Healthful Antioxidant Levels Boosted by Putting the Squeeze on Fruit With 'Pascalization'

New evidence that a century-old food preservation technology is finding a new life amid 21st century concerns about food safety and nutrition, scientists are reporting. They say that the method more than doubles the levels of certain healthful natural antioxidants in fruit. The effect, reported here at the 242nd National Meeting & Exposition of the American Chemical Society (ACS), occurs as a bonus in addition to its effects in killing harmful bacteria, viruses and mold in food. The technology, called high-pressure processing (HPP) involves subjecting food to 40,000-80,000 pounds of pressure per square inch for about 15 minutes. That's about five times the pressure that an African elephant would exert if it stood on a postage stamp. Applied evenly, however, the force in HPP does not squash the food — which can be fresh, processed, liquid or in other forms. The pressure does change the molecular structure of the microbes in food in ways that kill bacteria, molds and viruses. The technique also is known as "pascalization" in honor of the 17th century French scientist Blaise Pascal, famous for research on the effects of pressure on liquids. It differs from the more familiar thermal pasteurization process, which involves heating milk, beer and other foods to kill bacteria. Carmen Hernandez-Brenes, Ph.D., presented results of the new study on HPP's effects on antioxidants in fruit. Her presentation was part of a symposium, which began today, entitled "Tropical and Subtropical Fruits: Flavors, Color, and Health Benefits." Abstracts of the nearly two dozen presentations by international authorities on those topics appear at the end of this press release.