BIOACTIVE PROFILE AND ANTIOXIDANT POTENTIAL OF ANTHOCYANIN-RICH NON-CONVENTIONAL EDIBLE PLANTS CULTIVATED IN AN URBAN COMMUNITY LABORATORY

Based in the Department of Nutrition of the Federal University of Rio Grande do Norte (UFRN), LabNutrir operates the Nutrir Community Garden to cultivate Brazilian biodiversity food plants. Clitoria ternatea and Oxalis triangularis are Non-Conventional Food Plants (PANCs) rich in phenolic compounds with bioactive potential, especially anthocyanins. This is a promising pigment source for food applications that confer antioxidant activity and interfere with the color of the products. This study characterized the total phenolic content (TPC), total monomeric anthocyanin (TMA) content, ABTS antioxidant capacity, and HPLC phenolic profile of aqueous extracts from C. ternatea (CT) and O. triangularis (OT) cultivated at LabNutrir/UFRN. Extracts were prepared using a 45 °C heated bath for 30 min (1:25 g dried leaves/mL 0.1% trifluoroacetic acid water) and filtered. Analyses included Folin-Ciocalteu for TPC (mg GAE/g dry leaf [DL]), pH differential for TMA (mg cyanidin-3-glucoside eq./g DL), ABTS radical scavenging (mmol Trolox eq./g DL), and HPLC-DAD for identification of individual phenolics. Results showed high phenolic and anthocyanin contents with strong antioxidant capacity for both CT (TPC: 19.9 ± 0.23 mg GAE/g DL; TMA: 4.15 ± 0.67 mg c3g/g DL; ABTS: 7.83 ± 0.84 mmol TE/g DL) and OT (TPC: 16.8 ± 1.4 mg GAE/g DL; TMA: 3.69 ± 1.4 mg c3g/g DL; ABTS: 6.26 ± 0.33 mmol TE/g DL). HPLC revealed 23 compounds in CT, dominated by quercetin-3-glucoside (5,890.44 mg/L), kaempferol-3-glucoside (1,555.19 mg/L), and myricetin (408.93 mg/L), with minor cyanidin-3-glucoside, cyanidin-3,5-diglucoside, and pelargonidin-3-glucoside. The anthocyanin content of CT may be underestimated because ternatins were not quantified due to the lack of available standards. OT yielded 33 compounds, notably pelargonidin-3-diglucoside (3,214.55 mg/L), quercetin-3-glucoside (600.92 mg/L), procyanidin A2 (398.01 mg/L), rutin (346.15 mg/L), vanillin (340.02 mg/L), and myricetin (178.00 mg/L). Both extracts demonstrated significant bioactive and antioxidant potential, an important characteristic when investigating the incorporation of these plants as ingredients for food products and preparations. While PANCs are increasingly characterized for their phytochemicals and antioxidant capacity, key literature gaps must be closed to validate their dietary and therapeutic applications. Addressing these gaps confirms that PANCs are not mere regional curiosities, but globally significant opportunities for food science innovation and sustainable development. 

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal     de Nível Superior - Brasil (CAPES) - Finance Code 001.