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At least 991 records · Page 55Linked to original sources
PubMed2002

Development of a solid-phase cleanup and portable rapid flow-through enzyme immunoassay for the detection of ochratoxin a in roasted coffee.

A membrane-based flow-through enzyme immunoassay (patent application pending) for the detection of ochratoxin A (OA) in roasted coffee was developed. First, an extraction and solid-phase cleanup method was developed. A high partition coefficient for OA in the mobile phase was achieved by using methanol/5% aqueous NaHCO(3) as the sample extraction and cleanup solvent. The solid-phase (aminopropyl) cleanup was developed to chromatographically elute OA but retain cross-reacting compounds. Without using aminopropyl cleanup, cross-reacting compounds resulted in 100% false positives for both flow-through enzyme immunoassay and HPLC methods. However, after cleanup with aminopropyl, no false positives were observed. The flow-through results were visually evaluated. The sensitivity achieved for the flow-through was 4 microg kg(-1) in spiked roasted coffee. The assay was used to screen roasted coffee samples. Results were confirmed with HPLC with a detection limit of 1 microg kg(-1).

Chromatography, High Pressure Liquid↗
PubMed2003

Real-time monitoring of 4-vinylguaiacol, guaiacol, and phenol during coffee roasting by resonant laser ionization time-of-flight mass spectrometry.

The formation of 4-vinylguaiacol, guaiacol, and phenol during coffee roasting was monitored in real-time, using resonance enhanced multiphoton ionization and time-of-flight mass spectrometry. A model is proposed, based on two connected reaction channels. One channel, termed the "low activation energy" channel, consists of ester hydrolysis of 5-FQA followed by decarboxylation of the ferulic acid to form 4-vinylguaiacol, and finally polymerization at the vinyl group to form partly insoluble polymers (coffee melanoidins). The second "high activation energy" channel opens up once the beans have reached higher temperatures. It leads to formation of guaiacol, via oxidation of 4-vinylguaiacol, and subsequently to phenol and other phenolic VOCs. This work aims at developing strategies to modify the composition of coffee flavor compounds based on the time-temperature history during roasting.

Coffea↗
PubMed2003

Discrimination between arabica and robusta coffee species on the basis of their amino acid enantiomers.

This work reports the results for the composition of robusta and arabica coffee species in terms of their amino acid enantiomers in the green and roasted states. The analyses were conducted for the free amino acids, as well as for the amino acids obtained after acid hydrolysis. The amino acids were extracted/hydrolyzed and isolated by SPE on strong cation exchange columns, derivatized to their N-ethoxycarbonylheptafluorobutyl esters, and analyzed by gas chromatography/FID on a Chirasil l-Val column. Multivariate analyses applied to the results showed that the free amino acids can be used as a tool for discrimination between coffee species, with a special reference to l-glutamic acid, l-tryptophan, and pipecolic acid. There is also some evidence that these compounds can be used for discrimination between green coffees subjected to different postharvest processes. It is also shown that the amino acid levels observed after acid hydrolysis can be used for the same purposes, although displaying less discriminatory power.

Amino Acids↗
PubMed2003

Caffeine and resistance of coffee to the berry borer Hypothenemus hampei (Coleoptera: Scolytidae).

The role of caffeine as a chemical defense of coffee against the berry borer Hypothenemus hampei was investigated. No positive correlation was observed between resistance and caffeine content in experiments in which seeds from several coffee species presenting genetic variability for the alkaloid were exposed to adult insects. The same was observed in an experiment with coffee seeds that had their caffeine content doubled by imbibition with caffeine aqueous solutions. Other experiments showed that the attractiveness to insects was not related to the caffeine content of mature fruits. These results indicate that H. hampei has evolved an adaptation to handle the toxic effects of caffeine.

Animals↗
PubMed2006

Quantitative precursor studies on di- and trihydroxybenzene formation during coffee roasting using "in bean" model experiments and stable isotope dilution analysis.

