Sv.Momchilova¹, S.Taneva¹, R.Dimitrova¹, I.Marekov¹, D.Antonova¹, B.Damyanova¹, E.Blagoeva², M.Nikolova²

¹ Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 9, 1113 Sofia, Bulgaria (e-mail: svetlana@orgchm.bas.bg)

² Agricultural Experiment Station, Agricultural Academy, 1 Minjorska Str., 6600 Kardzhali, Bulgaria

 

Since ancient times, walnuts and hazelnuts have been a part of the human diet and an important source of energy. Due to their excellent taste and increasingly demonstrated health benefits, nuts are currently considered fundamental to several dietary guidelines worldwide. They contain high amounts of protein and fat, mostly unsaturated fatty acids, thus being an excellent source of the so-called essential fatty acids, which are indispensable for life and good health. The benefit of nuts consumption is already well recognized in Europe and, logically, research is focused on chemical characterization of their local varieties. Knowledge on the lipid composition of Bulgarian nuts will provide a tool for classification and identification of local and introduced walnut and hazelnut cultivars. In addition, the results will be very useful for proving the authenticity of nut oils that are currently popular as salad or cooking oils as well.

In this investigation, the lipid composition of five walnut and three hazelnut cultivars grown in Bulgaria was determined by various chromatographic methods (TLC, GC-FID, GC-MS, HPLC). The nuts characteristics analyzed in all samples were the fat content, total fatty acid composition and triacylglycerols. The neutral lipid classes and their individual fatty acid composition, as well as the sterols, were analyzed in single nuts cultivars. Chemometric approaches were applied for differentiation and classification of the nuts cultivars.

 

Key words: lipid composition, walnuts, hazelnuts, chromatography