Avelino, J.; Barboza, B.; Araya, J. C.; Fonseca, C.; Davrieux, F.; Guyot, B.; Cilas, C.
Effects of cultivation conditions on the quality of Costa Rican coffees were evaluated. In particular, samples from coffee plantations at Orosi (1020-1250 m above sea level) and Santa Maria de Dota (1550-1780 m above sea level) in Costa Rica were compared for yield and quality attributes of the harvested beans. East-facing slopes in both locations generally gave superior quality beans, particularly with regard to improved acidity, although yield was negatively linked to acidity in beans grown at Santa Maria de Dota. Altitude was positively related to coffee quality at both geographical locations. However, levels of individual constituents (caffeine, trigonelline, fat, sucrose and chlorogenic acid) did not show a strong correlation with sensory properties of the coffees. Coffees from Orosi and Santa Maria de Dota were characterized by floral and chocolate-like characteristics, respectively.
Cilas, C.; Bouharmont, P.
Genetic parameters relating to robusta coffee bean traits were studied using 2 mating designs for Coffea canephora cultivated in Cameroon (partial diallel with 18 parents and triangluar diallel with 6 parents). Bean traits studied included wt., length, width and thickness of normal coffee beans and percentage of peaberries. Correlations between bean traits and yield data (obtained over 14 yr) were also assessed. General combining ability was the main factor of variation for the traits studied revealing mainly additive transmission. There was no significant genetic correlation between coffee bean traits and yield, with the exception of peaberry percentage (a trait linked to fertility). Results suggest that a selection index could be established easily in order to combine increased yield with improved coffee bean traits.
Source : Mycologia vol. 97 (1), pp 191 - 201
Jaramillo, J.; Bustillo, A. E.; Montoya, E. C.; Borgemeister, C.
The potential of the eulophid parasitoid Phymastichus coffea LaSalle to control coffee berry borer Hypothenemus hampei (Ferrari) populations under field conditions in Colombia was evaluated. Parasitoid adults were released one, five and nine days after artificial infestations of 90-, 150- and 210-day-old coffee berries with H. hampei females. The position of the beetle inside the berry and the parasitism levels were assessed ten days after each P. coffea release. Parasitism of H. hampei by P. coffea was significantly affected by the age of the berries at the time of infestation, and by the position of the beetle inside the berries. Highest levels of parasitism were recorded in 150-day-old berries (75-85%) and in 90-day-old berries (75%) when P. coffea were released one day after the artificial infestation with H. hampei. In 150-day-old berries, highest levels of parasitism were recorded for H. hampei found in the outer layer of the endosperm followed by beetles penetrating the exocarp. Increasing the time of P. coffea releases after the artificial infestations with H. hampei led to decreased levels of parasitism in beetles attacking 90- and 150-day-old coffee berries. Low levels of parasitism were recorded in H. hampei females infesting older coffee berries because most of the beetles had already constructed galleries deep in the endosperm of the berries, i.e. out of reach of the parasitoid. The potential of P. coffea for biological control of coffee berry borer in Colombia is discussed.
Sagara, Y.; Kaminishi, K.; Goto, E.; Watanabe, T.; Imayoshi, Y.; Iwabuchi, H.
Volatile aroma compounds of freeze-dried soluble coffee were investigated to evaluate the effects of freeze-drying temperature conditions on intensities and aroma characteristics using GC-MS and charm analysis (GC-olfactometry (GC-O)). Coffee solutions with 40% solid content were freeze-dried; compounds identified based on human olfactory sense were different from those detected by GC-MS. The GC-O analysis method allowed evaluation of the characteristics and intensity of each compound and aroma profiles under different freezing and drying temperatures. The authors conclude that the GC-O method is suitable for detecting and identifying the volatile compounds of freeze-dried coffee, and that it can be used to obtain information for designing optimal aroma characteristics for final products.
Source : Drying Technology, 2005 vol. 23 (9-11), 2185-2196
Oliveira, L. S.; Franca, A. S.; Mendonca, J.-C. F.; Barros-Junior, M. C.
