Ginger, lemongrass, and stevia tea: antioxidant activity, alpha-glucosidase inhibitory, and sensory quality

Abstract

The incorporation of medicinal plants in the food business is witnessing significant expansion, specifically to fulfil consumer demands for functional foods and beverages. The study developed beverages combining ginger, lemongrass, stevia, and tea. This study aimed to identify the best components for ginger, lemongrass and stevia-infused herbal tea that would demonstrate the highest levels of antioxidants and α-glucosidase inhibition. The optimal ingredients were then evaluated through hedonic testing to evaluate customer satisfaction. The pattern of α-glucosidase inhibition was also examined. The results showed that the herbal tea formulation infused with ginger, lemongrass, and stevia exhibited antioxidant activity and inhibited α-glucosidase activity. Integrating ginger into the formulation could improve antioxidant activity and α-glucosidase inhibition. It can be concluded that the most optimal tea formulation was J3D3, consisting of tea, lemongrass, ginger, and stevia in quantities of 0.4, 0.2, 0.6, and 1.2 g, respectively. The sample had a free radical inhibition activity of 92.68 ppm, categorizing it as a potent antioxidant. Furthermore, the α-glucosidase inhibitory capacity of the best herbal tea was 287.65 ppm. The sensory evaluation formulation had a sensory evaluation of taste, colour, and flavour (specifically in the "like" category). The J3D3 exhibited an uncompetitive inhibition pattern against α-glucosidase, significantly suppressing the enzyme's activity by forming a complex with the substrate enzyme. This finding suggested ginger, lemongrass, and stevia-infused herbal tea could be developed into a commercially available antidiabetic functional beverage due to the in vitro α-glucosidase inhibitory activity.