Coffee adulteration: more than two decades of research

Abstract Coffee is a ubiquitous food product of considerable economic importance to the countries that produce and export it. The adulteration of roasted coffee is a strategy used to reduce costs. Conventional methods employed to identify adulteration in roasted and ground coffee involve optical and electron microscopy, which require pretreatment of samples and are time-consuming and subjective. Other analytical techniques have been studied that might be more reliable, reproducible, and widely applicable. The present review provides an overview of three analytical approaches (physical, chemical, and biological) to the identification of coffee adulteration. A total of 30 published papers are considered. It is concluded that despite the existence of a number of excellent studies in this area, there still remains a lack of a suitably sensitive and widely applicable methodology able to take into account the various different aspects of adulteration, considering coffee varieties, defective beans, and external agents.

Calibração de um equipamento TDR (Reflectometria por Dominio do Tempo) para a Determinação da Umidade da Madeira de Grevillea robusta (Cunn.)

This study aimed to establish a calibration model of a TDR equipment to determinate thewood moisture of Grevillea robusta (Cunn.). It was selected alleatory, 11 logs of Grevillea robusta (Cunn.), it was dried in a regulate electric greenhouse at 40o C. During the dry process, the moisture was determinate, periodically and systematically by gravimetric and TDR methods. Through the gravimetric method, moisture vary from 125,88% to 6,62% while the TDR method, the variation was from 119,83% to 5,79%. The best model adjusted to the wood moisture in the determination of the function of relative dielectric constant, using this technique, was the exponential 50,20 132,72 140,27 K U e − = − ⋅ , with a R2 = 0,96, with indicator of trust or performance 0,97 they were classified as very good, according to Camargo and Sentelhas (1997). The correlation between the gravimetric method (reference) and TDR, showed to be equivalent for both methodologies. It was concluded that the TDR can be used to the determination of wood moisture of Grevillea robusta (Cunn.), in a precise and fast way, once it was established it calibration.

Organic coffee under perspective of energy efficiency

The energy analysis development in this study contributes to the understanding of the dynamics of the organic coffee productive system, in particular to assess the independence of this system with respect to the use of industrialized input products. Thus, it provides information about the sustainability of that production system. Technical itineraries used in this study consist of energy expenditure made with coffee cultivation, according to the type, source and form of energy inputs, agricultural machines, equipment and labor force used in that production system. The energy expenditure, converted into energy units, quantified the input energy. And the organic coffee production, measured in kilograms of processed coffee beans, was the output energy. Primary data used in this study were obtained from organic coffee producers in the Southern region of Minas Gerais State, Brazil, in 2011. Energy balance identified was positive, since the estimated output energy was 626.465 MJ/ha and the energy expenditure was 112.998 MJ/ha, during the useful life of the crop.

Coffee processing residues as a soil potassium amendment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Endophytic microorganisms isolated from coffee leaves, roots and branches as plant growth promoters and biocontrol agents of coffee leaf rust

Suppression of plant diseases and growth promotion due to the action of endophytic microorganisms has been demonstrated in several pathosystems. Experiments under controlled conditions involving 234 endophytic bacteria and fungi isolated from coffee leaves, roots and branches were conducted with the objective of evaluating the germination inhibition of Hemileia vastatrix urediniospores, the control of coffee leaf rust development in tests with leaf discs and on plastic bags seedling, and to promote growth of coffee seedlings. None of the fungal isolates induced plant growth or reduced disease severity. The bacterial isolates (identified by the fatty acids profile analysis) 85G (Escherichia fergusonii), 161G, 163G, 160G, 150G (Acinetobacter calcoaceticus) and 109G (Salmonella enterica) increased plant growth, the maximum being induced by 85G. This isolate produced in vitro phosphatase and indol acetic acid. In assay to control rust on coffee leaf disc, nine bacterial isolates, 64R, 137G, 3F (Brevibacillus choshinensis), 14F (Salmonella enterica), 36F (Pectobacterium carotovorum), 109G (Bacillus megaterium), 115G (Microbacterium testaceum), 116G and 119G (Cedecea davisae) significantly reduced disease severity, when applied 72 or 24h before challenging with the pathogen. In seedling tests most disease severity reduction was achieved by the isolates 109G and 119G. There was no correspondence between the organisms that promoted seedling growth and those that reduced rust severity on seedlings or leaf discs.

