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Measuring antioxidants 
There is growing evidence that dietary antioxidants - such as vitamins C and E, anthocyanins and polyphenols - can help reduce the risk of cardiovascular disease and some cancers. This has stimulated interest in measuring the antioxidant capacity of foods. Claims relating to dietary sources of natural antioxidants have provided a marketing opportunity for food producers, while nutritionists and consumers are looking for data to compare products. But, as interest in antioxidants has increased, so have the number of methods for measuring their activity. It is important that methods used are consistent and allow comparison of results, especially if regulatory agencies are to define quality standards to substantiate health claims. The methods used for testing at CCFRA are those that have been put forward for standardisation by the USDA (United States Department for Agriculture). For example, ORAC - the oxygen radical absorbance capacity - can provide a comparative measure of the antioxidant capacity of foods. Total polyphenols can also be measured by a fast yet robust test method - again allowing useful comparisons. For wider comparisons we compare the data obtained for particular products with values published by the USDA, for over 100 different foods. Contact: Dr Helen Brown |