Antioxidant activity of collards leaves produced in the Federal District, Brazil

Collards leaves are nutritionally rich foods for the human diet. They contain vitamins, minerals, antioxidant compounds. Among the antioxidant components are phenolic compounds and vitamin C, important for the prevention of human diseases. In the human body phenolic compounds exert effects on various metabolic enzymes and signaling, acting against free radicals, inflammatory processes, allergies, platelet aggregation, viruses, tumors. For plants, phenolics are essential in growth and reproduction, as well as being responsible for color, astringency, aroma. Vitamin C is needed to maintain the health of the skin, formation of collagen, absorption of inorganic iron, reduction of cholesterol level, strengthening of the immune system. The objective of this work was to quantify total phenolic compounds and vitamin C in 29 genotypes of collards produced and consumed in the Federal District, Brazil. The sample of collards were mixed with 70% ethanol, Folin-Ciocalteu reagent and sodium carbonate solution. The mixture was centrifuged and, after standing at room temperature, the absorbance was read at 735 nm. The mean values ​​of phenolic values ​​were 37.64 mg of gallic acid equivalent (GAE) of phenolics per 100 g^‑1 of fresh collards. The mean values ​​measured for vitamin C were 114.39 mg vitamin C 100 g^‑1 collards. This quantity is considered adequate in relation to other studies that quantified phenolic compounds and vitamin C in Brassicas. Collards is a food rich in phenolic compounds and vitamin C, important functional components of the diet, and its consumption is a good choice to take care of health preventively.