory reaction time and improved sentence verification accuracy. 'Headache' and 'tired' ratings were reduced and 'alert' ratings increased. There was also a significant positive caffeinexl-theanine interaction on delayed word recognition reaction time. These results suggest that beverages containing l-theanine and caffeine may have a different pharmacological profile to those containing caffeine alone.

Source :  Biol Psychol 2008 vol.77 (2), pp 113 - 122

Induction of cancer chemopreventive enzymes by coffee is mediated by transcription factor Nrf2. Evidence that the coffee-specific diterpenes cafestol and kahweol confer protection against acrolein

Higgins, L. G.; Cavin, C.; Itoh, K.; Yamamoto, M.; Hayes, J. D.

Mice fed diets containing 3% or 6% coffee for 5 days had increased levels of mRNA for NAD(P)H:quinone oxidoreductase 1 (NQO1) and glutathione S-transferase class Alpha 1 (GSTA1) of between 4- and 20-fold in the liver and small intestine. Mice fed 6% coffee also had increased amounts of mRNA for UDP-glucuronosyl transferase 1 A6 (UGT1 A6) and the glutamate cysteine ligase catalytic (GCLC) subunit of between 3- and 10-fold in the small intestine. Up-regulation of these mRNAs was significantly greater in mice possessing Nrf2 (NF-E2 p45 subunit-related factor 2) than those lacking the transcription factor. Basal levels of mRNAs for NQO1, GSTA1, UGT1A6 and GCLC were lower in tissues from nrf2(-/-) mice than from nrf2(+/+) mice, but modest induction occurred in the mutant animals. Treatment of mouse embryonic fibroblasts (MEFs) from nrf2(+/+) mice with either coffee or the coffee-specific diterpenes cafestol and kahweol (C+K) increased NQO1 mRNA up to 9-fold. MEFs from nrf2(-/-) mice expressed less NQO1 mRNA than did wild-type MEFs, but NQO1 was induced modestly by coffee or C+K in the mutant fibroblasts. Transfection of MEFs with nqo1-luciferase reporter constructs showed that induction by C+K was mediated primarily by Nrf2 and required the presence of an antioxidant response element in the 5'- upstream region of the gene. Luciferase reporter activity did not increase following treatment of MEFs with 100 mumol/l furan, suggesting that this ring structure within C+K is insufficient for gene induction. Priming of nrf2(+/+) MEFs, but not nrf2(-/-) MEFs, with C+K conferred 2-fold resistance towards acrolein.

Source : Toxicol Appl Pharmacol 2008 vol.226 (3), pp 328 - 337

Caffeine increases ambulatory glucose and postprandial responses in coffee drinkers with type 2 diabetes

Lane, J. D.; Feinglos, M. N.; Surwit, R. S.

No abstract available

Source : Diabetes Care 2008 vol.31 Iss(2), pp 221 - 222

Maternal smoking, alcohol consumption, and caffeine consumption during pregnancy in relation to a son\'s

Mongraw-Chaffin, M. L.; Cohn, B. A.; Cohen, R. D.; Christianson, R. E.

The Child Health and Development Studies is a > or =40-year follow-up of 20,754 pregnancies occurring between 1959 and 1967 in California. There were 84 cases of undescended testes at birth persisting to at least age 2 years among 7,574 liveborn sons whose mothers were interviewed in early pregnancy. Cases were matched to three controls on birth year and race. Compared with mothers of controls, mothers of cryptorchid boys consumed more caffeine during pregnancy (odds ratio = 1.4, 95% confidence interval: 1. 1, 1.9 for an interquartile range equivalent to three cups of coffee per day) but were not more likely to smoke or drink alcohol when all behaviors were considered together. Other maternal and perinatal risk factors were not significantly associated with persistent cryptorchidism and did not confound the association with caffeine.

Source :  Am J Epidemiol 2008 vol.167 (3), pp 257 - 261

Timing of blood pressure measurement related to caffeine consumption

Mort, J. R.; Kruse, H. R.

OBJECTIVE: To determine whether patients should wait 30 minutes after caffeine consumption to have their blood pressure measured. DATA SOURCES: Literature was obtained by searching MEDLINE (1980- September 2007), International Pharmaceutical Abstracts (1980-September 2007), and the Cochrane Database of Systematic Reviews (1994-September 2007). Search terms included caffeine and blood pressure. Literature was also obtained from citations in relevant articles. STUDY SELECTION AND DATA EXTRACTION: Articles that examined caffeine's acute effect on blood pressure were reviewed, with additional focus on caffeine tolerance and hypertensive status. DATA SYNTHESIS: Caffeine appears to affect blood pressure through adenosine receptor inhibition and an increased release of select neurotransmitters. Caffeine levels peak 30-120 minutes after oral intake and caffeine's half-life is 3-6 hours. The effect of caffeine on blood pressure has been examined for decades, with variable results depending on factors such as population examined (eg, hypertensive status, physical stressors, age) and study design (eg, acute effects, chronic ingestion, retrospective epidemiologic review). Caffeine tolerance diminishes the acute effect of caffeine on blood pressure, and hypertensive individuals are more susceptible to blood pressure changes. Reviews of caffeine's acute effect on blood pressure indicate changes of 3-15 mm Hg systolic and 4-13 mm Hg diastolic. Typically, blood pressure changes occur within 30 minutes, peak in 1-2 hours, and may persist for more than 4 hours.

CONCLUSIONS: Having a patient abstain from caffeine for 30 minutes prior to blood pressure monitoring is not adequate to avoid caffeine's potential effects. An alternative approach to blood pressure monitoring would be to ask the patient about recent caffeine consumption and interpret the blood pressure reading based on this information. In addition, healthcare practitioners should provide education regarding caffeine's effects.

Source : Ann Pharmacother 2008 vol.42 (1), pp 105 - 110

Comparison of the effects of inorganic phosphate on caffeine-induced Ca2+ release in fast- and slow-twitch mammalian skeletal muscle

Posterino, G. S.; Dunn, S. L.

