Hinniger, C.; Caillet, V.; Michoux, F.; Ben Amor, M.; Tanksley, S.; Lin, C.; McCarthy, J.
Dehydrins, or group 2 late embryogenic abundant proteins (LEA), are hydrophilic Gly-rich proteins that are induced in vegetative tissues in response to dehydration, elevated salt, and low temperature, in addition to being expressed during the late stages of seed maturation. With the aim of characterizing and studying genes involved in osmotic stress tolerance in coffee, several full-length cDNA-encoding dehydrins (CcDH1, CcDH2 and CcDH3) and an LEA protein (CcLEA1) from Coffea canephora (robusta) were isolated and characterized. * Methods The protein sequences deduced from the full-length cDNA were analysed to classify each dehydrin/LEA gene product and RT-PCR was used to determine the expression pattern of all four genes during pericarp and grain development, and in several other tissues of C. arabica and C. canephora. Primer-assisted genome walking was used to isolate the promoter region of the grain specific dehydrin gene (CcDH2). * Key Results The CcDH1 and CcDH2 genes encode Y(3)SK(2) dehydrins and the CcDH3 gene encodes an SK(3) dehydrin. CcDH1 and CcDH2 are expressed during the final stages of arabica and robusta grain development, but only the CcDH1 transcripts are clearly detected in other tissues such as pericarp, leaves and flowers. CcDH3 transcripts are also found in developing arabica and robusta grain, in addition to being detected in pericarp, stem, leaves and flowers. CcLEA1 transcripts were only detected during a brief period of grain development. Finally, over 1 kb of genomic sequence potentially encoding the entire grain-specific promoter region of the CcDH2 gene was isolated and characterized. * Conclusions cDNA sequences for three dehydrins and one LEA protein have been obtained and the expression of the associated genes has been determined in various tissues of arabica and robusta coffees. Because induction of dehydrin gene expression is associated with osmotic stress in other plants, the dehydrin sequences presented here will facilitate future studies on the induction and control of the osmotic stress response in coffee. The unique expression pattern observed for CcLEA1, and the expression of a related gene in other plants, suggests that this gene may play an important role in the development of grain endosperm tissue. Genomic DNA containing the grain-specific CcDH2 promoter region has been cloned. Sequence analysis indicates that this promoter contains several putative regulatory sites implicated in the control of both seed- and osmotic stress-specific gene expression. Thus, the CcDH2 promoter is likely to be a useful tool for basic studies on the control of gene expression during both grain maturation and osmotic stress in coffee.
Kouadio, A. I.; Agbo, N. G.; Lebrihi, A.; Mathieu, F.; Dosso, M.
Effects of mixing frequency during solar drying of coffee cherries on the kinetics of the drying, fungal growth and ochratoxin A (OTA) production were investigated. Initial moisture content (approx. 60%) was reduced to between 11 and 12% in 31, 22, 16, 12 and 11 days, respectively, for coffee cherries mixed 2, 4, 6, 8 and 10x/day. Results showed that the more coffee cherries were mixed, the quicker they dried. This rapidity of drying led to a reduction of fungal development. Coffee cherries mixed 8 or 10x/day dried most quickly. Aspergillus niger, Aspergillus carbonarius and Aspergillus ochraceus were commonly found on the surface of the coffee cherries. Frequency of mixing affected the types of fungal contamination on the coffee cherries; for example, coffee cherries mixed 2x/day were more contaminated by yeasts than Aspergillus species. All strains of A. carbonarius and A. ochraceus isolated from the coffee were potential OTA producers; in contrast, only 5.8-15.4% of A. niger strains were capable of OTA production. The highest level of OTA contamination (0.35-5.46 mug/kg) was found in coffee cherries mixed 4x/day. It was concluded that OTA contamination was essentially due to the presence of Aspergillus species capable of producing OTA inside the coffee cherries.
Source : Food Additives and Contaminants, 2006 vol. 23 (3), pp 295 - 304
Masoud, W.; Kaltoft, C. H.
