Impact of high-pressure and traditional thermal processing of tomato purée on carotenoids, vitamin C and antioxidant activity

9 páginas, 1 figura, 5 tablas.Bioactive compounds (carotenoids and vitamin C) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging activity [50% depletion of initial DPPH• radical (EC50) and antiradical efficiency (AE)], in aqueous (AQ) and organic (OR) fractions, were measured in tomato purée subjected to high-pressure (HP) (400 MPa/25 °C/15 min), low pasteurisation (LPT) (70 °C/30 s), high pasteurisation (HPT) (90 °C/1 min), freezing (F) (−38 °C/15 min), and HPT plus F (HPT + F). In addition, physical and physicochemical parameters were evaluated. CIELab uniform colour space parameters (lightness, L*; green-red tonality, a*; and blue-yellow tonality, b*) were significantly higher both in the untreated and in the HP tomato purée than in the rest of the samples. Individual and total carotenoids, and provitamin A carotenoids, were significantly higher in HP tomato purée than in the untreated and other treated tomato purées. Ascorbic acid and total vitamin C were significantly lower in HP, LPT, HPT, and HPT + F tomato purées than in the untreated and F purées. In the AQ fractions, we found an inverse significant correlation between both ascorbic acid and total vitamin C and EC50AQ; and a positive significant correlation with AEAQ. In the OR fractions, a significant correlation was found between EC50OR and AEOR parameters and lycopene and total carotenoids. Total scavenging activity (AQ + OR fractions) in HP tomato purée was similar to that in LPT, HPT, and HPT + F purées.This research was supported by funding from Comunidad Autónoma de Madrid (Grants 07G/0040/2000- 07G/0041/2000, and 07G/0053/2003) and the Ministry of Science and Technology (Grant AGL2002- 04059-C02-02). C Sánchez-Moreno was supported by a Ramón y Cajal Research Contract from the Ministry of Science and Technology.Peer reviewe