Antioxidant Capacity of Tomato Juice: Effects of Processing

In recent years, nutritionists and the public have come to regard foods as more than sources of energy and essential nutrients. Tomatoes are rich in health- related food components. The tomato processing industry aims to maintain viscosity, antioxidant capacity and attractive red color of tomato juice. We investigate acidification and blanching treatments, their effects on PE activity, color and antioxidant properties of tomato juice. We found acidification at pH 2 for 1h increased significantly the main nutritional factors and health-promoting properties, as well as the color parameters of cold break tomato juice. Furthermore, blanching tomatoes at 100ºC for 1mn was the best treatment in providing the lowest PE activity, the highest a* and chroma values, antioxidant properties. Moreover, the acidified cold break tomato juice as the hot break tomato juice exhibited better antioxidant capacity than BHA and ?-tocopherol. Variations with storage time were more marked at 25ºC than at 4ºC. This book should help the tomato processers and be useful to consumers or anyone else who may be interesting to functional foods.