Chemical and physical characterization of 'egusi' melon seeds and prediction of fat content by NIR Spectroscopy

Abstract Egusi seeds are integral to the culinary traditions of many tropical/ sub-tropical communities. However, the lack of comprehensive studies on their nutritional and physical properties limits their potential for food and nutrition intervention endeavours. This study aimed to determine the physical and chemical characteristics of egusi seeds (‘Neri’ and ‘Akatoa’ varieties) from two major egusi -producing districts in Ghana and use near-infrared spectroscopy (NIRS) to classify and predict their fat content. Standard methods were employed in the physical and chemical characterization of the seeds, while Linear discriminant analysis (LDA) and partial least squares regression (PLSR) were used for the classification and fat content prediction. Significant differences ( p < 0.05) were found in the physical properties of the seeds. Seed lengths ranged from 8.92 to 18.65 mm, widths from 3.83 to 7.74 mm, and thicknesses from 1.33 to 1.74 mm. Small ‘Neri’ had the highest sphericity at 45.58%, while the white melon seed variety from Chereponi had the least at 34.08%. Proximate composition showed high levels of fat, ash, and crude protein, with total carbohydrate content ranging from 3.10 to 10.89 g/100 g. Mineral contents included iron (4.60 to 17.35 mg/100 g) and zinc (0.82 to 3.80 mg/100 g). Predictive models for fat content performed well, highlighting the potential use of NIRS for rapid assessment. This study demonstrates NIRS's potential for egusi seed classification and fat content prediction while providing essential insights into the composition and physical characteristics of different egusi melon seeds to inform future valorization endeavours for the seeds.