Effects of elevated atmospheric carbon dioxide on the biological control of coffee leaf rust under controlled conditions

The effect of elevated atmospheric CO2 concentration on biological control of coffee leaf rust, caused by Hemileia vastatrix, was evaluated by leaf disc assay, under controlled conditions. The biocontrol agents Bacillus subtilis, Bacillus pumilus and Lecanicillium longisporum were applied 24h before, 24h after, and simultaneously with the H. vastatrix on leaf discs (diameter of 1.5cm). The CO2 concentrations tested were: 380, 430, 700 and 1300ppm for B. subtilis and B. pumilus; and 380, 430, 670 and 1200ppm for L. longisporum. The antagonists were not affected by CO2 concentrations. B. subtilis was the most effective in controlling the disease when applied before and simultaneously with pathogen.

Coffee growth, pest and yield responses to free-air CO2 enrichment

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Using GIS to Locate Areas for Growing Quality Coffee in Honduras

Abstract Small-scale coffee producers worldwide remain vulnerable to price fluctuations after the 1999-2003 coffee crisis. One way to increase small-scale farmer economic resilience is to produce a more expensive product, such as quality coffee. There is growing demand in coffee-producing and coffee-importing countries for user-friendly tools that facilitate the marketing of quality coffee. The purpose of this study is to develop a prototypical quality coffee marketing tool in the form of a GIS model that identifies regions for producing quality coffee in a country not usually associated with quality coffee, Honduras. Maps of areas for growing quality coffee were produced with information on climate, soils, topography, areas vulnerable to environmental degradation, the location of current quality coffee farms, and infrastructure. The maps depict suitable coffee-growing land in portions of eight western Honduran departments.

Sugars metabolism and ethanol production by different yeast strains from coffee industry wastes hydrolysates

Significant amounts of wastes are generated by the coffee industry, among of which, coffee silverskin (CS) and spent coffee grounds (SCG) are the most abundantly generated during the beans roasting and instant coffee preparation, respectively. This study evaluated the sugars metabolism and production of ethanol by three different yeast strains (Saccharomyces cerevisiae, Pichia stipitis and Kluyveromyces fragilis) when cultivated in sugar rich hydrolysates produced by acid hydrolysis of CS and SCG. S. cerevisiae provided the best ethanol production from SCG hydrolysate (11.7 g/l, 50.2% efficiency). On the other hand, insignificant (<= 1.0 g/l) ethanol production was obtained from CS hydrolysate, for all the evaluated yeast strains, probably due to the low sugars concentration present in this medium (approx. 22 g/l). It was concluded that it is possible to reuse SCG as raw material for ethanol production, which is of great interest for the production of this biofuel, as well as to add value to this agro-industrial waste. CS hydrolysate, in the way that is produced, was not a suitable fermentation medium for ethanol production; however, the hydrolysate concentration for the sugars content increase previous the use as fermentation medium could be an alternative to overcome this problem. (C) 2011 Elsevier Ltd. All rights reserved.

Gene expression profile during coffee fruit development and identification of candidate markers for phenological stages

The objective of this work was to identify genes that could be used as suitable markers for molecular recognition of phenological stages during coffee (Coffea arabica) fruit development. Four cultivars were evaluated as to their differential expression of genes associated to fruit development and maturation processes. Gene expression was characterized by both semi-quantitative and quantitative RT-PCR, in fruit harvested at seven different developmental stages, during three different seasons. No size polymorphisms or differential expression were observed among the cultivars for the evaluated genes; however, distinct expression profiles along fruit development were determined for each gene. Four out of the 28 evaluated genes exhibited a regular expression profile in all cultivars and harvest seasons, and, therefore, they were validated as candidate phenological markers of coffee fruit. The gene a-galactosidase can be used as a marker of green stage, caffeine synthase as a marker of transition to green and yellowish-green stages, and isocitrate lyase and ethylene receptor 3 as markers of late maturation.

Medium Light and Medium Roast Paper-Filtered Coffee Increased Antioxidant Capacity in Healthy Volunteers: Results of a Randomized Trial

