Long Storage May Decrease Tea's Health Benefits

Green tea leaves produce antioxidative organic compounds, called catechins, that are reported to have beneficial health effects such as fighting bacteria, viruses and cancer.

But consumers need to be aware of possible adverse consequences of long-term storage of commercial tea brands, say researchers Mendel Friedman and Carol E. Levin of the U.S. Department of Agriculture (USDA) Western Regional Research Center in Albany, California, and S.U. Lee and N. Kozukue of Uiduk University in Korea, in an article in the Journal of Food Science.

Because tea generally does not spoil, it can be stored for extended periods. However, catechins in commercial tea leaves may not remain stable during long-term storage in the solid state. Degradation of catechins in commercial tea leaves during a storage time of six months in warehouses, stores or even the home could adversely impact tea's potential health benefits. Even in the absence of moisture, the quality of teas may degrade with time.