超声协同果胶酶提取黑木耳糖醛酸工艺优化

Optimization of Ultrasound-assisted and Pectinase-added Extraction for Uronic Acid from Auricularia auricula (L. ex Hook) Underw

【目的】优化黑木耳糖醛酸提取工艺,提高黑木耳资源的开发、应用价值。【方法】通过比较热水、超声波、微波、光波、中性蛋白酶、纤维素酶、果胶酶等方法的黑木耳糖醛酸提取率,得到最佳提取方法;通过单因素试验比较黑木耳粒径、果胶酶添加量、液料比、提取温度、提取时间、pH值、超声功率、超声时间等对黑木耳糖醛酸提取率的影响,得到关键影响因素;在单因素实验基础上,以液料比、提取温度、超声功率和pH值为自变量,利用4因素3水平响应面法优化黑木耳糖醛酸提取工艺。【结果】超声波、微波、光波等3种物理破壁方法和中性蛋白酶、纤维素酶、果胶酶等3种生物酶法中分别以超声波法和果胶酶法最佳;单因素提取黑木耳糖醛酸的最佳条件分别为:黑木耳粒径58μm、果胶酶0.25%、液料比100mL·g^-1、提取温度50℃、提取时间2h、pH值5.50、超声功率540W、超声时间30min;确定响应面最优工艺参数为:液料比110mL·g^-1、pH5.60、超声功率540W、提取温度49℃。本研究在超声波协同果胶酶提取黑木耳糖醛酸的最佳条件下,糖醛酸提取率达7.95‰,比传统热水法提高了201%。【结论】通过超声波与果胶酶协同提取超微粉碎的黑木耳粉的糖醛酸工艺,确定响应面最优工艺参数为:液料比110mL·g^-1、pH5.60、超声功率540W、提取温度49℃。

【Objective】To improve the development and application value of resourcos of Auricularia auricula (L.ex Hook) Underw,extraction process of uronic acid from Auricularia auricula (L.ex Hook) Underw was optimized.【Method】By comparing the uronic acid yield,applications of ultrasound,microwave,light,neutral protease,cellulase,and/or pectinase were incorporated in the extraction to maximize the production.Critical processing conditions including substrate particle size,pectinase dosage,solvent to substrate ratio,temperature,time,pH,ultrasonic power,and ultrasound application time were evaluated in a single factor test.The ultrasound-assisted process with added pectinase was selected for the process optimization using the response surface method with 4 factors and 3 levels.【Result】The optium method for extracting uronic acid from A.auricula were ultrasound and pectinase.The optimum extraction conditions were determined to include the substrate particle size of 58 μm,pectinase addition at 0.25%,solvent to substrate ratio at 100 mL·g^-1,temperature at 50℃,2 h process duration,pH at 5.50,and 540 W ultrasonic treatment for 30 min.The response surface experiment indicated that a solvent to substrate ratio of 110 mL·g^-1,pH at 5.60,ultrasonic power of 540 W,and temperature at 49℃ would maximize the uronic acid yield at 7.95‰,which was 201% of what a traditional hot water method delivered.【Conclusion】The newly established highly efficient process to extract uronic acid from ultra-fine A.auricula powder applied 540 W ultrasound,added pectinase,used 110 mL per gram of substrate,adjusted pH to 5.60,and maintained a temperature at 49℃ throughout the process,which optimized the extration process of uronic acid of A.auricula,improved the economic value and provided reference for exploiting resources of A.auricula.