Cinética de secagem convencional e por micro-ondas da polpa do fruto macaúba (Acrocomia aculeata)

Abstract

The macaúba (Acrocomia aculeata) is a palm native to Brazil with multiple industrial uses, primarily in the food industry, where its fruits are used for producing sweets, ice creams, liqueurs, and other products. However, these fruits have a high moisture content, which contributes to the growth of microorganisms and complicates their preservation and storage. Studying the drying kinetics of this raw material is essential for selecting the most suitable method, and mathematical modeling plays a fundamental role by enabling the simulation, optimization, and scaling of the drying system, facilitating its application on a commercial scale. In this context, the present study aimed to evaluate the drying kinetics of macaúba fruit pulp using conventional and microwave methods. The experiment was conducted in the fruit laboratory at Campus III of the Federal University of Paraíba, where the macaúba pulp was subjected to conventional drying in a practical dryer at 60 °C, with five repetitions, and microwave drying at powers of 20% (280W) and 30% (420W), with three repetitions for each treatment. The drying curves obtained were analyzed, and the data underwent mathematical modeling, allowing for the comparison of moisture removal rates between the two methods. Thirteen models were tested, and the selection of the most suitable model considered three criteria: the coefficient of determination (R²), the mean square error (MSE), and the chisquare (χ²). A model was considered satisfactory when it provided consistent and standardized results across the three treatments. The results showed that microwave drying at 420W was significantly faster, with a drying time of 17 minutes, compared to conventional drying, which took about 600 minutes (10 hours). Additionally, this technique exhibited higher values of k (0.182728) and n (1.75715). Thus, the conclusions of this study indicate that the Modified Page 2 model was the most appropriate for describing the drying kinetics of both tested methods. Furthermore, microwave drying proved to be more efficient and has the potential to be explored on a larger scale for the preservation of macaúba fruit.