Engineering properties of okra (Abelmoschus esculentus) seed

Engineering properties of two Indian okra varieties (Pusa A4 & Punjab-8) were evaluated in laboratory conditions at two moisture regimes i.e. unsoaked and soaked (24 h). The geometric mean diameter and test weight of Punjab-8 and Pusa A4 were respectively found to be 4.69 mm, 4.78 mm and 52.67 g, 63.0 g at 8.51%, 7.37% moisture content on a dry basis (db). Whereas the geometric mean diameter went up to 5.42 mm and 5.76 mm due to increase in moisture content at 73.62%, 67.31% on a dry basis (db) and test weights were increased to 72.33 g and 101.0 g at 73.62% and 67.31% moisture content respectively. The bulk density of the seed was found to decrease with increase in moisture content, it was 0.547g/cm³ at 8.51% moisture content and 0.489g/cm³ at 73.62% for Punjab-8 seed variety and a similar trend was observed in Pusa A4. The angle of repose and coefficient of friction on mild steel surface were also increased with increase in moisture content. The angle of repose of the two varieties was 24.24° and 23.37° in unsoaked condition and 33.30⁰ and 31.24⁰ for the soaked condition. The coefficient of friction was 0.40 and 0.39 for Punjab-8 & Pusa A4 under unsoaked condition and increased to 0.47 and 0.44 in soaked condition. The average value of sphericity and roundness was found to be more in case of Pusa A4 as compared to Punjab-8.