Chemometrics as a tool to discriminate geographical origin of Cyperus esculentus L. based on chemical composition

In the present study the chemical composition of Cyperus esculentus L. (tiger nut) from four distinct geographical origin (Spain, Egypt, Nigeria, and South Africa) was assessed to observe the possible effect of the cultivation site in the fatty acids profile, sterols composition, and squalene and alpha-tocopherol content. It was verified that the individual fatty acids as well as the different fatty acids fractions were severely affected by the geographical origin. Tiger nut oils were predominantly monounsaturated with lower prevalence of saturated fatty acids, and with capability to provide appreciable amounts of essential fatty acids. The sterols fraction was affected as well, but in lower extent. beta-sitosterol was the most abundant sterol found, reaching nearly 60% of the total sterols found in tiger nut oils, with significant differences among geographical origins. The fatty acids data, together with the sterols and alpha-tocopherol and squalene data were capable to separate tiger nut samples according to their chemical composition and geographical origin when a principal component analysis was applied. The fatty acids profile could be applied as a possible geographical authenticity marker. (C) 2013 Elsevier B.V. All rights reserved.