Immediate differentiation of unusual seed oils by easy ambient sonic-spray ionization mass spectrometry and chemometric analysis
Vegetable oils have gained continuous economic importance being increasingly used as renewable raw materials by the food, cosmetics and biofuel industries. As an alternative to the traditional sources of oils, unusual vegetable oils from Jatropha curcas, Bombacopsis glabra, Capparis flexuosa, Siparuna guianensis, Moringa oleifera, Hibiscus tiliaceus, Virola bicuhyba, Pouteria caimito and Syagrus coronata seeds are used. We describe herein the immediate as well as direct, fast and low cost characterization of such seed oils via triacylglycerol (TAG) and free fatty acid (FFA) profiles by easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and chemometric analysis. The oils are shown to display indeed typical and unique chemical profiles of triacylglycerol (TAG) and free fatty acids (FFA) with contrasting carbon lengths, degree of unsaturation or with the presence of other chemical functions on the alkyl chain. V. bicuhyba and S. coronata seed oils were found to be constituted of relatively short chain TAG making them potential raw materials for obtaining biogasolines or biokeresones, which are used as aviation fuels. The TAG profiles of H. tiliaceus were very similar to those of soybean, P. caimito similar to those of andiroba oil, and C. flexuosa and S. guianensis similar to those of palm oil. FFA compositions from H. tiliaceus, P. caimito, C. flexuosa and S. guianensis are rich in oleic or linoleic acids, which are an important requirement of feedstock for biodiesel production. Some polyphenolic compounds determined by EASI-MS in some of these oils are also known to provide important nutritional and therapeutic benefits to human health. EASI-MS can therefore offer immediate characterization of such oils and help in quality monitoring and control of adulteration and to guide their application in food, cosmetics and the biofuel industries.