Mansingh, Gunjan; Reichgelt, Han; Bryson, Kweku Muata-Osei
Over the last few years, environmental concerns have led to the emergence of the integrated management of pest and pesticides (IMPP) as a new way to deal with pests and pesticides in agriculture. Although the environmental and economic benefits of IMPP are beyond doubt, its use has been somewhat limited. One reason is the sheer amount of knowledge required of such things as climate, topography, soil type of the farm, agronomic practices, crop phenology, biology and damage potential of the pests and options available for suppressing their population below the economic injury levels. Unfortunately, such knowledge typically resides within a few experts and is not easilyavailable to farmers. In order to make this knowledge more widely available, we developed CPEST, an expert system for managing pest and diseases of coffee in a developing country. The paper describes the architecture and development of CPEST, gives examples of the interface that a farmer would use to enter information and provides an evaluation of the quality of the advice that CPEST provides.
Source : Expert Systems with Applications, 2007 vol.32 (1), pp 184 - 192
Chen, Z.; Liang, J.; Zhang, C.; Rodrigues, C.-J. Jr
Colletotrichum kahawae is the causal agent of coffee berry disease. Appressorial melanization is essential for the fungal penetration of plant cuticle. Epicatechin is abundant in green coffee berry pericarp. Inoculation of C. kahawae conidial suspension containing 1.2 mg epicatechin or catechin/ml did not affect conidial germination or appressorial formation but appressorial melanization was completely inhibited and infection by the treated conidia was less than 30% of the untreated control. Epicatechin and catechin may, therefore, prevent coffee berry disease by inhibition of the appressorial melanization of C. kahawae.
Cruz, L. P.; Gaitan, A. L.; Gongora, C. E.
Beauveria bassiana is an entomopathogen widely used to control the coffee berry borer in Colombia, as part of an Integrated Pest Management strategy. Traditionally, the development of fungal insect pathogens as biocontrol agents in crop pests has been oriented towards the selection and formulation of elite clonal strains. Instead, we explored the potential application of genetic diversity in B. bassiana by determining the effect of strain mixtures on coffee berry borer mortality compared to clonal isolates. Genomic DNA from 11 strains was characterized using internal transcribed spacers and beta-tubulin sequences as well as amplified fragment length polymorphism markers. Cluster analysis produced three genetic groups and confirmed the low but significant intraspecific genetic diversity present among the strains. Single strain virulence towards the coffee berry borer under laboratory conditions, using 1x10(6) conidia ml(-1), ranged between 89.9 and 57.5%. All the inoculations with mixtures resulted in coinfection events. Combinations of genetically similar strains showed no significant differences when their virulences were compared. However, mixtures of genetically different strains led to both antagonism and synergism. The lowest virulence percentage (57%) was obtained by putting together the most virulent strain of each group, contrary to the highest virulence percentage (93%) that resulted from mixing the three least virulent strains. The results indicate the promising potential of designing strain mixtures as an alternative for the biocontrol of Hypothenemus hampei and other pests and provide tools for the understanding of the ecological dynamics of entomopathogen populations under natural conditions.
Source : Appl Microbiol Biotechnol, 2006 vol.71 (6), pp 918 – 926
Fujii, S.; Reche-Ribeiro, R. M.; Santos-Scholz, M.-B. dos; Ono, E.-Y. S.; Prete, C.-E. C.; Itano, E. N.; Ueno, Y.; Kawamura, O.; Hirooka, E. Y.
An indirect competitive ELISA (ic-ELISA) based on a monoclonal antibody (mAb) for ochratoxin A (OTA) was developed and compared with HPLC analysis. The ic-ELISA was applied in a survey of freshly harvested coffee beans (n = 68 samples) from the north of Parana State, Brazil. The anti-OTA mAb showed high specificity and low cross-reactivity with OTA analogues (OTB and OTalpha) but cross-reacted with OTC. Detection limit of the ic-ELISA was 3.75 ng/g sample compared with 0.80 ng/g by HPLC. The ic-ELISA/HPLC correlation coeff. was 0.90. In the coffee beans, natural contamination was detected in 10 samples (14.7%) by both methods. The ic-ELISA values (3.9-7.3 ng/g) were 1.1- to 1.6-x higher than HPLC values (2.7-4.7 ng/g). Five samples (7.4%) were OTA positive (range 0.84-1.30 ng/g) only by HPLC assay, presumably because of differences between the detection limits of the 2 analytical techniques. OTA was not detected in 53 samples (77.9%) by both methods, while all positive samples (range 0.84-7.30 ng/g) showed OTA levels <8 ng/g (the EU recommended MRL). The matrix interference of green coffee was minimized by dilution of sample extracts before carrying out the ELISA assay. It is concluded that the mAbbased ic-ELISA provides a simple, sensitive method for OTA screening of coffee.
Esteban, A.; Abarca, M. L.; Bragulat, M. R.; Cabanes, F. J.
Aspergillus carbonarius is claimed to be a key source for ochratoxin A (OTA) contamination in grapes, vine fruits and coffee. The effects of water activity (0.78-0.99) and temperature (15 and 30 C) on the growth of several strains of Aspergillus carbonarius in two culture media were studied in order to understand the effects of environmental conditions on growth and OTA production. OTA production was higher at 15 C, and both fungal growth and OTA production were detected only in the 0.94-0.99 water activity range. The implications these findings for storage risks and control measures for OTA are considered.
Vargas, E. A.; Whitaker, T. B.; Santos, E. A.; Slate, A. B.; Lima, F. B.; Franca, R. C. A.
Regulatory guidelines have been set in many countries for the level of ochratoxin A in coffee, so there is a need to develop effective sampling plans for the assessment of batches of green coffee without misclassifying shipments. This study investigated the effect of increasing sample size or number of samples and changing the accept/reject limit on the performance of ochratoxin sampling plans for green coffee. Increasing sample size reduced the uncertainty associated with the test procedure. Decreasing the accept/reject limit increased the number of good batches rejected but decreased the number of bad batches accepted.
Hernandez, J. A.; Heyd, B.; Irles, C.; Valdovinos, B.; Trystram, G.
In this paper, an experimental and theoretical analysis of the heat and mass transfer was carried out to evaluate the coffee bean\'s temperature and moisture content during the roasting in batch system. Arabica coffee from Colombian origin was roasted using different air temperatures between 190 and 300°C, during 10min. Bean\'s temperature and weight loss have been measured on-line by robust sensors. The experimental results allowed better understanding of the phenomena that appears during roasting. For example, an evident increase of the bean\'s temperature curve tendency is observed when this one exceeds the 250°C, it is probably due to the end of 2 exothermic reactions and to the beginning of the bean burn. The experimental data of moisture shown a decrease of 10.5% d.b. to 0-7% d.b. A dynamic model is evaluated and analyzed to predict bean\'s temperature and moisture content during roasting. The results (simulations and experimental kinetics) were in good agreement. This model can be used for on-line estimation and control of coffee roasting.
