| 摘要 |
PURPOSE:To facilitate the regeneration of a basic anion exchange resin, which was used in the refining process for a crude stevioside extract, with high efficiency and to enhance the refining efficiency also, by passing hydrochloric acid and then an aqueous alkali solution through the resin. CONSTITUTION:An adsorbent or a flocculant is added to a stevioside extract, and the resulting precipitate is filtered from the extract to prepare a crude stevioside extract. This extract is directly refined by an acidic cation exchange resin and then a basic anion exchange resin. In the refining process, the used basic anion exchange resin is regenerated by prepassing hydrochloric acid through the resin and then passing an aqueous alkali solution through the resin. The basic anion exchange resin is preferably a tertiary amine-type weak basic anion exchange resin having a bulky net structure. The concentration of hydrochloric acid to be used for the regeneration of such a basic anion exchange resin is preferably 0.5-3wt%, and its pH is preferably controlled at 1 or lower. |
