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PubMed1991

Coffee and alcohol as determinants of risk of pancreas cancer: a case-control study from Toronto.

Results are reported from a population-based study of 249 cases of pancreas cancer and 505 controls carried out in Toronto, Canada, between 1983 and 1986. Lifetime consumption of coffee and alcohol and medical histories were assessed by personal interviews. No evidence of any association was found with different types of coffee or alcohol after adjusting for smoking, calories and fibre intake. There was a significant increased risk associated with a history of diabetes mellitus within 5 years of cancer development. A protective effect of a history of some allergic conditions, hay fever, eczema and asthma, was observed, although the relative risks were not significant (p value greater than 0.10).

Adult↗

PubMed1993

Cigarette smoking, alcohol, tea and coffee consumption and pancreas cancer risk: a case-control study from Opole, Poland.

A population-based, case-control study of pancreas cancer was undertaken in Opole, Poland, within the framework of the SEARCH Programme of the International Agency for Research on Cancer: this is the first aetiological study of pancreas cancer reported from Poland where the reported mortality rate has doubled since 1963. This study of pancreas cancer has provided some further supporting evidence of an association between increased pancreas risk with increasing levels of cigarette smoking. The risk rose with increasing lifetime cigarette consumption with a trend which was weakly significant (p = 0.061). Findings regarding lifetime tea and coffee consumption were not consistent with intake of either beverage increasing the risk of this disease. There was a strongly significant trend of decreasing risk with increasing lifetime consumption of tea (p < 0.001), which was also apparent when the analysis was restricted to subjects who were interviewed directly. For coffee consumption, which is low in Poland, there was also a negative association apparent in the data which was not statistically significant among the sub-set of subjects who were directly interviewed. The findings regarding alcoholic beverages were overall null, although the weakly positive trend in risk with spirits consumption (p = 0.71) may deserve further investigation in view of the special nature of the source of spirits (vodka) in Poland.

Adult↗

PubMed1992

Tannin content of tea and coffee.

The tannin content of over-the-counter Indian tea, of green coffee beans and of the roasted coffee beans prepared from the same green beans was determined with a radial diffusion-protein precipitation technique and with a spectrophotometric method. The green beans contained 6.6 +/- 0.6 mg g-1 weight tannic acid equivalents as found by protein precipitation (n = 5, +/- SD) or 6.8 +/- 2.3 mg g-1 by spectrophotometry. The same figures for roasted beans were 18 +/- 1.7 and 17 +/- 2.7 mg g-1, respectively. Tea contained 37 +/- 2.6 mg g-1 weight tannic acid equivalents as analysed by spectrophotometry and 24 +/- 2.8 mg g-1 by the protein precipitation technique. The latter finding may show that the biological reactivity of tannins is variable, although no major changes in the tannin-precipitated albumin occurred as shown by electrophoretic analysis. Both methods provide an easy analysis of the reportedly carcinogenic plant tannins.

Coffee↗

PubMed1984

In vitro interaction of neuroleptics and tricylic antidepressants with coffee, tea, and gallotannic acid.

The in vitro interaction of selected drugs with coffee, tea, gallic acid, and gallotannic acid was examined by mixing solutions of drug with each of these four preparations. Results of these experiments indicate that significant precipitation occurs for a variety of agents, including several phenothiazines, amitriptyline, haloperidol, imipramine, and loxapine. The strong complex which is formed between these drugs and tannins is probably the basis of the interaction of these drugs with coffee and tea. Although precipitates did occur with a number of neuroleptics, two members of this drug class, thiothixene and molindone, failed to interact with the solutions used.

Antidepressive Agents, Tricyclic↗

PubMedDate not supplied

Comparison of GC and HPLC for the quantification of organic acids in coffee.

A GC and an HPLC method for the quantification of organic acids OAs in coffee have been compared. The GC procedure, employing trimethylsilyl derivatives, was found to be very tedious. The HPLC method, which employed an ion exchange column using a flow gradient of water containing 1% phosphoric acid and UV detection (210 nm), was found to be much simpler for the quantification of eight organic acids (oxalic, succinic, fumaric, malic, tartaric, citric, quinic and fumaric acids) in four representative coffee samples. The HPLC procedure was more convenient than that described in the literature since no pre-purification was required for quantification of the OAs.

Carboxylic Acids↗

PubMed2003

Classification of green coffee beans by differences in protein composition obtained by matrix-assisted laser desorption/ionization mass spectrometry.