Ochratoxin A (OTA) is a secondary metabolite of species of Aspergillus and Penicillium, and it has been detected in foods, such as wine, beer, coffee and grape juice. This study investigated the effects of Pichia anomala, Pichia kluyveri and Hanseniaspora uvarum, predominant during coffee processing, on the growth and OTA production by Aspergillus ochraceus. Two strains of Aspergillus ochraceus showed good growth and production of OTA in malt-extract-agar and coffee-agar media. Pichia anomala, Pichia kluyveri and Hanseniaspora uvarum reduced growth of Aspergillus ochraceus and prevented biosynthesis of OTA on malt-extract-agar medium. On coffee-agar medium, Pichia anomala and Pichia kluyveri reduced growth of Aspergillus ochraceus and prevented the production of OTA. The possibility of using Pichia anomala and Pichia kluyveri in the biological control of OTA-producing fungi during coffee fermentation is discussed.
Peterson, S. W.; Vega, F. E.; Posada, F.; Nagai, C.
Penicillium coffeae is described as a novel endophyte isolated from a Coffea arabica L. plant in Hawaii. The species is slow growing with short, vesiculate, monoverticillate conidiophores. Phylogenetic analysis using three loci shows that P. coffeae forms a strongly supported clade with P. fellutanum, P. charlesii, P. chermesinum, P. indicum, P. phoeniceum and P. brocae. Phenotypic ally these species are quite similar but can be distinguished. The EF-1alpha gene from P. fellutanum, P. charlesii, P. chermesinum and P. indicum lack introns, P. coffeae and P. phoeniceum have a previously unknown intron at codon 20 and P. brocae and P. thiersii isolates have a single intron at codon 26. The most parsimonious interpretation of intron changes on the strongly supported phylogenetic tree requires the gain of a novel intron at position 20 and loss of intron 26 to arrive at the current distribution of introns in this gene. This is one of only a few examples of intron gain in genes.
Neves, L.; Oliveira, R.; Alves, M. M.
The feasibility of the anaerobic co-digestion of coffee solid waste and sewage sludge was assessed. Five different solid wastes with different chemical properties were studied in mesophilic batch assays, providing basic data on the methane production, reduction of total and volatile solids and hydrolysis rate constant. Most of the wastes had a methane yield of 0.24-0.28 m3 CH4(STP)/kg VS(initial) and 76-89% of the theoretical methane yield was achieved. Reduction of 50-73% in total solids and 75-80% in volatile solids were obtained and the hydrolysis rate constants were in the range of 0.035-0.063 d(-1). One of the solid wastes, composed of 100% barley, achieved a methane yield of 0.02 m3 CH4(STP)/kg VS(initial), reductions of 31% in total solids, 40% in volatile solids and achieved only 11% of the theoretical methane yield. However, this waste presented the highest hydrolysis rate constant. Considering all the wastes, an inverse linear correlation was obtained between methane yield and the hydrolysis rate constant, suggesting that hydrolysis was not the limiting factor in the anaerobic biodegradability of this type of waste.
Farah, A.; Monteiro, M. C.; Calado, V.; Franca, A. S.; Trugo, L. C.
Brazilian arabica coffee is classified for trading according to the quality of the beverage obtained after roasting and brewing. In the present study, Brazilian green and roasted coffee beans were investigated for possible correlations between cup quality and the levels of sucrose, caffeine, trigonelline and chlorogenic acids, determined by HPLC analysis. Trigonelline and 3,4-dicaffeoylquinic acid levels in green and roasted coffee correlated strongly with high quality. To a lesser extent, caffeine levels were also associated with good quality. On the other hand, the amount of defective beans, the levels of caffeoylquinic acids (predominantly 5-caffeoyilquinic acid), feruloylquinic acids, and their oxidation products were associated with poor cup quality and with the Rio-off-flavor. The fact that similar correlations between cup quality and chemical attributes were observed in green and light roasted samples - the latter used for coffee cup classification - indicates that chemical analysis of green beans may be used as an additional tool for coffee quality evaluation.
Nunes, F. M.; Domingues, M. R.; Coimbra, M. A.
