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This study was designed to determine the levels of coffee oil and diterpenes and evaluate the correlation between the effect of excessive roasted coffee consumption on non-high-density lipoprotein cholesterol (non-HDL) and the roasting degree effect on the levels of coffee oil and diterpenes extracted from Coffea arabica. The coffee oil and diterpenes were extracted using soxhlet and liquid-liquid extraction. Sixty-six healthy normolipidemic male participants were assigned for this study which consisted of two stages. The first stage is the coffee abstaining stage where subjects were requested to abstain from drinking coffee for 2 weeks. The second stage is the coffee drinking stage which consisted of groups (the control group and coffee-drinking group). The levels of TC, TG, LDL-C, HDL-C, and non-HDL were determined in all participants before and after the experiment. The results indicated that the coffee roasting degree demonstrated a significant increase in the levels of coffee oil and diterpenes ranging from 9.31% (green coffee) to 15.64% (dark roast) and from 0.205% (green coffee) to 0.300% (dark roast) for diterpenes. In conclusion, the current study revealed that excessive consumption of medium roasted coffee was associated with elevated non-HDL levels in normotensive nonsmoker healthy men which might be attributed to the positive association between the degree of roasting and diterpenes levels.

The valuable products that can be isolated from spent coffee ground (SCG) biomass consist of a high number of bioactive components, which are suitable for further application as raw materials in various production chains. This paper presents the potential value of the SCG obtained from large and local coffee beverage producers, for the production of valuable, biologically active products. Despite its high potential, SCG has not been utilized to its full potential value, but is instead discarded as waste in landfills. During its decomposition, SCG emits a large amount of CO2 and methane each year. The main novelty of our work is the implementation of sequential extraction with solvents of increased polarity that allows for the maximal removal of the available extractives. In addition, we have compared different extraction techniques, such as conventional and Soxhlet extraction, with more effective accelerated solvent extraction (ASE), which has seen relatively little use in terms of SCG extraction. By comparing these extraction methods and highlighting the key differences between them in terms of extraction yield and obtained extract composition, this work offers key insights for further SCG utilization. By using sequential and one-step accelerated solvent extraction, it is possible to obtain a significant number of extractives from SCG, with a yield above 20% of the starting biomass. The highest yield is for coffee oil, which is obtained with n-hexane ranging between 12% and 14% using accelerated solvent extraction (ASE) according to the scheme: n-hexane→ethyl acetate→60% ethanol. Using single-stage extraction, increasing the ethanol concentration also increases the total phenolic content (TPC) and it ranges between 18.7–23.9 Gallic acid equivalent (GAE) mg/g. The iodine values in the range of 164–174 using ASE and Soxhlet extraction shows that the hexane extracts contain a significant amount of unsaturated fatty acids; coffee oils with a low acid number, in the range of 4.74–6.93, contain few free fatty acids. The characterization of separated coffee oil has shown that it mainly consists of linoleic acid, oleic acid, palmitic acid, stearic acid and a small number of phenolic-type compounds.

Lubrication is the primary solution to reduce friction and wear. However, conventional lubricants cause pollution when not properly disposed of or due to accidental leaks. Therefore, environmentally friendly lubricating fluids are welcome in any application where they can meet the performance requirements. This study suggests using coffee oil produced from spent coffee grounds to improve the lubricity of water-based lubricating fluid. Bis(2-hydroxyethyl)ammonium oleate protic ionic liquid facilitates the dispersion of coffee oil in water. Kinematic viscosity, wettability, corrosion prevention, and lubricity tests were performed to evaluate the tribological properties provided by these additives. It was observed that a higher amount of coffee oil could be dispersed with the introduction of a higher amount of protic ionic liquid. In this study, ten wt.% of coffee oil was successfully dispersed using one wt.% of protic ionic liquid. Introducing additives increased dispersions’ viscosity, improved wettability, provided protection against corrosion, and reduced wear and friction. It was proposed that polar molecules of protic ionic liquid were responsible for most of the improvement, while coffee oil contributed by increasing viscosity. Further studies could be directed toward determining rational concentration to meet each particular application’s requirements.

