Premium
Evaluation of heat and oxidative damage during storage of processed tomato products. II. Study of oxidative damage indices
Author(s) -
Lavelli Vera,
Giovanelli Gabriella
Publication year - 2003
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.1433
Subject(s) - chemistry , antioxidant , lycopene , ascorbic acid , food science , pulp (tooth) , rutin , autoxidation , hydrogen peroxide , maillard reaction , lipid peroxidation , carotenoid , kinetics , linoleic acid , xanthine oxidase , lipid oxidation , radical , biochemistry , fatty acid , medicine , physics , enzyme , pathology , quantum mechanics
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/CuSO 4 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 J mol −1 for tomato pulp and 23 600 J mol −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 J mol −1 for tomato pulp and 20 200 J mol −1 for tomato paste. It is concluded that significant ‘oxidative damage’ can occur in tomato products during their commercial shelf‐life. Copyright © 2003 Society of Chemical Industry