Authenticity analysis of orange (Citrus sinensis) essential oils

Abstract

Orange essential oils have a lot of applications in industrial fields such as pharmaceuticals, cosmetics, and high demand for food and fragrances. Adulteration in essential oils is common, and this replaces the high-cost ingredients with cheaper and lower quality substitutes, which can be attractive and lucrative, and it has implications for the health of consumers like skin infections reported in previous studies. Therefore, it is necessary to have an analytical methodology with highly selective and sensitive to authenticate and quantify natural essential oils and their level of adulteration. The nonvolatile fraction of orange essential oils is commonly undervalued due to their insignificant contribution to the smell profile. However, these compounds may be the key to develop an analytical approach, but there is not enough information reported regarding authentication techniques for the flavor and fragrances industry. The purpose of this project is to develop a methodology that allows authenticating orange essential oils by chromatographic techniques. It is proposed a Reversed-Phase High-performance Liquid Chromatography (RP-HPLC) method for the compositional identification of polymethoxyflavones (PMFs) in orange essential oils. Twenty-eight samples of orange essential oils accomplished this study subjecting a solid-phase extraction (SPE) cartridges (C18). Then samples were filtered through the nylon membrane of 0.45 µm pore size, later were subjected to RP-HPLC analysis conditions, and for the identification of these compounds was carried out on Acquity UPLC H class with QDa mass detector (along with PDA). The compounds PMFs found were sinensetin, hexamethoxyflavone, nobiletin, tetra-o-methyl-scutellarein, heptamethoxyflavone, and tangeretin. A statistic tool with a high level of confidence allows identifying adulteration in orange essential oils.