AGRONOMY

The influence of shade trees on coffee quality in small holder coffee agroforestry systems in Southern Colombia

Bosselmann, A. S.; Dons, K.; Oberthur, T.; Smith-Olsen, C.; Raebild, A.; Usma, H.

Production of coffee, especially by small holders, is often associated with various forms of shade management. To analyse the effects of shade on physical coffee quality and on sensorial cup quality of Coffea arabica L. cv. Caturra KMC, a study was carried out with 94 plots on 16 farms in two municipalities, Timaná and Oporapa, located at elevations from 1272 to 1730 masl. in Huila, Colombia. The study was designed with emphasis on shade cover variation within each of the two study areas, while minimizing the variability of environment, agronomic management other than shade, and post-harvest processing. 46 samples of shade coffee and 46 samples of sun coffee were evaluated for physical and sensorial attributes using three professional coffee cuppers (assessors). A principal component analysis including all quality and environmental variables showed that sensory attributes were influenced negatively by shade, and that physical attributes were influenced positively by altitude. A mixed linear model, with coffee cupper and farm as random variables, revealed different shade effects on coffee quality in the two areas. In Oporapa, situated at high altitudes, shade had a negative effect on fragrance, acidity, body, sweetness and preference of the beverage, while no effect was found on the physical quality. In Timaná, situated at lower altitudes, shade did not have a significant effect on sensorial attributes, but significantly reduced the number of small beans. At high altitudes with low temperatures and no nutrient or water deficits, shade trees may thus have a partly adverse effect on C. arabica cv. Caturra resulting in reduced sensory quality. The occurrence of berry borer (Hypothenemus hampei) was lower at high altitudes and higher under shade. Future studies on shade and coffee quality should focus on the interaction between physical and chemical characteristics of beans.

Source : Agriculture Ecosystems & Environment 2009 vol. 129 (1-3), pp 253 - 260

MICROBIOLOGY

Incidence and distribution of filamentous fungi during fermentation, drying and storage of coffee (Coffea arabica L.) beans

Ferreira-Silva, C.; Roberto-Batista, L.; Freitas-Schwan, R.

The objective of this work was to isolate and characterize filamentous fungi present in different stages of harvest, fermentation, drying and storage of coffee beans processed by natural methods. The cherries were hand-picked and then placed on a cement drying platform where they were dried to 11% humidity. Microbial counts were found in all samples during fermentation and drying of the coffee beans. Counts of fungi in the coffee cherries collected from the tree (time 0) were around 1.5 x 103 cfu/g. This number increased slowly during the fermentation and drying reaching values of 2 x 105 cfu/g within 22 days of processing. 263 isolates of filamentous fungi were identified. The distribution of species during fermentation and drying was very varied while there was a predominance of Aspergillus spp. during the storage period. The genera found were Pestalotia (n = 4), Paecelomyces (n = 4), Cladosporium (n = 26), Fusarium (n = 34), Penicillium (n = 81) and Aspergillus (n = 112) and comprised 38 different species.

Source : Brazil J Microbiol 2008 vol.39 (3), pp 521 - 526

CHEMISTRY / SENSORICS

Discrimination between arabica and robusta coffee species on the basis of their tocopherol profiles

Alves, R. C.; Casal, S.; Alves, M. R.; Oliveira, M. B.

extraction method was used, and the quantification performed by normal-phase HPLC/diode-array/fluorescence detection. Regarding green arabicas, the mean contents were 2.7 ± 0.4 mg/100 g, for alpha-tocopherol, and 8.0 ± 0.9 mg/100 g, for beta-tocopherol. For green robustas, mean values of 1.7 ± 0.3 and 2.1 ± 0.3 mg/100 g were found for alpha- and beta-tocopherol, respectively. Generally, more than 90% of tocopherols remained after the roasting procedure, except for beta-tocopherol in robustas, whose mean degradation was approximately 25% when expressed as dry weight. No gamma-tocopherol was detected in any sample. The results show that tocopherol profile could be useful in the discrimination of arabica and robusta coffees (either green or roasted).

