Correlation Between Phenolic, Flavonoid, and Mineral Contents With Antioxidant Activity of Underutilized Vegetables

Abstract

Natural antioxidants and minerals are important to nutritionists, food manufacturers, and consumers due to their presumed safety and potential therapeutic value. Underutilized vegetables were sampled to evaluate antioxidant activity (AOA), total phenolic content (TPC), total flavonoid content (TFC), and free radical scavenging activity. Significant positive linear correlations occurred between AOA, TPC, and TFC. Nitrogen (N), phosphorus (P), calcium (Ca), sodium (Na), magnesium (Mg), potassium (K), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), lead (Pb), and arsenic (As) contents were determined. The most common elements were N, P, and K followed by Ca and Fe. A moderate correlation was observed between K content and 2,2′-diphenyl-1-picryl hydrazyl (DPPH), ferric-reducing antioxidant power (FRAP), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), TPC, and TFC. The underutilized vegetables can be used as sources of natural antioxidants and minerals.