Physicochemical analysis, antioxidant activity and research of saponins in fresh and blanched caruru (Amaranthus deflexus Linn) and ora-pro-nóbis (Pereskia aculeata Miller) leaves

Abstract

Caruru and ora-pro-nóbis are unconventional food plants rich in proteins, essential amino acids, fibers, vitamins, minerals, and bioactive compounds but contain antinutritional factors. Blanching is one of the recommended methods to eliminate antinutrients, but it can change the chemical composition of foods. Therefore, the study’s objective was to evaluate the physicochemical characteristics (pH and acidity), the proximate composition, the bioactive compounds (total phenolic compounds and vitamin C), the antioxidant activity and the presence of saponins in fresh caruru and ora-pro-nóbis leaves and subjected to blanching. The analyzed samples showed significant content of moisture, ash, protein, fiber, total phenolic compounds, vitamin C and antioxidant activity. In caruru, blanching increased pH, total solids, proteins, lipids, and carbohydrates while decreasing moisture, antioxidant activity and saponins. In ora-pro-nóbis, this processing increased pH, fiber, and total phenolic compounds and decreased vitamin C and saponins.