METHOD OF PREPARING STEVIA EXTRACT USING ULTRASONIC WAVE OSCILLATION

摘要

PURPOSE: A method of preparing an extract of Stevia rebaudiana Bertoni with a forced aging method by use of weak ultrasonic wave oscillation during the aging process of the extract is provided which shortens an aging time by the conventional process of 1-3 months to 3hr or less and improves productivity. CONSTITUTION: Stevia powder is put into a heat resistant bag having water permeability and heated at 80 to 120deg.C for 1 to 2hr to produce a first extract, which is cooled when a sugar content attains about 8%, moved to an absolutely closed concentration vessel, heated at 55 to 60deg.C for 2 to 3hr while maintaining at a negative pressure of 600 to 700mmHg for 2 to 3hr, and cooled when a sugar content attains about 20%.