Physicochemical, antioxidant, and in vitro cell viability properties of commonly consumed yams in Australia

Yam (Dioscorea spp.), a high-calorie food, has long been a staple among Australian First Nation people; however, limited research exists on commercially available yams in Australia. This study investigated three genotypes (A, B, and C) of commercially grown yams in Australia for nutritional properties, such as total starch content and total dietary fibre, by using Megazyme kits, total phenolic content by the Folin–Ciocalteu method, antioxidant activity by FRAP (Ferric ion reducing antioxidant power) and ABTS (2,2’-Azinobis-3-Ethylbenzthiazolin-6-Sulfonic Acid), and in vitro cell viability properties using Caco2 and HT29 cell lines. The results showed that the flesh of genotype C had superior nutritional and antioxidant properties with higher total starch content (85.64%), dietary fibre content (10.34% (flesh), 50.15% (peel)), total phenolic content (15.17 (flesh) and 62.21 (peel) mg GAE/g), FRAP (23.10 (flesh) and 70.34 (peel) mmole Fe2+ eq/ g DW), and ABTS (607.08 (flesh) and 1099.8 (peel) μmole TE). The cell viability assay indicated that the peel had a stronger inhibitory effect on the growth of Caco2 and HT29 cell lines. Flesh extract concentrations of 678.2-8605 µg/mL and peel extract concentrations of 802.1-7657 µg/mL showed a 50% inhibition of growth in the HT29 cells. For Caco2 cells, flesh extract concentrations of 925.3-8245 µg/mL and peel extract concentrations of 1413-6943 µg/mL resulted in 50% inhibition. The results suggest that these yams may be considered nutritious, with potential health benefits, and useful as an ingredient in functional food products.