Changes of flavonoid content in some vegetables and fruits during cooking

本研究的目的是调查蔬菜和水果中黄酮类的含量及其在加热过程中的变化，以期为人们摄入黄酮类物质提供实际数据。选择几种蔬菜和水果，提取、水解制得样品溶液。主要研究结果如下：1.辣椒中的总黄酮含量因肤色不同而不同。辣椒与传统青椒的总黄酮含量有显著差异。2.柑橘果实中含有丰富的柚皮素和橙皮素，这两种成分占总黄酮量的90%以上。3.蔬菜中主要含有槲皮素、山奈酚、木犀草素和芹菜素。根据蔬菜类型的不同，总黄酮类的含量有很大的不同。一般来说，在微波炉中煮沸或加热后，总黄酮容易减少。

The purpose of this study is to investigate the quantities of flavonoids contained in vegetables and fruits together with their changes due to heating in order to provide practical data for the intake of flavonoids. Several kinds of vegetables and fruits were selected, extracted and hydrolyzed to obtain sample solutions. Here are the new results of the analyses of flavonoids by high-performance liquid chromatography ;1.The total flavonoids in paprika showed differences depending on the color of skin. Comparison of the total flavonoids between paprika and conventional green peppers reveals significant differences between the two.2.Naringenin and hesperetin are abundantly contained in citrus fruits, and these two ingredients account for 90 percent or more of the total flavonoids.3.Chiefly quercetin, kaempferol, luteolin and apigenin are found in vegetables. These are considerable differences in the total flavonoids depending on the type of vegetable. As a general rule, total flavonoids are prone to decrease after boiled or heated in a microwave oven.