2025, Vol. 13, Issue 5, Part C

Stevioside and rebaudioside-A are diterpenoid glycosides found in Stevia rebaudiana Bertoni that provide intense sweetness with low caloric value, making them valuable alternatives to synthetic sweeteners. This study aimed to identify and quantify stevioside and rebaudioside in dry stevia leaves using a range of analytical methods, including Anthrone, 3,5-dinitrosalicylic acid (DNSA), thin-layer chromatography (TLC), and spectrophotometry, alongside extraction optimization through ultrasonic-assisted extraction (varying probe size, amplitude, and time), soaking, alcoholic extraction, and supercritical fluid extraction (SCFE). Experimental results demonstrated that ultrasonic treatment at 50 µm amplitude for 5 min (14 mm probe) yielded higher stevioside concentrations compared to lower amplitudes or shorter durations. Alcoholic extraction consistently produced higher stevioside yields than aqueous extraction. TLC confirmed the presence of stevioside and rebaudioside, while SCFE with cosolvents improved the quality of extracts by reducing bitter aftertaste. Results highlight the influence of extraction parameters on yield and purity, supporting process optimization for large-scale applications in the food and nutraceutical industry.