The effect of food processing on bioavailability of tomato antioxidants

The role of antioxidants in human nutrition has gained increased interest, especially due to their associated health-beneficial effects for a number of chronic diseases, including certain types of cancer and cardiovascular disease. There is a particular interest in tomato as it is a major component in the so-called 'Mediterranean diet' which has been associated with a healthier lifestyle. Tomatoes are rich sources of key antioxidant components such as carotenoids and polyphenols. They are consumed both as fresh produce and after having been processed in a wide variety of ways. Many researches have been carried out on the biochemical composition of tomato and its processed forms. However, in order to measure the real impact of tomato processing, bioavailability (the proportion of an ingested nutrient that is available for its intended mode of action) is more relevant than the total amount of antioxidants present in the original tomato or tomato product. Processing of tomatoes into different end products includes mechanical treatments, several thermal treatment steps, and the addition of ingredients such as oil or salt, which may result in changes in bioavailability of tomato antioxidants. In this review, we critically discussed the findings on the effects of different food processing techniques on in vivo and in vitro bioavailability of tomato antioxidants.