We compared the effects of medium light roast (MLR) and medium roast (MR) paper-filtered coffee on antioxidant capacity and lipid peroxidation in healthy volunteers. In a randomized crossover study, 20 volunteers consumed 482 +/- 61 ml/day of MLR or MR for four weeks. Plasma total antioxidant status (TAS), oxygen radical absorbance capacity (ORAC), oxidized LDL and 8-epi-prostaglandin F2 alpha, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity were measured at baseline and after the interventions. MLR had higher chlorogenic acids-(CGA; 334 mg/150 mL) and less caffeine (231 mg/150 ml) than MR had (210 and 244 mg/150 ml, respectively). MLR also had fewer Maillard reaction products (MRP) than MR had. Compared with baseline, subjects had an increase of 21 and 26 % in TAS, 13 and 13 % in CAT, 52 and 75 % in SOD, and 62 and 49 % in GPx after MLR and MR consumption (P < 0.001), respectively. ORAC increased after MLR (P = 0.004). No significant alteration in lipid peroxidation biomarkers was observed. Both coffees had antioxidant effects. Although MLR contained more CGA, there were similar antioxidant effects between the treatments. MRP may have contributed as an antioxidant. These effects may be important in protecting biological systems and reducing the risk of diseases related to oxidative stress.

Coffee is highly tolerant to cadmium, nickel and zinc: Plant and soil nutritional status, metal distribution and bean yield

Sewage sludge has been used to fertilize coffee, increasing the risk of metal contamination in this crop. The aim of this work was to study the effects of Cd, Zn and Ni in adult coffee plants growing under field conditions. Seven-year-old coffee plants growing in the field received one of three;loses of Cd, Zn or Ni: 15,45 and 90 g Cd plant(-1); 35, 105 and 210 g Ni plant(-1); and 100, 300 and 600 g Zn plant(-1), with all three metals in the form of sulphate salts. After three months, we noticed good penetration of the three metals into the soil, especially in the first 50 cm, which is the region where most coffee plant roots are concentrated. Leaf concentrations of K, Ca, Mg, S, B, Cu, Fe and Mn were nor affected. N levels did not change with the application of Ni or Zn but were reduced with either 45 or 90 g Cd plant(-1). Foliar P concentrations decreased with the addition of 45 and 90 g Cd plant(-1) and 600 g Zn plant(-1). Zn levels in leaves were not affected by the application of Cd or Ni. The highest concentrations. of Zn were found in branches (30-230 mg kg(-1)), leaves (7-35 mg kg(-1)) and beam (4-6.5 mg kg(-1)); Ni was found in leaves (4-45 mg kg(-1)), branches (3-18 mg kg(-1)) and beans (1-5 mg kg(-1)); and Cd was found in branches (0-6.2 mg kg(-1)) and beans (0-1.5 mg kg(-1)) but was absent in leaves. The mean yield of two harvests was not affected by Ni, but it decreased at the highest dose of Zn (600 g plant(-1)) and the two higher doses of Cd (45 and 90 g plant(-1)). Plants died when treated with the highest dose of Cd and showed symptoms of toxicity with the highest dose of Zn. Nevertheless, based on the amounts of metal used and the results obtained, we conclude that coffee plants are highly tolerant to the three metals tested. Moreover, even at high doses, there was very little transport to the beans, which is the part consumed by humans. (C) 2011 Elsevier B.V. All rights reserved.

Enrichment of Pleurotus ostreatus mushrooms with selenium in coffee husks

Pleurotus ostreatus fungus forms an edible mushroom that possesses important nutritional and medicinal properties. Selenium (Se) is essential to human diets and it is in low concentration in the soil, and consequently in food. P. ostreatus was grown in coffee husks enriched with various concentrations of sodium selenite. The biological efficiency of P. ostreatus was affected by the addition of high concentrations of Se. The highest level of Se absorption was obtained by adding 51 mg kg(1) of sodium selenite. The mushrooms from first flush contained more Se than the further flushes. These results demonstrate the great potential of coffee husks in the production of Se-enriched mushrooms and show the ability of this fungus to absorb and biomagnify Se. (C) 2011 Elsevier Ltd. All rights reserved.

Mating Behavior of the Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae)

The mating behavior of the coffee berry borer, (Ferrari), was observed under laboratory conditions. Pairs of adult virgin male and female beetles were placed in the wells of a polystyrene microtiter plate, one pair per well. The mating activity of each pair was recorded for 24 h. The mating behavior of the coffee berry borer was similar to that of other Scolytinae and was clearly divided into precopulatory, copulatory and postcopulatory phases. The beetles started to mate within a few hours of emergence. Repeated mating occurred during the 24-hour period and increased in frequency with age. However, we cannot address multiple matings in , since we did not simulate the female-biased sex ratio of this species and the experimental design did not allow females to avoid additional mating attempts by males. In addition, further studies are necessary that focus on the effectiveness of sperm transmission and direct and indirect effects of multiple matings on the ei females and their offspring.