Cafestol Contents Research Articles

Composition of Coffea canephora Varieties from the Western Amazon

This research aimed to compare the composition profiles of roasted Coffea canephora varieties (conilon, robusta, and intervarietal hybrids) grown in the Western Amazon. Ten coffees of each variety were evaluated. No difference in the contents of caffeine (1427 to 3364 mg 100 g-1) and kahweol (absence to 25.7 mg 100 g-1) was observed. Hybrid coffees were discriminated from traditional varieties (conilon and robusta) and stood out for their higher content of trigonelline, chlorogenic acids, and total diterpenes (mean values of 613,3791, and 471 mg 100 g-1, respectively), higher cafestol/kahweol ratio (7.6 to 15.0), and higher frequency of kahweol presence. Traditional varieties only differed in cafestol and 16-O-methylcafestol contents. Robusta coffees stood out for their lower cafestol content (116 mg 100 g-1), and conilon for their lower 16-O-methylcafestol content (139 mg 100 g-1). Differences between the traditional varieties are smaller than that observed among them and the intervarietal hybrid coffees.

Optimization of ultrasonic-assisted extraction of kahweol and cafestol from roasted coffee using response surface methodology

Kahweol and cafestol were extracted by ultrasound-assisted extraction, replacing the conventional liquid: liquid method. Three parameters of extraction were investigated: amplitude level (41, 102. 5 and 164 μm), extraction time (2, 4 and 6 min) and solvent volume (2, 4 and 6 mL). All parameters had a significant effect on the extraction (p < 0.05). Higher amplitude (164 μm) and volume near the central point (4 mL) significantly increased kahweol and cafestol contents. The process time effect was differentiated for each diterpene. Optimum conditions for diterpene simultaneous extraction was chosen: 164 μm, 4 mL of solvent and 6 min-extraction. Scanning electron microscopy images showed that the ultrasound treatment caused a physical modification in the matrix. The kahweol and cafestol contents obtained by sonication were lower compared to the observed for liquid/liquid extraction (13% for kahweol and 3% for cafestol). However, sonication had a positive impact, intensifying and accelerating the process. The use of sonication allowed the extractive process to be simplified, reducing the number of stages (two steps compared to the conventional method), the amount of solvent and the analysis time.

Physical characteristics of the paper filter and low cafestol content filter coffee brews

The results found in the literature concerning the effect of consuming filter coffee brews on increasing the blood cholesterol levels due to the presence of diterpenes, are divergent. Thus the present research evaluated the diterpene (cafestol and kahweol) concentrations in filter coffee brews prepared with paper filters of different sizes, colors and origins (Brazil, Japan, The United States of America, Germany, France and the Netherlands), with and without micro perforations. This is the first study that reports the physical characteristics of paper filter and its importance to obtain filter coffee brew with low cafestol content. Thus, a sample of Catuai cultivar coffee with high cafestol content was roasted to a medium-light degree and used to prepare the brews in a 1:10 ratio (coffee powder to water). The diterpenes were extracted by direct saponification and quantified and identified by HPLC-DAD-MS/MS. The paper filters were physically characterized by measuring their grammage, and the fat permeation rate calculated in order to better understand the differences between the filters which allow one to obtain higher or lower diterpene contents. The cafestol and kahweol concentrations in the brews varied from 1.62 to 2.98 mg/L and from 0.73 to 1.96 mg/L, respectively. The highest cafestol and kahweol concentrations were obtained using paper filters with micro perforations, considering similar sized paper filters. The paper filters showed high fat permeability and grammages between 50.46 and 67.48 g/m2. The diterpene retention capacities of the filters produced in the different countries were similar. The results showed that the porosity of the paper filter and the particle size of the ground roasted coffee were determinant factors in obtaining filter coffee brews with lower cafestol contents.

