低聚半乳糖酶法合成条件的研究

Study on Enzymatic Synthesis Conditions of Galactooligosaccharides

研究了低聚半乳糖(galactooligosaccharides,GOS)的酶法合成条件,利用高效液相色谱方法进行检测,以GOS产率为指标,考察了缓冲溶液类型及浓度、起始乳糖浓度、反应温度、加酶量、pH、反应时间等因素对GOS产率的影响。结果表明,酶法合成GOS的最佳条件为:缓冲溶液选取0.1 mol/L、pH 7.0的Na2HPO4/NaH2PO4,起始乳糖浓度为45%(W/V),反应温度为55℃,加酶量为20 U/g乳糖。在此条件下反应12 h,GOS产率可达44.5%。

This investigation focused on the conditions influencing the enzymatic synthesis of galactooligosacchar- ides （GOS）. The GOS yield was analyzed by HPLC and used as experimental index. This article had evaluated the influences of the type and concentration of the buffer solution, the initial lactose concentration, the reaction tempera- ture, enzyme dosage, pH and reaction time on the yield of GOS. The results showed that the optimal conditions for the enzymatic synthesis of GOS were as follows： 0.1 mol/L, pH 7.0 Na2HPO4/NaH2PO4 as buffer solution, the ini- tial lactose concentration of 45% （w/v） , the reaction temperature of 55℃ , action time of 12 h. Under these conditions, the maximum GOS yield was enzyme dosage of 20 U/g lactose and re- achieved 44.5 %