Determinação das curvas de secagem das sementes de andiroba em secador solar

Abstract

R E S U M OComumente, o óleo de andiroba é extraído na Amazônia pelo método tradicional ou ainda por prensa. A eficiência na extração está relacionada ao aquecimento e ao teor de água das sementes. Desta forma, a determinação de um modelo de secagem que represente satisfatoriamente os dados experimentais é de suma importância para minimizar as alterações promovidas pelo processo obtendo-se, consequentemente, produto de qualidade. O objetivo do trabalho foi descrever a cinética de secagem das sementes de andiroba, tal como ajustar os modelos matemáticos aos dados experimentais usando-se secador solar. Foi utilizado, como critério do ajuste dos modelos matemáticos, o coeficiente de determinação, a magnitude do erro médio relativo e o desvio-padrão da estimativa. A secagem em menor tempo (14 dias) da Carapa surinamensis para atingir o teor de água de equilíbrio (12,28%) se deve, possivelmente, ao menor tamanho das sementes e à maior quantidade de óleo em relação à Carapa guianensis. O modelo Logarítmico e o de Midilli et al. foram os que melhor se ajustaram aos dados experimentais para as sementes das duas espécies de andiroba. Determination of drying curves of crabwood in solar dryer A B S T R A C TThe oil of crabwood is commonly extracted in Amazon by traditional or by pressing method. The extraction efficiency is related to the heating and water content of the seeds. Thus, the determination of a drying model that represent satisfactorily the experimental data is of paramount importance to minimize the changes introduced by the process, consequently obtaining a quality product. The objective of this study was to describe the drying kinetics of seeds of crabwood as well as adjust the mathematical models to the experimental data, using solar dryer. The coefficient of determination, the magnitude of the mean relative error and standard deviation of the estimate was used as the criterion of fit of mathematical models. Drying in a shorter period of time (14 days) of Carapa surinamensis to reach the water equilibrium content (12.28%) may be attributed to the smaller size of the seeds and the greater amount of oil compared to Carapa guianensis. Logarithmic and Midilli et al. were the model that best fitted the experimental data for seeds of both species of Andiroba. Palavras-chave: modelos matemáticosCarapa surinamensis Miq Carapa guianensis Aubl

Drying kinetics and physical and chemical characterization of white-fleshed ‘pitaya’ peels

“…Among the tested mathematical models, Page showed the highest R² (> 0.998) and lowest MSD (< 0.02) at all temperatures and was the only one to obtain random RD under all drying conditions, corroborating Mendonça et al (2015), who also found that the Page model showed random RD for crabwood seeds. Goneli et al (2011) reported that a model is considered as acceptable if the residuals exhibit random distribution.…”

Drying kinetics of ‘babassu’ mesocarp

“…The literature indicates that the capacity of a model to accurately describe a certain physical process is inversely proportional to the SE value, i.e., the lower the SE, the better the fit of the model (Draper & Smith, 1998;Siqueira et al, 2013;Mendonça et al, 2015).…”

“…Drying occurred in two forms: (i) drying in forced-air oven at speed of 3.0 m s -1 with control of temperatures of 40, 50 and 60 °C and weighings at regular time intervals until reaching equilibrium water content (5, 10, 15, 20, 30 and 60 min); and (ii) drying in the solar dryer described by Mendonça et al (2015), with weighing every 24 h and daily record of temperature and relative humidity using a digital thermo-hygrometer during the day. The initial and final water contents were determined through the standard method of the oven at 105 ± 3 o C, for 24 h, in four replicates (BRASIL, 2009b).…”

“…In general, flour production is made by family activities in rudimentary molds with quality evaluation through color and taste of the product. Drying is performed on concrete floors using natural ventilation, and the water content is controlled empirically (Mendonça et al, 2015). There is little information in the literature on the drying kinetics or even about the effect of the management of 'babassu' mesocarp on the quality of the produced flour.…”

“…Thus, obtaining a drying model that satisfactorily represents the experimental data is of fundamental importance to minimize the alterations promoted by the drying, consequently leading to good quality products (Mendonça et al, 2015).…”