The objective of this study was to investigate the potential of various raw bean components as precursors of pyrogallol (1), hydroxyhydroquinone (2), catechol (3), 4-ethylcatechol (4), 4-methylcatechol (5), and 3-methylcatechol (6) under quasi "natural" roasting conditions by using the recently developed "in bean" model roast experiments. Freeze-dried, fully extracted bean shells were loaded with aqueous solutions of either single coffee compounds or fractions isolated from the raw bean solubles. After freeze-drying, these reconstituted beans were roasted, aqueous coffee brews were prepared, and the target phenols were quantified by means of a stable isotope dilution assay with LC-MS/MS detection. On the basis of the quantitative data, it can be concluded that upon coffee bean roasting, catechol (3) is primarily formed by degradation of caffeoylquinic acids from both the caffeic acid and the quinic acid moiety of the molecule, as well as from Maillard-type reactions from carbohydrates and amino acids. In contrast, pyrogallol (1) and hydroxyhydroquinone (2) are efficiently generated from carbohydrates and amino acids and, in addition, from free or chlorogenic acid bound quinic acid moieties. 4-Ethylcatechol (4) is exclusively generated upon thermal breakdown of caffeic acid moieties. 3-Methylcatechol (6) is formed primarily from the Maillard reactions and, to a minor extent, also from various phenolic precursors, whereas 4-methylcatechol (5) is produced in trace amounts only from all of the different precursors investigated. On the basis of this precursor study, reaction routes explaining the formation of the target phenols are proposed.

Catechols↗
PubMed2004

Customers' exposure to PM2.5 and polycyclic aromatic hydrocarbons in smoking/nonsmoking sections of 24-h coffee shops in Taiwan.

In Taiwan 24-h coffee shops have become popular gathering areas for young people. This study assesses customers' exposures to PM(2.5) and gaseous/particulate polycyclic aromatic hydrocarbons (PAHs) in such an environment. Potential influential factors were also evaluated. Two coffee shops with different types of smoking/nonsmoking divisions were selected. Sampling was conducted from 1300 to 2100 hours on Saturdays and Sundays during December 2000 and January 2001. Personal environmental monitors mounted with Teflon filters and polyurethane foams were used for particulate and gaseous sampling. PAHs were analyzed with GC-FID. Principal component analysis was used to explore the differences in the patterns of gaseous and particulate PAHs. Stepwise regression analysis was used to evaluate the contribution of various factors. The geometric mean (GM) of PM(2.5), particulate and gaseous PAH exposures were 83.7, 0.46 and 1.01 microg/m(3), respectively. Their exposure concentrations were about two to five times those of residential indoor environments in Taiwan. Smoking and vehicle exhaust were two major exposure sources. The gaseous PAH concentrations in the two sections of both shops were significantly correlated. The divisions between smoking and nonsmoking sections in neither of the coffee shops were effective to prevent dispersion of gaseous pollutants. In both shops, the concentrations of PM(2.5) and associated PAHs, respectively, were about 22-28 microg/m(3) and 0.07 microg/m(3) higher in smoking areas compared to nonsmoking areas. It was also found that each additional cigarette resulted in a 0.22-0.42 microg/m(3) PM(2.5) incremental increase in nonsmoking customers' exposure in the smoking section.

Air Movements↗
PubMed1991

Leishmaniasis vector potential of Lutzomyia spp. in Colombian coffee plantations.

Potential vectors of Leishmania braziliensis Vianna were assessed at four study sites in the mountainous Valle del Cauca, western Colombia, from March to June 1989. In an active focus of transmission at 1450 m altitude, a coffee plantation at Versalles, there were high densities of antropophilic phlebotomines: Lutzomyia columbiana (Ritorcelli & Van Ty) and Lu.townsendi (Ortiz), both in the verrucarum species group, and of Lu.pia (Fairchild & Hertig). At a comparable altitude in a forest reserve at Yotoco where leishmaniasis is unknown, Lu.pia was the prevalent species and Lu.townsendi was absent. In two localities at 1150 m altitude, there were plentiful Lu.lichyi (Floch & Abonnenc) plus both species in the verrucarum group, but Lu.pia was absent. One of these localities, a coffee plantation at Villa Hermosa where a leishmaniasis outbreak occurred in 1986, was compared with a leishmaniasis-free, partly wooded nature reserve at Mateguadua. No natural infections of Leishmania were found in a total of 1896 wild-caught female phlebotomines belonging to at least seven species. It remains unclear why Leishmaniasis transmission is associated with coffee plantations in this part of Colombia. Laboratory-bred Lu.lichyi females were invariably autogenous, and blood-seeking females of this species were always parous. Parity rates in wild-caught females of other species were 55% Lu.pia, 24% Lu.columbiana and 14% Lu.townsendi. Female Lutzomyia infected artificially with Le.braziliensis promastigotes developed peripylarian infections. Higher proportions of Lu.townsendi (96%) and Lu.columbiana (78%) became infected but these species developed lower rates of stomodaeal infections (P less than 0.1) than Lu.lichyi (37%) or Lu.pia (44%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice.

