Patents Cover Green Tea and Shelf Life, Esters and Melting Points

WASHINGTON--Two major companies in the food and health care industries received patents for new technologies involving green tea extract and plant sterol and stanol esters. The Procter & Gamble (P&G) received U.S. Patent No. 6,268,009 for manipulating green tea extract to have improved clarity, color and shelf life. In addition, the patented extract may also be used in artificially sweetened beverages to mask the aftertaste of aspartame. Minerals (i.e., calcium, magnesium, aluminum) inherent to green tea may oxidize the tea's healthful catechins, including epigallocatechingallate (EGCG), that may in turn make the green beverage astringent, cloudy and even brown. Therefore, the patent details how the minerals are extracted, improving the shelf life of green tea and incidentally nullifying the aftertaste of aspartame in diet drinks.

The second patent, U.S. Patent No. 6.267,963, was given to Kraft Foods Inc. for its technology in changing the melting point for plant sterols without changing its mouthfeel. Usually, plant sterols have high melting points, between 130 and 180 degrees C, which may crystallize plant sterols and make them have a grittier texture in foods. The patent stated that plant sterol-emulsifier complexes prevent the plant sterols from crystallizing and lower their melting point by 30 degrees C. Emulsifiers include glycol monoester, lactylate monoglycerides and sodium stearoyl lactylate. The modified esters can be still used in either full-fat or fat-free products, and the stability and textural characteristics of food may improve through this new process.

More can be found on these patents on the U.S. Patent & Trademark Office Web site (www.uspto.gov).