Production Practices and Quality Assessment of Food Crops. Vol. 1

Effects of Agronomic Practices 39
Figure 1. Total flavonol content in Favorita tomatoes from different countries (modified from Steward
et al., 2000).
than that of tomatoes harvested at red ripe stage (Thompson et al., 2000). In another
study, tomatoes were harvested at five different maturity stages (green, white, yellow,
light red, red) (Cabibel and Ferry, 1980). While β-carotene and lutein were present
already in the mature green tomatoes, lycopene was analysed first in the light red
stage. The contents of β-carotene and lutein did not change in the first two maturity
stages. The β-carotene concentration increased in the yellow tomatoes compared
to the white tomatoes. In contrast, lutein content first increased in the light red stage.
In the light red tomatoes lycopene was analysed first. Its content significantly
increased in the red stage, becoming the main carotenoid of red tomatoes (Cabibel
and Ferry, 1980).
Observing four ripening stages (green, yellow, pink, red), Abushita et al. (1997)
analysed the contents of ascorbic acid, β-carotene and tocopherols. Ascorbic acid
content of Floriset tomatoes significantly increased from green stage to yellow stage
and decreased while ripening more. In contrast, β-carotene and α-tocopherol as well
as β-tocopherol contents significantly increased with ripening stage. γ-tocopherol
approached its maximum in yellow fruits, then declined similar to ascorbic acid
(Abushita et al., 1997).
Investigations on phenolics were done in five different maturity stages (immature
green, mature green, breaker, pink, red) of tomatoes (Buta and Spaulding, 1997).
The three predominant phenolics chlorogenic acid, p-coumaric acid glucoside and
rutin were analysed in all samples. The content of chlorogenic acid (5′-caffeoylquinic
acid) declined from immature to mature green, increasing to the breaker stage.
This stage showed the maximum of chlorogenic acid with decreasing concentration
during further ripening. No large fluctuation in p-coumaric acid glucoside
occurred during ripening, except in the pulp with increases until breaker stage and
then decreasing contents. Rutin concentration significantly declined from immature
to mature green stage, being stable while ripening more (Buta and Spaulding, 1997).