Vacuum Drying of Annatto Seeds (Bixaorellana): Drying Kinetics, Optimization and Stability Study

Abstract

The aim of this work was to study the vacuum drying on some quality properties of annatto seeds ( Bixaorellana . Quality properties of the dried product were analyzed using the Response Surface Methodology (RSM) considering the vacuum pressure and temperature of the drying process. In addition, the drying kinetics and stability of the dried product were studied. The analysis of the results indicated that Page’s model was the most suitable to describe the drying behavior, where the bulk density of the final product and total color change between fresh annatto seeds and dry seeds were not statistically significant. The optimum vacuum drying conditions were 45°C, 10.45 mbar and 12 h, with values of 0.358 for the water activity, 7.588 %(w.b) for the moisture content and 9.61% for the bixin content. Additionally, the bixin content presents a decreasing trend during storage for both conditions of light and darkness, where during 28 days of storage, the loss of bixin was 5.27% for light and 4.14% for darkness.