Effect of peeling and heating on carotenoid content and antioxidant activity of tomato and tomato-virgin olive oil systems

The effects of peeling and laboratory- or industrial-scale heating on carotenoid content and radical scavenging activity of tomato and tomato-virgin olive oil mixtures were investigated. A decrease in carotenoid content was detected only after long heating times. Such a decrease was lower for the unpeeled than for the peeled tomatoes. No change, either in lycopene concentration or in the chain-breaking activity of the lipophilic fractions, was observed when both laboratory- and industrial-scale heating treatments were performed on peeled-tomato puree containing 5% virgin olive oil. The aqueous fractions, including high-molecular-weight brown polymers formed as a consequence of heating, were also characterized for color, elementary composition and antioxidant activity.