Rapid authentication of edible oils by matrix-assisted laser desorption/ionization mass spectrometry

T-T Ng, P-K So, B. Zheng, Z. Yao
The Hong Kong Polytechnic University,
Hong Kong

Keywords: edible oils, mixed edible oils, recycled cooking oils, matrix-assisted laser desorption/ionization mass spectrometry, authentication


Authentication of edible oils has been an important issue in food safety, particularly important with the widespread use of recycled cooking oils (gutter oils) in recent years. However, conventional analytical approaches for analysis of edible oils are labor intensive and time consuming, and there have been no widely accepted scientific methods for rapid screening of mixed edible oils and recycled cooking oils. We have developed direct analysis of edible oils using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and established a preliminary spectral database of edible oils. Since different types of edible oils have different MALDI-MS spectral patterns, the authenticity of an edible oil sample can be determined by comparing its MALDI-MS spectrum with those of its labeled oil in the established database. Our results revealed that mixed edible oils and recycled cooking oils could be screened out from the pure edible oils using the approach, since heating and mixing of edible oils could change their MALDI-MS spectral patterns. This approach is rapid, simple and can analyze one edible oil sample within minutes.