We compared the effects of 50 mM P(i) on caffeine-induced Ca(2+) release in mechanically skinned fast-twitch (FT) and slow-twitch (ST) skeletal muscle fibers of the rat. The time integral (area) of the caffeine response was reduced by approximately 57% (FT) and approximately 27% (ST) after 30 s of exposure to 50 mM P(i) in either the presence or absence of creatine phosphate (to buffer ADP). Differences in the sarcoplasmic reticulum (SR) Ca(2+) content between FT and ST fibers [ approximately 40% vs. 100% SR Ca(2+) content (pCa 6.7), respectively] did not contribute to the different effects of P(i) observed; underloading the SR of ST fibers so that the SR Ca(2+) content approximated that of FT fibers resulted in an even smaller ( approximately 21 %), but not significant, reduction in caffeine-induced Ca(2+) release by P(i). These observed differences between FT and ST fibers could arise from fiber-type differences in the
ability of the SR to accumulate Ca(2+)-P(i) precipitate. To test this, fibers were Ca(2+) loaded in the presence of 50 mM P(i). In FT fibers, the maximum SR Ca(2+) content (pCa 6.7) was subsequently increased by up to 13 times of that achieved when loading for 2 min in the absence of P(i). In ST fibers, the SR Ca(2+) content was only doubled. These data show that Ca(2+) release in ST fibers was less affected by P(i) than FT fibers, and this may be due to a reduced capacity of ST SR to accumulate Ca(2+)-P(i) precipitate. This may account, in part, for the fatigue-resistant nature of ST fibers.

Source :  Am J Physiol Cell Physiol 2008 vol.294 (1), pp C97 - C105

Combined effects of smoking, coffee, and NSAIDs on Parkinson\'s disease risk

Powers, K. M.; Kay, D. M.; Factor, S. A.; Zabetian, C. P.; Higgins, D. S.; Samii, A.; Nutt, J. G.; Griffith, A.; Leis, B.; Roberts, J. W.; Martinez, E. D.; Montimurro, J. S.; Checkoway, H.; Payami, H.

Inverse associations of Parkinson's disease (PD) with cigarette smoking, coffee drinking, and nonsteroidal anti-inflammatory drug (NSAID) use have been reported individually, but their joint effects have not been examined. To quantify associations with PD for the individual, two-way and three-way combinations of these factors, a case-control association study with 1,186 PD patients and 928 controls was conducted. The study setting was the NeuroGenetics Research Consortium. Subjects completed a structured questionnaire regarding smoking, coffee, and NSAID consumption. Odds ratios were calculated using unconditional logistic regression. Smoking, coffee, and over the counter NSAID use as individual factors exhibited significantly reduced risks of 20% to 30%. The two-way and three-way combinations were associated with risk reduction of 37% to 49%, and 62%, respectively. Smoking and coffee exhibited significant inverse risk trends with increasing cumulative exposures, suggesting dose-response relations. With respect to the combination of all three exposures, persons who were at the highest exposure strata for smoking and coffee and used NSAIDs had an estimated 87% reduction in risk (OR = 0. 13, 95% CI = 0.06-0.29). Whether this finding reflects true biologic protection needs to be investigated.

Source : Mov Disord 2008 vol.23 (1), pp 88 - 95

Caffeine inhibits UV-mediated NF-kappaB activation in A2058 melanoma cells: an ATM-PKCdelta-p38 MAPK-dependent mechanism

Ravi, D.; Muniyappa, H.; Das, K. C.

Mammalian ultraviolet (UV) radiation response is a gene induction cascade activated by several transcription factors, including NF-kappaB. Although NF-kappaB is induced by UV radiation, the signal transduction mechanism remains relatively unclear. In the present study, we show that UV-induced NF-kappaB activation is mediated by the activation of Ataxia telangiecia mutated (ATM) and protein kinase C (PKC). We also show that caffeine specifically inhibits UV-mediated NF-kappaB activation, but not TNFalpha-mediated NF-kappaB activation. In addition, our study shows that ATM, but not ATM-Rad3- related (ATR) or DNA-dependent protein kinase (DNA-PK) is involved in UV-induced NF-kappaB activation. Because SB203580 (a p38 MAPK inhibitor), or Calphostin C or rottlerin (PKC inhibitors) was able to inhibit UV-mediated NF-kappaB activation, we evaluated whether caffeine could inhibit p38 MAPK or PKC activity. Caffeine or rottlerin inhibited UV-induced phosphorylation of p38 MAPK, but not anisomycin-induced phosphorylation of p38 MAPK, suggesting that p38 MAPK is downstream of PKC. Additionally, caffeine could effectively inhibit UV-induced increases in PKC activity. Taken together, our study demonstrates that caffeine is a potent inhibitor of UV-induced NF-kappaB activation. Additionally, this inhibition occurs due to the inhibitory action of caffeine on ATM and PKC, resulting in the inhibition of p38 MAPK activation.

Source : Mol Cell Biochem 2008 vol.308 (1-2), pp 193 - 200

Caffeine regulates alternative splicing in a subset of cancer-associated genes: a role for SC35

Shi, J.; Hu, Z.; Pabon, K.; Scotto, K. W.

Alternative splicing of pre-mRNA contributes significantly to human proteomic complexity, playing a key role in development, gene expression and, when aberrant, human disease onset. Many of the factors involved in alternative splicing have been identified, but little is known about their regulation. Here we report that caffeine regulates alternative splicing of a subset of cancer-associated genes, including the tumor suppressor KLF6. This regulation is at the level of splice site selection, occurs rapidly and reversibly, and is concentration dependent. We have recapitulated caffeine-induced alternative splicing of KLF6 using a cell-based minigene assay and identified a "caffeine response element" within the KLF6 intronic sequence. Significantly, a chimeric minigene splicing assay demonstrated that this caffeine response element is functional in a heterologous context; similar elements exist within close proximity to caffeine-regulated exons of other genes in the subset. Furthermore, the SR splicing factor, SC35, was shown to be required for induction of the alternatively spliced KLF6 transcript. Importantly, SC35 is markedly induced by caffeine, and overexpression of SC35 is sufficient to mimic the effect of caffeine on KLF6 alternative splicing. Taken together, our data implicate SC35 as a key player in caffeine-mediated splicing regulation. This novel effect of caffeine provides a valuable tool for dissecting the regulation of alternative splicing of a large gene subset and may have implications with respect to splice variants associated with disease states.

Source : Mol Cell Biol 2008 vol.28 (2), pp 883 - 895

Caffeine - a valuable tool in excitation-contraction coupling research

Stephenson, D. G.

Topic : action of caffeine on the activation of skeletal muscle.

Source : J Physiol 2008 vol.586 (Pt 3),  pp 695 - 696 (full Paper)

Coffee, heart and blood vessels

Anon.

