METHOD FOR PRODUCING OF STEVIOSIDE Russian patent published in 2005 - IPC

FIELD: food-processing industry.

SUBSTANCE: method involves extracting ground dry leaves of Stevia Rebaudiana B. plant by liquefied CO₂ in sub-critical or above-critical state; providing aqueous extraction of leaves at temperature of 30-90°C in rotary-cavitational type extractor with cavitation index K=0.8-1.9; separating extract from solid residue by centrifuging process, with following separation thereof for separating of suspensions; providing ultra-filtering cleaning of extract at temperature of 20-95°C, under pressure of 0.1-2.0 MPa and liquid flow rate of 1.0-8.0 m/s above membrane; subjecting resultant concentrate to diafiltering by means of membranes with average pore size of 25-500 Å; after diafiltering, concentrating extract by back osmosis process and subjecting to additional cleaning procedure on ion-exchange columns; concentrating clean concentrate in thin-film vacuum evaporation apparatus at temperature of 45-95°C and drying concentrate in sprayer-type drier at temperature of 100-160°C until residual moisture content of powder is below 10%.

EFFECT: high extent of cleaning of extract, reduced loss of stevioside, increased yield and purity of ready product.

4 cl, 2 ex