Stevia By-product Fraction has Antioxidant Capacity and has been Evaluated for its Antihyperglycemic and Antilipid Potential

Introduction/Objective: The ethanolic pretreatment of stevia leaves is considered ecologically favorable and increases its yield, purity level, and sensory profile of sweeteners. We investigated the by-product generated so that we can provide a viable and applicable destination to effectively contribute to the production and industrial chain of stevia sweeteners. Recently, an antioxidant and antidiabetic fraction was obtained through stevia methanolic extraction. However, this process is costly, has a low yield, and is non-green. In this study, we got an antioxidant fraction of stevia from its pretreatment by-product, the ethanolic extract, characterized its bioactive compounds – mainly phenolic acids and flavonoids – and evaluated its antidiabetic and antilipid capacity. Methods: The ethanolic extract was fractionated, then the ethyl acetate fraction was microencapsulated. Physicochemical, Mass Spectrometry (UHPLC/MS-MS), scanning electron microscopy, microencapsulation efficiency, and antioxidant capacity analyses were carried out. The antioxidant capacity was evaluated. Antihyperglycemic capacity was assessed by inhibition of α-glucosidase and α-amylase. For antilipid potential, inhibition of pancreatic lipase was measured. Results: Antioxidant potential was observed mainly in the fraction. Microencapsulation improved the stability of the fraction. Mass spectrometry allowed comparison with phenolic and flavonoid compounds from the methanolic and ethanolic fractions of the by-product. Many compounds were coincident, which may explain the similar antioxidant capacity found. The samples showed more than 90% inhibition of alpha-glucosidase, which may indicate potential antidiabetic activity. All samples showed inhibition of the pancreatic lipase enzyme higher than 80%, reaching 91.05% for the free fraction. Conclusion: This study represented the recovery of a by-product and showed that this antioxidant fraction deserves further investigation for its bioactive potential, especially antioxidant, antidiabetic, and anti-lipid.