Methods: The flavonids were extracted by ethanol as the solvent from onion with ultrasonic wave and ethanol extraction.Using spectrophotometry to extract and check the flavanone of onion.

• 方法:采用超声波乙醇浸提法从洋葱中提取黄酮类物质,对所提取的黄酮类物质进行验证,并用紫外分光光度法测定含量。