Orientador: Ana Carla Kawazoe Sato Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Resumo: A prensagem mecânica dos grãos de café verde para obtenção do óleo resulta em baixo rendimento de processo, o que consequentemente gera expressiva quantidade de torta, ainda pouco explorada. Nesse contexto, para contornar esses problemas e aproveitar o teor de óleo e proteína presentes nos grãos de café, foi avaliado a extração de óleo e proteína a partir da farinha de café verde por meio da extração aquosa (AEP) e extração aquosa enzimática (EAEP). Tais processos produzem três frações principais: a skim (fração desnatada rica em proteínas), a fase creme (emulsão rica em lipídios), além dos insolúveis (fase residual rica em fibras). A abordagem sequencial utilizada para o café verde na EAEP (triagem enzimática, seguida de otimização e desenvolvimento de EAEP contracorrente em dois estágios) permitiu não só uma redução de 80% na quantidade de enzima e 60% no consumo de água requeridos pelo processo, se comparado as condições iniciais testadas, mas também uma melhora significativa no rendimento de extração de proteína (de 65,7% para 72,3%) e óleo (de 46,0% para 57,9%), tal como observado para extração contracorrente em dois estágios. Embora diferentes sistemas de agitação (impulsor vs. placa de agitação) tenham sido empregados nas escalas laboratório e piloto, a capacidade de extração de óleo e proteína foram mantidas constantes (57,4% para óleo e 72,8% para proteína, respectivamente). Também, a extração EAEP gerou um creme mais fácil de ser demulsificado quando combinado a uma demulsificação química, enquanto a demulsificação enzimática maximizou a liberação de óleo retido no creme AEP. Logo, destaca-se a importância do uso de enzimas na extração ou na demulsificação para obter alta liberação de óleo das matrizes de café. Pela primeira vez na literatura é reportado o efeito das condições do processo de extração na funcionalidade das proteínas do café verde, sendo que o tratamento enzimático (em dois estágios), além de aumentar em 13% a quantidade de proteínas extraídas comparado à extração aquosa, alterou as características físico-químicas das proteínas, aumentando o grau de hidrólise e reduzindo a hidrofobicidade superficial (H0). Consequentemente, a EAEP promoveu melhor solubilidade proteica entre pH 3,0 a 5,0 se comparada às proteínas da skim AEP. Semelhantes propriedades emulsificantes foram observadas para ambas as skims AEP e EAEP, exceto para pH 3,5, em que AEP apresentou maior índice de atividade emulsificante (EAI 28,9 vs. 11,9 m²/g). As propriedades espumantes foram melhores para proteínas obtidas por extração aquosa, em geral, possivelmente devido à maior H0 das proteínas. Por fim, as skims obtidas demonstraram ser altamente digeríveis (>97%) e são boas fontes de peptídeos e compostos fenólicos com excelente capacidade antioxidante, além de serem efetivas na inibição das enzimas lipase e enzima conversora de angiotensina (ECA), indicando potencial uso no tratamento de obesidade e doenças cardiovasculares. Em síntese, foi demonstrado o uso positivo da extração aquosa e extração aquosa enzimática, aplicada em um ou dois estágios, para obter simultaneamente proteína e óleo a partir da farinha de café verde, além da obtenção de skims com boas propriedades biológicas e funcionais Abstract: The mechanical pressing