Source : Food Chemistry 2009 vol.114 (1), pp 295 - 299

Beta-cyclodextrin complexes with chlorogenic and caffeic acids from coffee brew: spectroscopic, thermodynamic and molecular modelling study

Gornas, P.; Neunert, G.; Baczynski, K.; Polewski, K.

Coffee brew is rich in chlorogenic and cinnamic acids, potent antioxidants. Its interaction with beta-cyclodextrin leads to formation of inclusion complexes which affect the physicochemical properties of the guest molecule. We investigated spectral changes in coffee-originated phenols, chlorogenic (CHA) and caffeic (CA) acids, due to complexation with beta-cyclodextrin (betaCD) in aqueous solutions and studied thermodynamic properties of the complexes formed. The spectroscopic data (absorption and fluorescence) were used for deducing the position of both phenols inside the beta-cyclodextrin cavity, as well as to calculate the binding constants of the complexes. The obtained data indicate the formation of a 1:1 complex between betaCD and CHA or CA. The temperature-dependence of the latter allowed the calculation of thermodynamic parameters (DELTAH, DELTAS and DELTAG) of the complexation. The negative values of all the thermodynamic parameters indicated that the formation of these inclusion complexes was an enthalpy-driven process in which a crucial role is played by weak van der Waals forces and hydrogen bonds. Molecular modelling confirmed experimental observations that, in aqueous phase, betaCD-CHA and -CA complexes are stable and energetically favourable, and additionally provided information regarding conformation and interaction between atoms forming the complexes. The experimental data were used to characterise the molecular mechanism of the complexation.

Source : Food Chemistry 2009 vol. 114 (1), pp 190 - 196

Effect of roasting degree, equivalent thermal effect and coffee type on the radical scavenging activity of coffee brews and their phenolic fraction

Sacchetti, G.; Di Mattia, C.; Pittia, P.; Mastrocola, D.

Coffee is a major source of antioxidants, but these can be affected by processing conditions. This study investigated the relationships between the free-radical-scavenging activity (FRSA) of coffee brews obtained from different types of coffee, and the roasting degree. It was found that brews extracted from medium-roasted coffee had higher FRSA than those from green coffee. This was attributed to roasting increasing the levels of Maillard reaction products (MRPs) with antioxidant activity. Further roasting to produce dark coffee gave brews with lower FRSA as a result of polyphenol degradation, the contribution of MRPs to FRSA being much lower than that of the polyphenols. Roasting processes with the same equivalent thermal effect values gave coffee with similar FRSA, independent of average temperature (170-190 C) and coffee type. Antioxidant activity was found to be more dependent on roasting severity than coffee type.

Source : J Food Eng 2009 vol.90 (1), pp 74-80

Comparing capillary electrophoresis-mass spectrometry fingerprints of urine samples obtained after intake of coffee, tea, or water

Allard, E.; Backstrom, D.; Danielsson, R.; Sjoberg, P.-J. R.; Bergquist, J.

Metabolomic fingerprinting is a growing strategy for characterizing complex biological samples without detailed prior knowledge about the metabolic system. A 2-way analysis system with liquid separation and MS detection provides detail-rich data suitable for such fingerprints. As a model study, human urine samples, obtained after intake of coffee, tea or water, were analysed with capillary electrophoresis electrospray ionization time-of-flight MS (CE-ESI-TOF-MS). In-house-developed software (in Matlab) was utilized to manage and explore the large amount of data acquired (230 CE-MS runs, each with 50-100 million nonzero data points). After baseline and noise reduction, followed by suitable binning in time and m/z, the data sets comprised 9 and 14 million data points in negative and positive ESI mode, respectively. Finally, a signal threshold was applied, further reducing the number to approx. 100 000 data points per data set. A set of interactive exploratory tools, utilizing principal component analysis (PCA) and analysis of variance (ANOVA) results based on a general linear model, facilitated visual interpretation with score plots (for group assessment) and differential fingerprints (for 'hot spot' detection). In the model study highly significant differences due to beverage intake were obtained among the 10 first principal components (P < 10-6 for 2 of the components in both ESI modes). Especially, the contrasts between 'coffee' and 'tea or water' indicated several 'hot spots' with highly elevated intensities (e.g., for uncharged masses 93, 94, 109, 119, 123, 132, 148, 169, 178, 187, 190 and 193) suitable for further analysis, for example, with tandem MS.