This supplement looks at health issues with regard to coffee consumption, reviewing the state of research into risks with regard to heart and circulatory disease, coffee's effect on serum cholesterol levels, and coffee and blood pressure.

Source : Voeding-Nu  2007 vol.9 (11), supplement 'Coffee - heart and blood vessels.', 36pp  (not availabe on-line)

The effects of methylmercury on motor activity are sex- and age-dependent, and modulated by genetic deletion of adenosine receptors and caffeine administration

Bjorklund, O.; Kahlstrom, J.; Ogren, S. O.; Vahter, M.; Jiang, Fan Chen; Fredholm, B. B.; Dare, E.

Developmental neurotoxicity resulting from perinatal exposure to methylmercury (MeHg), a fish

pollutant, was investigated in mice with particular focus on the role of the adenosine receptor system. Experiments were conducted in which adenosine receptors were either partially blocked by caffeine or eliminated through genetic deletion (A1 R and A2AR knock-out mice). Mice were fed from day 7 of gestation to day 7 of lactation using drinking water containing 1 muM MeHg and/or 0.3 g/l caffeine in order to mimic human intakes. Open field analyses were conducted on offspring at postnatal day 21 and 2 months. Time-dependent behavioural changes were noted in mice exposed to MeHg, particularly males. Results indicated that the neurotoxicity resulting from MeHg exposure during pregnancy and lactation was reduced by inactivation of adenosine A1 and A2A receptors through caffeine treatment or genetic modification.

Source  : Toxicology 2007 vol.241 (3), pp 119 - 133

Evidence that a Ca2+ sparks/STOCs coupling mechanism is responsible for the inhibitory effect of caffeine on electro-mechanical coupling in guinea pig ureteric smooth muscle

Borisova, L.; Shmygol, A.; Wray, S.; Burdyga, T.

Recent studies have highlighted the role of the sarcoplasmic reticulum (SR) in controlling excitability, Ca2+ signalling and contractility in smooth muscle. Caffeine, an agonist of ryanodine receptors (RyRs) on the SR has been previously shown to effect Ca2+ signalling but its effects on excitability and contractility are not so clear. We have studied the effects of low concentration of caffeine (1 mM) on Ca2+ signalling, action potential and contractility of guinea pig ureteric smooth muscle. Caffeine produced reversible inhibition of the action potentials, Ca2+ transients and phasic contractions evoked by electrical stimulation. It had no effect on the inward Ca2+ current or Ca2+ transient but increased the amplitude and the frequency of spontaneous transient outward currents (STOCs) in voltage clamped ureteric myocytes, suggesting Ca2+-activated K+ channels (BK) are affected by it. In isolated cells and cells in situ caffeine produced an increase in the frequency and the amplitude of Ca2+ sparks as well the number of spark discharging sites per cell. Inhibition of Ca2+ sparks by ryanodine (50 microM) or SR Ca2+-ATPase (SERCA) cyclopiazonic acid (CPA, 20 microM) or BKCa channels by iberiotoxin (200 nM) or TEA (1 mM), fully reversed the inhibitory effect of caffeine on Ca2+ transients and force evoked by electrical field stimulation (EFS). These data suggest that the inhibitory effect of caffeine on the action potential, Ca2+ transients and force in ureteric smooth muscle is caused by activation of Ca2+ sparks/STOCs coupling mechanism.

Source : Cell Calcium 2007 vol.42 (3), pp 303 - 311

Changes in sensitivity of response distributions to changing reinforcement ratios during exposure to ephedrine, caffeine, and ephedrine-caffeine combinations

Borre, Y.; Chandrashekar, S.; Dougan, J. D.; Heidenreich, B. A.; Farmer-Dougan, V.

Changes in the sensitivity of response distributions to changes in reward distribution (reinforcer distribution sensitivity) were examined when rats were exposed to low and moderate doses of caffeine, ephedrine, and caffeine-ephedrine combinations. The data show significant decreases in sensitivity in response distributions to changes in reward schedule values during exposure to caffeine and ephedrine/caffeine combinations, whereas ephedrine alone resulted in overmatching comparable with baseline and NaCl conditions. Rats treated either with 3.0-mg/kg or 10.0-mg/kg doses of caffeine and all combinations of ephedrine at doses of 1.8 or 5.6 mg/kg with caffeine at 3.0 or 10.0 mg/kg showed reduced sensitivity in response distributions to differences in reinforcement schedule ratios. In contrast, when rats were exposed to ephedrine at 1.8 or 5.6 mg/kg, they maintained or increased the degree of overmatching. Although reinforcer distribution sensitivity was altered, drug exposure did not significantly affect the absolute rates of responding. Bias varied after exposure to caffeine, ephedrine, and their combinations, but not systematically. Finally, whereas the estimates of goodness of fit (r2) to the matching equation showed some decreases during drug exposure, these were neither statistically significant nor correlated with drug dose. These results suggest differential effects of ephedrine and caffeine on the sensitivity of response distributions to changes in reinforcement ratio distributions, with deleterious effects of caffeine and ephedrine/caffeine combinations.

Source : Behav  Pharmacol 2007 vol.18 (7). pp 609 - 622

Effects of caffeine and siloxanetriol alginate caffeine, as anticellulite agents, on fatty tissue: histological evaluation

Velasco, M. V.; Tano, C. T.; Machado-Santelli, G. M.; Consiglieri, V. O.; Kaneko, T. M.; Baby, A. R.

Background Cellulite is a physiological condition that presents etiologic plurality. Caffeine and its derivatives are used in anticellulite cosmetics due to their lipolytic activity on fatty cells. Siloxanetriol alginate caffeine (SAC) is a silanol derived from organic silicon. Radicals primarily from SAC are caffeine and the mannuronic acid. Aims This study aims to analyze the effects of caffeine and siloxanetriol alginate caffeine on fatty tissue by histological evaluation. Methods Formulations were developed with caffeine, caffeine + sodium benzoate or SAC and were applied topically for 21 days on Wistar female mice. The study regarded the histological aspects by determination of diameter and number of fatty cells with a light microscope. Results Emulsion with caffeine caused a reduction of 17% on the diameter of the fatty cells compared with the control. The emulsion with caffeine + sodium benzoate did not cause alterations on cell diameter. Emulsion with SAC provoked reduction on fatty cell diameters of 16%. No significant alterations were observed on the diameter of the fatty cells treated with gels, although it was noticed that gel with SAC promoted a reduction of 26% on the number of fatty cells. Conclusions Emulsion with SAC was considered more indicated to promote the lipolytic action on fatty tissue, acting as a complement to treat cellulite. When sodium benzoate was added to the preparations, it inhibited the caffeine efficiency. Gel was not an adequate vehicle to be incorporated with caffeine and SAC.

