Optical properties of edible oils within spectral range from 300 to 2500 nm determined by double optical pathlength transmission method

摘要

The optical properties of nine different samples of edible oils were experimentally determined by double optical pathlength transmission method in the spectral range from 300 to 2500 nm between 20 degrees C and 80 degrees C. The index of refraction exhibits little difference from the different types of edible oils. The index of absorption of all brands of studied edible oils decreased with the increasing temperature in the spectral range from 500 to 1100 nm. The variation of index of absorption was found to be insensitive to the increasing of temperature in the spectral range from 300 to 500 nm and from 1100 to 2500 nm. The absorption peaks locating at 900, 1210, 1400, 1750, 2150, and 2300 nm of the measured edible oils were corresponding to the result of overtones and combinations of C-H stretching vibration of various chemical groups. A difference of index of absorption was observed among the peanut oil, soybean oil, and sunflower oil in the spectral range from 300 to 500 nm. (C) 2015 Optical Society of America