Morphological characteristic analysis of dry fruits of annatto (Bixa orellana L.)

Abstract

The present research work was performed to explore the engineering properties of annatto (Bixa orellana L.) fruits and seeds in dried large and small variety. The geometric properties (length, breadth, thickness, arithmetic mean diameter, geometric mean diameter, sphericity, aspect ratio and surface area), gravimetric properties (bulk density, true density and porosity) and frictional properties (angle of repose and static coefficient of friction) were determined for small pods, large pods, small seeds and large seeds of annatto fruit by following standard methods. The moisture content of dried annatto fruits were ranged from 11.27 to 9.36% (w.b.) and for the seeds 6.67±1.5% (w.b.). The average arithmetic mean diameter of large pods was 30.33±3.19 mm and for small fruits was 23.49±2.29 mm. The true density, bulk density and angle of repose were also determined for small and large pods and seeds. The coefficient of friction was maximum (0.53±0.05) for small annatto pods in cardboard surface and minimum (0.14±0.057) for large dried pod in rubber surface. These properties finds application in developing a power operated decorticator to ease the separation of seeds from annatto pods without losing its valuable pigment present in its seed coat.