Source : J Cosmet Dermatol 2008 vol.7 (1), pp 23 - 29

Pregnancy and lactation

Allen, L. H.

This chapter reviews human nutritional requirements to ensure health during pregnancy and lactation. It includes changes in maternal physiology during pregnancy, such as hormonal changes, changes in blood and other fluids, and weight gain (with tables of changes in serum hormone concentrations and in tissue and nutrient deposition, and of pregnancy weight gain recommendations); metabolism and recommended intakes of nutrients, with a table of recommended nutrient intakes for non-reproducing, pregnant and lactating women; recommended dietary intakes for energy, essential fatty acids, protein, vitamins A, D, B6 and folic acid, and minerals (calcium, iron, zinc and iodine); other nutrition-related conditions, such as pregnancy complications in obese women, gestational diabetes, pre-eclampsia, and effects of alcohol and coffee; and the physiology of lactation, human milk composition (with a table of the effects of maternal micronutrient deficiencies and supplements during lactation on human milk and infant micronutrient status), and maternal nutrient requirements during lactation.

Source : Present knowledge in nutrition 2007 Vol 2. (not available on line)

Coffee, caffeine, and coronary heart disease

Cornelis, M. C.; El Sohemy, A.

This review summarizes and highlights recent advances in current knowledge of the relationship between coffee and caffeine consumption and risk of coronary heart disease. Potential mechanisms and genetic modifiers of this relationship are also discussed. RECENT FINDINGS: Studies examining the association between coffee consumption and coronary heart disease have been inconclusive. Coffee is a complex mixture of compounds that may have either beneficial or harmful effects on the cardiovascular system. Randomized controlled trials have confirmed the cholesterol-raising effect of diterpenes present in boiled coffee, which may contribute to the risk of coronary heart disease associated with unfiltered coffee consumption. A recent study examining the relationship between coffee and risk of myocardial infarction incorporated a genetic polymorphism associated with a slower rate of caffeine metabolism and provides strong evidence that caffeine also affects risk of coronary heart disease. Several studies have reported a protective effect of moderate coffee consumption, which suggests that coffee contains other compounds that may be beneficial. SUMMARY: Diterpenes present in unfiltered coffee and caffeine each appear to increase risk of coronary heart disease. A lower risk of coronary heart disease among moderate coffee drinkers might be due to antioxidants found in coffee.

Source : Curr Opin  Clin  Nutr Metab Care 2007 vol.10 Issue 6 pp 745 - 751

Transient inhibition of astrocytogenesis in developing mouse brain following postnatal caffeine exposure

Desfrere, L.; Olivier, P.; Schwendimann, L.; Verney, C.; Gressens, P.

Caffeine is frequently administered in human preterm newborns. Although some data suggest a potential risk for the developing brain, its impact has not been fully evaluated. We used a murine model of postnatal caffeine treatment in which mouse pups received intraperitoneal injections of caffeine from postnatal days 3 to 10. Caffeine exposure resulted in a transient reduction of glial fibrillary acidic protein and S100beta protein expression in various brain areas during the first 2 postnatal weeks (19.8% and 23.2% reduction in the hippocampus at P1 5, respectively). This effect was dose-dependent and at least partly involved a reduction of glial proliferation, as a caffeine-induced decrease of 5-bromodeoxyuridine incorporation was observed in the dentate gyrus and subventricular zone (25.8% and 26.6%, respectively) and no increase of programmed cell death (cleaved caspase-3 immunostaining) was observed at postnatal day 7. This effect could be reproduced with an antagonist of A(2a) adenosine receptor (A(2a)R) and was blocked by co-injection of an agonist. These results suggest that postnatal caffeine treatment might induce an alteration of astrocytogenesis via A(2a)R blockade during brain development. Although
no obvious neuritic abnormalities (microtubule-associated protein 2 and synaptophysin immunostaining) were observed, postnatal caffeine treatment could have long-term consequences on brain function.

Source : Pediatr Res 2007 vol.62 (5), pp 604 - 609 

Idebenone, green tea, and Coffee berry extract: new and innovative antioxidants

Farris, P.

The use of topical antioxidants is gaining favor among dermatologists because of their broad biologic activity. Many are not only antioxidants but also have antiinflammatory and anticarcinogenic activities. Thus for dermatologists these cosmeceuticals have many potential applications. In general, topical antioxidants exert their effects by down-regulating free radical mediated pathways that damage skin. The present study will describe the science behind some of the newest topical antioxidants and outline how they can be used as part of a comprehensive skin care regimen.

Source : Dermatol Ther 2007 vol.20 (5), pp 322 - 329

Influence of dietary catechols on the growth of enteropathogenic bacteria

Freestone, P. P. E.; Walton, N. J.; Haigh, R. D.; Lyte, M.

Infectious microorganisms have been found to respond to non-nutritional components of foods, such as catecholamines. This study examined whether other, non-catecholamine, dietary catechols, in plant foods, can also affect enteropathogen growth in an environment similar to that found in the gastrointestinal tract. The ability of a range of catechol-rich foods, including tea and coffee, and fruit and vegetable extracts, and purified preparations of dietary catechols, to modulate the growth of the Gram-negative enteric pathogens, Escherichia coli O157:H7 and Salmonella Enteritidis, was determined. Dose-dependent bacteriostatic effects were found for some catechols in iron-replete, rich medium, but in iron-restricted medium, all dietary catechols produced growth stimulation that was greater than that for non-supplemented controls. The authors conclude that under iron-restrictive conditions, these non-nutritional components of foods might provide iron and allow the growth of enteric bacterial pathogens.

Source : Intern J Food Microbiol 2007 vol.119 (3), pp 159-169

Determinacion de ocratoxina A en plasma humano y en cafe de Costa Rica por un metodo de ELISA. [Ocratoxin A in human plasma and coffee from Costa Rica by ELISA]

Guzman, E. M.; Guerrero, F. A.; Chaves, J. A.

