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Processing and Bioavailability (WG2) page 20
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in nitrogen-packed samples. The authors concluded that while lycopene reversion and
consequent colour deepening were favoured by increased storage temperatures (up to 20°C),
oxidation was accelerated by higher temperatures. Carotenoid stability in dehydrated
tomatoes thus depended upon a number of favourable and unfavourable factors, which had to
be taken into account when selecting storage conditions.
A study on vacuum-dried tomato powder showed that in-package desiccation and
packaging in an inert atmosphere (e.g. nitrogen) favoured colour retention, while the presence
of air caused a loss of lycopene and colour fading by oxidation (Kaufman et al., 1957).
Analyses of the storage-study samples for lycopene (Wong and Bohart, 1957) showed that
air-packed samples retained the lowest lycopene levels, and all air-packed samples showed a
progressive loss of lycopene throughout the storage period. The most important factor
contributing to degradation is availability of oxygen during storage. With careful selection of
storage conditions to protect the products from such factors as air by storing in an inert
atmosphere or under vacuum, it is possible to retain initial color levels during storage.
Table 3 - Total lycopene retention in tomato powder stored in different atmospheres and
temperatures for different time lengths.
Storage period (days) Storage conditions Total lycopene retention. (%)
Fresh tomato
powder
30
80
160
210
385
from Lovric et al. (1970)
100
N2, 2°C 85.5
N2, 20°C 90.0
air, 2°C 37.0
air, 20°C 46.3
N2, 2°C 66.3
N2, 20°C 78.5
air, 2°C 11.3
air, 20°C 28.7
N2, 2°C 54.2
N2, 20°C 76.5
air, 2°C 9.35
air, 20°C 25.5
N2, 2°C 53.3
N2, 20°C 69.8
air, 2°C 8.55
air, 20°C 23.0
N2, 2°C 53.0
N2, 20°C 65.8
air, 2°C 8.2
air, 20°C 21.8
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