Source : Anal Chem 2008 vol.80 (23), pp 8946 - 8955

Risks and pitfalls of sensory data analysis for shelf life prediction: data simulation applied to the case of coffee

Guerra, S.; Lagazio, C.; Manzocco, L.; Barnaba, M.; Cappuccio, R.

Sensory evaluation is used to predict the shelf life of products, and the subjectivity in the choice of some parameters for data collection and analysis can affect the final result. Typical problems to be avoided when planning the test and analysing data are considered in this study. Commonly used techniques in sensory data processing for predicting shelf life are compared, and the effects of the choice of acceptability limits and of data variability are discussed. Choices that can affect the determination of sensory shelf life of coffee are considered.

Source : LWT-Food-Science-and Technology 2008  vol.41 (10), pp 2070-2078

COFFEE & HEALTH

Attenuation of oxidative neuronal cell death by coffee phenolic phytochemicals

Eun, Sun Cho; Young, Jin Jang; Mun, Kyung Hwang; Nam, Joo Kang; Ki, Won Lee; Hyong, Joo Lee

Neurodegenerative disorders such as Alzheimer's disease (AD) are strongly associated with oxidative stress, which is induced by reactive oxygen species (ROS) including hydrogen peroxide (H2O2). Recent studies suggest that moderate coffee consumption may reduce the risk of neurodegenerative diseases such as AD, but the molecular mechanisms underlying this effect remain to be clarified. In this study, we investigated the protective effects of chlorogenic acid (5-O-caffeoylquinic acid; CGA), a major phenolic phytochemical found in instant decaffeinated coffee (IDC), and IDC against oxidative PC12 neuronal cell death. IDC (1 and 5 μg/ml) or CGA (1 and 5 μM) attenuated H2O2-induced PC12 cell death. H2O2-induced nuclear condensation and DNA fragmentation were strongly inhibited by pretreatment with IDC or CGA. Pretreatment with IDC or CGA also inhibited the H2O2-induced cleavage of poly(ADP-ribose) polymerase (PARP), and downregulation of Bcl-XL and caspase-3. The accumulation of intracellular ROS in H2O2-treated PC12 cells was dose-dependently diminished by IDC or CGA. The activation of c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) by H2O2 in PC12 cells was also inhibited by IDC or CGA. Collectively, these results indicate that IDC and CGA protect PC12 cells from H2O2-induced apoptosis by blocking the accumulation of intracellular ROS and the activation of MAPKs.

Source : Mutat Res Fund & Mol Mech Mutage 2009 vol.661 (1-2),  pp 18 - 24

The effects of caffeine on L-arginine metabolism in the brain of rats

Ofluoglu, E.; Pasaoglu, H.; Pasaoglu, A.

In our study, the short-term effects of caffeine on L-arginine metabolism in the brains of rats were investigated. Caffeine was given orally at two different doses: 30 mg/kg and 100 mg/kg (a high non-toxic dose). Brain tissue arginase activity in rats from the caffeine-treated groups decreased significantly compared with the control group. Malondialdehyde (MDA) levels in the brain tissue and serum of animals in the caffeine groups also decreased significantly. Brain tissue and serum nitric oxide (NO) levels increased significantly after caffeine administration. Tumor necrosis factor-alpha (TNF-alpha) levels were also investigated in rat serum, but there was no statistically significant difference between the TNF-alpha levels of the caffeine-treated rats groups and the control rats. Our study indicates that brain arginase activity decreases after caffeine administration at doses of 30 mg/kg and 100 mg/kg. As a result, we can say that arginine induces production of NO in the organism.

