Efficacy of Microwave Heating Parameters on Physical Properties of Extracted Oil from Turmeric (Curcuma longa L.)

In the study, essential oil extraction from turmeric was carried out using modified microwave distillation system and rotary evaporator unit. In present study, effect of input parameters i.e. microwave power (200, 250, 300, 350 and 400 W) and extraction time (10, 15, 20, 25 and 30 min.) on physical properties (oil yield, specific gravity, refractive index and colour) of essential oil were studied. Fixed ratio samples (1:1:1) i.e. turmeric powder, solvent and distilled water was used during the experiment conducted. Essential oil yield using hexane varied from 1.895% to 4.973% while from 0.180% to 1.226% using petroleum ether solvents. Quality parameters varied i.e. specific gravity from 0.910 to 0.923, refractive index from1.478 to 1.506, colour values for oil ranges L* from 70.60 to 98.60, a* from –25.60 to 15.1 and b* from 82.1 to 88.5. Optimum values of process parameters for maximum oil recovery (4.973%) and best quality of oil (specific gravity: 0.915; refractive index: 1.485) was found at microwave power 300 W and extraction time 20 min.