Abstract:

Gum Arabic, an ideal raw material for preparing L-arabinose, can be catalytically hydrolyzed by sulfur acid to obtain the hydrolysate containing L-arabinose, D-galactose and L-rhamnose. In order to ensure the stability of subsequent purification process as well as product quality, optimization of the acid hydrolysis process is necessary. In this work, single factor experiments are performed to determine the key parameters of acid hydrolysis reaction. The effects of reaction time, acid concentration, temperature and solid-to-liquid ratio on the hydrolysis are investigated. The results show that the temperature affects more significantly on the yield rate of L-arabinose. The degree of hydrolysis as high as 85% and the relative purity of L-arabinose up to 85% or 87% can be obtained under the optimized hydrolysis conditions of 90 min reaction at 100℃ or 200 min reaction at 90℃ with 0.1 mol·L^-1 H₂SO₄ and solid-to-liquid ratio of 1:10 (g/ml).

Key words: Gum Arabic, L-arabinose, catalytic hydrolysis, catalyst, reaction

摘要：

阿拉伯胶是提取制备L-阿拉伯糖的理想原料,对阿拉伯胶进行酸催化水解可获得含L-阿拉伯糖、D-半乳糖、L-鼠李糖的反应液,优化酸水解条件使水解液中L-阿拉伯糖的含量和收率均达到最佳水平,是保证后续分离纯化工艺稳定性及产品品质的关键。利用单因素实验考察了反应时间、酸浓度、反应温度、固液比等因素对水解工艺的影响,获得了影响酸水解反应的关键因素及适宜的水解条件。结果表明:温度对L-阿拉伯糖的生成速率有明显影响。经优化,当固液比为1:10 (g/ml)、100℃、0.1 mol·L^-1 H₂SO₄水解90 min或90℃、0.1 mol·L^-1 H₂SO₄水解200 min,水解液中L-阿拉伯糖的相对纯度分别达85%和87%,水解收率高达85%。

关键词: 阿拉伯胶, L-阿拉伯糖, 催化水解, 催化剂, 反应