发芽咖啡豆α-半乳糖苷酶溶液的稳定性研究

Studies on the Stability of α-D-Galactosidase Solution from Germinating Coffee Beans

[目的]寻求提高发芽咖啡豆α-Gal溶液稳定性的方法。[方法]从发芽咖啡豆中提取α-Gal,通过α-Gal酶溶液单因素试验和热稳定性试验获得各因素参数,通过响应面分析优化各参数,得到复合稳定剂,并研究了胶体、金属离子对α-Gal溶液稳定性的促进作用。[结果]合适的黄原胶和Zn2+含量以及pH值都能增强α-Gal酶溶液的稳定性。α-Gal酶溶液复合稳定剂为:黄原胶1%(W/V),Zn12 mmol/L,pH值为5.0。在此参数条件下,试验酶活保留率为76%,是对照样品(26%)的2.9倍。α-Gal酶溶液室温保存试验表明,室温放置60 d,添加复合稳定剂的α-Gal酶溶液的酶活保留率为89.2%,比对照(78.6%)提高13.5%。[结论]添加复合稳定剂能提高α-Ga酶溶液的稳定性。

[Objective] The purpose of study was to seek for the method of increasing the stability of α-D-galactosidase （α-Gal） solution from germinating coffee beans. [Method] α-Gal was extracted from germinating coffee beans. The factor parameters were obtained through single factor experiments and in the thermal stability experiment of α-Gal solution, the parameters were optimized through response surface analysis. Then the complex stabilizer was got and the promoting effects of colloid and metal ion on the stability of α-Gal solution were studied. [Result] The appropriate xanthan and Zn^2＋ contents and pH value could increase the stability of α-Gal solution. The complex stabilizer of α-Gal solution was mixture of 1%（W/V） xanthan and 12 mmol/L Zn^2＋ with pH value of 5.0. Under this parameter condition, the retaining rate of enzyme activity was 76% in the experiment and 2.9 times of control sample （26 %）. The experiment of storing α-Gal solution at room temperature showed that after storing at room temperature for 60 d, the retaining rate of enzyme activity was 89.2% in the α-Gal solution added complex stabilizer and enhanced 13.5 % in comparison with the control （78.6 %） lConclusionl The stabilitv of α-Gal solution could be increased hy adding complex stabilizer.