Defective coffee beans are responsible for the depreciation of the quality of roasted coffee consumed in Brazil. The extraction of the oil of defective beans for applications in the food and pharmaceutical sectors is being considered as an alternative use for those beans. The objective of this work was to determine the composition of the fatty acid fraction of the pressed oil and the proximate composition of crude defective beans in order to provide subsidiary information for proposals of alternative uses for these beans. The 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 than that from healthy mature coffee beans.
Source : LWT Food Science and Technology, 2006 vol. 39 (3), pp 235 - 239
Reh, C. T.; Gerber, A.; Prodolliet, J.; Vuataz, G.
Green coffee behaves very differently at high and low water content with a number of unwanted consequences like microbial growth, mycotoxin formation, altered sensorial quality of end product, instable production conditions and unclear trade issues. Generally, a water content ranging between 8.0% and 12.5% is considered to be adequate to avoid the mentioned issues. ISO has therefore issued a number of standards for reference, routine and rapid methods. Nevertheless, on-going discussions on how effective the methods are capable to principally determine the water content lead to modifications of the official approach. This work was therefore focused on clarifying the specificity and accuracy of several available methods. We could demonstrate that only ISO 1446 exclusively measures water but leaves some residual water content difficult to extract from the dried coffee matrix. For all drying oven based methods we observe degradation of the product contributing to the overall weight loss. We used near-infrared spectroscopy and color measurement to establish the degree of degradation and the completeness of the drying process. Repeatability was found excellent for all methods despite degradation and incomplete drying which should negatively affect accuracy.
Vargas, E. A.; Whitaker, T. B.; Dos-Santos, E. A.; Slate, A. B.; Lima, F. B.; Franca, R. C.
The establishment of maximum limits for ochratoxin A (OTA) in coffee by importing countries requires that coffee-producing countries develop scientifically based sampling plans to assess OTA contents in lots of green coffee before coffee enters the market thus reducing consumer exposure to OTA, minimizing the number of lots rejected, and reducing financial loss for producing countries. A study was carried out to design an official sampling plan to determine OTA in green coffee produced in Brazil. Twenty-five lots of green coffee (type 7 - approximately 160 defects) were sampled according to an experimental protocol where 16 test samples were taken from each lot (total of 16 kg) resulting in a total of 800 OTA analyses. The total, sampling, sample preparation, and analytical variances were 10.75 (CV = 65.6%), 7.80 (CV = 55.8%), 2.84 (CV = 33.7%), and 0.11 (CV = 6.6%), respectively, assuming a regulatory limit of 5 microg kg(-1) OTA and using a 1 kg sample, Romer RAS mill, 25 g sub-samples, and high performance liquid chromatography. The observed OTA distribution among the 16 OTA sample results was compared to several theoretical distributions. The 2 parameter-log normal distribution was selected to model OTA test results for green coffee as it gave the best fit across all 25 lot distributions. Specific computer software was developed using the variance and distribution information to predict the probability of accepting or rejecting coffee lots at specific OTA concentrations. The acceptation probability was used to compute an operating characteristic (OC) curve specific to a sampling plan design. The OC curve was used to predict the rejection of good lots (sellers' or exporters' risk) and the acceptance of bad lots (buyers' or importers' risk).
Delgado, Andrade C.; Rufian-Henares, J. A.; Morales, F. J.
The use of melanoidins as an oxidative stabiliser in foods is being examined, and this study evaluated the antioxidant properties of melanoidins in coffee brews from different roasting degrees using different antioxidant methods. The higher contribution of melanoidins to the total antioxidant activity of coffees was caused by the low-molecular-weight compounds linked non-covalently to the melanoidin skeleton. Coffee brews, melanoidins and bonded-melanoidin compound fractions exerted the highest antioxidant activity in aqueous media. Further studies are suggested.
Kuballa, T.; Stier, S.; Strichow, N.
