December 29/Guangzhou, China/Health & Medicine Week -- Current study results from the report "Optimization of the Microwave-assisted Extraction Conditions of Tea Polyphenols from Green Tea" have been published. "Green tea, a popular drink with beneficial health properties, is a rich source of polyphenols that have a wealth of physiological activities. The purpose of the present study was to develop a microwave-assisted extraction (MAE) of green tea polyphenols," scientists in Guangzhou, People's Republic of China, report.

"MAE of tea phenols from green tea was investigated through orthogonal array design. The content of total phenols in tea infusions was determined using UV/vis spectrophotometric methods. Four factors (microwave intensity, microwave irradiate time, microwave irradiate number of times and tea/water ratio) have a substantial impact on the extraction," wrote D.C. Li and colleagues, South China University of Technology.

The researchers concluded, "The extraction conditions of tea polyphenols are optimized, and the order of importance that influenced the extraction rate was found to be: microwave radiate time >microwave intensity >tea/water ratio >radiate number of times, and the optimal performance of extraction was obtained under microwave intensity 600 W, microwave radiate time three minutes and microwave radiate number of times once with tea/water ratio 1:20.MAE offers important advantages over conventional methods, such as shorter extraction times, substantial savings of energy and a reduced environmental burden."

Li and colleagues published their study in International Journal of Food Sciences and Nutrition ("Optimization of the Microwave-assisted Extraction Conditions of Tea Polyphenols from Green Tea," International Journal of Food Sciences and Nutrition, 2010;61(8):837-45).

For more information, contact D.C. Li, South China University of Technology, College of Food and Bioengineering, Guangzhou, China.

From the January 10, 2011, Prepared Foods E-dition