Fabrication, performance evaluation and optimization of Sal (shorea robusta) seed decorticator

Sal (Shorea robusta) seed is a nontimber forest product, mainly processed for its oil. This oil is used in various food and nonfood industries. Prior to extraction of oil, sal seeds are manually broken to obtain sal kernel. This traditional manual de-shelling process is very tedious, time consuming and unhygienic. Hence, in this research, a sal seed decorticator was designed, fabricated and its performance was evaluated. The performance parameters of the machine were tested with varying moisture content from 10.49% to 21.95% (d.b) and different concave clearance varying from 10 mm to 19 mm. The decorticating efficiency, machine efficiency, and kernel percentage were found to have a maximum value of 99.15 +/- 0.04%, 93.62 +/- 0.87%, and 62.71 +/- 1.73%, respectively at 13.63% (d.b) moisture content and 13 mm concave clearance. Results were fitted in response surface methodology to optimize the parameters and to find the level of significance between the independent and dependent variables. Practical applicationsA sal seed decorticator was developed based on physical and mechanical properties of sal seed. The developed machine is designed to run by manpower (manually operated) which can be suitable for hilly and forest region. This decorticator can be used to decorticate sal seeds to get sal kernels. At a seed moisture content of 13.63% (d.b.), the decorticator yields 62.71% of kernels (machine efficiency of 93.62%). These kernels are processed for extraction of oil. This machine is very useful for rural people, farmers and small-scale industries for post-harvest processing of sal seeds.