High pressure phase equilibrium of the crude green coffee oil – CO2 – ethanol system and the oil bioactive compounds

Green coffee oil (GCO) is highlighted for applications in cosmetics industry, however GCO is usually obtained by cold pressing. In order to develop its extraction by supercritical technology experimental equilibrium data are required. This work presents phase equilibrium data of systems containing GCO, supercritical carbon dioxide (scCO2) and ethanol, and evaluates the content of free fatty acids (FFA) and diterpenes in the samples. GCO solubility was evaluated at different temperatures (40–60°C), pressures (200–400bar) and scCO2/ethanol ratios (0–5.7% w/w of ethanol). GCO solubility in scCO2 was similar to other vegetable oils and Chrastil semi-empirical model fit well to the experimental data. By using 2.9% ethanol, the GCO solubility increased 63%. The samples presented FFA, kahweol and cafestol contents up to 3.4, 4.4 and 4.0 times higher than commercial GCO, respectively. The use of scCO2 with or without ethanol promotes the extraction of GCO with higher FFA and diterpene contents.

Is cafestol retained on the paper filter in the preparation of filter coffee?

Coffee brew presents sensory, stimulatory and antioxidant properties highly appreciated by consumers, despite being associated with an increase in the level of blood cholesterol due to the effects of the diterpenes, especially cafestol, present in the lipid fraction. Although it is believed that the paper filter retains the brew diterpenes, new studies have shown that sometimes coffee filtered through paper can also increase the blood cholesterol level, putting in doubt the efficiency of the paper filter in retaining the diterpenes. Thus the objective of the present study was to verify the distribution of cafestol between the paper filter, the spent coffee and the coffee brew itself, from two coffee samples containing high and low cafestol contents selected from 13 samples of different cultivars and from different locations. In addition, the effect of the roasting degree on the cafestol contents of the roasted coffee was evaluated and the relationship between particle size of the roasted coffee and the extraction of solids. The highest cafestol content was found in the lightly roasted coffee, and the coffee brew presented higher solids contents when the particle size of the coffee powder was below 500μm. The results showed that of the initial cafestol concentration present in the roasted coffee, the paper filter retained 12.41%, the spent coffee 87.45% and the brew 0.15%. Thus, one can conclude that the greater part of the coffee cafestol is retained by the spent coffee, due to the low extraction of the lipid fraction by the hot water.

Diterpenes in Coffea canephora

The presence of diterpenes in coffee has received a great deal of attention in recent years, due to their physiological effects on human health. Some studies related to kahweol and cafestol contents in Coffea arabica are available in the literature; however, information on the impact of genetic variability on the profile of diterpenes in Coffea canephora is scarce. This work evaluates the contents of kahweol, cafestol and 16-O-methylcafestol in 15 genotypes of C. canephora. Coffees corresponded to three cultivars – Diamante ES8112, ES8122 ‘Jequitibá’ and Centenária ES8132 – with different fruit-ripening seasons (early, medium and late). Coffees were grown at two locations in the state of Espírito Santo, the largest C. canephora growing region in Brazil, resulting in 30 samples. Kahweol was absent in 70% of the samples and the highest content observed was 14.1mg 100g−1 in the Jequitibá cultivar. Cafestol was present in all samples and it was the main representative of the diterpene class, with contents varying from 152mg 100g−1 to 360mg 100g−1. Contents of 16-O-methylcafestol varied from 26.3mg 100g−1 to 132mg 100g−1. A significant difference among genotypes was observed, and there was an interaction between genotypes and growing site for the three diterpenes studied.

Profile of the diterpenes, lipid and protein content of different coffee cultivars of three consecutive harvests

Some compounds found in coffee, such as cafestol and kahweol, have been linked to human health, whereas others, such as lipids and proteins, are associated with beverage quality. Several factors affect the concentration of these compounds in coffee. This study aimed to evaluate the profile of cafestol, kahweol, lipids and proteins in coffee cultivars of different genetic background grown in the same edapho-climatic conditions in three consecutive harvests. Cultivars derived from introgression of C. canephora genes via Timor Hybrid and Villa Sarchi presented high kahweol and low cafestol content that remained stable for three years. In the principal component analysis, cafestol, protein and lipid values contributed highly to the separation of the three harvests, whereas kahweol values separated cultivars among harvest years. There is no year effect on the diterpene profile among the cultivars. Thus, due to the profile and the stability of diterpenes at this location, and taking into consideration healthy issues related to coffee consumption, we can begin to recommend coffee cultivars with different diterpenes concentrations.