of green coffee beans to obtain oil usually results in low process yields, which consequently generates a significant amount of cake that is still little explored. In this context, to overcome these problems and take advantage of both oil and proteins present in the coffee beans, we evaluated the simultaneous extraction of oil and protein from green coffee flour by aqueous extraction (AEP) and enzymatic aqueous extraction processes (EAEP). These processes produce three main fractions: the skim (protein-rich skimmed fraction), the cream phase (lipid-rich emulsion), in addition to the insolubles (fiber-rich residual phase). The sequential approach used for green coffee when using EAEP (enzymatic screening, followed by optimization and development of a two stage EAEP countercurrent process) not only allowed an 80% reduction in the amount of enzyme and 60% decrease in the water consumption required by the process, when compared to the initial conditions, but also pointed out to a significant improvement in both protein (from 65.7% to 72.3%) and oil (from 46.0% to 57.9%) extractability for the two-stage countercurrent process. Although different agitation systems (impeller vs. magnetic stir plate) were employed at laboratory and pilot scales, the oil and protein extraction capacities were kept constant (57.4% for oil and 72.8% for protein, respectively). Moreover, the EAEP extraction yielded a cream that was easier to demulsify when combined with a chemical demulsification, while an enzymatic demulsification showed better results to maximize oil release from the AEP cream. Thus, our study highlights the importance of using enzymes either during extraction or demulsification to obtain a high release of oil from coffee matrices. For the first time in the literature, it is reported the effects of the extraction conditions on the functionality of green coffee proteins. The enzymatic treatment in the 2-stage countercurrent extraction, besides increasing the amount of extracted protein in 13% when compared to the aqueous process, changed the physical-chemical characteristics of proteins by increasing the degree of hydrolysis and by decreasing the surface hydrophobicity (H0) of proteins. Consequently, EAEP promoted better protein solubility between pH 3.0 to 5.0 when compared to proteins from the AEP skim. Similar emulsifying properties were observed for both AEP and EAEP skim fractions, except for pH 3.5, in which AEP presented higher emulsifying activity index (EAI 28.9 vs. 11.9 m²/g). The foaming properties were better for proteins obtained by aqueous extraction, in general, possibly due to the higher H0 of the proteins. Finally, the coffee skims were highly digestible (> 97%) and are good sources of peptides and phenolic compounds with excellent antioxidant capacity, in addition to being effective in inhibiting lipase and angiotensin converting enzyme (ACE). Therefore, it is suggested a potential use in the treatment of obesity and heart diseases. In summary, our results demonstrated the positive use of aqueous extraction and aqueous enzymatic extraction applied in one or two stages for simultaneous obtaining proteins and oil from green coffee flour, besides obtaining extracts with good biological and functional properties Doutorado Engenharia de Alimentos Doutora em Engenharia de Alimentos CNPQ 141112/2018-2 CAPES 001

