NORWICH, England—An international team of scientists has found that the polyphenol content of fruits has been underestimated.
Polyphenol content in fruits usually refers to extractable polyphenols, but a scientist working at the Institute of Food Research (IFR) analyzed apple, peach and nectarine, and found nonextractable polyphenol content is up to five times higher than extractable compounds. This work has been published in the Journal of Agricultural and Food Chemistry (2009 Jul; 57(16), 7298–7303).
“These polyphenols need to be treated with acid to extract them from the cell walls of fruit in the lab,” said Sara Arranz from the Spanish Council for Scientific Research (CSIC) in Madrid. “If non-extractable polyphenols are not considered, the levels of beneficial polyphenols such as proanthocyanidins, ellagic acid and catechin are substantially underestimated.”
Dr. Paul Kroon from IFR explains: “In the human body these compounds will be fermented by bacteria in the colon, creating metabolites that may be beneficial, for example with antioxidant activity.”
