Nutritional Composition, Anti-oxidative and Anti-hyperglycemic Potential of the Kernels of Two Varieties of <em>Terminalia catappa</em> L.

Purpose: An attempt was made in this study to compare the differences in nutritional composition, antioxidant capacity, and anti-hyperglycemic effect of the kernel of purple and yellow varieties of Terminalia catappa L (T. catappa L).Research Method: Sampling of ripe fallen seeds of yellow and purple varieties of T. catappa L. was done in the Central Province of Sri Lanka from October to December 2022. Moisture, crude fat, ash, and crude protein contents of seed kernels of the two cultivars were determined using AOAC methods. The differences in fatty acid composition and micro-mineral distributions were also determined using the relevant methods. Sequential extraction of the powdered samples of individual cultivars was performed with hexane, ethyl acetate, and methanol as solvents. The total phenolic content, DPPH radical scavenging activity, alpha-amylase, and alpha-glucosidase inhibitory activities were determined in vitro using relevant assays.Findings: Regardless of the cultivar, the main constituents of the seed kernels were fat (63.30 ± 4.16%) followed by protein (25.58 ± 0.51%). Oleic, linoleic, and palmitic were detected as the major fatty acids of the oil fraction. Among the solvent extracts, the methanol extract of the purple variety had the highest total phenolic content (17.77 ± 0.15 mg of GAE/g). Interestingly, ethyl acetate extracts of both cultivars showed significantly (p<0.05) higher inhibition against alpha-glucosidase (IC50: 104.13a±1.22 mg/dm3)) while the methanol extract of the yellow variety showed the strongest alpha-amylase inhibitory activity (IC50: 2137.95 ± 118.54 mg/dm3).Value: The seed kernel of T. catappa L is a rich source of nutrients and can be used as a raw material for the development of foods meant for diabetic patients.