Araujo, J.-M. A.; Sandi, D.
Commercial green and roasted coffee beans were used to maximize oil extraction and conditions were studied to obtain the highest and lowest diterpene levels on green and roasted coffee oil, respectively. Thus, operational temperatures (60-90°C) and pressure (235-380bar) were optimized for coffee oil extraction. Oil content levels and diterpene oil concentration were compared to the results obtained with the extraction with Soxhlet apparatus, using hexane as solvent. In general, an inverse correlation was observed between the amount of extracted oil and diterpene concentration levels. As a result, different oil contents with different diterpene concentrations could be obtained. The HPLC analysis of cafestol and kahweol in the oil extracted from green coffee beans at 70°C/253bar resulted in the highest concentration (453.3mg100g-1), which was 48% lower than in the oil extracted with hexane while in the oil extracted from roasted coffee beans at 70°C/371bar, resulted in 71.2% reduction of diterpenes.
Benoit, I.; Navarro, D.; Marnet, N.; Rakotomanomana, N.; Lesage-Meessen, L.; Sigoillot,
J. C.; Asther, M.; Asther, M.
Two purified feruloyl esterases from Aspergillus niger were investigated for the ability to release added-value phenolic acids, such as ferulic acid, caffeic acid and pcoumaric acid, from agro-food industry by-products, such as wheat straw, coffee pulp and apple marc. Both enzymes were able to hydrolyse quinic esters and ester linkages between phenolic acids and lignin monomer.
Masoud, W.; Jespersen, L.
The ability of six strains of Pichia anomala, four strains of Pichia kluyveri and two strains of Hanseniaspora uvarum predominant during coffee processing to produce polygalacturonase (PG), pectin esterase (PE) and pectin lyase (PL) in yeast polygalacturonic acid medium (YPA) and in coffee broth (CB) was studied. For comparison, a reference strain of Kluyveromyces marxianus CCT 3172 isolated from cocoa and reported to produce high amount of PG was included. Initial screening of PG activity using YPA medium showed that K. marxianus CCT 3172, P. anomala S16 and P. kluyveri S13Y4 had the strongest activity. Enzymatic assays showed that the four yeast species secreted PG, but none of the yeasts investigated was found to produce PE or PL. P. anomala S16 and P. kluyveri S13Y4 were found to produce higher amounts of PG when grown in CB than in YPA. When K. marxianus CCT 3172, P. anomala S16 and P. kluyveri S13Y4 were grown in YPA broth adjusted to pH of 3.0-8.0 and incubated at temperatures of 15-40 degrees C, the three yeast species secreted the highest amount of PG at pH 6.0 and at 30 degrees C. For PG secreted by K. marxianus CCT 3172 and P. anomala S16, the optimum pH and temperature for the enzymatic activity were 5.5 and 40 degrees C, respectively. On the other hand, PG produced by P. kluyveri S13Y4 showed the highest activity at pH 5.0 and 50 degrees C. Significant differences in the extracellular activity of PG were found between the yeasts species as well as between strains within same species. High amounts of PG were produced by two strains of P. anomala and P. kluyveri. It is therefore likely that strains of those two species may be involved in the degradation of pectin during coffee fermentation.
Source : Int J Food Microbiol, 2006 vol. 110 (3), pp 291 – 296
Hiltunen, L. A.
To describe the associations between coffee consumption and glucose tolerance among elderly subjects.Design:A survey among an unselected noninstitutionalized elderly population. Diabetes was assessed on the basis of self-reports and 2-h oral glucose tolerance test for the subjects on diet treatment or with normal glucose tolerance (NGT). Coffee consumption was assessed by a questionnaire.Setting:Three municipalities in Northern Finland Subjects: All non institutionalized subjects with baseline normal glucose tolerance or impaired glucose tolerance (IGT) aged 70 years or over.Main outcome measures:Incidence, persistence or impairment of abnormal glucose tolerance (AGT).Results:Forty-two percent of those with NGT and 0-5 cups of coffee daily developed AGT, whereas the corresponding figure was 25% for those who drank more than five cups coffee daily. Fifty-five percent of the subjects with IGT or NGT who drank 0-5 cups coffee daily either persisted in IGT or developed AGT. The corresponding figure was 30% for those drinking more than five cups coffee daily. After adjustment for age, body mass index, cardiovascular disease, smoking, alcohol consumption and physical exercise, among those with NGT, the odds ratio (OR) for developing AGT was 2.3 for those drinking 0-5 cups compared to those drinking more than five cups of coffee daily (95% confidence interval (CI) 0.7-7.2). Correspondingly, low coffee consumption was the most powerful predictor associated with the persistence of IGT or the development of AGT (OR 2.9; 95% CI 1.2- 6.9). Conclusions: Low coffee consumption predicts impairment of AGT or persistence of IGT among elderly subjects.
Hamer, M.; Williams, E. D.; Vuononvirta, R.; Gibson, E. L.; Steptoe, A
Coffee is widely consumed in the Western diet and therefore has important implications for public health. Research findings pertaining to the effects of coffee consumption on cardiovascular health are conflicting, and the role of caffeine is not clear. OBJECTIVE: To examine the relationship between coffee intake, inflammation and cardiovascular function at baseline and during mental stress, both cross-sectionally and after a 4-week period of withdrawal of coffee during which intake of caffeine was maintained. METHODS: Eighty-five healthy, non-smoking men with varying coffee-drinking habits were recruited. Blood pressure, heart rate, and markers of inflammation [C-reactive protein (CRP), von Willebrand factor antigen (vWF)], were measured at baseline and during mental stress. These measures were repeated after a 4-week period of withdrawal of coffee, during which intake of caffeine was maintained. Habitual levels of coffee and caffeine consumption were assessed from a self-reported questionnaire, and saliva samples for the analysis of caffeine concentrations were collected regularly throughout the period of withdrawal, to confirm compliance. RESULTS: Multiple linear regression analysis of pre-withdrawal data, adjusted for age, body mass index and intake of tea, red wine, fruit, vegetables, oily fish and dietary supplements revealed that coffee consumption was positively related to baseline systolic blood pressure, and increased heart rate and vWF responses to mental stress. Four weeks after withdrawal of coffee, the heightened vWF and heart rate responses to stress in habitual coffee drinkers persisted, whereas baseline systolic blood pressure had decreased. Total caffeine intake was unrelated to any measures of physiological function. CONCLUSIONS: Habitual coffee consumption is associated with heightened acute vascular inflammatory responses to mental stress, although these effects are not affected by short-term abstinence from coffee. These findings suggest that the relationship between coffee and markers of cardiovascular risk may be explained by residual or unmeasured confounding factors.
