Refractive index (at 40 degrees Celsius)
This is the ratio of the velocity of light in vacuum to the velocity of light in the oil or fat. Refractive index varies with temperature and wavelength. For soyabean oil, it should be between 1.4649 and 1.4710. All brands were within the specified limit. They were clear and without any haziness. Nature Fresh Acti-Lite, Mahakosh, Nutrela and
Fortune scored higher in this parameter.