Scientists have analysed the properties of fruits - including apples, peaches and nectarines - and found levels of a key antioxidant was previously underestimated. A study by an international team at the Institute of Food Research in Norwich have discovered the content of super-chemical polyphenol in fruits was up to five times higher than previously recorded.

Dr Paul Kroon said: "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."The research, published in the Journal of Agricultural and Food Chemistry, shows the chemical which is normally not considered by food chemists - is an important part of a healthy diet. Professor Fulgencio Saura-Calixto, who led the project, said: "These polyphenols are major constituents of the human diet with important health properties. "To consider them in nutritional and epidemiological research may be useful for a better understanding of the effects of plant foods in health."