Effect of oven roasting treatment on the antioxidant activity, phenolic compounds, fatty acids, minerals, and protein profile of Samh (Mesembryanthemum forsskalei Hochst) seeds

Abstract

The flour of roasted Samh seeds, from a rarely studied and unconventional wild cereal plant, is used by Bedouins in Saudi Arabia as a substitute or supplement for wheat flour during the preparation of several traditional dishes. This study investigated the effect of roasting on the antioxidant activity, bioactive compounds, fatty acids, and minerals contents, and the protein profile of Samh seeds. The results showed that gallic and linoleic acids represented key phenolic compounds and fatty acids, respectively, in Samh seeds. The unsaturated to saturated fatty acid ratios were 5.64 and 5.78 in unroasted and roasted seeds, respectively. Roasting enhanced the antioxidant activity, and the total phenolic, total flavonoid, and oil contents of the seeds (P < 0.05). However, roasting had various effects on the contents of phenolic compounds, fatty acids, and minerals (P < 0.05). Roasting increased the concentrations of most flavonoid compounds, some phenolic acids, essential fatty acids, especially linoleic acid and major minerals, such as potassium and calcium. However, roasting reduced trace minerals and some phenolic compounds and fatty acids. Overall, Samh seeds can be used as a gluten-free food with good nutritional quality, which can be improved by roasting.