Orientador: Miriam Dupas Hubinger Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos Resumo: O presente trabalho teve como objetivo o estudo da microencapsulação do óleo de café através de secagem por atomização. Inicialmente, foram avaliadas as variáveis de concentração de sólidos, concentração de óleo em relação aos sólidos e temperatura na secagem por spray dryer, através de um delineamento experimental composto central rotacional completo (23), usando goma arábica como material de parede, sobre as seguintes respostas: umidade, densidade aparente, higroscopicidade, óleo superficial, óleo total, retenção de óleo e eficiência de encapsulação. Nas condições otimizadas do planejamento (30% de sólidos, 15% de óleo em relação aos sólidos e 170º C) foi avaliado o efeito da homogeneização da emulsão a alta pressão (200, 600 e 1000 bar) nas características do pó, comparando-o com o pó obtido a partir de emulsão homogeneizada com o uso de um homogeneizador do tipo rotor-estator. A aplicação de alta pressão reduziu o tamanho das partículas da emulsão, aumentou a eficiência de encapsulação e reduziu o tamanho das partículas do pó, contudo reduziu a retenção de óleo. Ainda, nas mesmas condições selecionadas no planejamento, foram avaliados diferentes materiais de paredes combinados (proteína de soro de leite isolada e maltodextrina; goma arábica e maltodextrina) em diferentes razões (3:1, 1:1 e 1:3) ou puros (goma arábica e proteína de soro de leite). O emprego de materiais de parede diferentes resultou em alterações na viscosidade, no tamanho das gotas das emulsões, na higroscopicidade, densidade e molhabilidade. A mistura de proteína e maltodextrina resultou em alta eficiência de encapsulação e mostrouse como uma possível substituta para a goma arábica. Em seguida, avaliou-se a estabilidade das microcápsulas produzidas com diferentes materiais de parede (goma arábica, maltodextrina e proteína de soro de leite - nas razões 3:1, 1:1, 3:1- e proteína de soro de leite), através da construção de isotermas de sorção e determinação da temperatura de transição vítrea. As microcápsulas produzidas com proteína apresentaram baixa higroscopicidade e alta estabilidade mesmo em ambientes com alta umidade relativa. Foi ainda avaliada a estabilidade oxidativa do óleo de café puro e microencapsulado com diferentes materiais de parede às temperaturas de 25 e 60º C. Tanto o óleo de café puro quanto o microencapsulado apresentaram alta estabilidade oxidativa a 25º C. Já as amostras armazenadas a 60º C apresentaram maiores valores de índice de peróxidos, contudo observou-se uma melhora, ainda que pequena, na estabilidade oxidativa do óleo de café microencapsulado em relação à do óleo puro Abstract: The objective of this work was studying coffee oil microencapsulation by means of spray drying. Initially, the solid concentration, oil concentration in relation to solids and drying temperature were evaluated by using a complete central rotational experimental design (23), using arabic gum as wall material, on the following responses: moisture content, bulk density, hygroscopicity, superficial oil, total oil, oil retention and encapsulation efficiency. Using the planning optimized conditions (30% of solids, 15% of oil in relation to solids, and 170º C) the effect of high-pressure homogenization (200, 600 and 1000 bar) on the powder characteristics was evaluated in comparison with the powder obtained from a homogenized emulsion with the use of a rotor-stator homogenizer. The use of high-pressure reduced the size of emulsion particles, increased encapsulation efficiency and reduced powder particle size; however, it also reduced oil retention. Applying the same conditions selected in the planning, different combined wall materials were evaluated (isolated whey protein and maltodextrin; arabic gum and maltodextrin) in different ratios (3:1, 1:1 and 1:3) or pure (arabic gum and isolated whey protein). The use of different wall materials resulted in changes on viscosity, emulsion particle size and powder's properties, such as hygroscopicity, density and wettability. The combination of protein and maltodextrin resulted in higher encapsulation efficiency and proved itself as a possible substitute for arabic gum. Further, the stability of microcapsules made of different wall materials (arabic gum, maltodextrin and whey protein - in rates 3:1, 1:1 and 1:3- and sole whey protein) was evaluated, by the construction of sorption isotherms and glass transition temperature determination. The microcapsules made of protein presented low hygroscopicity and stability, even in high relative humidity environments. Finally, the oxidative stability of pure and microencapsulated coffee oil with different wall materials was analyzed at 25 and 60º C. Both pure coffee oil and the microencapsulated one presented high oxidative stability at 25º C. The samples stored at 60º C presented high peroxide index values, even though a minor improvement in the oxidative stability was noticed for the microencapsulated coffee oil in comparison with the pure one Mestrado Mestre em Engenharia de Alimentos

