1. A method of increasing the solubility of rebaudioside D ("Reb D") in aqueous liquids, comprising: a. preparing a clear Reb D solution by adding Reb D powder to water and heating to completely dissolve the Reb D powder, or by extracting Reb D from a stevia plant with hot / boiling water or a water / ethanol mixture, while the temperature of the clear Reb solution D support above 70 ° C； b. mixing a transparent Reb D solution with a solubility enhancing substance, wherein the temperature of the improved Reb D solution is maintained above 70 ° C, where the solubility enhancing substance is a water soluble salt of an organic acid, a water soluble organic acid or a hydroxyl-containing sweetener； c. adding a stabilizer to the improved Reb D solution to obtain a stabilized Reb D solution； wherein the stabilizer contains a thickener or anti-agglomeration agent； and d. spray drying a stabilized Reb D solution to obtain a powder. 2. The method according to p. 1, where the concentration of Reb D in a transparent solution of Reb D in stage (a) is from 0.05% of the mass. up to 2.5% of the mass. 3. A method according to claim 1, comprising adding Reb D powder to water at a temperature above 70 ° C or adding Reb D powder to water, and then heating to a temperature above 70 ° C. The method of claim 1, wherein the temperature in step (a) is from 80 to 100 ° C. 5. A method according to claim 1, wherein the temperature of the improved Reb D solution is maintained above 70 ° C in order to maintain a clear solution. The method according to claim 1, wherein the temperature of the stabilized Reb D solution is maintained above 70 ° C in order to maintain a clear solution. The method of claim 1, wherein the ratio of hydroxyl-containing sweetener to Reb D is from 0.01: 1 to 100: 1.8. The method of claim 1, wherein the ratio of hydroxyl-containing sweeten1. Способ повышения растворимости ребаудиозида D («Reb D») в жидкостях на водной основе, включающий:a. приготовление прозрачного раствора
