Journal of the Brazilian Chemical Society
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13322
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Item Evaluation of the metabolic profile of arabica coffee via NMR in relation to the time and temperature of the roasting procedure(Sociedade Brasileira de Química, 2021) Alves, Roger P.; Antoniosi Filho, Nelson R.; Lião, Luciano M.; Flores, Igor S.Coffee is one of the most popular and consumed products in the world, with high nutritional value and economic importance. However, some factors can change the organoleptic properties of a coffee species, without causing significant damage such as loss of important components. The present study evaluated the chemical profile, via nuclear magnetic resonance (NMR), of the main biological properties and substances of the drink, verifying similarities in the composition of different types of arabica coffee made in different conditions, such as the roasting time and temperature. The main components were identified, using information from the literature and a database, and compared with the experimental data of 1D and 2D ¹H NMR. The spectral data were analyzed and grouped via principal component analysis (PCA) using the Bruker Amix 3.9.14 software. ¹H NMR was able to monitor the roasting process and qualify the intact bean and chemical profile of the coffee according to the roasting conditions. Due to the importance of the monitored components, the coffee species analyzed can be identified, along with the appearance of unwanted or adulterating compounds that are normally added to the product to reduce the cost of commercialization.Item 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.