A review of advanced techniques for detecting the authenticity and adulteration of camellia oil

Camellia oil, one of the four major woody oils globally, possesses exceptional nutritional value due to its high contents of unsaturated fatty acids and functional compounds like tocopherols, phenolics, and chlorophyll. Unfortunately, due to high demand and cost, fraudsters deliberately mix lower-quality vegetable oils with camellia oil for profits. This has raised concerns among stakeholders, prompting the need for robust authentication methods. This review provides a concise overview of various analytical techniques employed to assess the authenticity, quality, and potential adulteration of camellia oil. Several techniques, such as chromatography, isotope-ratio mass spectrometry (IRMS), ion mobility spectrometry (IMS), differential scanning calorimetry (DSC), plasma-based and deoxyribonucleic acid (DNA)-based techniques, as well as emerging methods like electronic noses and electronic tongues, are discussed. Notably, traditional chromatographic techniques (GC and HPLC) are reported to be time-consuming, laborious, employ toxic chemicals, and require complicated sample pretreatments. DNA techniques also face challenges in detecting adulterants due to the complex refining processes of camellia oil, including high-temperature decolorization and deodorization, which reduce DNA content and induce degradation. In contrast, spectroscopic techniques such as fluorescence spectroscopy, nuclear magnetic resonance, and infrared (near, mid, far) spectroscopy combined with chemometric analyses, have emerged as reliable, rapid, simple, sensitive, and accurate alternative analytical tools for the quality control of camellia oil.