Source : Neurochem Res 2009 vol.34 (3), pp 395 - 399

Alcohol, coffee, and bladder cancer risk: a review of epidemiological

Pelucchi, C.; Vecchia, C. la

Epidemiological studies were reviewed that evaluated the association between consumption of coffee and alcohol, and urinary bladder cancer. The Medline database was searched for observational studies of bladder neoplasms that included information on coffee or alcohol drinking, and looked for papers quoted as references in reviews of risk factors for bladder cancer and in studies that had been selected for inclusion. Results from epidemiological studies allowed excluding a strong association between coffee and bladder cancer. Several studies reported a moderate increase in risk in coffee drinkers as compared with nondrinkers, but no trend with dose has been established. Epidemiological data on alcohol drinking and bladder cancer were suggestive of no association, although findings were not always consistent. For both habits, an explanation of the moderate increase in risk observed in some investigations might be attributed to residual confounding by smoking, or to an association between alcohol, coffee, and yet unidentified risk factors for bladder cancer.

Source : Eur J Cancer Prev 2009 vol.18 (1), pp 62 - 68

Dissociations between motor timing, motor coordination, and time perception after the administration of alcohol or caffeine

Terry, P.; Doumas, M.; Desai, R. I.; Wing, A. M.

The impacts of psychoactive drugs on timing have usefully informed theories of timing and its substrates. OBJECTIVES: The objectives of the study are to test the effects of alcohol and caffeine on the explicit timing involved in tapping with the implicit timing observed in the coordinated picking up of an object, and with the temporal discrimination. MATERIALS AND METHODS: Participants in the "alcohol" experiment (N = 16) received placebo, "low" (0.12 g/kg or 0.14 g/kg for women/men, respectively) or "high" (0.37 g/kg or 0.42 g/kg, respectively) doses of alcohol, and those in the "caffeine" experiment (N = 16) received placebo, 200 or 400 mg caffeine. Time production variability was measured by repetitive tapping of specified intervals, and sources of variance attributable to central timer processes and peripheral motor implementation were dissociated. The explicit timing in tapping was compared with the implicit timing in the coordinated picking up of an object. Time perception was measured as discrimination thresholds for intervals of similar duration. Drug effects on reaction time were also measured. RESULTS: For tapping, alcohol significantly increased timer variability, but not motor variability; it did not affect coordination timing in the grip-lift task. Conversely, for time perception, the low dose of alcohol improved temporal discrimination. Caffeine produced no effects on any of the timing tasks, despite significantly reducing reaction times.

CONCLUSIONS: The effects of alcohol argue against a common clock process underlying time interval perception and production in the range below 1 s. In contrast to reaction time measures, time perception and time production appear relatively insensitive to caffeine.

Source : Psychopharmacology (Berl)  2009 vol.202 (4), pp 719 - 729

Caffeine does not modulate inhibitory control

Tieges, Z.; Snel, J.; Kok, A.; Richard-Ridderinkhof, K.

The effects of a 3mg/kg body weight (BW) dose of caffeine were assessed on behavioral indices of response inhibition. To meet these aims, we selected a modified AX version of the Continuous Performance Test (CPT), the stop task, and the flanker task. In three double-blind, placebo-controlled, within-subjects experiments, these tasks were administered to healthy participants. While the results for the AX-CPT were indicative of improved response inhibition after caffeine, they might also reflect caffeine-induced changes in mechanisms other than response inhibition (e.g., attentional processes). The results for the stop task and flanker task were more straightforward. That is, the effects of caffeine on overall flanker performance and selective response suppression as revealed by distribution-analytical techniques were negligible. In the stop task a global effect of caffeine on processing speed was seen, rather than specific effects on response inhibition. Taken together, these experiments showed that both active and reactive inhibition were not significantly modulated by caffeine. The present results are linked to neural circuits that underlie inhibitory control and the role of caffeine-induced strategic changes.

Source : Brain Cogn 2009 vol.69 (2), pp 316 - 327

Long-term caffeine consumption reverses tumor-induced suppression of the innate immune response in adult mice

Anup, Mandal; Poddar, M. K.

