Exploring the antioxidant potential of Philippine native corn varieties

Native corn varieties are mostly found in areas where corn is used as staple. Eating quality has been the primary basis for selecting the varieties, and the farmers keep the seeds from selected varieties to be grown the next season. However, nutritional composition based on proximate components and phytochemical properties of different native corn varieties has not been available. The objective of this study is to evaluate the antioxidant potential of the Philippine native corn varieties. Seed samples from 46 Philippine native corn varieties were evaluated with three replications. These collections came from the three main regions of the country and have been characterized with different Kernel color. Total phenolic content (TPC), total flavonoids content (TFC) and total carotenoids were determined. Although these compounds are considered non-nutritive, the interest in their antioxidant properties has increased due to their potential health. In addition, the antioxidant activity was evaluated as 2,2- diphenyl -1- picrylhydrazyl (DPPH) radical scavenging activity. Variations in antioxidant potential were observed on different native corn varieties. The different varieties showed good variability on antioxidant activity, with the highest scavenging ability percentages observed on UPLBCnN11 (13.52%) and UPLBCnN15 (12.98%). Three varieties, UPLBCnN20, UPLBCnN32, and UPLBCnN36, have high carotenoid contents of 2.19, 2.15, and 2.09 mg/100 g, respectively. High total phenolic contents were observed on UPLBCnN3 (7.06%) and UPLBCnN2 (6.74%). In addition, UPLBCnN2 had highest total flavonoids content of 7.11 mg CE/100 g, followed by UPLBCnN20 (7.03 mg CE/100 g). Based on the antioxidant potential of the native corn varieties, TPC was positively correlated with TFC. Profiling of phenolic compounds present using RP-HPLC with UV/Vis detector is still on going. The variability observed among the native corn varieties for antioxidant potential will be useful in developing corn varieties for better health and wellness.