Rodrigues, I. M.; Klein, L. C.
Caffeine is the most widely consumed psychostimulant drug in the world that mostly is consumed in the form of coffee. Whether caffeine and/or coffee consumption contribute to the development of cardiovascular disease (CVD), the single leading cause of death in the US, is unclear.This article examines the effects of caffeine intake, both alone and via coffee consumption, on key blood markers of CVD risk: lipoproteins (cholesterol, triglycerides), fibrinogen (a biomarker of blood clotting) and C-reactive protein (CRP; a biomarker of inflammation). These blood markers and their role in the development of CVD are reviewed first. Studies examining caffeine and coffee effects on each of these blood markers are then presented. Next, biobehavioural moderators of the relationship between caffeine and/or coffee consumption and CVD are discussed, including genetics, sex and tobacco smoking.The literature indicates a strong relationship between boiled, unfiltered coffee consumption and elevated cholesterol levels; however, there is a critical gap in the literature regarding the effects of coffee or caffeine consumption on fibrinogen or CRP, which is an independent predictor of CVD risk. Available studies are limited by small samples sizes, inclusion of only men (or few women) and unrepresented age or ethnic groups. Thiere is a critical need for controlled laboratory and epidemiological studies that include fibrinogen and CRP markers of CVD risk before conclusions can be drawn regarding the health effects of caffeine and/or coffee in a normal, healthy population of men and women.
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, 2006 vol.13 (2), pp 268 – 273
Lopez-Garcia, E.; van Dam, R. M.; Qi, L.; Hu, F. B.
In several short-term studies, coffee consumption has been associated with impairment of endothelial function. OBJECTIVE: The objective was to assess the relation between long-term caffeinated and decaffeinated filtered coffee consumption and markers of inflammation and endothelial dysfunction. DESIGN: We conducted a cross-sectional study of 730 healthy women and 663 women with type 2 diabetes from the Nurses\' Health Study I cohort, who were aged 43-70 y and free of cardiovascular disease and cancer at the time blood was drawn (1989-1990). Dietary intake was assessed with a validated food-frequency questionnaire in 1986 and 1990. RESULTS: About 77% of the healthy women consumed >/=1 cup (237 mL) caffeinated coffee/mo and 75% consumed >/=1 cup decaffeinated coffee/mo; the corresponding intakes for women with type 2 diabetes were 74% and 63%, respectively. In healthy women, no appreciable differences in plasma concentrations of the markers were found across categories of caffeinated coffee intake. In women with type 2 diabetes, higher caffeinated coffee consumption was associated with lower plasma concentrations of Eselectin (adjusted percentage change per 1 cup/d increment = -3.2%; P = 0.05) and Creactive protein (adjusted percentage change = -10.2%; P < 0.001). Higher decaffeinated coffee consumption was associated with lower plasma concentrations of E-selectin (adjusted percentage change = -2.5%; P = 0.08) and C-reactive protein (adjusted percentage change = -7.9%; P = 0.02) only in healthy women. The results were similar when we also adjusted the models for other dietary factors and blood lipids and when we excluded participants with hypertension or hypercholesterolemia. CONCLUSIONS: These results indicate that neither caffeinated nor decaffeinated filtered coffee has a detrimental effect on endothelial function. In contrast, the results suggest that coffee consumption is inversely associated with markers of inflammation and endothelial dysfunction.
Bidel, S.; Hu, G.; Qiao, Q.; Jousilahti, P.; Antikainen, R.; Tuomilehto, J.
Higher habitual coffee drinking has been associated with a lower risk of developing type 2 diabetes. The relation between coffee consumption and risk of cardiovascular disease (CVD) has been examined in many studies, but the issue remains controversial. This study was designed to assess the association between coffee consumption and CVD mortality among patients with type 2 diabetes. METHODS: We prospectively followed 3,837 randomly ascertained Finnish patients with type 2 diabetes aged 25 to 74 years. Coffee consumption and other study parameters were determined at baseline. The International Classification of Diseases was used to identify CHD, CVD and stroke cases using computerised record linkage to the national Death Registry. The associations between coffee consumption at baseline and risk of total, CVD, CHD, and stroke mortality were analysed by using Cox proportional hazards models. RESULTS: During the average follow-up of 20.8 years, 1,471 deaths were recorded, of which 909 were coded as CVD, 598 as CHD and 210 as stroke. The respective multivariate-adjusted hazard ratios in participants who drank 0-2, 3-4, 5-6, and >/=7 cups of coffee daily were 1.00, 0.77, 0.68 and 0.70 for total mortality (P<0.001 for trend), 1.00, 0.79, 0.70 and 0.71 for CVD mortality (P=0.006 for trend), 1.00, 0.78, 0.70 and 0.63 for CHD mortality (p=0.01 for trend), and 1.00, 0.77, 0.64 and 0.90 for stroke mortality (p=0.12 for trend). CONCLUSIONS/INTERPRETATION: In this large prospective study we found that in type 2 diabetic patients coffee drinking is associated with reduced total, CVD and CHD mortality.
Larsson, S. C.; Giovannucci, E.; Wolk, A.
Few prospective studies have examined the relationship between coffee consumption and risk of stomach cancer, and the findings have been inconsistent. We prospectively investigated the association of long-term coffee consumption with risk of stomach cancer in a population-based cohort study of 61,433 Swedish women. Information on coffee consumption was collected with a food-frequency questionnaire at baseline (1987-1990) and updated in 1997. During a mean follow-up of 15.7 years from 1987 through June 2005, 160 incident cases of stomach cancer were diagnosed. Coffee consumption was positively associated with the risk of stomach cancer. Compared to women who consumed 1 or fewer cups of coffee per day, the multivariate hazard ratios were 1.49 (95% = 0.97-2.27) for women who drank 2-3 cups per day and 1.86 (95% CI = 1.07-3.25) for those who drank 4 or more cups per day (p for trend = 0.01). An increase of 1 cup of coffee per day was associated with a statistically significant 22% increased risk of stomach cancer (hazard ratio = 1.22; 95% CI = 1.05-1.42). These prospective data suggest that coffee consumption may increase the risk of stomach cancer in a dose-response manner. This finding needs to be confirmed in other prospective studies.
Steinkellner, H.; Hoelzl, C.; Uhl, M.; Cavin, C.; Haidinger, G.; Gsur, A.; Schmid, R.; Kundi,
M.; Bichler, J.; Knasmuller, S.
