Valorization of Wasted Plant Parts: Mineral Bioavailability, Antioxidant, and Antimicrobial Properties of Wasted Aerial Parts of Selected Root Vegetables

This study aims to investigate the valorization of the wasted aerial parts of root vegetables (onion, white radish, red radish, carrot, and beetroot) as a source of minerals and antioxidant compounds. The findings revealed that the aerial parts of the plants contained valuable amounts of the total phenolic and total flavonoid content with high antioxidant activity, particularly those of carrots. Additionally, the contents of vitamin C, gamma-aminobutyric acid (GABA), and anthocyanin were found in appreciable amounts in most of the samples, except those parts of onion in which the lowest quantity of vitamin C and GABA were detected. Among the phenolic and flavonoid compounds, quercetin was recorded as the major phenolic compound, followed by kaempferol in beetroot, carrot, white radish, and red radish aerial parts. Interestingly, the extraction from the wasted parts of the studied plant exhibited high antimicrobial activity against several species of pathogenic bacteria. Moreover, these aerial wasted parts of the root vegetables had considerable Ca, Mg, Na, K, P, Zn, and Fe content with moderately high bioavailability. Overall, the aerial wasted parts of root vegetables are rich in bioactive compounds and minerals, paving the way for potential utilization in food and feed applications.