Otimização do processo de secagem do extrato de beterraba em leito de espuma

• Autor(a) principal: Santos, Patrick Pereira dos
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/8091
• topic: Secagem em leito de espuma; Extrato vegetal; Beterraba; Otimização; DCCR; Função desejabilidade; Beet; Optimization; Foam mat drying; Desirability function; Ciência e Tecnologia de Alimentos; Alimentos - Desidratação; 664

Beet (Beta vulgaris L.) belongs to Chenopodiaceae family and is a source of minerals, vitamins and rich in antioxidants, notable for its characteristic red color. This red color is the result of the presence of the betalains, water soluble pigments. The objective of the present study was to optimize the drying of aqueous beet extract by foam mat drying process. In a first step concentrations of the foaming agents maltodextrin and Emustab® were optimized. For this, a Central Composite Rotational Design (CCRD) was used, with concentrations of the two agents varying from 0 to 8%, evaluating the influence of these two factors on the responses: specific mass and foam stability, solubility, water content and time wettability of the dried extract, process yield and drying time. For the simultaneous optimization of these seven response variables, the desirability function was used. The optimum condition is expected at the concentrations of 2.4% maltodextrin and 7.44% Emustab®. In a second step the drying temperature of the obtained foam according to the optimum condition of the first step was optimized. For this, five levels of the drying temperature were tested, ranging from 40oC to 80oC, evaluating the effect of this factor on the responses drying time, time wettability, water activity and energy consumption. For the simultaneous optimization of these four variables, it was also used the desirability function. The optimal condition is predicted at the temperature of 60.96oC. In both stages, the drying kinetics of beet extract foam were evaluated, comparing Lewis, Henderson and Pabis, Page and Midili models. The Midili model was the one that presented the best performance in all tested treatments, since it was the one that presented the highest values of adjusted coefficient of determination and the lowest values of standard error of the regression.