A number of animal studies indicate that coffee protects against chemical induction of cancer; also human studies suggest that coffee consumption is inversely related with the incidence of different forms of cancer. The protective effects were attributed to induction of glutathione-S-transferases (GSTs) and aim of the present human study was to find out if coffee causes induction of GSTs and protects against DNA-damage caused by (+/-)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), the DNA-reactive metabolite of benzo(a)pyrene. Ten participants consumed 1L unfiltered coffee/d over 5 days. Before and after the intervention, saliva and blood were collected and the overall GST activity was measured with 1-chloro-2,4-dinitrobenzene (CDNB). Additionally, GSTP and GSTA were determined in plasma with immunoassays. In blood, only weak (p=0.042) induction of GST (CDNB) was found. Furthermore, pronounced (three-fold) induction of GSTP was observed in blood, whereas GSTA was not altered. No crrelations were seen between induction of GST (CDNB) and GSTP activities and the GSTP1 genotypes of the participants. Also clinical parameters (creatinine, alanine, aminotransferase, aspartate aminotransferase, alkaline phosphatase), which are markers for organ damage, were monitored. None of them was altered by coffee, but serum cholesterol levels were slightly (not significantly) enhanced. In a second trial (n=7), GSTP induction by unfiltered and paper filtered coffees, differing in cafestol and kahweol contents, were compared. The participants consumed 1L coffee/d over 3 days. Again significant (three-fold) induction of GSTP was observed. The effects seen with the two coffees were identical, indicating that the diterpenoid concentrations are not responsible for the effects. In a further trial (n=7), the effect of coffee (unfiltered, 1L/d, 5 days) on BPDE induced DNA-migration was studied in comet assays. A 45% reduction effect was observed. Our findings show that coffee induces GSTP in humans and indicate that consumption may lead to protection towards polycyclic aromatic hydrocarbons
Atanasov, A. G.; Dzyakanchuk, A. A.; Schweizer, R.-A. S.; Nashev, L. G.; Maurer, E. M.; Odermatt, A.
Recent epidemiological studies have demonstrated a beneficial effect of coffee consumption for the prevention of type 2 diabetes; however, the underlying mechanisms of this effect remain unknown. This study demonstrates that coffee extract, corresponding to an Italian Espresso, inhibited recombinant and endogenous 11betahydroxysteroid dehydrogenase type 1 (11beta-HSD1) activity. The inhibitory component was found to be heat-stable with considerable polarity. The coffee extract blocked 11beta-HSD1-dependent cortisol formation, prevented the subsequent nuclear translocation of the glucocorticoid receptor and abolished glucocorticoid-induced expression of the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase. It is suggested that at least part of the anti-diabetic effect of coffee consumption is due to inhibition of 11beta-HSD1-dependent glucocorticoid reactivation.
Greenberg, J. A.; Boozer, C. N.; Geliebter, A.
Several prospective epidemiologic studies over the past 4 y concluded that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. This finding is at odds with the results of trials in humans showing that glucose tolerance is reduced shortly after ingestion of caffeine or caffeinated coffee and suggesting that coffee consumption could increase the risk of diabetes. This review discusses epidemiologic and laboratory studies of the effects of coffee and its constituents, with a focus on diabetes risk. Weight loss may be an explanatory factor, because one prospective epidemiologic study found that consumption of coffee was followed by lower diabetes risk but only in participants who had lost weight. A second such study found that both caffeine and coffee intakes were modestly and inversely associated with weight gain. It is possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss. Caffeine and caffeinated coffee have been shown to acutely increase blood pressure and thereby to pose a health threat to persons with cardiovascular disease risk. One short-term study found that ground decaffeinated coffee did not increase blood pressure. Decaffeinated coffee, therefore, may be the type of coffee that can safely help persons decrease diabetes risk. However, the ability of decaffeinated coffee to achieve these effects is based on a limited number of studies, and the underlying biological mechanisms have yet to be elucidated.
Bchir, F.; Dogui, M.; Ben Fradj, R.; Arnaud, M. J.; Saguem, S.
The present study investigated pharmacokinetic and electroencephalographic responses to caffeine (140 mg) in two groups of healthy volunteers reporting, or not, caffeine-related sleep disturbances. Significant differences in caffeine consumption and smoking habits were observed between the two groups. Plasma samples were taken from each subject before (T0) and after caffeine intake at 0.5, 1, 2, 4, 6 and 24 h. Three pharmacokinetic parameters: half-life (t1/2), maximum time (Tmax) and maximum plasma concentration (Cmax) were calculated from caffeine plasma concentration measurements determined by reversed phase HPLC analysis. Caffeine-sensitive subjects showed significantly greater half-life values when calculated on 24 h after the administration than tolerant subjects (p<0.05). Since the elimination kinetics were similar on the first 6 h after caffeine administration, the increased caffeine clearance observed overnight, when smoking was resumed in the control group, may indicate a short delay for the induction of hepatic cytochrome, reported here for the first time. Electrophysiological responses to caffeine, including vigilance and cortical activity, were assessed by ambulatory electroencephalographic (EEG) recorded during a period of 6 h before and after caffeine consumption. Following caffeine intake, the caffeineintolerant subjects presented an increase in vigilance levels with faster peak alpha, beta frequency and lower delta and theta power when compared to tolerant subjects. Pharmacokinetic parameters and EEG data showed significant differences between sleep-sensitive and control subjects. These variations may be, in part, explained by cigarette smoking and the higher caffeine intake observed in the subjects of the control groups while caffeine sleep-sensitive subjects have a significantly lower caffeine intake, as already reported in previous studies on patients with sleep disturbances.
Tan, E. K.; Lu, Z. Y.; Fook-Chong, S. M.; Tan, E.; Shen, H.; Chua, E.; Yih, Y.; Teo, Y. Y.; Zhao, Y.
Caffeine is an adenosine receptor A1 and A2A receptor antagonist and a putative functional genetic variant of the A2A receptor (2592C > Tins) mediates caffeine-induced anxiety. Here we investigated the potential interaction of this A2A genetic variant with the quantity of coffee and tea intake and their relationship with the risk of PD. A total of 441 subjects consisting of 222 PD and 219 race, gender and age matched controls were included. A multivariate analysis of the variables including the 2592C > Tins A2A genotypes, age of onset, gender, and the quantity of tea and coffee intake, interaction of the A2A genotypes with coffee intake, interaction of A2A genotypes with tea intake demonstrated the quantity of coffee intake to be significantly associated with PD (P < 0.0005, OR = 0.922, 95% CI: 0.881, 0.964). However, there was no significant interaction of the A2A genotypes with the quantity of coffee and tea intake in modulating the risk of PD. The dose dependent protective effect of coffee intake in PD was independent of the 2592C > Tins A2A genotype suggesting that the pharmacogenetic action of caffeine in PD may be mediated differently from other caffeine-induced neurologic syndromes.
Source : Am J Med Genet B Neuropsychiatr Genet, 2006 vol. 141 (6), pp 634 – 636
Aguiar, L. M.; Nobre, H.-V. Jr; Macedo, D. S.; Oliveira, A. A.; Freitas, R. M.; Vasconcelos, S. M.; Cunha, G. M.; Sousa, F. C.; Viana, G. S.
