Navegando por Assunto "Paullinia cupana"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Aplicação de modelos matemáticos bi e tri-paramétricos na predição de isotermas de adsorção de umidade do guaraná (Paullinia cupana) em pó
(2000-04) PENA, Rosinelson da Silva; RIBEIRO, Claudio Cavalcanti; GRANDI, José Glauco
In this study, twelve mathematic models (six biparametrics and six triparametrics), applied in the prediction of isotherms, were studied on prediction of moisture adsorption isoterms of guarana (Paullinia cupana) powder obtained in spray dryer. The moisture adsorption isotherms of the product were fitted at 15° C, 25° C and 35° C, by nonlinear regression analysis, using the software STATGRAPHICS 5.1. The best results among studied models on prediction of moisture adsorption isotherms were GAB, modified BET and Anderson equations (triparametric), Handerson and Oswin equations (biparametric).
Acesso aberto (Open Access)
Influência da temperatura nos parâmetros de modelos bi-paramétricos que predizem isotermas de adsorção de umidade do guaraná (Paullinia cupana) em pó
(1997-12) PENA, Rosinelson da Silva; RIBEIRO, Claudio Cavalcanti; GRANDI, José Glauco
Eight biparametric mathematic models of the literature and widely applied in the prediction of moisture adsorption isoterms were analised. The guarana (Paullinia cupana) powder used in this study, was obtained in spray dryer from a hidroalcoholic extract. The experimental points of the moisture adsorption isotherms of the product at 15°C, 25°C and 35°C were fitted by non-linear regression analysis. To study temperature effect in the parameters of the models were used linear, exponential, logarithmic and inverse regressions. They were also used to fit the software STATGRAPHICS 5.1. The Handerson, Oswin and Mizrahi equations presented the best results among tested models.