Costa Rica is not an exception in the prevalence of ochratoxin A in human plasma, in this research the presence of the micotoxin was found in 95% of the 149 samples studied. The presence of ocratoxina A also was studied in 110 samples of toasted and grounded coffee from the most important 12 coffee factories of the country and from 7 supermarkets. With the exception of one negative sample the rest of them have concentrations of micotoxin below 4000 ng/kg. An association between the coffee consumption and the presence of ochratoxin A in plasma was attempted to be found as well as in the consumption of beer, but there were any statistically significant difference in the average level of mycotoxin between the coffee consumers and non coffee consumers neither between beer consumers and no beer consumers.

Source : Arch Latinoam Nutr 2007 vol.57 (2), pp 168 - 172 (full text)

Review of functional studies of beverage components acting on the recombinant GABAA neuroreceptor, and Na+/glucose cotransporter-response using the Xenopus oocyte expression system and electrophysiological measurements

Hossain, S. J.; Aoshima, H.; Koda, H.; Kiso, Y.

Beverages such as teas, coffee, cacao and liquors are produced in large quantities and consumed all over the world. Natural components from beverages affect neurotransmitter receptors, especially the GABAA receptors, which are involved in defining mental state and therefore have a role in stress management in modern society. These components of beverages modulating the responses of GABAA receptors or other neurotransmitter receptors that affect mental state linked to stress and mood can be detected by expressing the receptors in Xenopus oocytes and making voltage-clamp electrophysiological measurements. This approach could be extended to detect food-components, which are functionally active on various transporters such as Na+/glucose cotransporters operating in the small intestines to transport glucose into blood, which are inhibited by (+)-catechin and its derivatives in teas. Using this technique, it appears that beverages for stress and mood management have long-chain normal alcohols but short-chain esters and phenol derivatives having low numbers of OH- or phenol groups in addition to fragrant compounds such as geraniol, linalool, cis-jasmone, methyl jasmonate, 1-octen-3-ol, myrcenol, terpinen-4-ol and ethyl phenyl propanoate. It is suggested that this technique could also be used to assess the toxicity of food-components to cells, as was reported for saponin and tannic acid which produce large electrical responses in the oocyte. Further, (+)-catechin and its derivatives, and aqueous extracts of coffee, green tea, oolong tea and black tea, dose-dependently produce nonspecific currents, suggesting that high concn. of these beverages may be detrimental to the health.

Source :  Food Biotechnol 2007 vol.21(3), pp 237 - 270

Coffee and tea consumption and the risk of Parkinson\'s disease

Hu, G.; Bidel, S.; Jousilahti, P.; Antikainen, R.; Tuomilehto, J.

Several prospective studies have assessed the association between coffee consumption and Parkinson's disease (PD) risk, but the results are inconsistent. We examined the association of coffee and tea consumption with the risk of incident PD among 29,335 Finnish subjects aged 25 to 74 years without a history of PD at baseline. During a mean follow-up of 12.9 years, 102 men and 98 women developed an incident PD. The multivariate-adjusted (age, body mass index, systolic blood pressure, total cholesterol, education, leisure-time physical activity, smoking, alcohol and tea consumption, and history of diabetes) hazard ratios (HRs) of PD associated with the amount of coffee consumed daily (0, 1-4, and > or = 5 cups) were 1.00, 0.55, and 0.41 (P for trend = 0.063) in men, 1.00, 0.50, and 0.39 (P for trend = 0.073) in women, and 1.00, 0.53, and 0.40 (P for trend = 0.005) in men and women combined (adjusted also for sex), respectively. In both sexes combined, the multivariate-adjusted HRs of PD for subjects drinking > or = 3 cups of tea daily compared with tea nondrinkers was 0.41 (95% CI 0.20-0.83). These results suggest that coffee drinking is associated with a lower risk of PD. More tea drinking is associated with a lower risk of PD.

Source : Mov Disord 2007 vol.22 (15), pp 2242 - 2248

\"No thanks, it keeps me awake\": the genetics of coffee-attributed sleep disturbance

Luciano, M.; Zhu, G.; Kirk, K. M.; Gordon, S. D.; Heath, A. C.; Montgomery, G. W.; Martin, N. G.

Previous genetic investigations of sleep disturbance have shown various measures of sleep quality and sleep pattern to be heritable. But none of these studies have investigated the genetic predisposition to sleep disturbance attributed to caffeine. In this study, the heritability of coffee-attributed sleep disturbance and its relationship with other sleep measures were estimated, and chromosomal regions influencing this trait were identified. DESIGN: A classical twin design was used to estimate the heritability of coffee-attributed sleep disturbance and its genetic covariance with other measures of sleep disturbance (e.g., due to anxiety, depression) and sleep quality (e.g., variability in sleep quality). To locate quantitative trait loci influencing coffee-attributed sleep disturbance, a genome¬wide linkage screen of 1395 microsatellite markers was performed. PARTICIPANTS: The study included 3808 Australian adult twin pairs (n = 1799 monozygous pairs; n = 2009 dizygous pairs). A subsample of 1989 individuals from 1175 families was used for the linkage analysis. MEASUREMENTS AND RESULTS: The heritability of coffee-attributed sleep disturbance (measured by self report) was approximately 0.40, with three fourths of this genetic variance explained by genes unrelated to the general sleep disturbance factor. One region of significant linkage to coffee-attributed sleep disturbance was identified on chromosome 2q (LOD score of 2.9).

CONCLUSIONS: Although no candidate genes known to be related to caffeine metabolism or sleep disorder were identified in the significant linkage region, 2 candidates were found under a smaller peak on chromosome 17q.

Source : Sleep 2007 vol.30 (10), pp 1378 - 1386 (full text)

Early menopause, association with tobacco smoking, coffee consumption and other lifestyle factors: a cross-sectional study

Mikkelsen, T. F.; Graff-Iversen, S.; Sundby, J.; Bjertness, E.

