microencapsulation of steviol glycosides (stevia rebaudiana bertoni) by a spray drying method – evaluation of encapsulated products and prepared syrups

The aim of this study was to encapsulate the steviol glycosides (SGs), derived from Stevia rebaudiana (Bert) Bertoni leaves, by applying a spray-drying method. The purpose was to minimize the bitter aftertaste of the SGs as well as to ameliorate/improve their properties. The encapsulation agents used were maltodextrin (19 DE) and inulin in a ratio of 80 : 20, while three levels of SGs in total solids (1.5, 2.5 and 3.5 %) were studied. The encapsulated SGs products were evaluated for their hygroscopicity, solubility, moisture content and microencapsulation efficiency (MEE %). Also, syrups prepared with encapsulated SGs, at 1 % w/v, were tested for their viscosity, refractive index, turbidity and sensory properties. Significant differences (P<0.05)  in MEE %, moisture content, hygroscopicity and solubility values of the encapsulated SGs products were observed depending on the level of SGs in total solids. In particular, the MEE %, the hygroscopicity and the solubility values ranged from 62.36, 82.46 to 94.67 %, 21.51, 26.67 and 24.25 % and 99.93, 97.50 to 96.03 % for encapsulated SGs products produced with 1.5, 2.5 and 3.5 % SGs in total solids, respectively. The encapsulated product produced with 2.5 % steviol glycosides in total solids presented the most appealing sensory and quality characteristics.