Nutritional characterisation of commercial traditional pasteurised tomato juices: carotenoids, vitamin C and radical-scavenging capacity

Commercial conventional thermal pasteurised tomato juices were nutritionally evaluated, at the same point in their commercial shelf lives, for their carotenoid contents, vitamin C, and antioxidant activities and physical and physicochemical characterisation. Higher lycopene epoxide, lycopene, gamma-carotene, beta-carotene contents, and vitamin A values were found in those juices obtained from a concentrated tomato source, suggesting structural changes in the tomato tissue due to the concentration process. The stability of vitamin C seems to be affected by the type of container. Radical-scavenging capacity., measured on the basis of the DPPH center dot stable radical, was higher in the aqueous (AQ) fractions than in the organic (OR) fractions of tomato juices. Results suggest that vitamin C was mainly responsible for the DPPH center dot radical-scavenging of the AQ tomato fractions, whereas lutein and lycopene were the individual carotenoids responsible, not only for the EC50, but also the kinetic changes of the DPPH center dot of the OR tomato fractions. These results extend the research in processed tomato products to other bioactive components, different from the most generally studied lycopene. (c) 2005 Elsevier Ltd. All rights reserved.