微波耦合漆酶法水提枇杷叶浸膏工艺的响应面优化

Response Surface Optimization of Water Extraction Technology of Loquat Leaves Extract by Microwave-coupled Laccase

以阴干粉碎枇杷叶为原料,采用常压微波反应合成装置耦合酶(漆酶)法(microwave irradiation-enzyme coupling catalysis,MIECC)水提枇杷叶浸膏。在漆酶(2×10^(4) U/g)添加量为2%条件下,研究微波功率、微波温度、微波时间及水料比对枇杷叶浸膏得率的影响,并采用响应面法优化提取工艺,另外,采用扫描电镜观察枇杷叶粉末微观结构,并用红外光谱检测浸膏中三萜类物质。结果显示:在最佳条件为微波功率530 W,微波温度54℃,微波时间20 min,水料比22∶1(mL/g),提取液经真空浓缩、干燥后枇杷叶浸膏得率为30.84%±0.47%。扫描电影结果表明微波耦合酶法对枇杷叶组织结构的破坏程度最大,可有效提高枇杷叶活性成分的浸出率。红外光谱检测结果显示:浸膏中三萜类物质可能为乌苏烷型或齐墩果烷型,该浸膏可作为功能性食品开发的浓缩型产品原料。

The dried and crushed leaves of loquat were used as raw materials,and the loquat leaves was extracted with water by using an atmospheric pressure microwave reaction synthesis device coupled with enzyme(laccase)(microwave irradiation-enzyme coupling catalysis,MIECC).Under the condition that the amount of laccase(2×10^(4) U/g)was 2%,the effects of microwave power,microwave temperature,microwave time and water-to-material ratio on the yield of loquat leaves extract were studied,the response surface method was used to optimize,and the results showed that:The optimum extraction conditions were microwave power of 530 W,microwave temperature of 54℃,microwave time of 20 min,water-to-material ratio of 22∶1(mL/g),the extract was concentrated in vacuum and dried,and the yield of loquat leaves extract was 30.84%±0.47%.Scanning electron microscope results showed that the microwave-coupled enzymatic method had the greatest damage to the tissue structure of the leaves,and the leaching rate of the active ingredient of the leaves could be effectively improved.Infrared spectroscopy results showed that the triterpenoids in the extract may be ursane type or oleanane type,the extract could be used as a concentrated product raw material for functional food development.