Stability of carotenoids, phenolic compounds, ascorbic acid and antioxidant capacity of tomatoes during thermal processing.

摘要

This study investigated the stability of lycopene, beta-carotene, ascorbic acid, polyphenolic compounds and total antioxidant capacity (AC) during the concentration of tomatoes into 2 tomato pastes (10 and 15 degrees Brix) by thermal processing. Thermal processing increased the content of lycopene, total phenolic compounds, total flavonoids, and the individual phenolic compounds quercetin, rutin, chlorogenic and caffeic acids, whereas it decreased the other analysed compounds. However, lycopene content in the 15 degrees Brix-tomato paste decreased due to the extended thermal processing, which led to degradation. The AC of aqueous and organic extracts was measured and different AC values were observed depending on the antioxidant profile of the extract and assay used (TEAC and FRAP). AC expressed in DM decreased as a result of ascorbic acid losses. Overall, it is concluded that thermal processing enhanced the nutritional value of tomatoes, mainly by increasing the lycopene and phenolic antioxidants contents, but the processing must be controlled to prevent lycopene degradation.