Nutritional, anti-nutritional, physicochemical and functional properties of raw and roasted Salvia Schimperi (Lamiaceae) seeds: Ethiopian indigenous plant

Abstract

<h2>Abstract</h2> Though, Ethiopia is home to a variety of edible plants, such as <i>Salvia schimperi</i> (<i>S. schimperi</i>) seeds, which have been traditionally consumed in the community, there is a paucity of information concerning the nutritional composition of <i>S. schimperi</i> seeds. Therefore, this study aimed to determine the nutritional, anti-nutritional, physicochemical, and functional properties of raw and roasted <i>S. schimperi</i> seeds. <i>S. schimperi</i> seeds were collected from Menz Mama Midir, North Shewa, Amhara regional state of Ethiopia. The proximate composition, mineral content, fatty acid profile, functional properties of both raw and roasted seed flour and physicochemical properties of the oil, were evaluated following standard procedures. Data obtained showed that both the raw and roasted seeds of <i>S. schimperi</i> are excellent sources of protein possessing, (16.45 g/100g) for the raw seed and 20.36 g/100g for the roasted sample, while the raw seed sample had crude fiber content of 27.67 g/100g and roasted sample contained 18 g/100g. The calcium content of raw and roasted seeds was 235.32 and 310.35 mg/kg respectively. The potassium content of raw and roasted seeds was 807.72 mg/kg and 924.21 mg/kg and the iron content of raw and roasted seeds was 5.81 and 10.03 mg/kg respectively. In the raw seeds, oleic acid was the dominant fatty acid (42.64 %), while in the roasted seeds, linoleic acid was the predominant one (43.04 %). Roasting at 185 °C for 15 min significantly changed the proximate composition, mineral content, fatty acid profile, phytate content, iodine value, acid value, water absorption capacity, and water solubility index of the seeds. The total flavonoid content was higher in the roasted seeds (135.04 mg of CAT/100g) than in the raw seeds (71.60 mg of CAT/100g), whereas the total phenolic content of the raw seeds was higher (215.07 mg of GAE/100g). Furthermore, raw <i>S. schimperi</i> seed oil has comparable peroxide values (3.99 meq O₂/kg oil) to the roasted seeds (4.00 meq O₂/kg oil). <i>S. schimperi</i> seed is a significant source of macro and micronutrients. Additionally, the seed oil has the desirable physicochemical qualities of edible vegetable oils. However, <i>S. schimperi</i> seeds have high anti-nutritional content such as phytate, in both raw and roasted seeds which needs further studies on advanced processing techniques.