Biblioteca do Café
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Item Bioactive Diterpenes and Serotonin Amides in Cold-Pressed Green Coffee Oil (Coffea arabica L.)(Sociedade Brasileira de Química, 2024-02-09) Silva, Rodrigo M. V.; Brand, Ana Laura M.; Tinoco, Natalia A. B.; Freitas, Suely P.; Rezende, Claudia M.Cold pressing is an environment-friendly mechanical extraction for oils from seeds. In this work, cold-pressed green Arabica coffee oil was investigated related to the influence of the pressing variables (preheating, exit diameter, screw speed, and particle size) on the chemical oil composition, mainly on the diterpenes and, for the first time in the scientific literature, on the content of serotonin amides (N-alkanoyl-5-hydroxytryptamides (Cn-5HT)). The oil yield from screw pressing varied from 2.65 to 6.27%, with major yields obtained as the size of the particle and temperature increased. Soxhlet extraction produced 9.46 ± 0.04% of oil. The fatty acid content of the oils varied from 32.79 to 33.49% and showed no significant difference among the different pressing conditions. The amount of the diterpenes kahweol and cafestol ranged from 13.33 to 16.72 mg g-1 and 37.11 to 47.14 mg g 1 of oil, respectively, summing 50.44 to 63.86 mg g 1 of diterpenes. The total content of Cn-5HTs ranged from 307.92 to 1716.52 µg g 1, being 114.42 to 577.37 µg g 1 for arachidic acid-5-hydroxytryptamide, (C20-5HT) and 193.50 to 1068.08 µg g 1 for behenic acid-5-hydroxytryptamide (C22-5HT) in oil, the most abundant in coffee bean. From the 16 cold press treatments, six conditions showed significant amounts of these compounds. Aspects related to the biological activity and relevance of coffee lipid diterpenes and Cn-5HTs are discussed.Item Discriminação entre estádios de maturação e tipos de processamento de pós-colheita de cafés arábica por microextração em fase sólida e análise de componentes principais(Sociedade Brasileira de Química, 2011) Arruda, Neusa P.; Hovell, Ana M. C.; Rezende, Claudia M.; Freitas, Suely P.; Couri, Sonia; Bizzo, Humberto R.A fruit chemical composition reflects its maturation stage. For coffee, it is also the reflex of the post harvesting processing type, dry, semi-wet and wet. The object of this work was to verify if headspace solid phase microextraction coupled to gas chromatography (HS-SPME-GC) could be used to discriminate between samples harvested in different maturation stages and treated by different processes. With application of principal component analysis to the area of 117 compounds extracted by SPME, using divinylbenzene/Carboxen/polydimethylsiloxane fiber, it was possible to discriminate, in the roasted and ground coffee, the maturity stage and processing type used.