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Processing and Bioavailability (WG2) page 28
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9 Evaporation ( puree, paste) D Avoid fouling
Survey of references
In general, data are reported which reveal the values of lycopene in fresh tomato and in
concentrates. Unfortunately, the products are hardly ever comparable, either because the fresh
tomato is not the same as that utilised for the concentrate or because the concentration ratios
are not fixed, or else because measurements are taken of all the processes and not only at the
concentration stage. It must, however, be borne in mind that the concentration by evaporation
occurs under vacuum and at temperatures lower than those utilised at the breaking and
stabilisation stages, albeit for greater times.
Abushita et al. (2000) evaluated the changes in carotenoids and antioxidant vitamins
(ascorbic acid and tocopherols) in tomatoes during industrial tomato paste production.
Products were sampled and analysed (solvent extraction followed by HPLC determination) at
3 processing stages: raw tomato, crushed-sieved puree, and pasteurised paste (28°Bx). The
authors observed an increase in the all-trans lycopene and total carotenoid content (on a dry
weight basis) during processing, which was ascribed to the removal of seeds and other by-
products. All-trans β-carotene concentration decreased from 37.2 in raw tomatoes to 26.3
mg/kg d.w. in tomato paste, while cis β-carotene increased (from