摘要茎用莴苣烹饪时一般为去皮烹饪，皮被丢弃，造成了浪费。茎用莴苣茎皮中含有很多活性物质，具有较高的营养保健价值，对茎皮中的这些活性物质用适当的方法进行提取并加以利用，可以变废为宝，避免浪费，并创造更多的经济价值。本课题主要研究茎用莴苣茎皮中多酚的提取方法。天然产物中活性成分的提取方法有很多种，本课题主要采用微波浸提法和超声波浸取法两种。样品中总酚含量的检测采用福林酚比色法。通过单因素实验和正交实验考察乙醇浓度，料液比，提取时间以及微波功率对提取率的影响，从而找出莴苣皮中多酚的最佳提取方法及其条件。实验证明微波提取法对莴苣皮中多酚的提取率高于超声波提取法，是相对更好的方法；微波提取的最佳条件为70%乙醇做溶剂，提取时间50min，微波功率800W，料液比1：40，多酚的提取率为31.01g/kg（干重）。44121

ABSTRACT   Stems with lettuce peel is commonly when cooking , skin is discarded, caused the waste. Stems with lettuce stem bark contains a lot of active material, has the high nutrition health care value, the bark of the active substances using appropriate methods to extract and take advantage of, avoid waste, and create more economic value. This subject mainly research the stem with lettuce in the stem bark of polyphenols extraction method. The method of extracting active ingredients in natural products has a lot of kinds, this topic mainly adopts two kinds of microwave extraction and ultrasonic extraction method. The total phenol content in the samples of detection using the forint phenol colorimetric method. Best extraction method for setting ethanol leaching solution of different concentrations, different material liquid ratio, extraction time and different microwave power, carries on the single factor experiment and orthogonal experiment, and find out the best in the lettuce peel polyphenols extraction methods and conditions. Experiments proved that microwave extraction of lettuce peel polyphenols extraction rate is higher than in the ultrasonic extraction method, is a relatively better way. The best condition of microwave extraction with 70% ethanol solvent, extracting time 50 min, microwave power 800 w, material liquid ratio 1:40, polyphenols extraction yields of 31.01 g/kg(dry weight). 

毕业论文关键词：茎用莴苣；多酚；提取方法；超声波提取；微波提取；

Keyword: stem lettuce；polyphenol；extraction method；ultrasonic extraction；microwave extraction；

目录

1前言1

1.1莴苣概述1

  1.1.1莴苣的主要成分1

  1.1.2莴苣的开发利用1

  1.1.3莴苣的主要功能2

1.2植物多酚2

  1.2.1植物多酚的定义2

  1.2.2植物多酚的结构和化学性质2

  1.2.3莴苣叶中多酚的提取3

1.3多酚类物质的提取和测定方法3

  1.3.1多酚类物质的提取方法3

  1.3.2多酚类物质的测定方法3

1.4本课题研究目的和内容4

  1.4.1课题研究目的4

  1.4.2课题的主要意义4

  1.4.3研究的主要内容4

2材料与方法5

2.1实验材料5

  2.1.1原料5

  2.1.2主要仪器与设备5

  2.1.3主要试剂5

2.2实验方法6

  2.2.1莴苣皮中多酚的提取方法选择6

  2.2.2莴苣皮中多酚含量的测定6

  2.2.3微波提取工艺优化实验6

3结果与分析8

3.1标准曲线的绘制8

3.2超声波和微波实验结果的比较8

3.3微波提取工艺优化实验结果9

  3.3.1单因素实验结果9

  3.3.2正交实验结果10

4结论11