Detection and Quantification of Adulteration in Olive Oil using a UV- Spectrophotometric Method

Abstract

A simple spectrophotometric method for detection and quantification of adulteration of olive oil with sunflower, corn and soybean oils was developed. This was done by measuring the characteristics of the absorption bands between 200 and 400 nm. It was found that max absorbance frequencies related to conjugated diene and triene systems which characterize the chemical composition of sunflower, corn and soybean refined oils was a wave length 268 nm. In order to quantify the adulteration; synthetic mixtures were made by 0.5%, 1%, 5%, 25%, 50% and 75% percents for each of the sunflower, corn and soybean oil in olive oil and the absorbance of each solution was measured at 268 nm against isooctane as a blank. Calibration curves were constructed and rational equations were obtained enabling detection and quantification of adulteration. The minimum detectable present of the examined oils in olive oil was 0.5%. This amount is very acceptable since blow it adulteration will be useless without any meaning.