ISHS Acta Horticulturae 542: VII International Symposium on the Processing Tomato
THE ANTIOXIDANT ACTIVITY OF TOMATO. IV. EFFECTS OF STORAGE ON OXIDATIVE AND HEAT DAMAGE |
| Authors: | G. Giovanelli, V. Lavelli, C. Peri, E. Pagliarini, B. Zanoni, P. Petrone |
| Keywords: | 5-hydroxymethyl-2-furfural, color, ascorbic acid, lycopene, β-carotene, polyphenols, antioxidant activity |
| Abstract:
Three commercial tomato products (tomato pulp, tomato puree, and tomato paste) were subjected to accelerated aging tests (3 months at 40°C) to evaluate the kinetics of variation of heat damage indexes (5-hydroxymethyl-2-furfural [HMF] and color [ΔE]) and oxidative damage indexes (lycopene,  -carotene, ascorbic acid, total phenolics, antioxidant activity of hydrophilic and lipophilic fractions). Experimental data were processed to obtain rate constant values.
HMF formation followed zero-order kinetics in tomato puree, and paste, and first-order kinetics in tomato pulp, to a final value of nearly 160, 200, and 495 mg/kg dw in tomato pulp, puree, and paste.
Significant colour changes were only observed in tomato concentrate.
Ascorbic acid decreased in all products according to pseudo-first-order kinetics, with a higher rate in tomato paste and puree.
A slight increase in total phenolics was observed in all products during storage.
Lycopene concentration was very stable in all products, whereas -carotene decreased at the same rate in all products, to a final 30–40% reduction.
The antioxidant activity of the hydrophilic fraction decreased, to a final reduction of 35–40% in all samples.
The antioxidant activity of the lipophilic fraction also decreased, although to a smaller extent, to a final reduction of about 30% in the three products.
Reduction of antioxidant activity can be ascribed to the loss in ascorbic acid and -carotene.
| |
Download Adobe Acrobat Reader (free software to read PDF files) | |