Furan was determined in a wide range of coffee and coffee beverage samples, including green coffee beans, roasted coffee beans, ground coffee, instant coffee, coffee substitutes, and coffee beverages made by various methods. Values for furan concn. included the following: green coffee beans, traces; roasted coffee beans, 4.66 mg/kg; ground coffee, approx. 1.92 mg/kg; instant coffee, 0.91 mg/kg; coffee substitutes, 1.23 mg/kg; and coffee beverages, 11-88 mug/l. The furan concn. in coffee beverages was dependent on the method used for preparation; concn. were highest in coffee made using a fully automatic coffee machine, followed by espresso coffee.
Source : Deutsche Lebensmittel Rundschau, 2005 vol.101 (6), pp 229 - 235 (not available on-line)
Marraccini, P.; Rogers, W. J.; Caillet, V.; Deshayes, A.; Granato, D.; Lausanne, F.; Lechat, S.; Pridmore, D.; Petiard, V.
alpha-d-Galactosidase (alpha-Gal; EC 3.2.1.22) is one of three principal enzymes involved in the modification or degradation of plant cell wall galactomannans. In the present paper it is shown that alpha-galactosidase activities in field-grown coffee beans are variable amongst cultivars of the two species investigated (Coffea arabica and C. canephora var. Robusta). Higher activities were found in Arabica cultivars. Using beans from greenhouse-cultivated C. arabica as a model, we showed that alpha-Gal activity was undetectable in the bean perispem tissue, but increased gradually during the endosperm development, to reach a peak at approximately 30 weeks after flowering (WAF) which coincided with the hardening of the endosperm. alpha-Gal-specific transcripts detected at 22 and 27 WAF accompanied the peak of alpha-Gal activity, but were reduced to be undetectable in mature beans at 30 WAF, while alpha-Gal activity still persisted. Two isoforms were distinguished in 2-DE profiles of crude protein extracts by N-terminal sequencing analysis. Analysis of two-dimensional gel electrophoresis profiles demonstrated that both isoforms accumulated in a linear fashion throughout grain maturation. alpha-Gal activity was also observed to increase to high levels during in vitro germination of coffee beans suggesting an important function of this enzyme in this process. alpha-Gal cDNA sequences from Arabica and Robusta were sequenced and their deduced proteins appeared to be very similar, differing by only eight amino acids. Southern-blot analysis suggests that the enzyme was encoded by at least two genes in C. arabica that could explain the existence of the two isoforms identified in 2-DE profiles.
Source : Plant Physiol Biochem, vol. 43 (10-11), pp 909 - 920
Baker, J. A.; Beehler, G. P.; Sawant, A. C.; Jayaprakash, V.; McCann, S. E.; Moysich, K. B.
Caffeine has been suggested as a possible risk factor for breast cancer, potentially through its effect of facilitating the development of benign breast disease. However, coffee and tea also contain polyphenols, which exhibit anticarcinogenic properties. A hospital-based, case-control study was conducted to evaluate the role of coffee, decaffeinated coffee and black tea in breast cancer aetiology. Study participants included 1932 cases with primary, incident breast cancer and 1895 hospital controls with nonneoplastic conditions. All participants completed a comprehensive epidemiological questionnaire. Among premenopausal women, consumption of regular coffee was associated with linear declines in breast cancer risk (P for trend = 0.03); consumers of 4 cups/day experienced a 40% risk reduction (odds ratio = 0.62, 95% confidence interval 0.39-0.98). No clear associations between intake of black tea or decaffeinated coffee and breast cancer risk were noted among premenopausal women, although black tea was associated with a protective effect unique to a subsample of cases with lobular histology. Among postmenopausal women, breast cancer risk was not associated with consumption of coffee, tea or decaffeinated coffee. Results among postmenopausal women did not differ by histologic subtype. These findings support a protective effect of coffee intake on premenopausal, but not postmenopausal, breast cancer risk.
Source : Journal of Nutrition, 2006 vol. 36 (1), pp 166 - 171
Lee, W. J.; Zhu, B. T.