The work shows the effects of caffeine after the intrastriatal injection of 6-OHDA in rats, considered as a model of Parkinson disease (PD). Two weeks after the 6-OHDA lesion, rats exhibit a characteristic rotation behavior as a response to the apomorphine challenge. Our results showed significant increases in the number of apomorphineinduced rotations in 6-OHDA-lesioned rats, as compared to sham-operated animals. A partial recovery was observed in 6-OHDA-lesioned rats, after caffeine (10 and 20 mg/kg, i.p., daily for 14 days) treatment. The stereotaxic injection of 6-OHDA produced loss of striatal neurons, as indicated by the decrease in monoamines levels, in the ipsilateral side (75-85%) when compared to the contralateral side. Significant decreases in noradrenaline levels were seen in the ipsilateral side of 6-OHDA group (62%), and this effect was not significantly reversed in caffeine-treated groups. While significant decreases in dopamine levels were seen in the ipsilateral side of 6-OHDA group (78%), in the caffeine-treated group (10 and 20 mg/kg, i.p.) the decreases were only 53 and 18%, indicating significant recoveries. In conclusion, our data demonstrated beneficial effects of caffeine in this model of PD, suggesting the potential use of A2A antagonists as a novel treatment for this neurodegenerative disease
Source : Pharmacol Biochem Behav , vol. 84 (3), pp 415 – 419
Bech, B. H.; Autrup, H.; Nohr, E. A.; Henriksen, T. B.; Olsen, J.
Cytochrome P4501A2 (CYP1A2) and N-acetyltransferase 2 (NAT2) are key enzymes in the metabolism of caffeine. The polymorphism of these genes facilitates the detection of fast and slow metabolizers, and if caffeine is causally related to stillbirth, we expect slow metabolizers to have a higher risk of stillbirth at any given intake of caffeine. Gluthatione S-transferase alpha1 (GSTA1) may also be active in the metabolism of caffeine as it conjugates glutathione to aromatic amines. Our study, therefore, included analyses of the association between GSTA1 and stillbirth. METHODS: A nested case non-case study among women who participated in the Danish National Birth Cohort: 142 cases of singleton stillbirths and 157 controls of singleton live births. RESULTS: Slow oxidizer status (CYP1A2), slow acetylator status (NAT2), and low activity of GSTA1 were not individually associated with the risk of 12 stillbirth [odds ratio (OR) = 1.06, 95% confidence interval (95% CI) 0.67-1.67, OR = 0.95, 95% CI 0.60-1.51, and OR = 1.42, 95% CI 0.88-2.28, respectively]. We did, however, observe that subjects with a combination of slow CYP1A2, slow NAT2, and low GSTA1 genes had almost a 2-fold risk of stillbirth compared with subjects with other combinations of genotypes. CONCLUSIONS: We found no link between any single genotype and the risk of stillbirth. An association between a combination of genotypes and stillbirth was discovered. Caffeine may be causally related to stillbirth, but larger studies using Mendelian randomization are needed to verify this.-
Vasconcelos, A.-L. S.; Franca, A. S.; Gloria, M.-B. A.; Mendonca, J.-C. F.
Differences in chemical attributes (proximate composition, water activity, sucrose, acidity and pH levels) and amine levels between defective and healthy coffee beans were studied. Before roasting, significant differences (p<0.05) were observed for the ash contents of the coffee samples, with the highest values found for black beans. Moisture content was higher for non-defective beans in comparison to defective beans. Non-defective coffee beans had higher lipids contents than both sour and black beans. There were no significant differences (p>0.05) for protein levels between defective and non-defective beans. After roasting, protein levels remained constant, there was a small decrease in ash contents and a slight increase in oil contents of black and sour beans. Both black and sour beans had higher acidity levels than immature and non-defective beans. Acidity levels decreased after roasting. Water activity levels also decreased with roasting, with slightly higher levels for defective beans in comparison to non-defective ones. Sucrose levels were much higher in non-defective beans, and the lowest values were in black beans, prior to roasting. After roasting, only traces of sucrose were found. Total amine levels were much lower for black beans, in comparison to the other coffee samples. Putrescine was the prevailing amine in all samples. Histamine was only detected in the defective coffee samples. Small amounts of serotonin, cadaverine and tryptamine were found in some of the samples. After roasting to a light degree, only traces of serotonin were detected and no amines were detected after roasting to medium and dark degrees.
Anand, S.; Rati, E. R.
The work was carried out to develop an immunoassay for estimation of Aspergillus ochraceus biomass on solid substrate. METHODS AND RESULTS: An indirect noncompetitive enzyme-linked immunosorbent assay (ELISA) was developed for determination of fungal biomass in food commodities using antibody raised against A. ochraceus mycelial antigen. The sensitivity of the assay was linear in the range of 10-160 microg fungal biomass per millilitre extract of coffee (R(2)=0.989), poultry feed (R(2)=0.987) and chilli (R(2)=0.989). The growth of A. ochraceus in the food commodities like chilli, coffee beans and poultry feed, under the influence of two levels of moisture (20% and 30%) were monitored by the ELISA. The maximum fungal colonization was observed in poultry feed (9.8 and 11.8 mg g(-1)) followed by coffee beans (6.8 and 11.3 mg g(-1)) and chilli (5.1 and 6.3 mg g(-1)) at 20% and 30% moisture after 20 days of incubation. Similarly the fungus produced maximum ochratoxin A in poultry feed (25 and 120 microg g(-1)) followed by coffee beans (8 and 24 microg g(-1)) and chilli (0.2 and 0.45 microg g(-1)) at 20% and 30% moisture after 20 days of incubation. CONCLUSIONS: The method can be used for quantitative estimation of fungal biomass and comparison of fungal colonization in food substrates varying in composition. SIGNIFICANCE AND IMPACT OF THE STUDY: The method can be adapted for studying the fungal colonization in different solid substrates under different culture condition. The method is sensitive to mould colonization of >or=0.02% (w/w) and can be used for early detection of specific fungal infestation in food commodities
Murkovic, M.; Derler, K.
The analysis of carbohydrates and amino acids in green coffee is of the utmost importance since these two classes of compounds act as precursors of the Maillard reaction during which the colour and aroma are formed. During the course of the Maillard reaction potentially harmful substances like acrylamide or 5-hydroxymethylfurfural accrue as well. The carbohydrates were analysed by anion-exchange chromatography with pulsed amperometric detection and the amino acids by reversed phase chromatography after derivatization with 6-amino-quinolyl-N-hydroxysuccinimidyl carbamate and fluorescence detection. Both methods had to be optimized to obtain a sufficient resolution of the analytes for identification and quantification. Sucrose is the dominant carbohydrate in green coffee with a concentration of up to 90 mg/g (mean=73 mg/g) in arabica beans and significantly lower amounts in robusta beans (mean=45 mg/g). Alanine is the amino acid with the highest concentration (mean=1200 mug/g) followed by asparagine (mean=680 mug/g) in robusta and 800 mug/g and 360 mug/g in arabica respectively. In general, the concentration of amino acids is higher in robusta than in Arabica.
