Journal of the Brazilian Chemical Society

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Boron isotope dilution in cellular ractions of coffee leaves evaluated by inductively coupled plasma mass spectrometry with direct injection nebulization (DIN-ICP-MS)
(Sociedade Brasileira de Química, 2003) Bellato, Ana Cláudia S.; Menegário, Amauri A.; Giné, Maria Fernanda
Enriched 10B (94.14 atom %) was supplied to coffee plantlets for three months. Then boron isotope ratios were determined in the leaf cell compartments, cell wall, nuclei and chloroplast, after a sub-cellular fractionation procedure. The isotopic measurements were performed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) provided with a direct injection nebulizer (DIN), introducing a sample volume of 50 µL. Isotopic ratios from 1.002 to 1.326 were determined with precision characterized by RSD lower than 1.5% for the enriched cell fractions with B concentrations ranging from 3.3 to 10.8 µg g-1. The detection limit (3σ) was 0.5 ng B mL-1. The average enrichments in 10B atom % found in the cell walls, nuclei and chloroplasts were 46.7, 44.5 and 48.8, respectively.
A solid-phase microextraction method for the chromatographic determination of organophosphorus pesticides in fish, water, potatoes, guava and coffee
(Sociedade Brasileira de Química, 2005) Capobiango, Helena L. V.; Cardeal, Zenilda L.
This paper describes a Solid Phase Microextraction method (SPME-CG) to the determination of organophosphorus pesticides in samples of fresh-water fish, water, potatoes, guava and coffee by capillary gas chromatography with nitrogen phosphorus detector. The samples were collected from October 2002 to April 2003 in the tributaries and sub-tributaries of the Paranaiba River, which supplies the city of Patos de Minas, Minas Gerais, Brazil. The determination of the pesticides: co-ral (O,O-diethyl O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) phosphorothioate), DDVP (2,2-dichloroethenyl dimethylphosphate), disyston (O,O-diethyl S-[2-(ethylthio) ethyl] phosphorodithioate), ethion (O,O,O’,O’-tetraethyl S,S’-methylene bis(phosphorodithioate)), phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate), phosdrin (2-methoxycarbonyl-1-methylvinyl dimethyl phosphate), guthion (O,Odimethyl-S-[(4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl] phosphorodithioate)), malathion (diethyl (dimethoxy thiophosphorylthio succinate) and methyl-parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate) in samples of fish, water and others foods with a manual SPME-CG holder using a 100 μm PDMS microfiber, is simple, easy to handle and solvent-free. The optimised conditions for pesticides extraction by SPME-CG method were: sample agitation, absorption at room temperature for 40 min, desorption at 220°C for 10 min, and sample volume in the vial of 16.0 mL. Under these conditions, the analytical curves were linear in different ranges (depend of each pesticide) with correlation coefficients from 0.997 to 0.999 and the precision was good (RSD from 4.40 to 15.13%). The detection limit was 0.05 μg L-1 to 8.37 μg L-1 and the quantitation limit was 0.09 μg L-1 to 8.70 μg L-1. The method was employed to detect and quantify pesticides in 24 fish of three different species and also in water, potatoes, guava and coffee. The samples analyzed showed residues of six different organophosphorus pesticides.
Sistematic study of benzo[a]pyrene in coffee samples
(Sociedade Brasileira de Química, 2006) Badolato, Elza S. G.; Martins, Maristela S.; Aued-Pimentel, Sabria; Alaburda, Janete; Kumagai, Edna E.; Baptista, Gisleine G.; Rosenthal, Amaury
A method for extracting and quantifying benzo[a]pyrene (B[a]P) was evaluated and improved for samples of green and roasted ground Arabica (Coffea arabica) and Conillon (Coffea canephora) Brazilian coffees. The influence of the roasting process in B[a]P formation was considered too. These samples were extracted with acetone, followed by saponification and cyclohexane extraction. The extracts were cleaned by chromatography on a silica-gel. The quantification was done by HPLC with reversed-phase and fluorescence detection under isocratic conditions. The detection and quantification limits were 0.03 μg kg-1 and 0.10 μg kg-1, respectively. The recovery ranged from 76 to 116% for concentrations between 1.00 and 3.00 μg kg-1. The values obtained for B[a]P concentrations were from 0.47 to 12.5 μg kg-1 for samples of ground roasted coffee. B[a]P was absent in the green coffee samples. The control of the roasting parameters is fundamental for obtaining a good quality product.
