通过β-淀粉酶对未环化的直链淀粉进行降解,采用DNS法对反应体系中还原糖进行测定,依据环化反应前后还原糖的变化来计算环糊精的产率,研究底物浓度、酶量、温度、pH、麦芽糖、乙醇、二甲基亚砜对转化率的影响。结果表明,直链淀粉终浓度为0.1～0.125%时转化率最高,而酶用量对最终转化率影响不大,最适转化pH值和温度分别是6.5和40℃,麦芽糖对转化率起抑制作用,乙醇和二甲基亚砜则能够提高转化率。

Linear amylose is degraded to maltose by β-amylase.And the maltose can be determined using the DNS method to calculate the yield of the cyclodextrin.The impacts of substrate concentration,the dosage of enzyme,temperature,pH,maltose,ethanol and dimethyl sulfoxide on conversion rate were studied.The results showed that the conversion rate was the highest when the final concentration of amylose was 0.10%~0.125%.The dosage of enzyme had little effect on the final conversion rate.The optimum pH and temperature for cyclization were 6.5 and 40 ℃.And maltose inhibited the conversion rate.Ethanol and dimethyl sulfoxide improved conversion rates.