Changes of flavonoid content in some vegetables and fruits during cooking

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 15500542
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Eating habits, studies on eating habits
• Research Institution: HIROSHIMA UNIVERSITY
• Principal Investigator: MOCHIZUKI Teruyo Hiroshima University, Graduate School of Education, Professor, 大学院・教育学研究科, 教授 (90116682)
• Project Period (FY): 2003 – 2005
• Keywords: flavonoid / vegetables / fruits / HPLC / boiling / microwave oven

Research Abstract

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.