A good yield mild fractionation procedure was developed for the purification of mannans from green and roasted coffee infusions that included anion-exchange chromatography and phenylboronic acid immobilized Sepharose chromatography of the dialyzed and ethanol precipitated material. Enzymatic hydrolysis with endo-beta-mannanase and ESIMS allowed finding that the mannans from roasted coffee infusions, as well as those from green coffee, are acetylated (8 mol% and 11 mol%, respectively). Fragmentation pattern obtained by ESIMS/MS analysis of the acetylated oligosaccharide ions indicates that the acetylation also occurs at O-2 of the mannose residues. Doubly acetylated and contiguously acetylated hexose residues were also found. Arabinose residues, as side chains, were also found as structural features of hot water soluble green (2%) and roasted (<0.9 mol) coffee galactomannans. Methylation analysis, hydrolysis with specific glycosidases and GC-EIMS analysis of the reduced and methylated oligosaccharides allowed to conclude that beta-(1-->4)-linked glucose residues are also structural features of green and roasted coffee galactomannans (6 and 1 mol%, respectively). In hot water soluble green coffee mannans, glucose residues are a constituent of the mannan backbone, and in the roasted coffee they were detected only at the reducing end of the mannan backbone.
Denker, M.; Parat-Wilhelms, M.; Drichelt, G.; Paucke, J.; Luger, A.; Borcherding, K.; Hoffmann, W.; Steinhart, H.
The aim of this study was the investigation of the influence of milk proteins (casein and whey proteins) and milk fat on the release of flavour compounds from white coffee beverages in the oral cavity. For this reason a retronasal headspace technique for measurement of the after-flavour was adapted. A 'Gas Sampler' equipped with a mouthpiece was used as an 'Oral Breath Sampler (OBS)'. Analyses were performed by gas chromatography with mass spectrometric detection. It was noticed that the sampling at different hours resulted in different standard deviations. The flavour release is more constant in the morning (Variation coefficient from 3% to 28%; median: 10%) than in the afternoon (7-52%; median: 23%). The relationships between flavour release and some salivary parameters like salivation rate, buffer capability and protein content were also studied. The 'Oral Breath Sampling' was considered to be a valuable sampling method for the analysis of the retronasal aroma release from coffee beverages.
Oliveira, L. S.; Franca, A. S.; Mendonca, J. C. F.; Barros-Junior, M. C.
Defective coffee beans present in the coffee produced in Brazil cause depreciation in the quality of roasted coffee, and the extraction of the oil of these defective beans for use in the food industry is being considered. This study determined the composition of the fatty-acid fraction of the pressed oil, and the proximate composition of crude defective beans. Amounts of oil extracted from the defective beans were smaller than the amounts extracted from healthy mature beans; the fatty-acid composition of oils from defective beans was not significantly different from that derived from healthy mature coffee beans. The authors conclude that the oil and the resulting waste solids are suitable for use in formulations in the food industry.
Azevedo, A.; Barros, H.
Despite the amount of published studies on the subject, controversy still exists about the effect of coffee drinking on the occurrence of coronary heart disease. In general, epidemiological studies do not support the belief that it is a major risk factor. DESIGN: A community-based case-control study was conducted. METHODS: A random sample of men aged 40 years and over with no previous myocardial infarction was compared with patients with a first acute myocardial infarction (AMI). A structured questionnaire was used to collect information on sociodemographic characteristics, personal and family medical history and lifestyles. Dietary data were obtained by a food frequency questionnaire. Odds ratios were calculated by unconditional logistic regression. After exclusions, 290 cases and 364 controls were considered in the final analysis. RESULTS: Coffee drinking is a widespread habit in this population, and most individuals did not change their habit throughout life. Most participants reported the consumption of moderate amounts of coffee (<25% drank more than four cups a day) and espresso was by far the most commonly used brewing. The crude odds ratio for having ever drunk coffee regularly was 0.5 (95% confidence interval 0.3-1.1). However, there was a significant effect-measure modification by family history of AMI (P=0.02).
CONCLUSIONS : The results suggest different susceptibility to coffee drinking, such that coffee drinking was positively although not significantly associated with an increased risk of AMI in men with a family history of AMI, whereas there was a significant inverse association with the occurrence of myocardial infarction among men with no family history of AMI.
Source : Eur J Cardiovasc Prev Rehabil, vol. 13 (2), pp 268 - 273
Browne, M. L.