Comparative studies of the sample decomposition of green and roasted coffee for determination of nutrients and data exploratory analysis
(Sociedade Brasileira de Química, 2007) Amorim Filho, Volnei R.; Politoa, Wagner L.; Gomes Neto, José A.
The contents of some nutrients in 35 Brazilian green and roasted coffee samples were determined by flame atomic absorption spectrometry (Ca, Mg, Fe, Cu, Mn, and Zn), flame atomic emission photometry (Na and K) and Kjeldahl (N) after preparing the samples by wet digestion procedures using i) a digester heating block and ii) a conventional microwave oven system with pressure and temperature control. The accuracy of the procedures was checked using three standard reference materials (National Institute of Standards and Technology, SRM 1573a Tomato Leaves, SRM 1547 Peach Leaves, SRM 1570a Trace Elements in Spinach). Analysis of data after application of t-test showed that results obtained by microwave-assisted digestion were more accurate than those obtained by block digester at 95% confidence level. Additionally to better accuracy, Other favorable characteristics found were lower analytical blanks, lower reagent consumption, and shorter digestion time. Exploratory analysis of results using Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that Na, K, Ca, Cu, Mg, and Fe were the principal elements to discriminate between green and roasted coffee samples.
The use of fatty acid profile as a potential marker for brazilian coffee (Coffea arabica L.) for corn adulteration
(Sociedade Brasileira de Química, 2008) Jham, Gulab N.; Berhow, Mark A.; Manthey, Linda K.; Palmquist, Deborah A.; Vaughn, Steven F.
Fatty acid methyl ester (FAME) composition of the coffee (Coffea arabica L.) varieties Catuai, Catucaí, Bourbom, Mundo Novo, Rubí and Topázio known to produce beverage of intermediate, excellent, excellent, intermediate, intermediate and poor quality, respectively, was determined for the first time. Average area % of the FAMEs of the six varieties was: palmitic (38.2), stearic (8.3), oleic (8.6), linoleic (38.5), linolenic (1.6) and arachidic (3.6) acids, respectively. The method was very quick with complete characterization (>99%) of the samples studied being possible in less than 6 min. While these values may provide insights for evaluating the coffee quality, no significant effect (p < 0.05) of coffee variety was found on area % of the FAMEs. In addition, FAMEs of six corn samples, six commercial coffee brands and one commercial coffee sample intentionally contaminated with three levels of corn were compared. Although the linoleic/stearic ratio was significantly different in coffee and corn FAMEs, this probe could not be used a marker to detect corn adulteration in commercial coffees.
Age and time related pheromone production in coffee leafminer Leucoptera coffeella Guérin-Méneville (Lepidoptera: Lyonetiidae)
(Sociedade Brasileira de Química, 2008) Lima, Eraldo R.; Vilea, Evaldo F.; Lucia, Terezinha M. C. Della; Ataíde, Lívia M. S.
This study was undertaken to access the pattern of sex pheromone production in glands of virgin females of Leucoptera coffeella as an indirect measure of the calling behavior. The major compound, 5,9-dimethylpentadecane (1) was extracted from pheromone glands of virgin females to be used in two experiments. The first one investigated the effect of the pheromone production time by females (extracts of 10 females with age of two days were carried out at 2-hour intervals). The other experiment evaluated the effect of female age on pheromone production (10 females with age ranged from 1 to 5 days after emergence class were used). Hexane extracts were made with 5 ng µL-1 of 5,9-dimethylheptadecane (2) as internal standard and analyzed by GC. Females had the highest amount of pheromone at the last four hours in the dark and the two first hours in the light period. One-day old females produced the highest amount of pheromone in the glands.
