Assessment of Bioactive Compounds, Physicochemical Composition, and In Vitro Antioxidant Activity of Eggplant Flour

Abstract Background: The eggplant (Solanum melongena) is a fruit of world consumption. Its processing in the form of flour is a way to avoid losses and to take advantage of its nutritional characteristics. Objective: This study assessed the physicochemical composition (moisture, proteins, lipids, crude fiber, carbohydrates, minerals, niacin, saponins, titratable acidity, dietary fiber, and total phenols) of eggplant flour prepared from the whole fruit dehydrated in an oven. Methods: In vitro antioxidant activity was assessed using the following methods: 2.2-diphenyl-1-picrylhydrazyl radical (DPPH); Ferric Reducing/Antioxidant Power (FRAP); and analysis of polyphenols using HPLC (chlorogenic acid, caffeic acid, ferulic acid, and rutin). Results: It was possible to observe: 23.09% carbohydrates; 13.34% proteins; 1.85% lipids; 39.19% total fibers; 1,540 mg/100 g total soluble phenolic compounds; 840 mg/100 g saponins; minerals (potassium, magnesium, copper, iron, zinc, manganese); and niacin. In vitro antioxidant activity was observed through DPPH (455.6 mg ascorbic acid/100 g) and FRAP (486.8 mg ascorbic acid/100 g). The HPLC method determined the presence of ascorbic acid, tyrosine, and phenolic acids (chlorogenic acid, caffeic acid, and ferulic acid). Conclusion: The eggplant flour had great fiber content in addition to good content of phenolic compounds and saponins with important antioxidant capacity observed through in vitro assays. As a result, eggplant flour is a good addition to the diet of the population, since it can bring potential health benefits.