Source : J Biochem Biophys Methods , 2006 vol.69 (1-2), pp 25 – 32
Bonnlaender, B.; Cappuccio, R.; Liverani, F. S.; Winterhalter, P.
Enantiomeric distribution of linalool (3,7-dimethylocta-1,6-dien-3-ol) in green and roasted coffee was investigated. Coffee was extracted by simultaneous distillation extraction and stir-bar sorptive extraction, and the extracts were analysed using multidimensional GC and dual column switching GC MS. Sensory properties of the enantiomers were determined in water and by addition experiments to espresso coffee. Results indicated that post-harvest treatment of coffee shifts the enantiomeric ratio from racemic towards an excess of S-(+)-linalool.
Source : Flavour and Fragrance Journal, 2006 vol. 21 (4), pp 637 - 641
Caemmerer, B.; Kroh, L. W.
The total antioxidative activity of coffee beverages was measured by stabilized radical electron paramagnetic resonance (EPR) spectroscopy. Depending on which stabilized radical was used, Fremy\'s salt (potassium nitrosodisulphonate) or 2,2,6,6- tetramethyl-1-piperidin-1-oxyl (TEMPO), values differed significantly. For determination of antioxidative activity of Maillard reaction products in coffee, TEMPO appeared to be the better radical marker. Thus the contribution of both main antioxidative active compounds (polyphenols, melanoidins), whose ratio varies with roasting conditions, could be estimated. During storage experiments of coffee brews, changes in antioxidant action were found to be time dependent. Contents of chlorogenic acids increased significantly at higher storage temp., probably caused by release from polymeric structures. Additional antioxidant capacity of coffee melanoidins seemed to be strongly influenced by atmospheric O2. Highly roasted samples were less vulnerable than medium or lightly roasted coffee. Investigations with model systems showed that among all coffee constituents, carbohydrates were mainly responsible for the formation of O2 scavenging substances.
Source : Eur Food Res Technol, 2006 vol. 223 (4), pp 469 - 474
Cammerer, B.; Kroh, L. W.
This item reports on a study of the antioxidant action of brewed coffee to estimate the contribution of Maillard reaction products to overall antioxidant activity using methods that allowed the antioxidant potential of several different antioxidants to be distinguished. Following EPR-spectroscopy to establish total antioxidant activity of coffee, and spin labelling methods (Tempo, Fremy\'s salt) were used to estimate contribution of several different coffee constituents.
Source : Lebensmittelchemie, 2006 vol. 60 (4), pp 80 (not available on-line)
Spaniolas, S.; May, S. T.; Bennett, M. J.; Tucker, G. A.
Coffee is one of the most important world food commodities, commercial trade consisting almost entirely of Arabica and Robusta varieties. The former is considered to be of superior quality and thus attracts a premium price. Methods to differentiate these coffee species could prove to be beneficial for the detection of either deliberate or accidental adulteration. This study describes a molecular genetics approach to differentiate Arabica and Robusta coffee beans. This employs a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism to monitor a single nucleotide polymorphism within the chloroplastic genome. Samples were analyzed with a lab-on-a chip capillary electrophoresis system. Coffee powder mixtures were analyzed with this technique, displaying a 5% limit of detection. The plastid copy number was found to be relatively constant across a wide range of bean samples, suggesting that this methodology can also be employed for the quantification of any adulteration of Arabica with Robusta beans.
Source : J Agric Food Chem, 2006 vol. 54 (20), pp 7466 – 7470
Girard, P.; Stober, P.; Blanc, M.; Prodolliet, J.
Free and total carbohydrate profiles, together with total glucose and total xylose, have been identified as good indicators for authenticity assessment in instant coffee. Pragmatic specification limits have been set by coffee manufacturers\' associations for total glucose and total xylose. This study revisited these limits, determining levels in a large number of commercial coffee samples and applying a statistical model, known as mixture of distributions, to the results. Specification limits for adulteration of coffee were calculated using the maximum content value together with the measurement uncertainty value. Thus, specification limits for total glucose and total xylose for use in authenticity assessment of commercial instant coffee are proposed.
Clifford, M. N.; Marks, S.; Knight, S.; Kuhnert, N.
Chlorogenic acids, such as caffeic, ferulic and p-coumaric acids, are widely distributed in plants, but coffee beans are a rich source. There are many chlorogenic acids present in coffee beans that have not yet been reported or classified. This study used liquid chromatography mass spectrometry (LC-MS) to detect and characterise a number of minor chlorogenic acids in green coffee beans. A total of 15 p-coumaric acidcontaining chlorogenic acids found are listed, for whom structures have been assigned on the basis of LC-MS fragmentation patterns.
Lang, R.; Mueller, C.; Hofmann, T.
A straightforward stable isotope dilution analysis (SIDA) for determination of the di and trihydroxybenzenes, and potential carcinogens, catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol and 4-ethylcatechol in foods by means of HPLCMS/MS was developed. With or without sample preparation involving phenylboronyl solid phase extraction, the method allowed the quantification of the target compounds in complex matrices such as coffee beverages with quantification limits of 9 nmol/l for 4-ethylcatechol, 24 nmol/l for catechol, 3-methyl-, and 4-methylcatechol and 31 nmol/l for pyrogallol. Recovery rates for the analytes ranged from 97 to 103%. Application of the developed SIDA to various commercial food products showed that quantitative analysis of the target compounds is possible within 30 min and provided data on the amounts of di- and trihydroxybenzenes in coffee beverages, coffee powder, coffee surrogate, beer, malt, roasted cocoa powder, bread crust, potato crisps, fruits, cigarette smoke and
human urine. Model precursor studies revealed the carbohydrate/amino acid systems as well as the plant polyphenols catechin and epicatechin as precursors of catechol and 5-O-caffeoylquinic acid, caffeic acid as a precursor of catechol and 4-ethylcatechol, and gallocatechin, epigallocatechin and gallic acid as precursors of pyrogallol.
Source : J Agric Food Chem, 2006 vol. 54 (16), pp 5755 - 5762
Kasai, N.; Konishi, A.; Iwai, K.; Maeda, G.