Enrichment of diterpenes in green coffee oil using supercritical fluid extraction – Characterization and comparison with green coffee oil from pressing

Supercritical fluid extraction (SFE) was used to obtain green coffee oil (Coffea arabica, cv. Yellow Catuaí) enriched in the diterpenes, cafestol and kahweol. To obtain diterpenes-enriched green coffee oil relevant for pharmaceuticals, a central composite rotational design (CCRD) was used to optimize the extraction process. In this study, pressure and temperature did not have influences on cafestol and kahweol concentrations, but did affect the total phenolic content (TPC), which ranged from 0.62 to 2.62mg GAE/g of the oil. The analysis and quantification of diterpenes according to gas chromatography indicated that green coffee oil from SFE presented a cafestol content of 50.2 and a kahweol content of 63.8g/kg green coffee oil under optimal conditions. The green coffee oil produced from conventional pressing methods presented lower diterpenes content of 7.5 and 12.8g/kg green coffee oil for cafestol and kahweol, respectively. When SFE was used, the content of the diterpenes in the same green coffee beans was relatively higher, approximately 85% for cafestol and 80% for kahweol. Green coffee oil from SFE also presented fatty acids, such as palmitic acid (9.3mg MAE/g green coffee oil), the polyunsaturated linoleic acid (ω-6; 11mg MAE/g green coffee oil) and oleic acid (ω-9; 3.8mg MAE/g green coffee oil). The physical properties for green coffee oil produced from SFE and conventional pressings showed that densities and viscosities decreased with temperature. For oils produced from both extractions, the density behaviors were similar with values ranging from 0.9419g/cm3 (25°C) to 0.9214g/cm3 (55°C) from pressings and 0.9365g/cm3 (25°C) to 0.9157g/cm3 (55°C) for the oil obtained by the SFE. The dynamic viscosity for the pressed oil ranged from 127.8798mPa×s (25°C) to 35.0510mPa×s (55°C); for the oil from SFE, these lower values ranged from 84.0411mPa×s (25°C) and 24.2555mPa×s (55°C).

Roasting process affects the profile of diterpenes in coffee

There is no consensus in the literature regarding the decrease of kahweol and cafestol contents during coffee roasting, but it has been reported that these compounds can undergo dehydration under heat. Kahweol and cafestol were quantified in Arabica and Robusta coffees with different roasting degrees (2, 4, 6, 8 and 10 min at 230 °C). The structures of the diterpenes and the presence of derivative compounds were determined by liquid chromatography with UV–Vis and mass spectrometry detection. In the dark roast samples, dehydro derivatives were found. The roasting process influenced the level of diterpenes in both species of coffee, but the effect was dependent on the intensity of the process. Cafestol and kahweol were degraded (general losses from 60 to 75 % on a lipid basis) to dehydrocafestol and dehydrokahweol, respectively, after 8 min of process, which corresponds to the commercial roasting degree. On the other hand, the amounts of cafestol and kahweol (mg/100 g of coffee) remained stable during the roasting process due to relative increase in lipid concentration.

Cafestol extraction yield from different coffee brew mechanisms

The extraction yield of cafestol from roast and ground (R&G) coffee beans was evaluated using brews prepared by four brewing mechanisms (boiled, Turkish, French Press and Mocha Pot). The cafestol content of the R&G coffee and the resulting brews was measured and extraction yield calculated. The R&G coffee had an average cafestol content of 603mg/100g R&G coffee with a slight reduction at higher roast intensities. In the brews, preparation method had an impact on cafestol concentration with French, Turkish and boiled preparation methods producing the highest cafestol concentrations. The extraction yield of cafestol was shown to be dependent on the brew mechanism and roasting time, with the lightest roast coffee prepared by French press or boiled preparations having the highest cafestol extraction yield (6.5% and 5.84%) and dark roast Mocha and Turkish preparations had the lowest extraction yields of 2.42% and 2.88% respectively.

