Measurement of the degree of unsaturation of oils and fats using infra-red spectroscopy and its relationship with iodine value

Abstract

An spectroscopy method to fast determination of the degree of unsaturation of oils and fats is described by measurement of intensity of the olefinic band at 3007 cm-1 Using SNGLE program, the peak heigt and peak area and also 1st derivate and 2nd derivate at 3007 cm-1 are calculated and relationships between these parameters and iodine values are studied. The best relationships were obtained with the measurements of net absorbance (r=0,9992: error index=1,75%) and area (r=0,9992; error index= 1,77%).

Keywords

• edible fat
• edible oil
• infrared spectrophotometry
• iodine number
• unsaturation degree (determination)