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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item The effect of gravity-drip filtration methods on the chemical and sensorial properties of coffee (Coffea arabica L. var. Castillo)(Editora UFLA, 2019-07) Zapata, Angela María Ormaza; Arango, Félix Octavio Díaz; Rojano, Benjamín AlbertoCoffee prepared via gravity-drip filtration is an alternative to obtain varied sensorial profiles and determine the acidity, bitterness, and body thereof. In the present study, the retention of certain bioactive components was determined, as was the antioxidant activity and cup profiles for coffee beverages prepared by way of seven different gravity-drip filtration methods. The methods which registered the greatest bioactive metabolite retention were the Vietnamese, Clever, and RS 16 methods. The greatest hydroxycinnamic acid content was obtained with the Clever, Yama, Vietnamese, and V60 methods, in descending order. Antioxidant capacity was proportional to the retention of bioactive components, by way of ABTS and ORAC techniques, in the beverages prepared. The V60 and V60 Kalita methods retained the lowest amounts these compounds and their activity. The most predominant hydroxycinnamic acid in the seven evaluated preparations was chlorogenic acid. In accordance with consumer preferences, which seek functional food, it is recommended that coffee be consumed using the Clever or Vietnamese preparation methods, which present fuller body and enhanced bitter notes. In their absence, the RS 16 method is suggested, which presents a sensorial profile identical to that of the U.G.Q. pattern, with less intensity of bitterness.Item Stomatal behavior and components of the antioxidative system in coffee plants under water stress(Escola Superior de Agricultura "Luiz de Queiroz", 2011-01) Deuner, Sidnei; Alves, José Donizeti; Zanandrea, Ilisandra; Goulart, Patrícia de Fátima Pereira; Silveira, Neidiquele Maria; Henrique, Paôla de Castro; Mesquita, Alessandro CarlosCoffee (Coffea arabica) plants show a positive relationship between stomatal closure and formation and accumulation of H2O2. However, for coffee plants under water restriction such relationship has never been studied. The objective of the present study was evaluate the stomatal movement and the antioxidant capacity of coffee seedlings under different water regimes. Eight months old coffee seedlings of cv. Catuaí IAC 99 were submitted to field capacity, gradual and total suspension of irrigation during a period of 21 days. Evaluations of leaf water potential (Ψ w) were performed in the beginning of the morning, and stomatal resistance, transpiration rate and vapor pressure deficit were determined at 10 am and 5 pm. All biochemical and enzymatic determinations were performed in leaves collected at 5 pm. Evaluations and samplings were performed at three days intervals. There was no variation in Ψ w during the evaluated period for plants in field capacity. However, an expressive decrease of Ψ w following day 12, reaching values near -2.5 MPa at the end of the experiment was observed for plants submitted to gradual suspension of irrigation. For plants submitted to total suspension of irrigation, Ψ w decreases after the sixth day, reaching -2.5 MPa at day 15. The decay of Ψ w in plants submitted to gradual and total suspension of irrigation reflected in increased stomatal resistance and in a decreased transpiration rate leading to an increase in hydrogen peroxide formation and, on final stages, increase in lipid peroxidation. As a conclusion, an increase in the activity of antioxidant enzymes as well as in the levels of ascorbate and dehydroascorbate was observed, which act in the detoxification of free radicals formed as result of the water stress.