This study (open access) evaluated lipid profiles in five oils: three laboratory-prepared reference avocado oils — a cold-pressed oil (O), one from pulp alone (P) and one from pulp with peel (PB) — and two commercial samples declared by the supplier as refined avocado oil (R) and a blend of refined and virgin avocado oil (RB).
The researchers found that R and RB had lower palmitoleic and higher stearic acid proportions than the reference oils, outside the Codex compositional ranges. Trans fatty acid isomers were detected only in R and RB, consistent with their declared refined oil content. R and RB showed higher relative proportions of stigmasterol and Δ7-stigmastenol than those observed in the reference avocado oils. Erythrodiol and uvaol were not detected in O, P or PB, Total C40–C46 waxes was higher in R and RB than in the reference oils.
The authors hypothesise that these differences, despite R and RB being declared as refined, may be compatible with the presence of an undeclared oil fraction. The findings highlight triterpene dialcohols and waxes as promising complementary markers of avocado oil authenticity, warranting further investigation in a larger and representative set of authentic samples.
The authors conclude that
- Erythrodiol and uvaol may be potential purity markers for avocado oil.
- High wax content indicates avocado oil adulteration with pomace or refined olive oils.
- Stigmasterol, Δ7-stigmastenol and stearic acid reveal avocado oil adulteration.
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