Early onset of menopause is a risk factor for several health problems. In this study, the associations between early menopause and current, past active and passive smoking were investigated. In addition, the association between coffee and alcohol consumption and early menopause was studied. Participants studied included a sub-sample of 2123 postmenopausal women born in 1940-41 who participated in the Oslo Health Study, Norway. Early menopause was defined as menopause occurring at an age of <45 yr. Logistic regression analyses (crude and adjusted odds ratio (OR)) were used to examine the association between early menopause and selected lifestyle factors. Current smoking was significantly associated with early menopause (adj. OR, 1.59; 95% CI, 1.11-2.28). Stopping smoking more than 10 yr before menopause considerably reduced the risk of early menopause (adj. OR, 0.13; 95% CI, 0.05-0.33). Total exposure to smoking (the product of number of cigarettes per day and time as a smoker) was positively related to early menopause and, at the highest doses, nearly doubled the odds (adj. OR, 1.93; 95% CI, 1.12-3.30). Results indicated a possible dose-response relationship between total exposure to smoking and early menopause, but no dose-response relationship was detected for the other variables examined. No significant association of coffee or alcohol consumption with early menopause was found. Of the lifestyle factors tested, high educational level (adj. OR, 0.50; 95% CI, 0.34-0.72) and high social participation (adj. OR, 0.60, 95% CI, 0.39-0.98) were negatively associated with early menopause. This cross-sectional study showed an association between current smoking and early menopause. It is suggested that the earlier a woman stops smoking the more protected she is from early menopause. Early menopause was not significantly associated with passive smoking, or alcohol or coffee consumption.

Source : BMC Public Health 2007 vol.7 (July), pp 8 (full text)

Green coffee extract Svetol can manage weight: a review

Nardon, K.; Lafay, S.; Lemaire, B.

The green coffee bean extract Svetol has been developed as an appetite suppressant to help address the increasing imbalance between energy intake and expenditure in developed countries. This paper describes the epidemiological data obtained to support the claim that Svetol can help body weight control - mainly the results of two clinical trials, which showed that 400 mg/day Svetol reduced post-load glycaemia and body weight. The result of in vitro studies indicate that Svetol works by inhibiting glucose-6-phosphatase, a hepatic enzyme involved in glucose release in the bloodstream.

Source : Agro Food Ind Hi-Tech 2007 vol.18 (5), supplement 'Focus on obesity', pp 37-39  

1,3,7-trimethylxanthine (caffeine) may exacerbate acute inflammatory liver injury by weakening the physiological immunosuppressive mechanism

Ohta, A.; Lukashev, D.; Jackson, E. K.; Fredholm, B. B.; Sitkovsky, M.

The genetic elimination of A2A adenosine receptors (A2AR) was shown to disengage the critical immunosuppressive mechanism and cause the dramatic exacerbation of acute inflammatory tissue damage by T cells and myeloid cells. This prompted the evaluation of the proinflammatory vs the anti-inflammatory effects of the widely consumed behavioral drug caffeine, as the psychoactive effects of caffeine are mediated largely by its antagonistic action on A2AR in the brain. Because caffeine has other biochemical targets besides A2AR, it was important to test whether the consumption of caffeine during an acute inflammation episode would lead to the exacerbation of immune-mediated tissue damage. We examined acute and chronic treatment with caffeine for its effects on acute liver inflammation. It is shown that caffeine at lower doses (10 and 20 mg/kg) strongly exacerbated acute liver damage and increased levels of proinflammatory cytokines. Because caffeine did not enhance liver damage in A2AR-deficient mice, we suggest that the potentiation of liver inflammation was mediated by interference with the A2AR-mediated tissue-protecting mechanism. In contrast, a high dose of caffeine (100 mg/kg) completely blocked both liver damage and proinflammatory cytokine responses through an A2AR-independent mechanism. Furthermore, caffeine administration exacerbated liver damage even when mice consumed caffeine chronically, although the extent of exacerbation was less than in "naive" mice that did not consume caffeine before. This study suggests an unappreciated "man-made" immunological pathogenesis whereby consumption of the food-, beverage-, and medication-derived adenosine receptor antagonists may modify an individual's inflammatory status and lead to excessive organ damage during acute inflammation.

Source : J.Immunol 2007 vol.179 (11), pp 7431 - 7438

Effects of ingesting JavaFit Energy Extreme functional coffee on aerobic and anaerobic fitness markers in recreationally-active coffee consumers

Roberts, M. D.; Taylor, L. W.; Wismann, J. A.; Wilborn, C. D.; Kreider, R. B.; Willoughby, D. S

The purpose of this study was to examine the effects of ingesting JavaFittrade mark Energy Extreme (JEE) on aerobic and anaerobic performance measures in recreationally-active male and female coffee drinkers. Five male (27.6 +/- 4.2 yrs, 93.2 +/- 11.7 kg, 181.6 +/- 6.9 cm) and five female (29 +/- 4.6 yrs, 61.5 +/- 9.2 kg, 167.6 +/- 6.9 cm) regular coffee drinkers (i.e., 223.9 +/- 62.7 mg.d-1 of caffeine)
participated in this study. In a cross-over, randomized design, participants performed a baseline (BASELINE) graded treadmill test (GXT) for peak VO2 assessment and a Wingate test for peak power. Approximately 3-4 d following BASELINE testing, participants returned to the lab for the first trial and ingested 354 ml of either JEE or decaffeinated coffee (DECAF), after which they performed a GXT and Wingate test. Criterion measures during the GXT included an assessment of peakVO2 at maximal exercise, as well as VO2 at 3 minutes and 10 minutes post-exercise. Additionally, time-to-exhaustion (TTE), maximal RPE, mean heart rate (HR), mean systolic pressure (SBP), and mean diastolic blood pressure (DBP) were measured during each condition. Criterion measures for the Wingate included mean HR, SBP, DBP, peak power, and time to peak power (TTP). Participants then returned to the lab approximately one week later to perform the second trial under the same conditions as the first, except consuming the remaining coffee. Data were analyzed using a one way ANOVA (p < 0.05). Our results indicate that JEE significantly increased VO2 at 3 minutes post-exercise when compared to BASELINE (p = 0.04) and DECAF (p = 0.02) values, which may be beneficial in enhancing post-exercise fat metabolism.

Source :  J. Int. Soc. Sports Nutr. 2007 vol. pp 25

Effect of in vitro enzymatic digestion on antioxidant activity of coffee melanoidins and

Rufian-Henares, J. A.; Morales, F. J.

Coffee infusions are one of the main sources of melanoidins, and melanoidins have been studied for their nutritional, biological and health implications. It has been suggested, however, that the potential biological activity of melanoidins and related fractions should be evaluated after stimulating gastrointestinal digestion. This study investigated the antioxidant properties of coffee melanoidins, and the effect of a simulated gastrointestinal digestion on these properties. Antioxidant activity of high- and low-molecular-weight fractions was evaluated using different assays. Low-molecular-weight compounds released from the melanoidin after gastrointestinal digestion exerted the highest antioxidant activity, and gastrointestinal digestion was able to modify coffee melanoidins.

