Effect of combined treatments of high-pressure and natural additives on carotenoid extractability and antioxidant activity of tomato puree (Lycopersicum esculentum Mill.)

High-pressure is a new food processing technology aimed at achieving consumer demands for fresher products with reduced microbiological levels. The objective of this work was to evaluate the effect of combined treatments of high-pressure and natural additives (citric acid and sodium chloride) on lutein, lycopene, lycopene epoxide, γ- and β-carotene content, and vitamin A value, and on the in vitro antioxidant activity of tomato puree. The methods used to evaluate the antioxidant activity were the measurement of the DPPH· radical scavenging and the inhibition of lipid oxidation (linoleic acid/CuSO^sub 4^ system). The experimental design comprised a response surface methodology according to a central composite face-centred design. The variable ranges were 50-400 MPa, sodium chloride 0-0.8%, and citric acid 0-2%. Total carotenoid content showed the best extraction when pressure was increased up to 400 MPa without sodium chloride and citric acid. The effect of the moderately high-pressure treatment (under 200 MPa) on the structure of the cellular tomato matrix may lead to the different release of various carotenes on the basis of their chemical features and chromoplast location. Radical scavenging activity was higher in the aqueous extract than the organic extract of tomato puree. Significant correlation (P