We studied the modulating effects of caffeic acid and chlorogenic acid (two common coffee polyphenols) on the in vitro methylation of synthetic DNA substrates and also on the methylation status of the promoter region of a representative gene in two human cancer cells lines. Under conditions that were suitable for the in vitro enzymatic methylation of DNA and dietary catechols, we found that the presence of caffeic acid or chlorogenic acid inhibited in a concentration-dependent manner the DNA methylation catalyzed by prokaryotic M.SssI DNA methyltransferase (DNMT) and human DNMT1. The IC(50) values of caffeic acid and chlorogenic acid were 3.0 and 0.75 microM, respectively, for the inhibition of M.SssI DNMT-mediated DNA methylation, and were 2.3 and 0.9 microM, respectively, for the inhibition of human DNMT1-mediated DNA methylation. The maximal in vitro inhibition of DNA methylation was approximately 80% when the highest concentration (20 microM) of caffeic acid or chlorogenic acid was tested. Kinetic analyses showed that DNA methylation catalyzed by M.SssI DNMT or human DNMT1 followed the Michaelis-Menten curve patterns. The presence of caffeic acid or chlorogenic acid inhibited DNA methylation predominantly through a non-competitive mechanism, and this inhibition was largely due to the increased formation of S-adenosyl-l-homocysteine (SAH, a potent inhibitor of DNA methylation), resulting from the catechol-O-methyltransferase (COMT)-mediated O-methylation of these dietary catechols. Using cultured MCF-7 and MAD-MB-231 human breast cancer cells, we also demonstrated that treatment of these cells with caffeic acid or chlorogenic acid partially inhibited the methylation of the promoter region of the RARbeta gene. The findings of our present study provide a general mechanistic basis for the notion that a variety of dietary catechols can function as inhibitors of DNA methylation through increased formation of SAH during the COMT-mediated O-methylation of these dietary chemicals.
Nkondjock, A.; Ghadirian, P.; Kotsopoulos, J.; Lubinski, J.; Lynch, H.; Kim-Sing, C.; Horsman, D.; Rosen, B.; Isaacs, C.; Weber, B.; Foulkes, W.; Ainsworth, P.; Tung, N.; Eisen, A.; Friedman, E.; Eng, C.; Sun, P.; Narod, S. A.
Although there are several plausible biologic mechanisms whereby coffee consumption might influence the risk of breast cancer, epidemiologic evidence is limited. We assessed the association between coffee consumption and breast cancer risk among high-risk women who carry BRCA mutations. We performed a matched case-control analysis on 1,690 women with a BRCA1 or BRCA2 mutation from 40 centers in 4 countries. Average lifetime coffee consumption was estimated via a self-administered questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression. After adjustment for potential confounders, the ORs for breast cancer in BRCA carriers who habitually drank 0, 1-3, 4-5 and 6 or more cups of coffee were 1.00, 0.90 (95% CI 0.72-1.12), 0.75 (95% CI 0.47-1.19) and 0.31 (95% CI 0.13-0.71; p-trend = 0.02). The effect was limited to the consumption of caffeinated coffee. These results suggest that among women with BRCA gene mutation, coffee consumption is unlikely to be harmful and that high levels of consumption may in fact be related to reduced breast cancer risk.
Greenberg, J. A.; Axen, K. V.; Schnoll, R.; Boozer, C. N.