It is well known that proteins and peptides play an important role in the flavour of roasted coffee, but little is reported in the literature about their characterization. In view of the potential of matrix-assisted laser desorption/ionization mass spectrometry in the analysis of proteins in complex mixtures, two varieties of coffee green beans, Arabicas and Robustas, were analyzed by this technique, in order to obtain fingerprints of their native proteins. Differences were observed between Arabicas and Robustas green beans, and cluster analysis allows differentiation of samples of the same variety from different plantations.

Africa↗

PubMed1995

High-level expression and purification of coffee bean alpha-galactosidase produced in the yeast Pichia pastoris.

alpha-Galactosidase isolated from coffee beans cleaves the terminal alpha-galactose residues from oligosaccharide chains on blood group B red cells, thus generating group O cells. Such enzymatically converted red cells not only maintain full erythrocyte integrity and viability in vitro, but also demonstrate immune tolerance and a normal life span in vivo. In order to produce large quantities of recombinant alpha-galactosidase for use in the study of blood-type conversion, we subcloned the cDNA coding for coffee bean alpha-galactosidase into the EcoRI site of the vector pPIC9 in order to express the enzyme in Pichia pastoris, a methylotrophic yeast strain. After P. pastoris transformation, colonies were screened for high-level expression of alpha-galactosidase, based on enzyme activity. In order to increase enzyme production, the growth conditions in the shake flask culture and fermentor culture were optimized. Under the conditions applied, biologically active alpha-galactosidase was produced and secreted into the culture medium at a level of approximately 0.4 g per liter of the fermentor culture. The protein was purified to apparent homogeneity by a simple chromatography procedure, as suggested by a single band of 41 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its homogeneity was further confirmed by chromatofocusing and N-terminal sequencing. P. pastoris appears to be the choice as host for the large-scale production of recombinant alpha-galactosidase used for blood type conversion.

Amino Acid Sequence↗

PubMed1990

Inhibitory effects of chlorogenic acid, reserpine, polyprenoic acid (E-5166), or coffee on hepatocarcinogenesis in rats and hamsters.

Four different experiments were performed in order to examine the modifying effects of chlorogenic acid (CA), reserpine, polyprenoic acid (E-5166), and coffee on chemical carcinogenesis in rats or hamsters. Experiment 1: The numbers of hyperplastic liver cell foci and the incidence of colon tumors in male and female Syrian golden hamsters given a single intravenous injection of methylazoxymethanol (MAM) acetate and then fed the diet containing 0.025% CA for 24 wk were significantly lower than those of hamsters given MAM acetate alone. Experiment 2: The incidence of altered hepatocellular foci in female ACI/N rats given N-2-fluorenylacetamide (FAA, 0.02% in diet) for 10 wk and reserpine (weekly subcutaneous injections, 1 microgram/g body weight) during or after (17 wk) FAA exposure was significantly lower than that of rats given FAA alone. Experiment 3: The number of hepatocellular foci in male ACI/N rats given 0.02% FAA diet for 13 wk and E-5166 by gavage (40 mg/kg body weight, 3 times/wk) for 16 wk after the end of FAA exposure was significantly smaller than that in rats given FAA diet alone. Experiment 4: Incidences of liver tumors and hepatocellular foci of rats given concurrent dietary administration of aminopyrine (0.01%) and sodium nitrite (0.1%) and coffee solution as a drinking water for 630 da were significantly lower than those of rats given aminopyrine and sodium nitrite. Thus, the tested compounds had inhibitory effects on chemical carcinogenesis in liver or colon.

Animals↗

PubMed1993

Smoking, alcohol, coffee, tea, caffeine, and theobromine: risk of prostate cancer in Utah (United States).

Data from a population-based study of newly diagnosed cases of prostate cancer (n = 362) and age-matched controls (n = 685) conducted in Utah (United States) between 1983 and 1986 were used to determine if cigarette smoking, alcohol, coffee, tea, caffeine, and theobromine were associated with prostate cancer risk. These factors were examined since their use differs in the Utah population, which is comprised predominantly of members of the Church of Jesus Christ of Latter-day Saints (LDS or Mormon), from most other populations. Pack-years of cigarettes smoked, alcohol intake, and consumption of alcohol, coffee, tea, and caffeine were not associated with prostate cancer risk. Compared with men with very low levels of theobromine intake, older men consuming 11 to 20 and over 20 mg of theobromine per day were at increased risk of prostate cancer (odds ratio [OR] for all tumors = 2.06, 95 percent confidence interval [CI] = 1.33-3.20, and OR = 1.47, CI = 0.99-2.19, respectively; OR for aggressive tumors = 1.90, CI = 0.90-3.97, and OR = 1.74, CI = 0.91-3.32, respectively). We present biological mechanisms for a possible association between prostate cancer and theobromine. This finding needs further exploration in studies with a wider range of theobromine exposures and more men with aggressive tumors.

