NO - Besoin d'assistance

Composition of tomatoes and tomato products in antioxidants (WG1) page 28
__________________________________________________________________________________________
of maturity, the fruit carotenoid contents were increased by increasing levels of K (0 to 10
meq per litre, applied when the first fruit were 1.0-1.5 cm diameter) in the nutrient solution,
except β-carotene content (Trudel and Ozbun, 1970, 1971, Table 11). Lycopene content
sharply increased when the K level in the nutrient solution was increased with a maximum at
8 meq. Chlorophyll (a and b) content of tomato fruit regularly decreased during ripening,
from 8 mg/kg fresh matter to 1.5 mg/kg fresh matter in average. The decline of the green
pigment was more pronounced in high K fruit, and disrupted the grana to a greater extent than
in K-deficient fruit where carotenoid synthesis was lower.
Table 11. Tomato fruit carotenoid content (mg/kg fresh matter) in response to levels of
K in the nutrient solution (after Trudel and Ozbun, 1970, 1971)
K level
(meq/l)
Total
carotenoids
Phytoene Phytofluene β-carotene Lycopene
0 72 11.8 4.1 3.5 36.8
1 75 12.7 4.1 3.6 41.9
2 91 16.2 5.4 3.1 53.6
4 92 15.2 4.9 2.8 52.7
6 110 14.7 5.0 2.8 59.3
8 111 15.1 4.8 2.6 61.5
10 104 16.3 5.3 2.4 52.4
Winsor (1979) showed that increasing rates of potassium applied resulted in a striking
decrease in the incidence of ripening disorders (mainly colour uniformity) as well as in
increasing levels of titratable and total acidities (Table 12).