Green Coffea arabica L. seed oil (GCO) has been used as an active cosmetic ingredient in many skin care products, due to its composition and balance of fatty acids. On the other hand, while roasted coffee oil (RCO) is mainly used for imparting aroma in the food industry, there is no data available to suggest its safety in cell-based model systems. In this context, the present study aims to evaluate the chemical composition of GCO, RCO, and their correspondent polar fractions (PFs); and assess their cytotoxicity and antioxidant potential in vitro. RCO and RCO PF exhibited significantly higher amounts of phenolic compounds, when compared to both GCO and GCO PF. In the DPPH assay, after 5 min of incubation, RCO inhibited about 80% of radicals, while GCO only achieved half of this activity. Similar results were also obtained for their PFs. Upon exposure to GCO, no cytotoxic effects were observed, in fact, there were slight increments in cell proliferation. Nevertheless, cell exposure to RCO led to significant decreases in cell viability. Increases in the concentration of coffee oil PFs were associated with correspondent relevant increased cytotoxicity. Upon hydrogen peroxide-induced oxidative stress, neither GCO nor RCO treatment were effective in protecting cells.

The optimization of two parameters—espresso coffee oil extraction time and the ratio of dried spent coffee grounds (DSCG)-to-solvent—were conducted on DSCG employing four solvents. Extracted yields were investigated using response surface methodology. The two independent variables—ratio of DSCG-to-solvent (5.1–24.9 g/g) and extraction time (0.2–39.8 min)—were optimized in the batch mode. The predicted model was verified using actual experiments. The experimental yields achieved were 14.7 percent by weight (wt%; using hexane), 13.1 wt% (using anhydrous ethanol), 11.8 wt% (using hydrous ethanol), and 7.5 wt% (using methanol). Prototype extraction was tested using a circulation process. Approximately 11.8 wt% oil yield of prototype extraction could be obtained from DSCG under the optimal conditions of 30.4 min extraction time and 22.5 g/g ratio of DSCG-to-hexane from the laboratory-scale results. In this study, the miscella (the solution of coffee oil dissolved in the solvent) from up to six successive extractions was investigated to determine the optimal oil extraction process. The repeated miscella from each successive extraction showed high efficiency and stability of coffee oil yield similar to that obtained using fresh hexane.

The diterpene kahweol, a component of the unsaponifiable matter of coffee oil, has anticarcinogenic and antioxidant properties. Kahweol is specific to Coffea arabica, so it can be used to discriminate between coffee species. Chromatographic or infrared techniques are usually required for the evaluation of kahweol. The objective of this study was to develop a methodology to quantify kahweol based in colorimetric reactions and spectrophotometric measurements. The best extraction conditions were achieved by direct saponification of roasted and ground coffees, extraction with MTBE, cleaning the extract with water, reaction of the extract with KI, dilution with HAc 50% and absorbance analysis at 620 nm for quantification. This method demonstrated good precision (RSD below 5%) considering different extractions and intraday repeatability. Linearity was also observed (R2 = 0.996, p ≤ 0.05), with low limits of detection (5.16 mg 100 g−1) and quantification (17.2 mg 100 g−1). Kahweol contents were assessed at similar levels to those obtained using a standard HPLC methodology, and a good recovery was observed (116%).

In the present work, the extraction of oil from roasted coffee beans using supercritical carbon dioxide (CO) under different conditions of pressure (15-30 MPa) and temperature (40-60°C) was studied. A central composite experimental design was employed in order to establish the effect of these parameters on the yield and fatty acids composition that was determined by gas chromatography with flame ionization detector (GC-FID). The aroma was analyzed by headspace solid phase microextraction (HS-SPME). The optimum oil yield was 8.9%, obtained at 33.1 MPa and 35.9°C. The main fatty acids identified were palmitic (46.1%), linoleic (32.9%), oleic (8.0%), stearic (6.6%) and arachidic (1.9%). The volatile compounds of the coffee oil belong mainly to the family of furans and pyrazines, which maintain the particular features of the roasted coffee. This fact makes the coffee oil attractive to be used in the food and/or cosmetic industry., H.B. thanks to the University of Nariño for the financial support of the project. A.P.S.C. thanks the Administrative Department of Science, Technology and Innovation COLCIENCIAS (Colombia) for her Ph.D. Scholarship.

