Mathematical modeling for the annatto (Bixa orellana L.) seed drying process

Abstract

The pigment extraction process using annatto (Bixa orellana L.) seed produces a large amount of seed waste. Although most of these seeds are discarded, a number of studies report promising results with their use in animal feed. The good fiber content also suggests human nutrition applications, with possible incorporation in dietary foods. In the present study, annatto seeds derived from color extraction were dried, with and without the layer of oil left over from the process. Seeds were dried at 40, 50, 60 and 70 °C. Drying data were fitted to the Diffusion Approximation, Two Term, Midilli, Page and Thompson models. Drying was carried out up to a moisture content of approximately 5% wet basis. All the models studied exhibited adequate fit to the drying kinetics data of the annatto seeds, with coefficients of determination above 0.98 and root mean squared error (RMSE) below 1.0. Seeds with oil had longer drying times at 40 and 50 °C and shorter times at 60 and 70 °C. The coefficients of diffusion showed values between 2.67 × 10 -11 and 9.50 × 10 -11 m 2 s -1 and between 2.7 × 10 -11 and 6.21 × 10 -11 m 2 s -1 , while activation energies for liquid diffusions were 38.04 and 23.52 kJ mol -1 , for residual seed drying with and without oil, respectively.

Vacuum Drying of Annatto Seeds (<em>Bixaorellana</em>): Drying Kinetics, Optimization and Stability Study

“…The constants found in this research are in line with the results presented in Yacon (Reis et al, 2012), but in previously reported studies on the dehydration of annatto seeds using a convective dryer, the k and n values differed from those found using vacuum drying. The drying kinetics in forced hot air are rather slow and took more time to reach the equilibrium MC, which is Santos et al, 2013;Santos et al, 2012).…”

“…Traditional drying techniques are applied for seeds, where forced air convection drying is the most common (Da Costa- Santos et al, 2013;Santos et al, 2012). Taking into account that the price of annatto seeds usually depends on the bixin content, is important to study new techniques of drying that allow higher concentration values of the carotenoid to be obtained, while avoiding factors that affect the quality of the seeds, in order to obtain a better seller price.…”

Cinética de secagem das sementes da pitaya vermelha (Hylocereus polyrhizus)

“…Dentre os métodos que podem ser empregados, a secagem é mais utilizado, uma vez que controla o a atividade biológica (Santos et al, 2013a) através da redução da atividade de água, evitando desse modo o desenvolvimento de microrganismos e retardando as reações bioquímicas, o que aumenta a sua armazenabilidade (Santos et al, 2014). Muitos estudos foram conduzidos com o objetivo de investigar a secagem de sementes e grãos (Carlesso et al, 2007;Corrêa et al, 2007;Roberts et al, 2008;Diógenes et al, 2013;Santos et al, 2013b;Mendonça et al, 2015), porém não foram encontrados relatos acerca da desidratação de sementes de pitaya, sendo a maior parte das pesquisas relacionadas com o cultivo e a qualidade dos frutos, fato este que motivou a realização desta pesquisa.…”

“…Comportamento semelhante foi verificado por Diógenes et al (2013), Santos et al (2013b) e Roberts et al (2008) ao estudarem a secagem de grãos de abóbora, grãos residuais de urucum e sementes de uva, respectivamente.…”

Modelagem e propriedades termodinâmicas da secagem de fatias de acuri

“…Os coeficientes de difusão efetivos aumentaram linearmente e a sua dependência com relação à temperatura do ar de secagem foi descrita pela Equação de Arrhenius. A linearidade decrescente evidencia a uniformidade de variação da taxa de secagem dentro da faixa de temperatura estudada (Santos et al, 2013). A Ea encontrada para a secagem das fatias de acuri foi de 17,66 kJ mol -1 , apresentando-se dentro do intervalo de 12,7 a 110 kJ mol -1 relatado por Zogzas et al (1996) para produtos agrícolas.…”