Subcritical water extraction of steviol glycosides from Stevia rebaudiana leaves and characterization of the raffinate phase

•Stevia rebaudiana leaves were subjected to subcritical water.•Yielding 38.67mg stevioside and 35.68mg rebaudioside A per g dry leaves.•Raffinate phase was analyzed for total chlorophyll, carotenoid and dietary fibers.•Yielding 31.91mg/100g, 5.71mg/100g and 4.98%, respectively.•S. rebaudiana leaves can be utilized as sources of natural sweeteners, fibers and coloring agents in the industry. The objectives of this work were to obtain steviol glycosides of S. rebaudiana leaves, possessing natural and noncaloric sweetener properties, using subcritical water extraction; to assess optimum extraction conditions; to determine biological activities of Stevia extracts and to characterize the raffinate phase. A Box–“Bhenken” statistical design was used to evaluate the effects of various values of temperature (100–150°C), time (30–60min) and flow rate (2–6ml/min) at a pressure of 230bar applying a solid/liquid ratio of 1:10 (m:v). The most effective parameter was temperature (p