Caffeine, the active principle alkaloid of coffee and tea, inhibits tumour-induced suppression of the specific immune response in adult mice. Effects of long-term consumption of caffeine in the development of Ehrlich ascites carcinoma (EAC) cells in adult Swiss female mice, in relation to the innate immune response and tumour growth, were determined. Although consumption of caffeine alone for >12 consecutive days did not affect innate immune response parameters, continuation of its treatment following intraperitoneal EAC cell inoculation reduced in vivo tumour growth and reduced/restored the EAC cell-induced suppression of the innate immune response. Results suggest that caffeine may inhibit in vivo tumour growth through reduction of the cancer cell-induced suppression of the innate immune response.

Source : Planta Medica 2008 vol.74 (15), pp 1779 - 1784

Tea or coffee? A case study on evidence for dietary advice

Binns, C. W.; Lee, A. H.; Fraser, M. L.

The level of evidence required to justify giving dietary advice to the public was investigated, with particular reference to tea and coffee consumption. There are important practical differences between the development of public health nutrition guidelines and guidelines for clinical practice. While the gold standard for evidence for clinical practice guidelines is a meta-analysis of a number of randomised controlled trials, this is often unrealistic and sometimes unethical for the evaluation of public health nutrition interventions. Hence, epidemiological studies make up the bulk of evidence for nutrition guidelines. Tea and coffee are an interesting case study in relation to this issue. They are 2 of the most commonly consumed beverages worldwide, yet there is little dietary advice on their use. The evidence for a relationship between coffee or tea consumption and several diseases is discussed. The available studies, predominantly epidemiological, together with animal and in vitro studies, indicate that coffee and tea are both safe beverages. However, tea is the healthier option because it has a possible role in the prevention of several cancers and CVD. While the evidence for such relationships is not strong, the public will continue to drink both tea and coffee, and will continue to ask nutritionists to make recommendations. It is therefore argued that advice should be given on the best available data, as waiting for complete data to become available could have severe consequences for public health.

Source : Public Health Nutrition 2008 vol.11 (11), pp 1132 - 1141

Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study

Care-Study-Group

It has been suggested that overconsumption of caffeine during pregnancy might contribute towards lowered birth weight. This study aimed to investigate the effects of maternal caffeine intake on foetal growth. The study involved 2,635 pregnant women, whose caffeine intake was assessed from 4 weeks prior to pregnancy and during the course of the pregnancy. It was found that caffeine intake throughout pregnancy of more that 300 mg/day was associated with an increased risk of foetal growth restriction compared with a caffeine intake throughout pregnancy of less than 100 mg/day. It is recommended that advice be given to pregnant women in order to help them limit caffeine intake during pregnancy.

Source : Brit Med J  2008 vol.8, 337 (7678), a2332  (full text)

Habitual coffee consumption and blood pressure: an epidemiological perspective

Geleijnse, J. M.

This paper summarizes the current epidemiological evidence on coffee consumption in relation to blood pressure (BP) and risk of hypertension. Data from cross-sectional studies suggest an inverse linear or U-shaped association of habitual coffee use with BP in different populations. Prospective studies suggest a protective effect of high coffee intake (4 or more cups per day) against hypertension, mainly in women. Furthermore, the risk of hypertension may be lower in coffee abstainers. Randomized controlled trials, which are mostly of short duration (1-12 weeks), have shown that coffee intake around 5 cups per day causes a small elevation in BP (approximately 2/1 mmHg) when compared to abstinence or use of decaffeinated coffee. With regard to underlying biological mechanisms, most research has been devoted to BP-raising effects of caffeine. However, there are many other substances in coffee, such as polyphenols, soluble fibre and potassium, which could exert a beneficial effect in the cardiovascular system. Although the precise nature of the relation between coffee and BP is still unclear, most evidence suggests that regular intake of caffeinated coffee does not increase the risk of hypertension.

Source : Vasc Health Risk Manag. 2008 vol.4 (5), pp 963 - 970  (full text)