Screening of effective food-processing cellulase for digestion of cell walls of coffee beans was performed, and the cellulase from Trichoderma sp. was selected. Cell walls of green and roasted coffee beans were digested by sequential procedures of alkali boiling (0.1M Na2CO3 buffer, pH 10 and 0.1M NaOH), cellulase digestion, autoclaving with 0.1M NaOH and cellulase redigestion. Total digestion yields were >95 and >96% for the 1st and 2nd digestion stages, respectively. Cell walls became thin, and the final residues of the cell walls were easily broken into small pieces. Neutral sugar analysis of the digestion or the extract and the residues and microscopy observations with staining with toluidine blue O, Yariv reagent, and calcofluor for the residue in each step were investigated. 4 structures, the galactomannan-cellulose (centre part), the membrane of the arabinogalactan protein, the cellulose-rich galactomannan layer, and the arabinogalactan protein-rich layers (outer part), were found in cell walls.
Bekedam, E. K.; Schols, H. A.; van Boekel, M. A.; Smit, G
The composition of high molecular weight (HMw) coffee melanoidin populations, obtained after ethanol precipitation, was studied. The specific extinction coefficient (K(mix)) at 280, 325, 405 nm, sugar composition, phenolic group content, nitrogen content, amino acid composition, and non-protein nitrogen (NPN) content were investigated. Results show that most HMw coffee melanoidins are soluble at high ethanol concentrations. The amino acid composition of the HMw fractions was similar, while 17% (w/w) of the nitrogen was NPN, probably originating from degraded amino acids/proteins and now part of melanoidins. A strong correlation between the melanoidin content, the NPN, and protein content was found. It was concluded that proteins are incorporated into the melanoidins and that the degree of chemical modification, for example, by phenolic groups, determines the solubility of melanoidins in ethanol. Although the existence of covalent interaction between melanoidins and polysaccharides were not proven in this study, the findings suggest that especially arabinogalactan is likely involved in melanoidin formation. Finally, phenolic groups were present in the HMw fraction of coffee, and a correlation was found with the melanoidins concentration.
Source : J Agric Food Chem, 2006 vol. 54 (20), pp 7658 – 7666
Houessou, J. K.; Delteil, C.; Camel, V.
Sample treatment procedures were tested for the determination of polycyclic aromatic hydrocarbons (PAHs) in ground coffee. Pressurized liquid extraction (PLE), under different conditions, was combined with several cleanup methods, namely in situ purification, C18-silica solid-phase extraction (SPE), silica SPE, acid digestion, and alkaline saponification. Soxhlet extraction and direct alkaline saponification were also tested. Best results were obtained using PLE with hexane/acetone 50:50 (v/v) under 150 degrees C. Alkaline saponification followed by cyclohexane extraction and silica SPE was required to eliminate interferent compounds. Finally, 11 PAHs could be quantified in ground coffee with limits of detection in the range of 0.11-0.18 microg kg(-1). Application to ground Arabica coffee lots from Colombia revealed the presence of several PAHs, giving an overall toxicity equivalence in the range of 0.16-0.87 microg
kg(-1). PAH identification was performed using both high-performance liquid chromatography-diode array detection and gas chromatography coupled to mass spectrometry
Source : J Agric Food Chem, 2006 vol. 54 (20), pp 7413 – 7421
Anese, M.; Manzocco, L.; Nicoli, M. C.
The secondary shelf life of ground roasted coffee was investigated. For this purpose, fresh dark-roasted ground coffee samples were equilibrated at increasing aw values up to 0.44 and stored at 30°C for up to 1 month. To simulate home storage conditions, the headspace atmosphere was periodically perturbed by opening for a short time and then closing the pack. The changes of some chemical and physicochemical indexes of coffee staling were studied, and sensory analysis was carried out to determine the end point of coffee acceptability. The results show that the volatile compounds content in the headspace is a representative index of the quality depletion of roasted ground coffee during home usage. Both sensory and instrumental results were used to develop a mathematical model allowing simple, rapid calculation of the secondary shelf life of coffee on the basis of its aw value at a given temperature.
Fujioka, K.; Shibamoto, T.
Antioxidative activities of a commercial brewed coffee were investigated by measuring malonaldehyde (MA) formation from oxidized cod liver oil using a GC method (MA-GC assay) and a thiobarbituric acid method (TBA assay). The highest antioxidative activity obtained using the MA-GC assay was from regular whole brewed coffee (97.8%) at a level of 20%, and the highest antioxidative activity obtained using the TBA assay was from decaffeinated whole brewed coffee (96.6%) at a level of 5%. Among 31 chemicals identified in a dichloromethane extract, guaiacol, ethylguaiacol and vinylguaiacol exhibited antioxidative activities, which were comparable to that of alpha-tocopherol. Among 9 chlorogenic acids identified (3 caffeoylquinic acids, 3 feruloylquinic acids and 3 dicaffeoylquinic acids), 5-caffeoylquinic acid contained the greatest amount both in regular (883.5 mug/ml) and in decaffeinated (1032.6 mug/ml) coffees; it exhibited 24.5% activity using the MA-GC assay and 45.3% activity using the TBA assay at a level of 10 mug/ml. Caffeic and ferulic acids showed moderate antioxidative activities in both assays.
Lojkova, L.; Klejdus, B.; Moravcova, J.; Kuban, V.
Two polar analytes, 4(5)-methylimidazole (4-MeI) and 2-acetyl-4(5)-(1,2,3,4)-tetrahydroxybutyl-imidazole (THI), were extracted with supercritical carbon dioxide (CO2) modified with aqueous methanol. The method was applied to a roasted coffee powder with good recovery rates. Method efficiency was compared with that of solidphase extraction using SCX Disc cartridges and validated for spiked solid matrix. The analytes were determined using isocratic liquid chromatography-mass spectrometry (LC/MS) on an Atlantis HILIC Silica column (150 x 2.1 mm, 3 microm) with 80% methanol and 20% 0.01 mol l-1 ammonium formate as the mobile phase. The limit of quantification was around 1.5 pg for 4-MeI and 2.0 pg for THI. The linearity of thecalibration curves was satisfactory as indicated by correlation coefficients of >0.999. The coefficient of variation for the intra-day and inter-day precisions was <4% (n = 6). Accuracy was in the range 98-101%; recovery rates were >/= 98 and >/= 99% for THI and 4-MeI, respectively. Several samples of Arabica coffee from various locations and commercially available \'off-the-shelf\' coffee products (Arabica/Robusta mixtures) were analysed to test the method.
Petit, C.; Sieffermann, J. M.
A consumer study was conducted on iced-coffee in order to investigate the effect of the physical testing environment on liking and consumption of this refreshing drink by French consumers. A water-based product and a milk-based product were tested, and four testing procedures were compared: a classic laboratory test in a controlled environment; two situational consumer tests performed outside the laboratory in natural drinking situations; and a situational laboratory consumer test in an environment which was modified to evoke such a natural consumption situation. Results show that liking and consumption are both dependent on the testing situation, involving specific location and surroundings, and a specific consumers\' population. The two laboratory tests gave very similar results, which differ from those obtained outside the laboratory. This work raises methodological questions and clearly emphasizes the need for future studies comparing laboratory consumer tests and tests in natural consumption situations.