Source : J Agric Food Chem 2007 vol. 55 (24), pp 10016-10021

Aging and nocturnal driving: better with coffee or a nap? A randomized study

Sagaspe, P.; Taillard, J.; Chaumet, G.; Moore, N.; Bioulac, B.; Philip, P.

STUDY OBJECTIVE: To test the effects of coffee and napping on nocturnal driving in young and middle-aged participants. DESIGN: A cup of coffee (200 mg of caffeine), a placebo (decaffeinated coffee, 15 mg of caffeine), or a 30-minute nap were tested. Participants drove 125 highway miles between 18:00 and 19:30 and between 02:00 and 03:30 after coffee, placebo, or a nap. SETTING: Sleep laboratory and open French highway. PARTICIPANTS: Twelve young (range, 20-25 years) and 12 middle-aged participants (range, 40-50 years). MEASUREMENTS: Inappropriate line crossings, self-perceived fatigue and sleepiness, and polysomnographic recordings were analyzed. RESULTS: Compared to daytime, after placebo the number of inappropriate line crossings was significantly increased (2 versus 73 for young participants, P < 0.01 and 0 versus 76 for the middle-aged participants, P < 0.05). Both coffee and napping reduced the risk of inappropriate line crossings, compared with placebo, in young participants (respectively, by three-quarters, incidence rate ratios [IRR] = 0.26 95% confidence interval [CI], 0.09-0.74, P < 0.05 and by two thirds, IRR = 0.34 95% CI, 0.20-0.58, P < 0.001) and in middle-aged participants (respectively by nine tenths, IRR = 0.11 95% CI, 0.05-0.21, P < 0.001 and by one fifth, IRR = 0.77 95% CI, 0.63-0.95, P < 0.05). A significant interaction between age and condition (IRR = 2.27 95% CI, 1.28- 4.16 P < 0.01) showed that napping led to fewer inappropriate line crossings in younger participants than in middle-aged participants. During napping, young participants slept more (P < 0.01) and had more delta sleep (P < 0.05) than middle-aged participants. Self-perceived sleepiness and fatigue did not differ in both age groups, but coffee improved sleepiness (P < 0.05), whereas napping did not.

CONCLUSIONS: Coffee significantly improves performance in young and middle-aged participants. Napping is more efficient in younger than in older participants. Countermeasures to sleepiness should be adapted according to the age of drivers.

Source : Sleep 2007 vol.30 (12), pp 1808 - 1813

Risk factors for Parkinson\'s disease and impaired olfaction in relatives of patients with Parkinson\'s disease

Siderowf, A.; Jennings, D.; Connolly, J.; Doty, R. L.; Marek, K.; Stern, M. B.

Our objective was to assess the association between risk factors for Parkinson's disease (PD) and abnormal olfaction in first-degree relatives of patients with PD. Factors including lower cigarette smoking and lower caffeine consumption have been associated with increased risk of PD. Idiopathic hyposmia has also been associated with an increased risk of PD. The relationship between risk factors for PD and impaired olfactory function has not been evaluated in relatives of PD patients. We conducted a mail survey of odor identification ability in 173 first-degree relatives of PD patients using the 40-item University of Pennsylvania Smell Identification Test (UPSIT). Respondents also completed a questionnaire inquiring about risk factors for PD including caffeine consumption, tobacco use, exercise, and exposures to heavy metals, well-water, and pesticides. There was a direct relationship between olfactory performance and lifetime caffeine intake. After adjustment for age, gender, and smoking status, subjects who reported drinking 2 to 3 cups of caffeinated beverages per day (2.6 points higher 95% CI: 0.5, 4.5) and 4 or more cups per day (3.7 points higher, 95% CI: 0.6, 6.7) had significantly better UPSIT scores than those who consumed less than 1 cup per day. There was no significant relationship between olfactory performance and other risk factors. In conclusion, abnormal olfaction is associated with significantly lower lifetime caffeine consumption in first-degree relatives of PD patients. Further research is warranted to determine whether a history of lower caffeine consumption confers additional risk for the development of PD in hyposmic relatives of PD patients.

Source :  Mov Disord 2007 vol.22 (15), pp 2249 - 2255

Chlorogenic acid in coffee can prevent the formation of dinitrogen trioxide by scavenging nitrogen dioxide generated in the human oral cavity

Takahama, U.; Ryu, K.; Hirota, S.

: It has been suggested that the production of reactive oxygen and nitrogen species in the human oral cavity is related to periodontal diseases, and suppression of their formation is important in protecting the oral cavity. Coffee contains antioxidants, such as chlorogenic acid and its isomers, and this study examined the effects of coffee on the nitrite-induced dinitrogen trioxide formation using whole saliva and bacterial fraction prepared from the saliva. Coffee inhibited nitrite-induced fluorescence increase, and the
authors suggest that the reduction of nitrogen dioxide by chlorogenic acid and it isomers contributes to the coffee-dependent inhibition of fluorescence increase, as dinitrogen trioxide is formed from nitric oxide and nitrogen dioxide. The significance of coffee drinking for oral health is discussed.

Source : J Agric Food Chem 2007 vol.550(22), pp 9251-9258 

To sip or not to sip: the potential health risks and benefits of coffee drinking

Taylor, S. R.; Demmig, Adams B.

This review provides a comprehensive summary of current research into the health risks and benefits associated with coffee drinking. The effects of coffee consumption on cardiovascular disease, physical fitness, brain function, reproduction, bone and joint health, type-2 diabetes and weight loss, and the digestive system are considered. Coffee contains the stimulant caffeine as well as antioxidants and other phytochemicals, all of which affect disease risk. Overall, coffee drinking appears to be a non-harmful habit for those consuming coffee regularly and in moderation. Recent studies have suggested that coffee drinking may be beneficial for most consumers. Currently available evidence has suggested that coffee consumption may help reduce the risk of several diseases, in particular Alzheimer's disease, Parkinson's disease and type-2 diabetes, although underlying mechanisms for this effect are not yet known. Studies have indicated that drinking an average of two cups of regular, filtered coffee per day may offer protection against neurodegenerative and other diseases.

