Abstract

Introduction: The antioxidant fraction of Stevia rebaudiana has important antidiabetic potential, is poorly soluble, and has low stability, which makes its applicability difficult.

Materials and Methods: In this study, Stevia's fraction was obtained, characterized by Ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLCMS/ MS), and microencapsulated with maltodextrin (MDF), gum arabic (GAF), whey protein + maltodextrin (MDWF), and whey protein + gum arabic (GAWF). Then, the following parameters were evaluated: stability and antioxidant capacity over 30 days, physicochemical characteristics, preservation of bioactive compounds by digestion, and in vitro antidiabetic activity.

Results and Discussion: The microcapsule with gum arabic showed better microencapsulation efficiency, while its version with maltodextrin provided increased solubility. Microencapsulation reduced the humidity and water activity in the microcapsules, except for the microcapsules containing gum arabic. The combination of maltodextrin and whey protein showed greater luminosity and a whiter powder. The microcapsules with maltodextrin and its mixture with gum arabic kept the phenolic compounds stable for 30 days. The microencapsulation with whey protein increased the antioxidant activity after 15 days of the process and during in vitro digestion. All samples showed 96% inhibition of the α-glucosidase enzyme, and only the microcapsule with maltodextrin inhibited α-amylase (58%).

Conclusion: This study showed paramount results so that Antioxidant Stevia Fraction (ASF) can effectively be an adjuvant product to prevent and treat diabetes.

Keywords: Stevia extract, microencapsulation, gum arabic, maltodextrin, whey protein, liquid chromatography.