Coffee Science

URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3355

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2014 - 20162

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Autor: search.filters.author.Corrêa, Jefferson Luiz Gomes

Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
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    Spray drying of coffee leaf extract
    (Editora UFLA, 2016-07) Corrêa, Jefferson Luiz Gomes; Mendonça, Kamilla Soares de; Rodrigues, Leonardo Reis; Resende, Mário Lúcio Vilela; Alves, Guilherme Eurípedes
    The coffee leaf extract formulation has been used as resistance inductor in plants and to control phytopathologies. This work aimed to study the influence of spray drying process variables with the use of maltodextrin as carrier on the characteristics of the powder, by using a central composite rotational design (CCRD). The independent variables were maltodextrin concentration (X 1 , 0 to 30 % w/v), coffee leaf extract concentration (X 2 , 2 to 32 % w/v), inlet air temperature (X 3 , 180 to 250 °C) and air flow rate (X 4 , 3.5 to 5.5 m 3 min -1 ). The response variables were collection efficiency (h) , moisture content (MC), phenolic compounds content (Ph), soluble solids (S) content, wettability (We) and particle size (Me). The results showed that the combination of a higher concentrations of coffee leaf extract (X 2) (32%) and lower inlet air temperatures (X 3 ) (180°C) make the best drying performance. This process condition lead to a powder with higher Ph, S, We, Me and lower MC. Therefore, the use of high air flow rates (X 4 ) increase the collection efficiency (h) of process and the use of low maltodextrin concentration (X 1 ) lead to better preservation of phenolic compounds content (Ph) on coffee leaf extract powdered.
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    Drying of spent coffee grounds in a cyclonic dryer
    (Editora UFLA, 2014-01) Corrêa, Jefferson Luiz Gomes; Santos, Johnson Clay Pereira; Fonseca, Bruno Elyezer; Carvalho, Ana Gabriela da Silva
    Spent coffee grounds is a byproduct from the soluble coffee company. Besides its use as animal feed or lipid source, it presents a high potential as biofuel. Whatever the application, to be useful, the product has to loose great part of its moisture content. The drying of spent coffee grounds in a cyclonic dryer was studied in the present work. Based on a experimental design, the effects of temperature of the air (T a ) (59 to 271 oC) and of the ratio mass flow rate of spent coffee grounds to mass flow rate of air (W c /W a ) (0.1 to 3.6) on the moisture reduction (M r ) and average residence time of the particles on the cyclonic dryer (APRT) were studied. It was observed an inverse relation between M r and the ratio W c /W a and a direct relation between M r and T a . Regarding the APRT, it presented an inverse relation to W c /W a . Additionally, the characterization of the spent coffee grounds was performed with respect to the centesimal composition, density and granulometric distribution. It was observed increasing the density and particle size with moisture increasing. It was shown that the cyclone could be an efficient dryer for particulate solids with the advantages of high moisture reduction within short residence time.