Effect of wt. change on the relationship between coffee and tea consumption and diabetes risk was investigated. A prospective cohort study was conducted using data from the First National Health and Nutrition Examination Survey Epidemiologic Follow Up Study. Survival analyses were conducted using 301 self reported cases of diabetes and 8 documented diabetes deaths during an 8.4-yr follow-up. A total of 7006 subjects aged 32-88 yr with no reported history of diabetes were included in the study. Results showed that for all subjects combined, increases in consumption of ground-caffeinated coffee and caffeine at baseline were followed by decreases in diabetes risk during follow-up. There were significant statistical interactions between age and consumption of caffeine (P = 0.02) and ground-caffeinated coffee (P = 0.03). Age-stratified analysis showed that the decrease in diabetes risk only applied to <less than or equal to>60-yr-old subjects, for whom the decrease in diabetes risk also obtained for ground-decaffeinated coffee and regular tea. The multivariate hazard ratio (HR) and 95% confidence interval (CI) for a 2 cups/day increment in the intake of ground-caffeinated coffee, ground-decaffeinated coffee and regular tea was 0.86 (0.75-0.99), 0.58 (0.34-0.99) and 0.77 (0.59-1.00), respectively. The diabetes risk was negatively related to the consumption in a dose-response manner. There were strong statistical interactions between prior wt. change and beverage consumption for <less than or equal to>60-yr-old subjects. Further analysis revealed that the decrease in diabetes risk only applied to those who had lost wt., and that there was a positive dose-response relationship between diabetes risk and wt. change. For example, the multivariate HR and 95% CI for >0 vs. 0 cups/day of ground-decaffeinated coffee was 0.17 (0.04-0.74), 0.52 (0.19-1.42), 0.77 (0.30-1.96) and 0.91 (0.39-2.14) for subgroups with wt. change of <less than or equal to>0, 0-10, 10-20 and >20 lbs, respectively. There was no significant association between diabetes risk and consumption of instant-caffeinated coffee, instant-decaffeinated coffee or herbal tea. Caffeine intake appeared to explain some, but not all, of the diabetes-risk reduction and weight change. Thus, the negative relationship between diabetes risk and consumption of ground coffee and regular tea, observed for all NHEFS subjects, actually only applied to nonelderly adults who had previously lost weight.
Ito, H.; Gonthier, M. P.; Manach, C.; Morand, C.; Mennen, L.; Remesy, C.; Scalbert, A.
Polyphenols are the most abundant antioxidants in the diet, and their consumption has been associated with prevention of cancers, stroke, heart disease, neurodegenerative diseases and diabetes. Variations in urinary excretion of major dietary polyphenols after consumption of six polyphenol-rich beverages were investigated. A rapid HPLC-electrospray-tandem mass spectroscopy method suitable for analysis of polyphenols in urine selected as potential biomarkers of intake is described. Fifteen polyphenols including mammalian lignans enterodiol and enterolactone, phenolic acids including chlorogenic, caffeic, m-coumaric, gallic and 4-O-methylgallic acids, phloretin and flavonoids catechin, epicatechin, quercetin, isorhamnetin, kaempferol, hesperetin and naringenin were determined simultaneously using the proposed validated HPLC method. Levels of urinary excretion indicated that chlorogenic acid, gallic acid, epicatechin, naringenin or hesperetin might be used as specific biomarkers to evaluate consumption of coffee, wine, tea, cocoa or citrus juices, respectively.
Source : British Journal of Nutrition, 2005 vol. 94 (4), 500-509
Matijasevich, A.; Santos, I. S.; Barros, F. C.
The aim of this study was to evaluate the available epidemiological evidence of the effect of caffeine consumption during pregnancy on fetal mortality. A systematic qualitative review of observational studies that referred to any source of exposure to caffeine from food in pregnancy and to fetal mortality as the outcome was conducted in the databases MEDLINE and LILACS. Studies published between January 1966 and September 2004 were searched. The following descriptors were used: "caffeine", "coffee", "tea", "cola", and "cacao" to define the exposure and "fetal death", "stillbirth", "fetal demise", and "fetal loss" to define the outcome. The search strategy retrieved 32 publications, but only six met the inclusion criteria and three were included. One more article was found using "see related articles" feature in PubMed. A total of four publications were included in the review. The small number of publications addressing this subject, methodological limitations, inaccurate exposure assessment in all the studies, overall risks only marginally significant in most cases, and the possibility of publication bias preclude stating with certainty that caffeine consumption is actually associated with fetal death.