BACKGROUND: An epidemiological study conducted in Italy indicated that coffee has the greatest antioxidant capacity among the commonly consumed beverages. Green coffee bean is rich in chlorogenic acid and its related compounds. The effect of green coffee bean extract (GCBE) on fat accumulation and body weight in mice was assessed with the objective of investigating the effect of GCBE on mild obesity. METHODS: Male ddy mice were fed a standard diet containing GCBE and its principal constituents, namely, caffeine and chlorogenic acid, for 14 days. Further, hepatic triglyceride (TG) level was also investigated after consecutive administration (13 days) of GCBE and its constituents. To examine the effect of GCBE and its constituents on fat absorption, serum TG changes were evaluated in olive oil-loaded mice. In addition, to investigate the effect on hepatic TG metabolism, carnitine palmitoyltransferase (CPT) activity in mice was evaluated after consecutive ingestion (6 days) of GCBE and its constituents (caffeine, chlorogenic acid, neochlorogenic acid and feruloylquinic acid mixture). RESULTS: It was found that 0.5% and 1% GCBE reduced visceral fat content and body weight. Caffeine and chlorogenic acid showed a tendency to reduce visceral fat and body weight. Oral administration of GCBE (100 and 200 mg/kg. day) for 13 days showed a tendency to reduce hepatic TG in mice. In the same model, chlorogenic acid (60 mg/kg. day) reduced hepatic TG level. In mice loaded with olive oil (5 mL/kg), GCBE (200 and 400 mg/kg) and caffeine (20 and 40 mg/kg) reduced serum TG level. GCBE (1%), neochlorogenic acid (0.028% and 0.055%) and feruloylquinic acid mixture (0.081%) significantly enhanced hepatic CPT activity in mice. However, neither caffeine nor chlorogenic acid alone was found to enhance CPT activity. CONCLUSION: These results suggest that GCBE is possibly effective against weight gain and fat accumulation by inhibition of fat absorption and activation of fat metabolism in the liver. Caffeine was found to be a suppressor of fat absorption, while chlorogenic acid was found to be partially involved in the suppressive effect of GCBE that resulted in the reduction of hepatic TG level. Phenolic compounds such as neochlorogenic acid and feruloylquinic acid mixture, except chlorogenic acid, can enhance hepatic CPT activity.

Adipose Tissue↗
PubMed2004

Metaparasitylenchus hypothenemi n. sp. (Nematoda: Allantonematidae), a parasite of the coffee berry borer, Hypothenemus hampei (Curculionidae: Scolytinae).

Metaparasitylenchus hypothenemi n. sp. (Nematoda: Allantonematidae) is described from the coffee berry borer, Hypothenemus hampei (Ferrari) (Curculionidae: Scolytinae), in Chiapas, Mexico. This species differs from other members of the genus by its small size, annulated cuticle, lateral fields with 3 ridges, free-living stages with an excretory pore located between the pharyngeal gland orifices, a distinct stylet with basal swellings in free-living females, a postvulval uterine extension, a thin stylet lacking basal swellings in males, 2 separate spicules, a gubernaculum, and a peloderan bursa. Parasitic females are white, with a straight or slightly curved body and are ovoviviparous. Third-stage juveniles emerge from parasitized beetles and molt twice before reaching the adult stage. Because the coffee berry borer is the most important pest of coffee throughout the world and this parasite partially or completely sterilizes female beetles, it is worthy of further investigation as a potential biological control agent.

Animals↗
PubMed2001

[Contusion eye trauma caused by explosion of vacuumed coffee tin].

