Evaluation of the physico-chemical properties of Niger (Guizotia abyssinica Cass) seeds and oil

Abstract

The focus of agricultural research has been on staple crops, with little on underutilized species. One such is Guizotia abyssinica (Niger), a vibrant herbaceous plant with striking yellow flowers from the Asteraceae family. This study analysed the nutraceutical properties of G. abyssinica seeds and oil, via standard analytical methods. Comprehensive analysis revealed a balanced nutritional profile with significant protein (6.7%) and lipid (26%) content. Essential minerals (K: 3.071 mg/g, Fe: 0.110 mg/g, Ca: 11.890 mg/g, and Mg: 1.371 mg/g) were identified, highlighting their nutritional value. Linoleic acid dominated the oil’s fatty acid profile (74.608%), followed by traumatic acid (5.019%) and palmitic acid (3.692%). The oil exhibited favourable properties (high iodine value: 200.5 g I₂/100g, low acidity: 2.2 mg KOH/g) and strong antioxidant activity (IC50 = 6.953 mg/ml). Various bioactive compounds, including saponins, alkaloids, and phenols were identified. Spectrophotometric properties, including a UV-Visible ƛmax of 340 nm and strong FTIR peaks at 1742.59 cm^-1 (carbonyl stretching), and at 2360.35 cm^-1 and 2852.68 cm^-1 (suggesting the existence of alkynes and alkanes), provide reference spectra for quality assessment. These findings emphasize the nutritional significance of G. abyssinica seeds, suggesting application s in food science, nutrition, and allied industry as well as its chemical composition contributing to understanding this underexplored plant.