[关键词]
[摘要]
没食子酸在食品、化工和医药领域具有广泛的应用。相比传统化学法生产,酶法生产具有环境友好、副产物少的优点。本文利用前期开发的热稳定单宁酶Tan1,开发并优化塔拉单宁同步浸提-酶解工艺,实现没食子酸的高效酶法生产。首先通过单因素试验确定了初步浸提-酶解条件为塔拉粉料液比1:30、反应温度60 ℃、加酶量4 mL和反应pH=5。在此基础上,采用Plackett-Burman试验设计,考察不同因素对浸提-酶解反应条件的影响,研究发现温度、pH和料液比是影响提取过程的主要因素。进而,通过响应面试验确定最佳酶解方案为塔拉粉料液比1:40,反应温度65 ℃,pH=4,在此条件下没食子酸得率达到65.98%。此外还研究了在最佳浸提-酶解条件下的连续多次投料反应,结果表明在六次连续投料过程中,塔拉单宁均能被高效水解为没食子酸。此研究为塔拉单宁酶解生产没食子酸的工业化奠定基础。
[Key word]
[Abstract]
Gallic acid had wide application in food, chemistry and pharmaceutical industries. Compared with the traditional chemical production approach, the enzymatic hydrolysis had the advantages of environmental friendness and fewer by-product. In this work, a previously developed thermal stable tannase Tan1 was used for the simultaneous leaching-enzymolysis of Tara tannin and the hydrolysis conditions were optimized for the high efficiency enzymatic production of gallic acid. First, the preliminary hydrolysis conditions were optimized by single factor test as followed: Tara powder liquid ratio 1:30, reaction temperature 60 ℃, enzyme dosage 4 mL and reaction pH=5. Based on the single factor test, the Plackett-Burman design was performed to investigate the effects of different factors on the reaction conditions of tannase hydrolysis of Tara powder. It was found that temperature, pH and ratio of material to liquid were the significant factors that affect the hydrolysis process. Furthermore, the optimal hydrolysis conditions were optimized by response surface design as follows: Tara powder liquid ratio 1:40, reaction temperature 65 ℃, pH=4, the yield of gallic acid was 65.89%. The continuous feeding reaction was also investigated under the optimal hydrolysis conditions. The results indicated that Tara tannin could be hydrolyzed into gallic acid with high efficiency during six batch feeding process. This research laid the foundation for the industrialization of gallic acid produced by enzymatic hydrolysis of Tara tannin.
[中图分类号]
[基金项目]
福建省科技计划引导项目(2016N0021)