Aged↗

PubMed1989

Tobacco smoking, coffee, cocoa and tea consumption in relation to mortality from urinary bladder cancer in Italy.

This paper examines changes in mortality from urinary bladder cancer in Italy during the years 1950-81 in relation to changes in smoking habits and in coffee, cocoa and tea consumption. The authors found that, in both sexes and for all ages, mortality has been increasing throughout this period, although the rates and relative increase have consistently been much lower and more gradual for women than for men. From the analysis of age-cohort-period variation it seems that bladder cancer mortality can also be influenced by changes in smoking habit patterns and by variation in the quality of diagnoses. The increase in death risk for both sexes in Italy up to cohorts born around 1905-10 can be related to occupational exposures and to high-tar-content tobacco smoking, whereas the tendency for mortality rates to stabilize and decline in cohorts born after 1910 were influenced by changes from high-tar-content and no-filter cigarettes to low-tar-content and filter cigarettes and by prevention measures taken in at-risk working environments. The consumption of coffee, cocoa and tea does not seem to be related to the increase in bladder cancer risk in Italy.

Adolescent↗

PubMed1984

Influence of coffee on the excretion of noradrenaline and adrenaline in urine. A pilot study for the comparison of two methodical models.

In field studies, the excretion rate of urinary catecholamines is very often used as an indicator of strain. Interfering effects which are due to caffeine, for example, can only be quantified if the influence of coffee consumption on the excretion of catecholamines is known quantitatively. This was the aim of our study with five subjects, on five consecutive working days, and with a strict standardization of nutrition. The urine samples were specified with respect to the following parameters: sampling period, volume, urine status, density, creatinine, noradrenaline, and adrenaline. Adrenaline showed a significant correlation with coffee consumption, whereas noradrenaline did not. Moreover, it could be demonstrated that relating the concentration of catecholamines to the creatinine excretion is insufficient for work physiology studies, especially if the urine sampling periods are as short as 2h.

Adult↗

PubMed1978

[Phenols in roasted coffees of different varieties. I. (author's transl)].

Thirty phenols were isolated from roasted coffee by distillation-extraction, separated from other constituents by absorption-chromatography, and characterized by means of GC-MS. Robusta coffee contained the largest amount of phenols, followed by Arabusta (Côte d'Ivoire) and Arabica. Quantity and type of phenols depends on variety as well as on the roasting conditions.

Adsorption↗

PubMed1975

Nonenzymic browning. XII. Maillard reactions in green coffee beans on storage.

During storage of green coffee beans at increased temperature and at constant humidity reducing sugars present in original beans react with free amino acids with formation of colourless unstable products. Additional reducing sugars and free amino acids are produced by hydrolysis of polysaccharides and proteins, respectively. The second stage of storage is characterized by only slight changes in the content of free amino acids and sugars but by intensive browning reactions. This latter stage was characterized by deterioration of sensory quality of coffee beverage, especially of its odour. Lysine combined in protein was involved in browning reactions via colourless intermediary products.

Amino Acids↗

PubMed1978

Coffee and cola beverage consumption as heart disease risk factors in men.

The relationship of coffee drinking and cola beverage consumption to recognized heart disease risk factors was studied in 365 adult men. Cola beverage consumption was not positively related to any risk factor. Heavy coffee drinking seemed to reflect a life style characterized by infrequent eating, which was significantly correlated to all the heart disease risk factors studied.

Adolescent↗

PubMed2002

Enhancement of the chemoprotective enzymes glucuronosyl transferase and glutathione transferase in specific organs of the rat by the coffee components kahweol and cafestol.