PURPOSE: To report a rare case of eye contusion trauma, resulting from explosion of vacuumed coffee tin. MATERIAL AND METHODS: 7 years old patient underwent injury of the right eye while opening a vacuumed coffee tin. The examination consisted in: history, evaluation of the visual acuity and refraction, examination of intraocular pressure, biomicroscopy, ophthalmoscopy. RESULTS AND DISCUSSION: During the examination an edema has been found in the macula area. This edema lately degenerated. When the patient was admitted his visual acuity was 20/30 and did not change when he was released. The visual acuity of the left eye was 20/20. CONCLUSION: Contusion trauma, caused by vacuumed coffee, can be followed by constant changes in the area of the macula and result in decreasing of the visual acuity.

Adult↗
PubMedDate not supplied

New determinants for tolerance of coffee (Coffea arabica L.) seeds to liquid nitrogen exposure.

The present work establishes for the first time that tolerance of coffee seeds to liquid nitrogen (LN) exposure depends on the initial quality of the seedlot and on the rewarming regime employed. Seedlot quality was estimated by the parameters of a quantal response model of desiccation sensitivity developed previously. The percentage of seedlings recovered from cryopreserved seeds was very well correlated with the relative humidity (RH) at which 90 percent of the initial viability was retained, RH90, as estimated by the model. Whatever the cooling regime employed, rewarming the seeds slowly by exposing them to ambient air was highly detrimental. Slow rewarming-induced viability loss was not due to imbibitional damage since seeds pre-heated at 37 degree C after slow rewarming to 0 degree C exhibited a survival percentage lower than seeds thawed rapidly to 0 degree C before sowing. The optimal hydration status for coffee seed cryopreservation was also re-examined. Drying seeds in 81 percent RH provided survival percentages considerably higher than those obtained using the drying RH always employed until now, i.e. 78 percent. A new procedure for slowly precooling the seeds prior to immersion in LN was also established. It consisted of placing the vials containing the seeds in a dry ice-bath for 25 min. Using this procedure in combination with seed drying in 81 percent RH and rapid rewarming in a 37 degree C water-bath for 30 min ensured the highest survival percentages ever obtained with coffee seeds, i.e. 89 percent, a value which was not significantly different from the initial viability percentage.

Coffea↗
PubMed1983

[Anaphylaxis following ingestion of coffee, chronic urticaria and analgesics idiosyncrasy].

In a 45-year-old woman with chronic urticaria anaphylactoid reactions occurred after (1) ingestion of coffee and (2) taking an analgesic drug. Prick testing in the patient and passive cutaneous anaphylaxis with coffee extract in the monkey Macacus nemestrinus were positive. With regard to further prick tests and oral provocation tests there is conclusive evidence that anaphylactic hypersensitivity to coffee was co-existing with idiosyncrasy to acetylsalicylic acid, indomethacne, metamizole (dipyrone), and caffeine.

Analgesics↗
PubMed1998

Flavour of coffee. A review.

The concept of flavour analysis developed in our laboratory during the last decade to evaluate the key odorants of foods and beverages, is demonstrated in a review on coffee flavour. The results obtained by aroma extract dilution analysis (AEDA), gas chromatography/olfactometry of headspace samples and quantitation of potent odorants using corresponding stable isotopomers as internal standards are discussed. Finally, some sensory experiments performed on the basis of data assessed by instrumental analyses of roasted coffee samples are reported.

Coffee↗
PubMed1991

Tobacco, alcohol, and coffee and cancer of the pancreas. A population-based, case-control study in Quebec, Canada.

A population-based, case-control study of pancreatic cancer was carried out in greater Montreal between 1984 and 1988. A total of 179 cases and 239 population-based controls were interviewed. This study was part of the SEARCH program of the International Agency for Research on Cancer of the World Health Organization. A strong positive association was observed between total cigarette smoking and risk of pancreatic cancer (odds ratio [OR] = 3.76; 95% confidence interval [CI], 1.80 to 7.83). The OR for current smokers in the highest quintile of number of cigarettes was 5.15 compared with 3.99 for exsmokers. Those who consumed alcohol were in general at lower risk than nondrinkers. Coffee drinkers were collectively at lower risk than nondrinkers, particularly when coffee was consumed with meals, not on empty stomach.

Adult↗
PubMed2004

Potential chemoprotective effects of the coffee components kahweol and cafestol palmitates via modification of hepatic N-acetyltransferase and glutathione S-transferase activities.

