Discrimination of vegetable oils using monochromatic light

This paper describes a simple and inexpensive method to characterize and differentiate edible oils including castor, olive, sunflower, mustard and groundnut oil. In this method monochromatic light at wavelength 635nm, 565nm, 470nm and 430nm is passed through the oil sample. Some of the incoming light is absorbed by the oil sample as a result, light of lower intensity pass through the oil. The amount of light pass through the oil is measured using electronic circuit. The result shows that at wavelength 635nm, 565nm, and 470nm the output are quite close to each other however, at 430nm wavelength the separation of all oil classes is good. This technique is very useful to rapidly classify vegetable oil sample also the avoidance of consumable reagents and of extensive sample pre-treatment make the possibility of performing the measurement in situ with a portable instrument.