Green and roasted arabica coffees differentiated by ripeness, process and cup quality via electrospray ionization mass spectrometry fingerprinting
(Sociedade Brasileira de Química, 2009) Amorim, Ana Carolina L.; Hovell, Ana Maria C.; Pinto, Angelo C.; Eberlin, Marcos N.; Arruda, Neusa P.; Pereira, Elenilda J.; Bizzo, Humberto R.; Catharino, Rodrigo R.; Morais Filho, Zenildo B.; Rezende, Claudia M.
Direct infusion electrospray ionization mass spectrometry in both the negative ESI(-)-MS and positive ESI(+)-MS ion modes are investigated to differentiate green and roasted Arabica coffees with different stages of ripeness (green, ripe and overripe), post-harvesting process (dry, wet and semi-wet) and coffees with diferente cup qualities. In the ESI(-)-MS of green coffees, ions from deprotonated fatty acids and chlorogenic acids are the most important for ripeness discrimination. In the ESI(+)-MS, maturity is differentiated by ions from protonated caffeine, chlorogenic acids and K+ adducts of fatty acids. To differentiate between post-harvesting process in both ionization modes, ions from fatty acids, chlorogenic acids, sugars and carboxylic acids generated in the fermentation process are the most representative. Roasted Arabica coffees are also well discriminated: in the ESI(-)-MS, ions from chlorogenic acids and short-chain organic acids derived from sugars are important. In the ESI(+)-MS, discrimination are mainly performed by low m/z ions such as protonated pyridine and alkylpiridines formed via trigonelline degradation. Both ESI(+)-MS and ESI(-)-MS are able to differentiate cup quality for Arabica roasted coffees and the ions used to perform discrimination are the same ones described in ripeness and post-harvesting processes.
Comparative study of metal contents in Brazilian coffees cultivated by conventional and organic agriculture applying principal component analysis
(Sociedade Brasileira de Química, 2010) Santos, José S. dos; Santos, Maria Lúcia P. dos; Conti, Melina M.
The aim of this study was to evaluate of availability of nutrients and toxic elements in green coffees produced in traditional, technological and transitional organic farms in Southwest BahiaBrazil. Levels of the nutrients minerals were determined directly in samples of soils and coffee tissues from four farms by flame atomic absorption spectrometry (FAAS) and toxic elements (Cr, Ni, Cd and Pb) by inductively coupled plasma optical emission spectrometry (ICP OES). The application of statistical methods (cluster and principal components analysis) revealed the importance of the conversion period to guarantee a product genuinely organic during the change to organic agriculture. On the other hand, the study of correlations between agricultural methods and metals concentrations in coffee suggested that Cd, Cu, Zn and other toxic elements contained in some inorganic fertilizers used in the traditional and technological coffee farms may cause na increase of toxic metals concentration in the crop soil, be taken up by plants, and passed on in the food chain.
Discrimination of commercial roasted and ground coffees according to chemical composition
(Sociedade Brasileira de Química, 2012) Souza, Romilaine M. N. de; Benassi, Marta T.
Roasted and ground 38 commercial coffees and coffees of known species (arabica, robusta) were characterized by principal component analysis using as variables nicotinic acid, trigonelline, 5-o-caffeoylquinic acid (5-CQA), caffeine, kahweol and cafestol, which are potentially indicative of species. The objective of the study was to assess the relevance of such parameters in coffee discrimination. Nicotinic acid allowed the characterization of roasting degree. Trigonelline and 5-CQA presented variability among arabica and robusta coffees as well as among comercial ones. Thermostable parameters (caffeine, kahweol and cafestol) had high discriminative potential between the species. In general, high levels of caffeine and low levels of diterpenes (kahweol and cafestol) were related with higher proportions of robusta in the products, which were observed by the decreasing kahweol/cafestol ratio and increasing caffeine/kahweol ratio. The use of these new parameters (kahweol/cafestol and caffeine/kahweol ratios) was suggested as tools for assessing the addition of robusta in commercial coffees.