Caffeine is teratogenic in animal studies when administered at high concentrations. Previous review articles have concluded that maternal caffeine consumption does not influence the risk of congenital anomalies. These reviews were narrative rather than systematic. The objective of the current systematic review is to provide a critical appraisal of epidemiologic evidence. METHODS : A search of the MEDLINE/PUBMED database (1966-October 2004) was conducted for all published epidemiologic studies with maternal intake of caffeine as an exposure and major malformations as an outcome. Study characteristics were abstracted, internal validity evaluated, and study findings summarized. RESULTS : Twenty-five papers met the initial criteria for inclusion, of which 18 were subsequently excluded as a result of other limitations. Effect estimates for the remaining 7 studies were generally close to null. Specific subgroup analyses were summarized across studies (associations between coffee and cardiovascular malformations, coffee and oral clefts, and tea and cardiovascular malformations). Summary point estimates ranged from 1.0 to 1.2; the upper limits of all confidence intervals were less than 1.7.
CONCLUSIONS : There is no evidence to support a teratogenic effect of caffeine in humans. Current epidemiologic evidence is not adequate to assess the possibility of a small change in risk of congenital anomalies resulting from maternal caffeine consumption.
Homan, D. J.; Mobarhan, S.
Coffee consumption is a regular part of daily life throughout the world. Research into the effects of coffee on human health is ongoing, but a recent study suggests that coffee and caffeine consumption can reduce the risk of elevated alanine aminotransferase activity in individuals at high risk for liver disease. This review will analyze the results of that study in light of the current literature.
Source : Nutr Rev, vol. 64 (1), pp 43 - 46
Iso, H.; Date, C.; Wakai, K.; Fukui, M.; Tamakoshi, A.
In western populations, coffee consumption is associated with a reduced risk for type 2 diabetes; however, the effect of green, black, and oolong teas is unclear. OBJECTIVE: To examine the relationship between consumption of these beverages and risk for diabetes. DESIGN: Retrospective cohort study. SETTING: 25 communities across Japan. PARTICIPANTS: A total of 17,413 persons (6727 men and 10,686 women; 49% of the original study population) who were 40 to 65 years of age; had no history of type 2 diabetes, cardiovascular disease, or cancer at the baseline lifestyle survey; and completed the 5-year follow-up questionnaire. There was no difference in body mass index levels at baseline between respondents and nonrespondents. MEASUREMENTS: Questionnaire on consumption of coffee; black, green, and oolong teas; and physician-diagnosed diabetes. RESULTS: During the 5-year follow-up, there were 444 self-reported new cases of diabetes in 231 men and 213 women (5-year event rates, 3.4% and 2.0%, respectively). Consumption of green tea and coffee was inversely associated with risk for diabetes after adjustment for age, sex, body mass index, and other risk factors. Multivariable odds ratios for diabetes among participants who frequently drank green tea and coffee (> or =6 cups of green tea per day and > or =3 cups of coffee per day) were 0.67 (95% CI, 0.47 to 0.94) and 0.58 (CI, 0.37 to 0.90), respectively, compared with those who drank less than 1 cup per week. No association was found between consumption of black or oolong teas and the risk for diabetes. Total caffeine intake from these beverages was associated with a 33% reduced risk for diabetes. These inverse associations were more pronounced in women and in overweight men. LIMITATIONS: Diabetes was self-reported, no data were available on consumption of soda, and the follow-up rate was low.
CONCLUSIONS : Consumption of green tea, coffee, and total caffeine was associated with a reduced risk for type 2 diabetes.
Lafay, S.; Gil-Izquierdo, A.; Manach, C.; Morand, C.; Besson, C.; Scalbert, A.
The bioavailability of chlorogenic acid, a major polyphenol of the human diet that is particularly abundant in coffee and various fruits, was explored in rats. To identify the form under which it is absorbed through the gut mucosa and the site of absorption along the gastrointestinal tract, rats were fed a diet supplemented with chlorogenic acid (0.25%, wt./wt.). Chlorogenic acid and its metabolites were estimated in the stomach, small intestine and caecal contents as well as in bladder urine and plasma by HPLC with coulometric detection at several time points (1.5, 3, 4.5 and 7 h) after the beginning of the meal. Minor hydrolysis of chlorogenic acid (<1%) occurred in the stomach and small intestine contents, whereas 15-32% of ingested chlorogenic acid was hydrolysed into caffeic acid in the caecum. Chlorogenic acid and caffeic acid appeared early (at 1.5 h) in plasma and urine, suggesting absorption of chlorogenic acid into the upper part of the gastrointestinal tract. Gastric absorption of chlorogenic acid was further examined by infusing chlorogenic acid in the ligated stomach of food-deprived rats. After 30 min of infusion, intact chlorogenic acid was found in the gastric vein and aorta. No other metabolites could be detected by HPLC-electrospray ionization-MS-MS. These results show that chlorogenic acid is quickly absorbed in the rat stomach in its intact form.
