Optimization of process conditions of the neem fruit depulping machine for the production of premium quality seeds and oil

Neem ( Azadirachta indica ) seed is potential source of oil extraction, which is widely used as an alternative for synthetic chemicals in food preservation, active functional agent in food packaging, medicine, cosmetics and biopesticides. Neem seeds are obtained mainly through manual depulping, which resulted in seed damage, human drudgery, time consuming and yielded poor quality of neem oil. To overcome the limitations of manual process, a study was undertaken to design and develop a Neem fruit depulper with shearing mechanism. The process parameters were optimized by analyzing the effect of independent variables such as: roller speed (450, 550, and 650 rpm), capacity of the depulper (75, 100, 125 and 150 kg/h) and clearance between sieve and cylinder (10, 15, and 20 mm) on depulping efficiency and percentage of broken. The optimized process parameters were found to be roller speed of 550 rpm, capacity 125 kg/h and 15 mm clearance between sieve cylinder and roller. At this optimized condition, the depulping efficiency and broken percentage of the developed neem fruit depulper were recorded as 94.29 (wt.%) and 5.6 (wt.%). The depulped seeds were dried under sun drying and tray drying at the optimized temperature of 60 °C. The sun dried and tray dried neem seeds took 900 and 240 min to reach a final moisture content of 8 (% w.b.) The physicochemical properties (Azadirachtin content, Peroxide value, Acid value, Saponification value, Iodine value, Viscosity, Specific gravity, Density, pH and colour value (L*, a* and b*)) of sun and tray dried samples shows significant difference ( p