Source : Nutrit Food Sci 2007 vol.37 (6), pp 406-418

Effects of caffeine on physiological responses to exercise: boys versus men

Turley, K. R.; Desisso, T.; Gerst, J. W.

We compared the influence of caffeine on physiological responses to exercise between boys and men. Fifty-two participants (26 boys and 26 men) participated in a double blind, randomized, double crossover study. Each participant received the caffeinated (5 mg/kg) drink (CAF) and placebo (PL) twice each on 4 separate days. One hour after drink consumption preexercise heart rate (HR) and blood pressure (BP) were measured. Then while the participants rode stationary cycle ergometers at two different exercise intensities, HR, BP, and oxygen consumption (VO2) were measured. Blood pressure was not significantly affected by CAF, although on average it was always higher in boys for diastolic BP (3 mmHg) and systolic BP (3-4 mmHg) and men for diastolic BP (2-3 mmHg) and systolic BP (1-6 mmHg) both at rest and during exercise. HR was significantly (p < .05) lower at rest, 25W and 50W in CAF versus PL in boys, with no change in adults. During exercise, VO2 and respiratory exchange ratio (RER) were not different in CAF
versus PL in either group. In conclusion, metabolism is not affected by a moderate caffeine dose in children or adults. The same dose has a similar effect on BP in both groups. The effect on HR was different, however, with a significant (p < .05) lowering in children in CAF versus PL, with no adult effects.

Source : Pediatr Exerc Sci vol.19 (4), pp 481 - 492  (not available on line)

Adenosine and dopamine receptor interactions in striatum and caffeine-induced behavioral activation

Xie, X.; Ramkumar, V.; Toth, L. A.

This review will examine how dopamine, a monoamine neurotransmitter, and adenosine, a neuromodulator, regulate behavioral activation, primarily as reflected by locomotor activity, in rodents. Complex interactions among 2 major types of adenosine receptors (A1 AR and A2AAR) and 2 dopamine receptors (D1 R and D2R) occur due to physical interactions that alter their ligand-binding properties and subsequent effects on common postreceptor signaling molecules. The output from these interactions in striatum modulates neurotransmission and subsequently influences spontaneous locomotor activity. Caffeine is a nonselective adenosine receptor antagonist that blocks 2 major types of adenosine receptors, A1 AR and A2AAR, in the brain. Pharmacologic manipulation of these receptors with drugs such as caffeine offers potential therapeutic benefit for treatment of Parkinson disease.

Source : Comp Med 2007 vol. 57 (6), pp 538 - 545

Drastic effect of several caffeic acid derivatives on the induction of heme oxygenase-1 expression revealed by quantitative real-time RT-PCR

Suzuki, K.; Tanaka, I.; Nakanishi, I.; Kurematsu, A.; Yakumaru, H.; Ikota, N.; Ishihara, H.

Among antioxidative polyphenols, caffeic acid esters such as caffeic acid phenethyl ester (CAPE) and chlorogenic acid occur in propolis, vegetables and coffee. This study compared the efficacy of some polyphenols on the activation levels of a cytoprotective heme oxygenase-1 (HO-1) gene in RAW264.7 mouse macrophage cells, using quantitative real-time RT-PCR. The quantitative study revealed a variety of activation levels of the HO-1 gene by the chemicals. CAPE and caffeic acid ethyl ester (CAEE) at a final concn. of 2muM drastically activated the HO-1 gene 39.2- and 20.1-fold, respectively. Curcumin, structurally related to caffeic acid and a component of turmeric, induced the HO-1 gene 5.8-fold. In contrast, no activation was observed by other caffeic acid esters, such as chlorogenic acid and rosmarinic acid. Higher concn. were necessary for activation by the antioxidant, cysteamine, and the electrophile, diethyl maleate. Although the inducible activities of CAPE and chlorogenic acid were distinctly different, they showed similar reductive capacities when determined by cyclic voltammetry. These results show that the activation of the HO-1 gene by CAPE and CAEE is dependent upon their chemical structures, rather than the reductive activity of the polyphenols.

Source : Biofactors 2006 vol.28 (3-4), pp 151 - 158

Effects of caffeine and siloxanetriol alginate caffeine, as anticellulite agents, on fatty tissue: histological evaluation

Velasco, M. V.; Tano, C. T.; Machado-Santelli, G. M.; Consiglieri, V. O.; Kaneko, T. M.; Baby, A. R

Background Cellulite is a physiological condition that presents etiologic plurality. Caffeine and its derivatives are used in anticellulite cosmetics due to their lipolytic activity on fatty cells. Siloxanetriol alginate caffeine (SAC) is a silanol derived from organic silicon. Radicals primarily from SAC are caffeine and the mannuronic acid. Aims This study aims to analyze the effects of caffeine and siloxanetriol alginate caffeine on fatty tissue by histological evaluation. Methods Formulations were developed with caffeine, caffeine + sodium benzoate or SAC and were applied topically for 21 days on Wistar female mice. The study regarded the histological aspects by determination of diameter and number of fatty cells with a light microscope. Results Emulsion with caffeine caused a reduction of 17% on the diameter of the fatty cells compared with the control. The emulsion with caffeine + sodium benzoate did not cause alterations on cell diameter. Emulsion with SAC provoked reduction on fatty cell diameters of 16%. No significant alterations were observed on the diameter of the fatty cells treated with gels, although it was noticed that gel with SAC promoted a reduction of 26% on the number of fatty cells. Conclusions Emulsion with SAC was considered more indicated to promote the lipolytic action on fatty tissue, acting as a complement to treat cellulite. When sodium benzoate was added to the preparations, it inhibited the caffeine efficiency. Gel was not an adequate vehicle to be incorporated with caffeine and SAC.

Source :  J Cosmet Dermatol 2008 vol.7 (1), pp 23 - 29

CONSUMER SCIENCE

Sex differences in preferences for coffee sweetness among Japanese students

Yamazawa, K.; Hirokawa, K.; Shimizu, H.

The purpose of the present study was to examine sex differences in preferences for coffee sweetness. The participants were 59 Japanese undergraduate students. Men preferred sweeter coffee than women, while both men and women showed almost the same preference for acidic beverage sweetness. The sex difference in preferences for coffee sweetness may be related to coffee-drinking habits.

Source : Percept Mot Skills 2007 vol.105 (2), pp 403 - 404