Source : Journal of Nutrition, 2006 vol. 136 (5), pp 1192 - 1197
Larsson, S. C.; Bergkvist, L.; Giovannucci, E.; Wolk, A.
Investigators have reported an inverse association between coffee consumption and risk of colorectal cancer in several case-control studies, but prospective studies, most of them involving small numbers of cases, have not supported such a relation. In this analysis, the authors prospectively examined the association of coffee consumption with colorectal cancer risk among participants from two population-based cohort studies: 61,433 women in the Swedish Mammography Cohort and 45,306 men in the Cohort of Swedish Men. Information about coffee consumption was obtained from food frequency questionnaires in 1987-1990 and 1997 for women and in 1997 for men. The authors used Cox proportional hazards modeling for cohort-specific multivariate analyses, and results were pooled using random-effects models. During 1,240,597 person-years of follow-up, 1,279 incident cases of colorectal cancer were diagnosed. Coffee consumption was not associated with risk of colorectal cancer, colon cancer, or rectal cancer in either women or men. For both cohorts combined, the multivariate rate ratio for colorectal cancer for each additional cup of coffee per day was 1.00 (95% confidence interval: 0.97, 1.04). The associations were not modified by colorectal cancer risk factors. The findings from these two large prospective cohort studies do not support the hypothesis that coffee consumption lowers the risk of colorectal cancer.
Lopez-Garcia, E.; van Dam, R. M.; Willett, W. C.; Rimm, E. B.; Manson, J. E.; Stampfer, M. J.; Rexrode, K. M.; Hu, F. B.
We examined the association between long-term habitual coffee consumption and risk of coronary heart disease (CHD). METHODS AND RESULTS: We performed a prospective cohort study with 44,005 men and 84,488 women without history of cardiovascular disease or cancer. Coffee consumption was first assessed in 1986 for men and in 1980 for women and then repeatedly every 2 to 4 years; the follow-up continued through 2000. We documented 2173 incident cases of coronary heart disease (1449 nonfatal myocardial infarctions and 724 fatal cases of CHD) among men and 2254 cases (1561 nonfatal myocardial infarctions and 693 fatal cases of CHD) among women. Among men, after adjustment for age, smoking, and other CHD risk factors, the relative risks (RRs) of CHD across categories of cumulative coffee consumption (<1 cup/mo, 1 cup/mo to 4 cups/wk, 5 to 7 cups/wk, 2 to 3 cups/d, 4 to 5 cups/d, and > or =6 cups/d) were 1.0, 1.04 (95% confidence interval 0.91 to 1.17), 1.02 (0.91 to 1.15), 0.97 (0.86 to 1.11), 1.07 (0.88 to 1.31), and 0.72 (0.49 to 1.07; P for trend=0.41); among women, the RRs were 1.0, 0.97 (0.83 to 1.14), 1.02 (0.90 to 1.17), 0.84 (0.74 to 0.97), 0.99 (0.83 to 1.17), and 0.87 (0.68 to 1.11; P for trend=0.08). Stratification by smoking status, alcohol consumption, history of type 2 diabetes mellitus, and body mass index gave similar results. Similarly, we found no effect when the most recent coffee consumption was examined. RRs for quintiles of caffeine intake varied from 0.97 (0.84 to 1.10) in the second quintile to 0.97 (0.84 to 1.11) in the highest quintile (P for trend=0.82) in men and from 1.02 (0.90 to 1.16) to 0.97 (0.85 to 1.11; P for trend=0.37) in women.
CONCLUSIONS : These data do not provide any evidence that coffee consumption increases the risk of CHD.