Comparison of extraction methods for kahweol and cafestol analysis in roasted coffee
(Sociedade Brasileira de Química, 2013) Dias, Rafael C. E.; Faria, Adelia F. de; Mercadante, Adriana Z.; Bragagnolo, Neura; Benassi, Marta de T.
Kahweol and cafestol, diterpenes from the unsaponifiable fraction of coffee, present known effects on human health such as anticarcinogenic and hipercholesterolemic activities. There are discrepancies regarding the levels reported for these compounds in roasted coffee, probably due to the extraction processes. Therefore, four sample preparation methods were studied: direct hot saponification (DHS), direct cold saponification (DCS); and Bligh and Dyer (BD) or Soxhlet (SO) extraction followed by saponification. The levels of diterpenes and their dehydro derivatives obtained by high performance liquid chromatography with diode array and mass spectrometry detectors (HPLC-DAD-MS/MS) and the chromatographic profiles of roasted coffee, obtained by these four methods, were compared. DHS was more efficient for extraction, showing better separation of chromatographic peaks and levels of 930.2 (± 36.8), 113.2 (± 4.7), 568.6 (± 16.6) and 87.1 (± 3.7) mg 100 g–1 for kahweol, dehydrokahweol, cafestol and dehydrocafestol, respectively. The DHS extract presented a diterpene content (kahweol and cafestol) 15% superior to that of DCS and up to 88% superior than using SO and BD methods.
Spectroscopic and chromatographic fingerprint analysis of composition variations in Coffea arabica leaves subject to different light conditions and plant phenophases
(Sociedade Brasileira de Química, 2014) Delaroza, Fernanda; Rakocevic, Miroslava; Malta, Galileu Bernardes; Bruns, Roy Edward; Scarminio, Ieda Spacino
Fingerprints of self-shaded and sunlight-exposed leaves of the same Coffea arabica plant were obtained to determine metabolic concentration changes owing to different light environments and phenological stages. Leaf extract yields of the ethanol, acetone, dichloromethane and hexane solvents, as well as their statistical design mixtures, are reported. Highest yields are obtained with binary 1:1 ethanol-acetone mixtures for all sun-exposed and self-shaded leaves. Principal component analysis (PCA) of Fourier transform infrared (FTIR) spectra of leaf extracts indicate spectral differences between 2962-2828, 1759-1543 and below 1543 cm-1 that can be attributed to higher concentrations of fatty acid esters or the ester group in triglycerides, caffeine, chlorogenic acids and carbohydrates that are more prevalent in leaves of flowering plants. Highperformance liquid chromatography with UV diode array detector (HPLC-UV-DAD) spectra of the chromatographic peaks for the extracts showed that sun-exposed samples contain stronger absorptions for caffeine, chlorogenic acid and theobromine. Confirmatory experiments carried out with reference UV calibration curves determined caffeine contents for sun-exposed leaves that are about double those for self-shaded leaves of flowering plants. Knowledge of leaf caffeine content in Coffea arabica is of ecological importance since sun-exposed conditions seem more stressful than self-shading ones for this species. Lipid concentrations in self-shaded leaves are almost double those that were sun-exposed.
Ambient mass spectrometry employed for direct analysis of intact arabica coffee beans
(Sociedade Brasileira de Química, 2014) Garrett, Rafael; Schwab, Nicolas V.; Cabral, Elaine C.; Henrique, Brenno V. M.; Ifa, Demian R.; Eberlin, Marcos N.; Rezende, Claudia M.
