Insight into Bioactive Compounds, Antioxidant and Anti-Diabetic Properties of Rosehip (Rosa canina L.)-Based Tisanes with Addition of Hibiscus Flowers (Hibiscus sabdariffa L.) and Saffron (Crocus sativus L.)

Tisane is a fruit or herbal infusion, commonly referred to as herbal tea. These products are consumed as part of a balanced diet, which is closely related to the trend of a healthier lifestyle. In this work, tisanes prepared from rosehip (R), and herbal mixtures containing rosehip/hibiscus flowers (R/H) and rosehip/hibiscus flowers/saffron (R/H/S) were studied. Rosehip was dried by the convective drying method at 40, 50 and 60 degrees C. Total phenolic content (TPC), total flavonoid content (TFC), total flavonol content (TFlC), total anthocyanin content (TAC), antioxidant properties (DPPH center dot and ABTS(center dot+) assays) and in vitro inhibitory potential toward alpha-amylase of tisanes were examined. The highest TPC (based on dry weight (dw)) was measured in tisane obtained from rosehip dried at 60 degrees C (37.84 mg GAE/g dw). Tisanes prepared from a R/H/S mixture had the highest values of TFC (4.66-6.13 mg QUE/g dw), TFlC (2.67-3.98 mg QUE/g dw) and TAC (1.35-2.27 mg Cy 3-glc/g dw). The highest DPPH center dot scavenging activity (53.42 mg TE/g dw) was measured in rosehip (dried at 60 degrees C) tisane, whereas tisane prepared from a rosehip (dried at 60 degrees C)/hibiscus mixture expressed the best ABTS(center dot+) scavenging activity (107.44 mg TE/g dw). All tisane samples expressed high inhibitory potential toward alpha-amylase, with the highest activity of 85.03% and 89.90%, measured for tisanes prepared from rosehip/hibiscus flowers mixture (rosehip dried at 50 and 60 degrees C, respectively).