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Composition of tomatoes and tomato products in antioxidants (WG1) page 39
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increased (the highest i.e. +10% after 15 days, +9% after 30 days and +14% after 45 days in
carotenoids for 500 mg/kg) by the application of CCC or alar. Yields were increased by 250
mg/kg CCC (+7%) and by all doses of alar (+28% for 250 mg/kg, then with decreasing
influence). Mean fruit weight was reduced by 5% by CCC and increased by 9% by alar. Most
levels of CCC and alar seemed to increase total soluble solids in fruits, mainly alar (+10% at
135 days and +5% at 150 days after transplanting). No data about fruit carotenoids content
were provided.
In conclusion, the results about DCPTA, CPTA or CCC influence on carotenoid
concentration in tomato fruit seem to be interesting. They probably could hardly be directly
applied to field processing tomatoes. Studies of feasibility in open field and of the various
consequences of applications on the crop response should be undertaken.
6.2. Vitamin C
6.2.1. Introduction
Vitamin C concentration in tomato fruit may be influenced by many factors. Various
studies performed by Hamner et al.(1945) have demonstrated that very large variations in
ascorbic acid content of tomatoes may be associated with growing conditions, more than with
varietal differences, and have indicated that a factor of primary importance in determining the
ascorbic acid level may be the light intensity a few days previous to harvest.
From various sources of data collected in the 70’s, Davies and Hobson (1981)
mentioned a main influence of season, nutrition and environment on ascorbic acid content of
tomatoes and they indicated that current mean values ranged from 150 to 230 mg/kg raw
edible part of tomato fruit with a normal range from 84 to 590 mg/kg. Shi et al.(1999)
demonstrated that for plum tomatoes (var. Heinz 9478) the ascorbic acid content in the juice
in the locule section was 10% and 33% higher than in the mesocarp and pole sections
respectively at full maturity. According to Stevens and Rick (1986), there is large variations
in vitamin C levels among tomato cultivars and species (from 80 mg/kg in cultivated varieties
to 1190 mg/kg in the wild spieces L. peruvianum). In spite of considerable effort to develop
cultivars with high vitamin C levels, little success has been achieved. There appears to be a
relationship between high vitamin C levels and relatively poor yields. Indeed Murneek et
al.(1954) found that in the cultivar Marglobe and Stokesdale the larger the fruit the lower the