The ambient ionization mass spectrometry techniques: desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI) were explored as fast and simple ways to directly analyze the surface of intact green Arabica coffee beans treated by the dry, semi-dry and wet post-harvest methods. Five compounds were identified, including three components of the waxy layer that covers the green coffee beans (β N-arachinoyl-5-hydroxytryptamide, β N-behenoyl5-hydroxytryptamide, and β N-lignoceroyl-5-hydroxytryptamide) and that are commonly related to related to stomach irritations caused by coffee beverage consumption in sensitive people. Moreover, the multivariate statistical tool principal component analysis (PCA) was employed to differentiate the coffee post-harvest methods using data from the mass spectrometry fingerprinting analyses. Extraction procedures or sample pretreatment steps were not required for DESI and EASI analyses and the results obtained suggest therefore that these techniques could be used for rapid quality control and certification processes of coffees samples.
Evaluation of the bioaccessability of Ca, Fe, Mg and Mn in ground coffee infusions by in vitro gastrointestinal digestion
(Sociedade Brasileira de Química, 2014) Stelmach, Ewelina; Pohl, Pawel; Szymczycha-Madeja, Anna
The bioaccessibility of Ca, Mg, Mn and Fe in ground coffee brews was assessed through in vitro gastrointestinal digestion with stomach and intestinal juice solutions (pepsin, pancreatin and bile salts). Absorption of metals in the intestinal villi was simulated by ultrafiltration over a 3 kDa molecular weight cut-off semi-permeable membrane. Concentrations of Ca, Fe, Mg and Mn in coffee infusions and permeates of gastrointestinal incubates were measured by flame atomic absorption spectrometry. It was established that Mg, with a 62% contribution to the bioaccessible fraction, was the most bioaccessible. The bioaccessibilities of Ca (42%) and Fe (43%) were similar but individual results for both metals varied widely. The least bioaccessible metal was Mn, with an average contribution of 27%. Drinking one cup of coffee daily covers dietary reference intakes of Ca, Fe, Mg and Mn to a small degree (less than 3%).
Solubility and bioaccessibility of Ba, Ca, Cr, Cu, Fe, Mg, Mn, P, Sr and Zn in slim coffee infusions by in vitro gastrointestinal digestion
(Sociedade Brasileira de Química, 2015) Szymczycha-Madeja, Anna; Welna, Maja; Pohl, Pawel
Solubility and bioaccessibility of Ba, Ca, Cr, Cu, Fe, Mg, Mn, P, Sr and Zn in slim coffees were investigated using an in vitro method. Two different compositions of solutions simulating gastric and intestinal juices were tested: SGJ1 + SIJ1 (0.02% pepsin in 0.10 mol L-1 HCl; 0.015% pancreatin with 0.15% bile salts in 0.10 mol L-1 NaHCO3) and SGJ2 + SIJ2 (0.32% pepsin with 0.20% NaCl in 0.08 mol L-1 HCl; 0.40% pancreatin with 2.5% bile salts in 0.10 mol L-1 NaHCO3). Soluble and bioaccessible fractions (in %) in reference to total concentrations of studied elements in infusions were as follows: Ba (81.2, 34.2), Ca (84.4, 44.5), Cr (80.1, 44.8), Cu (69.2, 24.1), Fe (72.5, 6.6), Mg (89.5, 69.6), Mn (44.3, 28.4), P (96.6, 84.6), Sr (85.9, 46.8), Zn (80.8, 59.5). These results suggest that slim coffees are not a rich source of minerals.
Application of carbon composite adsorbents prepared from coffee waste and clay for the removal of reactive dyes from aqueous solutions
(Sociedade Brasileira de Química, 2015) Santos, Davis C. dos; Adebayo, Matthew A.; Lima, Eder C.; Pereira, Simone F. P.; Cataluña, Renato; Sauier, Caroline; Thue, Pascal S.; Machado, Fernando M.
