# Chemical, Nutritional and Antioxidant Characteristics of Different Food Seeds
###### Abstract  
The objective of this study was to determine the chemical composition of five different food seeds (sunflower, poppy, hemp, flax and sesame) regarding fatty acid, mineral (Fe, Cu, Zn, Na, Mg, K, Ca, Al) and protein content. In addition, the total antioxidant capacity of the seeds was evaluated using the photochemiluminescence assay. The food seeds were subjected to lipid extraction and converted into fatty acid methyl esters before the gas chromatography analysis. In all food seeds, the saturated (SFAs), monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) were identified, respectively. PUFAs were the most abundant fatty acids (\(61.2\%\pm 0.07\%\) and \(84.8\%\pm 0.08\%\) of total fatty acids), with the highest content in flax and hemp seed oil. Also, high amounts of omega-3 from PUFAs were determined in flax and hempseed oil. Based on the obtained results the sunflower, sesame and poppy seeds are good sources of omega-6, while flax and hemp seeds are good sources of omega-3. All samples are rich in minerals (Na, K, Ca, Mg) and have more than 20% protein content. seed; fatty acids; minerals; protein; antioxidant capacity +
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flaxseed and walnuts are rich in omega-3 FAs (C18:3, (n-3). The consumption of omega-3 FAs is recommended to improve immunity, brain function and human health [8; 9; 10]. Generally, the seeds are good sources of protein and carbohydrates due to their high oil content [11]. The hemp seeds (non-drug varieties of _Cannabis sativa_) contain also high levels of vitamins A, C and E, minerals (Ca, Mg, Zn, Fe, K, P), \(\beta\)-carotene and fibers [12]. In addition, poppy seeds are suitable for human nutrition due to their high content of FAs, such as linoleic, oleic, palmitic, stearic and \(\alpha\)-linolenic acids [13]. Flaxseed oil contains all the essential FAs, especially omega-3 FAs and amino acids, necessary to maintain proper cellular function through the synthesis of proteins [14]. The most widely used technique for FAs analysis in vegetable oils is gas chromatography (GC) coupled with flame ionization detector (GC-FID) or mass spectrometry (GC-MS) [15; 16]. Prior to GC analysis, FAs should be converted into fatty acid methyl esters (FAMEs), which are more volatile than their correspondent FAs [1]. The extraction is the most significant step for extraction of all FAs from seed samples. Usually, liquid-liquid extraction with solvent is used for separation of FAs from food samples. Thus, depending on the solvent used, several lipids, such as free FAs, triacylglycer, phospholipids, free sterols, sterol esters, etc. can be extracted [9]. The acid hydrolysis is used to improve the lipid extraction process from different food samples and the elimination of non-lipid compounds [17]. The obtained fat content by using the acid hydrolysis is considerably improved (36.74% from dried egg without hydrolysis and 42.39% using acid hydrolysis before extraction) [18]. [PERSON] et al. [19] used hydrolysis before solvent extraction of lipids from algae. These minerals play an important role in human growth and development due to their contribution to nutrient metabolism, hormonal function and cell differentiation [20]. Mineral deficiencies can be associated with growth stunting and cognitive impairment in the population [21]. The antioxidants can prevent lipid oxidation and deterioration of color, flavor and nutritional quality of food, but antioxidant properties are affected by processing, storage, and total solid and FAs content [5]. To our knowledge, the mineral content of selected seeds (sunflower, hemp, flax, poppy and sesame) were not completely characterized. Based on the importance of these food seeds as a mineral source, a complete characterization regarding the mineral composition of these foods will be proposed. The aim of this study was to determine the content of FAs (SFAs, MUFAs and PUFAs), omega-6 and omega-3 FAs, minerals and protein from poppy, sunflower, sesame, flax and hemp seeds.