The aim of this paper was to investigate the possibility of obtaining oil from spent coffee grounds, which are left behind after the coffee is prepared, as the potential feedstock for biodiesel production. The effect of process parameters, such as are the type of solvent, the ratio of spent coffee grounds/solvent and the extraction time on oil yielded from coffee grounds was examined. The oil was obtained by maceration and extraction in the Soxhlet apparatus. The obtain results show that the spent coffee grounds could be used as an alternative raw material for biodiesel production, because it contains a significant amount of oil that can be extracted. The oil yield depends on the extraction (maceration) process parameters. The maximum oil yield obtained by the Soxhlet extraction with the n-hexane for the period of 5 h was 11.85% (the weight percentage of oil on dry mater), whereas with petroleum ether the oil yield was slightly lower and amounted to 10.44%. The yield of the oil extracted by maceration increases with the decrease of spent coffee grounds/solvent ratio from 1/3 to 1/7 g/cm3, and other parameters being constant. The oil yield increases with the duration of the maceration. Greater oil yield, ranging from 3 to 8.5%, can be obtained with n-hexane compared to the extraction with petroleum ether. Furthermore, n-hexane is less volatile and flammable, compared to petroleum ether, so it is more convenient to use.

The unsaponifiable matter of coffee, which represents approximately 15–18% of coffee oil, is an extremely complex fraction that contains sterols, tocopherols, and high amounts of diterpene alcohols. This fraction has attracted increasing interest in recent years, not only because of its possible physiological effects, but also because of its extreme importance and usefulness as fingerprint for the identification of the botanical and geographical origin of coffee beans and for the authentication of coffee. For instance, 16-O-methylcafestol, which covers one-quarter of the unsaponifiable matter of green and roasted Robusta oil, is absent in Arabica, whereas diterpene E has been detected exclusively in roasted Arabica. Additionally, Robusta contains fivefold higher amounts of Δ 5 -avenasterol than Arabica, which shows higher content of tochopherols, especially beta-tocopherol. The purpose of this chapter is to discuss the influence of the species and manufacturing process conditions on the qualitative and quantitative composition of the unsaponifiable matter of coffee.

The lipid fraction of coffee is composed mainly of triacylglycerols, sterols and tocopherols, the typical components found in all common edible vegetable oils. Additionally, the so-called coffee oil contains diterpenes of the kaurene family in proportions of up to 20 % of the total lipids. Diterpenes are of interest because of their analytical and physiological effects. The composition of the main lipid components of the two most important coffee species, Coffea arabica and Coffea canphora var. Robusta is presented. In addition, the influences of typical processes like roasting and steaming on selected lipid components as well as the effects of the storage of green coffee beans under different conditions will be described. Furthermore, new findings regarding the 5-hydroxytryptamides, the main parts of the coffee wax located on the outer layer of the bean and the recently identified components coffeadiol and arabiol I will also be discussed. A fração lipídica do café é composta principalmente de triacilgliceróis, esteróis e tocoferóis, componentes típicos encontrados em todo óleo vegetal comestível comum. Adicionalmente, o chamado oleo de café contém diterpenos da família dos kaurenos, em proporção de até 20 % dos lipídeos totais. Diterpenos são de interesse por causa de seus efeitos fisiológicos. As composições dos principais componentes lipídicos das duas espécies mais importantes de café, Coffea arabica e Coffea canphora var. Robusta são apresentadas. Também, serão descritas as influências de processos tais como torração e "steaming" sobre determinados components lipídicos, assim como os efeitos do armazenamento do café verde sob diferentes condições. Além disso, serão discutidas as novas descobertas sobre as 5-hidroxitriptamidas, os principais componentes da cera de café, localizada nas camadas externas da semente, e os compostos "coffeadiol" e "arabiol I", recentemente identificados.

A preliminary analysis by GC-MS comparing the mass spectrum of the compounds with the Wiley 275 L mass spectral data base was used to identify the fatty acids and mainly, some volatile compounds responsible for the flavor of the roasted coffee oil. The oil was obtained by mechanical expelling of Brazilian beans (Coffea arabica) roasted at 238ºC for 10 minutes. Different sample preparation methodologies such as headspace, adsorbent suction trapping and esterification were used. It was possible to identify pyrazines, pyridines, furan derivatives and other compounds not reported in the literature. Análise preliminar utilizando GC-MS através da comparação dos espectros de massas dos compostos com aqueles da base de dados Wiley 275 L foi feita para identificar ácidos graxos e principalmente componentes voláteis responsáveis pelo aroma e odor do óleo de café torrado. O óleo foi obtido por prensagem dos grãos de café brasileiro (Coffea arabica), torrado a 238ºC por 10 min. Diferentes metodologias de preparo de amostra como "headspace", adsorção por sucção em armadilha com polímero e esterificação foram usadas. Foi possível identificar pirazinas, piridinas, derivados de furanos e outros componentes ainda não apresentados na literatura.