A novel carbon composite was prepared from a mixture of coffee waste and clay with inorganic:organic ratio of 1.3 (CC-1.3). The mixture was pyrolysed at 700 °C. Considering the application of this adsorbent for removal of anionic dyes, the CC-1.3 was treated with a 6 mol L−1 HCl for 24 h to obtain ACC-1.3. Fourier transform infrared (FTIR), N2 adsorption/desorption curves, scanning electron microscope (SEM) and powder X-ray diffractometry (XRD) were used for characterisation of CC-1.3 and ACC-1.3 carbon adsorbents. The adsorbents were effectively utilised for removal of reactive blue 19 (RB-19) and reactive violet 5 (RV-5) textile dyes from aqueous solutions. The maximum amounts of RB-19 dye adsorbed at 25 °C are 63.59 (CC-1.3) and 110.6 mg g−1 (ACC-1.3), and 54.34 (CC-1.3) and 94.32 mg g−1 (ACC-1.3) for RV-5 dye. Four simulated dye-house effluents were used to test the application of the adsorbents for treatment of effluents.
Chemometric analysis of UV characteristic profile and infrared fingerprint variations of Coffea arabica green beans under different space management treatments
(Sociedade Brasileira de Química, 2016) Terrile, Amélia E.; Marcheafave, Gustavo G.; Oliveira, Guilherme S.; Rakocevic, Miroslava; Bruns, Roy E.; Scarminio, Ieda S.
Ultraviolet characteristic profiles and infrared spectroscopic (FTIR) fingerprints of green bean extracts of Coffea arabica L., cv. IAPAR 59, cultivated in two planting patterns, rectangular and square, and at two different densities, 10,000 and 6,000 plants ha-1, identified as R10,R6,S10, and S6 were analyzed with principal component and hierarchical cluster analyses. A simplex centroid design for four solvents (ethanol, acetone, dichloromethane, hexane) was used for sample extraction. The largest chlorogenic acid (CGA) contents were found at the lower planting density. The dichloromethane extracts of the S10 treatment showed the highest levels of unsaponifiable lipids (cafestol and kahweol). The R6 treatment showed a slightly higher content of cafestol and kahweol. Cluster analysis of FTIR fingerprints confirmed that the CGA and caffeine levels differentiate the spatial arrangements. The FTIR fingerprints suggest that green beans from S6 and R10 were richer in lipids and the other two treatments had more sugars and proteins.
Differential scanning calorimetry and infrared spectroscopy combined with chemometric analysis to the determination of coffee adulteration by corn
(Sociedade Brasileira de Química, 2017) Brondi, Ariadne M.; Torres, Claudia; Garcia, Jerusa S.; Trevisan, Marcello G.
Roasted and ground coffee is targeted by fraudulent addiction of products. In this way the determination of contaminants in coffee has economic and nutritional importance. In this study, the coffee adulteration by corn were detected using DSC (differential scanning calorimetry) and FTIR (Fourier transform infrared spectroscopy) coupled to PCA (principal component analysis), and PLS (partial least squares) models. Three different levels of roasted and ground Coffea arabica L. were used to prepare mixtures with roasted and ground corn. The level of adulteration used was between 0.5 to 40% (m/m). It was observed that both DSC and FTIR coupled with PCA are able to discriminate adulterated from unadulterated samples of coffee by corn at levels below 1%. PLS models were built with DSC and FTIR data reaching good correlation between the values of estimated and reference concentrations, with RMSECV (root mean square error of cross-validation) lower than 3.5% for DSC data and 2.7% for FTIR data.
Irrigation and light acess effects on Coffea arabica L. leaves by FTIR-chemometric analysis
(Sociedade Brasileira de Química, 2018) Sanchez, Patrícia M.; Pauli, Elis D.; Scheel, Guilherme L.; Rakocevic, Miroslava; Brunsc, Roy E.; Scarminio, Ieda S.
