Tomato products (pulp, puree and paste) submitted to accelerated aging (30, 40 and 50 ◦C for 3 months) were studied to evaluate variations in the kinetics of the degradation of antioxidants and antioxidant activity. The carotenoids lycopene and β-carotene, ascorbic acid, rutin and total phenolics were analysed. The antioxidant activity was measured using (a) the xanthine oxidase (XOD)/xanthine system, which generates superoxide radicals and hydrogen peroxide, and (b) the linoleic acid/CuSO4 system, which promotes lipid peroxidation. The ascorbic acid content decreased even at 30 ◦C, following pseudo-first-order kinetics, with an activation energy of 105 200 Jmol−1 for tomato pulp and 23 600 Jmol−1 for tomato paste. The lower the initial ascorbic acid content, the higher was the degradation rate. Variations in phenolic compounds occurred at 40 ◦C and higher, following pseudo-zero order kinetics. The antioxidant activity of the hydrophilic fraction of the tomato products depended on both antioxidant degradation and the Maillard reaction and could not be described by a kinetic model. The β-carotene content decreased even at 30 ◦C, whereas the lycopene content was stable in all samples. The antioxidant activity of the lipophilic fraction of the tomato products decreased following pseudo-first order kinetics, with an activation energy of 22 200 Jmol−1 for tomato pulp and 20 200 Jmol−1 for tomato paste. It is concluded that significant ‘oxidative damage’ can occur in tomato products during their commercial shelf-life.
Evaluation of heat and oxidative damage during storage of processed tomato products. II. Study of oxidative damage indices / V. Lavelli, G. Giovanelli. - In: JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE. - ISSN 0022-5142. - 83:9(2003), pp. 966-971.
|Titolo:||Evaluation of heat and oxidative damage during storage of processed tomato products. II. Study of oxidative damage indices|
LAVELLI, VERA AGNESE (Primo)
GIOVANELLI, GABRIELLA (Ultimo)
|Parole Chiave:||Antioxidant activity; Ascorbic acid; Carotenoids; Phenolics; Storage; Tomato products|
|Settore Scientifico Disciplinare:||Settore AGR/15 - Scienze e Tecnologie Alimentari|
|Data di pubblicazione:||2003|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1002/jsfa.1433|
|Appare nelle tipologie:||01 - Articolo su periodico|