Coffee drinking has been associated with reduced incidence of colorectal cancer, possibly via chemoprotection/modification of the metabolism of dietary heterocyclic amine carcinogens such as 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine (PhIP) by kahweol and cafestol palmitates (K/C), two components of unfiltered coffee. Using the PhIP-exposed male Fisher F344 rat as a model, K/C have been shown to reduce colonic PhIP-DNA adducts by > 50%. We have used the male F344 rat to investigate the effects of dietary K/C (0.02-0.2% as a 1:1 mixture) on the metabolism of PhIP by N-acetyltransferase- (NAT), sulfotransferase- (SULT), and glutathione-dependent pathways. K/C decreased hepatic NAT-dependent PhIP activation by up to 80% in a dose-dependent manner. Conversely, hepatic glutathione S-transferase (GST) activity/expression increased, e.g., 3-4 fold toward 1-chloro-2,4-dinitrobenzene (total activity), up to 23-fold toward 4-vinylpyridine (rGSTP1), and approximately 7-fold for rGSTA2 protein. These effects had fully developed after 5 days of the test diet and persisted for at least 5 days after withdrawal of K/C. Hepatic glutathione increased two- to threefold and this increase was more short-lived than other changes. K/C did not modify hepatic SULT activity or colon NAT and GST activities. Benzylisothiocyanate and black tea, which have also been shown to reduce the formation of PhIP-DNA adducts in this model, had little effect on hepatic NAT, SULT, GST, or GSH. In primary culture of rat hepatocytes, both kahweol and cafestol palmitates reduced NAT activity by 80%. In summary, the unique potential of K/C to convert rapid acetylators to a slow acetylator phenotype, accompanied by GST induction, might contribute to chemoprevention against cancers associated with heterocyclic amines.

Acetyltransferases↗
PubMed1988

Increased sister chromatid exchange associated with smoking and coffee consumption.

Sister chromatid exchange (SCE) is a very sensitive cytogenetic assay for detecting exposure to chemical mutagens and carcinogens. One application of SCE is the monitoring of populations believed to be exposed to such agents. We have, however, relatively little knowledge about common lifestyle factors that may influence SCE and therefore complicate any study designed to examine the effects of exposure to genotoxins. In this study, we assessed the effect of cigarette smoking and coffee consumption on SCE. Smoking was associated with an increase of approximately 2 SCEs per cell and a decrease in cell proliferation. A positive linear relationship between SCE and coffee consumption was also observed. This effect was similar for smokers and nonsmokers. Additionally, the folic acid content of cell culture medium seemed to affect neither SCE nor cell proliferation.

Adult↗
PubMed2003

Coffee increases state anxiety in males but not in females.

Coffee, reproducing the conditions under which caffeine is normally ingested, containing 3, 75, 150 or 300 mg of caffeine was given to healthy male and female volunteers. 25-30 min after drinking the beverage, they completed the Spanish version of the state-trait anxiety inventory (STAI). The beverage increased state anxiety, in a dose-dependent manner, in males but not in females. This could be due to a lesser sensitivity of females to coffee.

Adolescent↗
PubMed1990

Risk of pancreatic cancer in relation to medical history and the use of tobacco, alcohol and coffee.

A population-based case-control study was conducted to examine the relationship between certain medical conditions, the use of tobacco, alcohol and coffee, and the incidence of pancreatic cancer. Cases (N = 148) were married men ages 20 through 74 years diagnosed with pancreatic cancer from July 1982 through June 1986. Controls (N = 188) were identified by random digit dialing. Wives, responding as surrogates for both cases and controls, were interviewed by telephone and completed, alone, a food frequency questionnaire. The risk of pancreatic cancer was increased in individuals with a history of diabetes or pancreatitis, and decreased in those with a history of tonsillectomy. Individuals who had ever smoked cigarettes were at elevated risk of disease. This excess risk was confined to current smokers, in whom the odds ratio was 3.2 (95% CI 1.8-5.7); the risk among former smokers resembled that in those who had never smoked. There was no excess risk of pancreatic cancer among those who had ever used other forms of tobacco, including pipe tobacco, cigars and chewing tobacco. After adjustment for demographic and dietary characteristics, there was no association between pancreatic cancer risk and the intake of coffee, beer, red wine, hard liquor or all alcohol combined; a slight reduction in risk was seen among those consuming white wine daily.

Adult↗