Gomes-Junior, R. A.; Moldes, C. A.; Delite, F. S.; Pompeu, G. B.; Gratao, P. L.; Mazzafera, P.; Lea, P. J.; Azevedo, R. A.
The antioxidant responses of coffee (Coffea arabica L.) cell suspension cultures to cadmium (Cd) were investigated. Cd accumulated very rapidly in the cells and this accumulation was directly correlated with an increase in applied CdCl(2) concentration in the external medium. At 0.05mM CdCl(2), growth was stimulated, but at 0.5mM CdCl(2), the growth rate was reduced. An alteration in activated oxygen metabolism was detected by visual analysis as well as by an increase in lipid peroxidation at the higher CdCl(2) concentration. Catalase (CAT; EC 1.11.1.6), glutathione reductase (GR; EC 1.6.4.2) and superoxide dismutase (SOD; EC 1.15.1.1) activity increased, particularly at the higher concentration of CdCl(2). Ascorbate peroxidase (APX; EC 1.11.1.11) activity was increased at the lower CdCl(2) concentration used, but could not be detected in cells growing in the higher CdCl(2) concentration after 24h of growth, whilst guaiacol peroxidase (GOPX; EC 1.11.1.7) did not show a clear response to Cd treatment. An analysis by non-denaturing PAGE followed by staining for enzyme activity, revealed one CAT isoenzyme, nine SOD isoenzymes and four GR isoenzymes. The SOD isoenzymes were differently affected by CdCl(2) treatment and one GR isoenzyme was shown to specifically respond to CdCl(2). The results suggest that the higher concentrations of CdCl(2) may lead to oxidative stress. The main response appears to be via the induction of SOD and CAT activities for the removal of reactive oxygen species (ROS), and by the induction of GR to ensure the availability of reduced glutathione for the synthesis of Cd-binding peptides, which may also be related to the inhibition of APX activity probably due to glutathione and ascorbate depletion.
Geromel, C.; Ferreira, L. P.; Guerreiro, S. M.; Cavalari, A. A.; Pot, D.; Pereira, L. F.; Leroy, T.; Vieira, L. G.; Mazzafera, P.; Marraccini, P.
Sucrose metabolism and the role of sucrose synthase were investigated in the fruit tissues (pericarp, perisperm, and endosperm) of Coffea arabica during development. Acid invertase, sucrose phosphate synthase, and sucrose synthase activities were monitored and compared with the levels of sucrose and reducing sugars. Among these enzymes, sucrose synthase showed the highest activities during the last stage of endosperm and pericarp development and this activity paralleled closely the accumulation of sucrose in these tissues at this stage. Carbon partitioning in fruits was studied by pulse-chase experiments with (14)C-sugars and revealed high rates of sucrose turnover in perisperm and endosperm tissues. Additional feeding experiments with (14)CO(2) showed that leaf photosynthesis contributed more to seed development than the pericarp in terms of photosynthate supply to the endosperm. Sugar analysis, feeding experiments, and histological studies indicated that the perisperm plays an important role in this downloading process. It was observed that the perisperm presents a transient accumulation of starch which is degraded as the seed develops. Two fulllength cDNAs (CaSUS1 and CaSUS2) and the complete gene sequence of the latter were also isolated. They encode sucrose synthase isoforms that are phylogenetically distinct, indicating their involvement in different physiological functions during cherry development. Contrasting expression patterns were observed for CaSUS1 and CaSUS2 in perisperm, endosperm, and pericarp tissues: CaSUS1 mRNAs accumulated mainly during the early development of perisperm and endosperm, as well as during pericarp growing phases, whereas those of CaSUS2 paralleled sucrose synthase activity in the last weeks of pericarp and endosperm development. Taken together, these results indicate that sucrose synthase plays an important role in sugar metabolism during sucrose accumulation in the coffee fruit
Koshiro, Y.; Xin, Qiang Zheng; Ming, Li Wang; Nagai, C.; Ashihara, H.
Changes in the contents of trigonelline and caffeine in 2 cultivars of Coffea Arabica (Mokka, Catimor) and 1 cultivar of C. canephora during 5 growth stages including \'ripening\' and \'fully-ripened\', were determined. Amounts of 3 transcripts and the pattern of gene expression for caffeine biosynthesis for each growth stage are described. Results suggest that the pericarp of coffee fruits is the active site of trigonelline synthesis, and that although the final concn. of trigonelline and caffeine are cultivar dependent, patterns of synthesis are similar
Leroy, T.; Alpizar, E.; Dufour, M.; Etienne, H.
Coffee (Coffea sp.) is a perennial plant widely cultivated in many tropical countries. It is a cash crop for millions of small farmers in these areas. As compared with other tree species, coffee has long breeding cycles that make conventional breeding programs time consuming. For that matter, genetic transformation can be an effective technique to introduce a desired trait in an already "elite" variety, or to study a gene function and expression. In this chapter, we describe two Agrobacterium-mediated transformation techniques; the first with A. tumefaciens to introduce an insect resistance gene and the second with A. rhizogenes to study candidate gene expression for nematode resistance in transformed roots.
Poncet, V.; Rondeau, M.; Tranchant, C.; Cayrel, A.; Hamon, S.; de Kochko, A.; Hamon, P.
Expressed sequence tags (ESTs) from Coffea canephora leaves and fruits were used to search for types and frequencies of simple sequence repeats (EST-SSRs) with a motif length of 1-6 bp. From a non-redundant (NR) EST set of 5,534 potential unigenes, 6.8% SSR-containing sequences were identified, with an average density of one SSR every 7.73 kb of EST sequences. Trinucleotide repeats were found to be the most abundant (34.34%), followed by di- (25.75%) and hexa-nucleotide (22.04%) motifs. The development of unique genic SSR markers was optimized by a computational approach which allowed us to eliminate redundancy in the original EST set and also to test the specificity of each pair of designed primers. Twenty-five EST-SSRs were developed and used to evaluate cross-species transferability in the Coffea genus. The orthology was supported by the amplicon sequence similarity and the amplification patterns. The >94% identity of flanking sequences revealed high sequence conservation across the Coffea genus. A high level of polymorphic loci was obtained regardless of the species considered (from 75% for C. liberica to 86% for C. canephora). Moreover, the polymorphism revealed by EST-SSR was similar to that exposed by genomic SSR. It is concluded that Coffea ESTs are a valuable resource for microsatellite mining. EST-SSR markers developed from C. canephora sequences can be easily transferred to other Coffea species for which very little molecular information is available. They constitute a set of conserved orthologous markers, which would be ideal for assessing genetic diversity in coffee trees as well as for cross-referencing transcribed sequences in comparative genomics studies.
Source : Mol Genet.Genomics, 2006 vol. 276 (5), pp 436 – 449