Discrimination of coffee species using kahweol and cafestol: effects of roasting and of defects

The two most commercialized coffee species worldwide are: Coffea arabica L. (arabica) and Coffea canephora Pierre ex A. Froehner (robusta). Since these coffees differ in their commercial value and acceptability, adulteration and mislabeling are major concerns. The diterpenes kahweol and cafestol are considered potential indicators of conilon coffee addition, as they are present in different contents in the species. The degree of roasting and the presence of defective beans may affect the theor of several coffee constituents. The aim of this work was to evaluate the possibility of discriminating the coffee species arabica and robusta through their kahweol and cafestol contents. Samples of arabica, robusta, and of their blends, with different amounts of defects and degrees of roasting (light, medium and dark) were studied. After direct saponification and extraction with terc-butyl methyl ether, the samples were analyzed by reverse-phase HPLC with UV detection. The kahweol content varied between 661 and 923 mg/100 g in the arabica coffee, and its presence was not observed in the conilon. Cafestol ranged from 360 to 478 mg in arabica, and from 163 to 275 mg/100 g in conilon coffee. The addition of conilon coffee reduced diterpene contents, but this effect varied according to the amount of defects and roasting degrees. A higher intensity roast did not affect diterpene degradation. No differences in the kahweol and cafestol levels, comparing defective or regular beans, were observed. In the analysis of coffee samples with different degrees of roasting and defects, the parameters kahweol and cafestol showed potential for discriminating between the species.

Separate effects of the coffee diterpenes cafestol and kahweol on serum lipids and liver aminotransferases

The coffee diterpene cafestol occurs in both robusta and arabica beans. It is present in unfiltered coffee brews and raises serum concentrations of cholesterol, triacylglycerols, and alanine aminotransferase in humans. The effects are linear with the cafestol dose. Unfiltered coffee also contains the related compound kahweol, which occurs only in the major coffee strain arabica. The activity of kahweol is unknown. In a randomized, double-blind crossover study, we gave 10 healthy male volunteers either pure cafestol (61-64 mg/d) or a mixture of cafestol (60 mg/d) and kahweol (48-54 mg/d) for 28 d. Relative to baseline values, cafestol raised mean (+/-SEM) total serum cholesterol concentrations by 0.79 +/- 0.14 mmol/L (31 +/- 5 mg/dL), low-density-lipoprotein (LDL) cholesterol by 0.57 +/- 0.13 mmol/L (22 +/- 5 mg/dL), fasting triacy-glycerols by 0.65 +/- 0.12 mmol/L (58 +/- 11 mg/dL), and alanine aminotransferase by 18 +/- 2 U/L (all P < 0.01). Relative to cafestol alone, the mixture of cafestol plus kahweol increased total cholesterol by another 0.23 +/- 0.16 mmol/L (9 +/- 6 mg/dL) (P = 0.08), LDL cholesterol by 0.23 +/- 0.16 mmol/L (9 +/- 6 mg/dL) (P = 0.09), triacylglycerols by 0.09 +/- 0.10 mmol/L (8 +/- 9 mg/dL) (P = 0.20), and alanine aminotransferase by 35 +/- 11 U/L (P = 0.004). Thus, the effect of cafestol on serum lipid concentrations was much larger than the additional effect of kahweol, and the hyperlipidemic potential of unfiltered coffee mainly depends on its cafestol content. Both cafestol and kahweol raised alanine aminotransferase concentrations, and their hyperlipidemic effect thus seems not to be coupled with their effect on liver cells.