Proximate composition, amino acid profile, carbohydrate and mineral content of seed meals from four safflower (Carthamus tinctorius L.) varieties grown in north-eastern Morocco

Abstract

The purpose of this study is to complete our work on the characterization of four safflower varieties produced in the oriental region of Morocco by determining the composition of their meals. This characterization was carried out by analyzing proteins, amino acids, fibers, carbohydrates and mineral elements. The results show that the protein content varies in a range of 17.06–27.05%, fibers 63.45–69.97%, carbohydrates 12.40–17.07% and ash 3.11–3.60% on dry weight basis. The most abundant amino acid in the studied safflower meals is glutamic acid (3.19–3.89% of dry matter), while lysine and methionine are the least abundant. Cellulose and hemicellulose are the most representative fibers (28.16–31.35% and 21.04–21.68% of dry matter, respectively). The main carbohydrate is xylose, whose content varies between 10.56–14.31% of dry matter. The results also show that the studied safflower meals constitute a good source of potassium (6.32–9.51 g kg −1 of dry matter), phosphorus (2.35–4.60 g kg −1 ), magnesium (2.25–4.25 g kg −1 ) and calcium (1.53–1.72 g kg −1 ). Amongst the identified microelements, iron is the major element in all the analyzed samples (53–125 mg kg −1 ). Moreover, the majority of the studied analytical parameters were strongly influenced by the cultivar factor ( p  < 0.05). In view of these analyses and pasture shortage, especially during the dry seasons in Morocco, the meal obtained from oil extraction from safflower seeds can be upgraded by the formulation of new animal feed products in this region.