Coffee bean chemical compositions has been extensively studied. However, there is a small amount of research on other parts of the coffee plant, including leaves. Fourier transform infrared (FTIR) spectral profiles of Coffea arabica L. cv. IAPAR 59 leaf extracts from a simplex-centroid design were studied by principal component analysis (PCA) to evaluate the effect of solvente extractor on its metabolites. PCA indicated that the extractor solvents containing ethanol were the most suitable for this study. FTIR spectra in conjunction with orthogonal signal correction and partial least squares-discrimination analysis (OSC-PLS-DA) were used to classify and discriminate the leaves of irrigated and non-irrigated plants by bands related to carbohydrates, amino acids and lipids. Leaves receiving different intensities of solar radiation were also discriminated by bands corresponding to caffeine, carbohydrates and lipids. FTIR spectral profile analyzed with chemometric tools showed to be a useful, powerful and simple procedure to discriminate coffee leaves collected from different microclimate conditions.
Integrated chemometric approach to optimize sample preparation for detecting metabolic changes provoked by abiotic stress in Coffea arabica L. leaf fingerprints
(Sociedade Brasileira de Química, 2019) Marcheafave, Gustavo G.; Tormena, Cláudia D.; Afoso, Sabrina; Rakocevic, Miroslava; Bruns, Roy E.; Scarminio, Ieda S.
The effects of water-deficit stress on irrigated and unirrigated field plants of Coffea arabica L. genotype IAPAR 59 were investigated. Plant extracts were obtained following an ethanoldichloromethane-hexane statistical mixture design. Proton nuclear magnetic resonance (1 H NMR) fingerprints of the extracts were discriminated using factor analysis (FA) and hierarchical clustering techniques. Extracts from the 1:1:1 ternary mixture presented the largest discriminations compared with those from the pure solvents or their 1:1 binary mixtures. Metabolites resulting from fermentation processes and nutritional deficiencies as well as senescence and abscission precursors such as lactate, arginine and methionine were prevalent in unirrigated plants that can provoke expressive decreases in bean productivity as well as premature plant aging. Amino acids that control regulatory, physiological processes and soil salinization have higher concentrations in the irrigated plants. The NMR assignments of eighteen substances observed here were confirmed by electrospray ionization mass spectrometry.
Production and characterization of the bio-oil obtained by the fast pyrolysis of spent coffee grounds of the soluble coffee industry
(Sociedade Brasileira de Química, 2019) Krause, Maurício C.; Moitinho, Adriana C.; Ferreira, Luiz Fernando R.; Souza, Ranyere L. de; Krause, Laiza C.; Caramão, Elina B.
Agro-industrial wastes are abundant and low-cost sources of energy and chemicals. Biomass account for 14% of the world’s energy production. Industrial residues of production of soluble coffee (spent coffee grounds - SCG) have great potential due to its large-scale production and can be transformed by pyrolysis, in liquid, solid and gaseous products with applications from energy to chemicals. This work has the objective of producing bio-oil from the pyrolysis of industrial SCG, characterize it by chromatography and indicate its possible applications. As SGC contains a large amount of glycerides, they were extracted from SGC before the pyrolysis, aiming to obtain a better bio-oil from the residue. The yield in vegetable oil was 5.2% and its analyses showed that 50% are saturated acids (mainly palmitic 27.6%) and other 50% are unsaturated ones (mainly linoleic acid 35.3%). This composition qualifies this oil for biodiesel purposes. The residue (SGC after extraction) was submitted to pyrolysis, yielding 30% in liquid products, being 6% bio-oil. The bio-oil was analyzed by gas chromatography being identified free fatty acids, hydrocarbons, phenols and N-compounds. The heteroatomic compounds limit the use as biofuel but can be interesting for the pharmaceutical, agrochemical and fine chemicals industries.