The coffee components kahweol and cafestol (K/C) have been reported to protect the colon and other organs of the rat against the formation of DNA adducts by 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP) and aflatoxin B1. PhIP is a cooked-food mutagen to which significant human exposure and a role in colon cancer etiology are attributed, and, interestingly, such cancers appear to develop at a lower rate in consumers of coffees with high amounts of K/C. Earlier studies in rodent liver have shown that a key role in the chemopreventive effect of K/C is likely to be due to the potential of these compounds to induce the detoxification of xenobiotics by glutathione transferase (GST) and to enhance the synthesis of the corresponding co-factor glutathione. However, mutagens like PhIP may also be detoxified by UDP-glucuronosyl transferase (UDPGT) for which data are lacking regarding a potential effect of K/C. Therefore, in the present study, we investigated the effect of K/C on UDPGT and, concomitantly, we studied overall GST and the pattern of individual GST classes, particularly GST-theta;, which was not included in earlier experiments. In addition, we analyzed the organ-dependence of these potentially chemopreventive effects. K/C was fed to male F344 rats at 0.122% in the chow for 10 days. Enzyme activities in liver, kidney, lung, colon, salivary gland, pancreas, testis, heart and spleen were quantified using five characteristic substrates and the hepatic protein pattern of GST classes alpha, mu, and pi was studied with affinity chromatography/HPLC. Our study showed that K/C is not only capable of increasing overall GST and GST classes alpha, mu, and pi but also of enhancing UDGPT and GST-theta. All investigated K/C effects were strongest in liver and kidney, and some response was seen in lung and colon but none in the other organs. In summary, our results show that K/C treatment leads to a wide spectrum of increases in phase II detoxification enzymes. Notably, these effects occurred preferentially in the well perfused organs liver and kidney, which may thus not only contribute to local protection but also to anti-carcinogenesis in distant, less stimulated organs such as the colon.

Animals↗

PubMed2006

Analysis of acrylamide in coffee and cocoa by isotope dilution liquid chromatography-tandem mass spectrometry.

An accurate and precise method for the quantification of acrylamide using stable isotope dilution liquid chromatography-tandem mass spectrometry was developed and used to measure acrylamide in coffee and cocoa samples. The sample preparation involved extraction of the analyte and its internal standard, 13C3-acrylamide, into water and subsequent defatting of the aqueous extract with dichloromethane. An aliquot of the resulting aqueous extract was then azeotropically dried under reduced pressure and subsequently purified using an aminopropyl-bonded silica cartridge. The purified extracts were then chromatographed on a 5-microm 2.1 x 150 mm Hypercarb column, the effluent of which was monitored for the analyte and its internal standard using positive-ion APCI-selected reaction monitoring. The intra-laboratory reproducibility of the method, expressed as a relative coefficient of variation (%, n=5), was determined at four levels of concentration (12.3, 42.3, 139.3 and 464.8 microg kg(-1)) and was found to vary between 0.6-2.5%. The accuracy of the method was assessed using a reference sample of coffee. The average result obtained using our method differed from the assigned value of the reference material by less than 1%. An analysis of a cocoa sample revealed that the method is capable of precisely estimating acrylamide in challenging matrices down to a level of at least 12.3 microg kg(-1).

Acrylamide↗

PubMed2000

Fourier transform infrared determination of caffeine in roasted coffee samples.

A new procedure has been developed for the FT-IR determination of caffeine in roasted coffee samples. The method involves wetting the coffee samples with a 0.25 M aqueous NH3 solution, extracting the caffeine with CHCl3, and measuring absorbance at 1,659 cm(-1) using a baseline established between 1,900 and 830 cm(-1). The procedure proposed is fast, only requiring a total extraction time of 16 min for each sample, and provides a drastic reduction of the organic solvent consumed, from the 200 mL diethyl ether and 50 mL CHCl3, required for each sample by the reference chromatographic UV-spectrometric determination to only 5 mL CHCl3. The method provides a limit of detection of the order of 3 mg L(-1) caffeine and a relative standard deviation of 0.4% for 3 independent analyses of a sample containing 18.6%mg/g caffeine. The accuracy of the FT-IR procedure was evaluated from recovery experiments on spiked samples providing values from 94.4 to 100.1% and from the comparison of results found for a series of commercial samples, by both FT-IR and the official reference procedure.

Ammonia↗

PubMed2001

Microbiological and biochemical study of coffee fermentation.

The coffee fermentation microflora were rich and mainly constituted of aerobic Gram-negative bacilli, with Erwinia and Klebsiella genuses at the highest frequencies. The best population increase was observed with lactic acid bacteria and yeasts, whereas those microorganisms that counted on a pectin medium remained constant during the fermentation step. Qualitatively, lactic acid bacteria belonged mainly to Leuconostoc mesenteroides species but the others microflora were relatively heterogeneous. The microorganisms isolated on pectin medium were Enterobacteriaceae, identified as Erwinia herbicola and Klebsiella pneumoniae, not reported as strong pectolytic strains. Throughout coffee fermentation, 60% of the simple sugars were degraded by the total microflora and not specifically by pectolytic microorganisms.

Carbohydrates↗