Cis-vaccenic acid: New maker to detect seed oil adulteration in avocado oil

Abstract

Efforts to ensure avocado oil purity have been made and standards are currently being developed, however, challenges still exist with differentiating avocado oil from high oleic seed oils, such as sunflower and safflower oils. Cis-vaccenic acid or C18:1 (n-7) is an oleic fatty acid isomer that has significantly different concentrations in avocado oil compared to high oleic sunflower and safflower oils, as well as other adulterants. High oleic safflower oil has cis-vaccenic values <0.75% of total fatty acid content and high oleic sunflower <1.3% total fatty acid content, while avocado oil has concentrations ranging from 5.5% to 7.5%. Standards on fats and oil typically only require for total oleic acid (sum of C18:1(n-9) and C18:1 (n-7)), however, this work demonstrates that there is an immediate need to consider including a separate standard for cis-vaccenic content in avocado oil to aid in detecting adulteration, particularly with seed oils.