Green and roasted coffee oil was extracted using supercritical CO2 at temperatures of (333, 343, 353 and 363) K and pressures from (235 to 380) bar, providing a CO2 densities range from (680 to 880) kg.m-3. The mathematical models of Del Valle-Aguilera and Chrastil were applied to predict the oil solubility. The Del Valle-Aguilera led to elevated deviations between the predict solubility values and those observed experimentally. The Chrastil model provided better results, with better fitting being observed. With this procedure, the mean percentage deviation was 0.16 and 0.19, respectively, for green and roasted coffee oil, showing a good correlation between the observed and predicted values.

Coffee beans contain the diterpene cafestol, which raises plasma cholesterol concentrations in humans. Daily consumption of 2 g coffee oil, which provides approximately 60 mg cafestol (equivalent to 5.7 mg cafestol/MJ), increases plasma cholesterol concentrations by 28%. We studied the effect of cafestol in coffee oil on gerbils and rats to determine whether the pathways that lead to cafestol-induced hypercholesterolemia in humans are also present in other species. We fed coffee oil from the same batch used in humans to female gerbils and rats. Gerbils were fed a semipurified diet containing 0.5% or 5% (w/w) coffee oil (equivalent to 8.7 and 86.8 mg cafestol/MJ, respectively) in the presence or absence of 0.05% (w/w) cholesterol for a period of 10 weeks. When compared with the gerbils fed no coffee oil, the addition of 0.5% coffee oil to the diets did not affect plasma cholesterol. Plasma cholesterol was significantly higher only when 5% coffee oil was fed, both in the absence (1.01 mmol/L, 33% higher) and presence (1.87 mmol/L, 70% higher) of dietary cholesterol. Liver weight was also significantly higher when 5% coffee oil was fed. Rats were also fed diets containing 0.5% or 5% coffee oil (equivalent to 8.7 and 86.8 mg cafestol/MJ) with and without 0.05% cholesterol for 8 weeks. Feeding 0.5% coffee oil compared with no coffee oil resulted in significantly higher plasma cholesterol levels throughout the study both in the absence (0.46 mmol/L, 27% higher) and presence (0.28 mmol/L, 15% higher) of dietary cholesterol. Diets containing 5% coffee oil appeared to be toxic. Thus, coffee oil diterpenes can result in higher plasma cholesterol in gerbils and rats. The failure to observe these effects in previous studies may be due to doses that were too low.

The paper reports on experimental data on the extraction of caffeine, coffee oil and chlorogenic acids from green coffee beans using pure supercritical CO2 and supercritical CO2 modified with ethanol (5% w/w) and isopropyl alcohol (5% w/w) at 50 and 60ºC and 15.2 24.8 e 35.2 MPa. In this study extraction kinetics were obtained for all assays i.e. samples were collected at several time intervals for each solvent and mixed solvent. When pure CO2 and CO2-ethanol mixed solvent were used, an increase in pressure resulted in an increase in the amount of oil extracted. When CO2 was modified with isopropyl alcohol, the amount of coffee oil extracted also increased with pressure. Caffeine extraction initially increased and subsequently decreased with pressure. Chlorogenic acids were only extracted when isopropyl alcohol was used as a co-solvent. An increase in extraction temperature resulted in a decrease of caffeine and oil extraction (retrograde condensation) when only CO2 was used as solvent. With the use of co-solvent this retrograde behavior was no longer observed and the increase in temperature resulted in the increase in the extracted amounts of caffeine, coffee oil and chlorogenic acids.