Journal of the Brazilian Chemical Society

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13322

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    Development of a Disposable Pipette Extraction Method Using Coffee Silverskin as an Adsorbent for Chromium Determination in Wastewater Samples by Solid Phase Extraction
    (Sociedade Brasileira de Química, 2022-05-02) Silva, Weida R.; Costa, Bruno E. S.; Batista, Alex D.; Alves, Vanessa N.; Coelho, Nivia M. M.
    A procedure using disposable pipette tips adapted for solid-phase extraction, known as DPX SPE, was used as an alternative way for the chromium determination in wastewater samples. DPX-SPE consists of a device which allows a dynamic contact between the sample and the solid-phase. A residue obtained from the processing of coffee beans, denominate coffee silverskin, was used as a new adsorbent. Characterization techniques revealed properties of lignocellulosic materials with potential application for chromium adsorption. The parameters including adsorbent mass (25.00 mg), elution solvent (0.1 mol L-1 HCl, 200 μL) and pH (2.0) were optimized. Thus, 1.00 mL of deionized water for conditioning, 4.00 mL of sample, 2 extraction cycles and 1 elution cycle were the employed conditions. Enrichment factor of 12, limit of detection of 6.00 µg L-1 and relative standard deviation (RSD) 1.3% (n = 3) were obtained. The method proved to be fast, cheap, environmentally friendly, and simple, providing good recoveries (104-113%), and it was satisfactorily applied in real samples.
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    Extracts of the Native Brazilian Tree Garcinia gardneriana Inhibit Urediniospore Germination of Coffee Leaf Rust Fungus
    (Sociedade Brasileira de Química, 2022-02-21) Silva, Ueveton P. da; Ferreira, Bruno W.; Sousa, Bianca L. de; Furlani, Gabriela M.; Barreto, Robert W.; Agrizzi, Ana Paula; Leite, João Paulo V.; Santos, Marcelo H. dos; Varejão, Eduardo V. V.
    The fungal Hemileia vastatrix is the causal agent of coffee leaf rust, one of the worst and devastating disease in coffee cultures worldwide. As a result of our research on natural products for the development of novel agrochemicals, we found that the hexane extract from leaves of the Brazilian medicinal plant Garcinia gardneriana, at 500 μg mL-1, inhibited in 98% the germination of H. vastatrix urediniospores. This extract showed no phytotoxicity when tested for seed germination and seedling growth inhibitory activity using sensible plant species. Also, the hexane extract from leaves was tested for anti-acetylcholinesterase activity, which constitutes a mechanism of action of major commercial insecticides used in agriculture, and showed low activity even at concentrations about two times higher than the half maximal inhibitory concentration (IC50) found in the antifungal assays. Gas chromatography-mass spectrometry (GC-MS) analysis showed that the hexane extract is constituted mainly by the pentacyclic triterpene lupeol, together with a series of sesquiterpenes as minor components. This is the first report on the investigation of antifungal, phytotoxic and acetylcholinesterase activities of extracts from leaves of G. gardneriana. These findings indicate that G. gardneriana may constitute a promising source of natural products for controlling the coffee leaf rust fungus.
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    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.
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    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.
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    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.
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    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%).
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    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.
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    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.
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    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.
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    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.