Total fat content and fatty acid profile of pseudocereals

Amaranth, quinoa, and buckwheat are called “pseudocereals” since they produce starch-rich seeds like cereals but they are dicotyledonous plants (and not monocotyledonous as cereals). According to some phylogenetic classifications, amaranth (Amaranthus) and quinoa (Chenopodium) genera belong to the order Caryophyllales, whereas buckwheat (Fagopyrum) belongs to Polygonales [1]. Pseudocereals have recently gained more popularity as a part of human diet thanks to their chemical composition, particularly as a source of protein, vitamins of B group, minerals and also for their gluten-free flour [2]. Some pseudocereals can even present a fat content three times higher than cereals, with a fatty acid profile dominated by unsaturated fatty acids [3-5]. The total fat content was determined using Soxhlet method, and the fatty acid profile was subsequently determined using gas chromatography with flame ionization detection (GC-FID). The results for total fat content ranged from 3.1% to 8.0%. and evidenced a significant predominance of unsaturated fatty acids. For amaranth and buckwheat unsaturated fatty acids composed up to 81% of the total chromatographic area while for quinoa this value ranged from 87.6% to 90.4%, depending on variety. Polyunsaturated fatty acids formed 48.8% in amaranth, 61.1-64.9% in quinoa and 40.9% while monounsaturated fatty acids compose 32.2% in amaranth, 26.7-29.2% in quinoa and 40.2% in buckwheat. Main unsaturated fatty acids consisted of linoleic acid followed by oleic, linolenic and nervonic acids. Main dominance for saturated fatty acids was for palmitic acid. Buckwheat shown significant differences in fatty acid composition having much higher amount of oleic acid but lower amount of linoleic acid and no signs of nervonic acid. This distinct fatty acid profile may be partially explained by the different botanical origin of buckwheat, which belongs to the Polygonales order, while amaranth and quinoa are classified into the Caryophyllales order.Thanks are due to Polytechnic Institute of Bragança, CIMO Research Unit, Latvia University of Agriculture, and the ERAMUS Mobility program for the financial support.