A Comparison of the Quality Characteristics of the Virgin and Refined Olive Oils Supplied in Tarom Region, Iran (2019)

Olive oil is one of the healthiest oils in the world with a high nutritional value. Zanjan province has the highest acreage under olive cultivation in Iran. Given the importance of olive oil purity, this study aimed to investigate the quality and authenticity of the olive oils produced in Tarom region, Iran during January-March 2019.

Bulk samples consisting of five virgin olive oils and brand samples consisting of two virgin and three refined olive oils were collected. The fatty acid profile, sterol and squalene contents, and iodine and Cox values of the samples were determined.

In terms of fatty acid composition, 30% of the samples were adulterated with other vegetable oils and contained more than 1% linolenic acid. The total sterol in the samples conformed to the standards (>1,000 mg/kg). However, the concentrations of campesterol and delta-7-stigmastenol in two bulk samples were above the national standard limits. The high content of squalene (55.37%) in a bulk sample was attributed to the soybean oil presence.

The quality properties of the brand samples complied with the national and Codex standards. Due to possible adulteration with other vegetable oils, the continuous monitoring of bulk olive oil supplies is recommended.