Agriculture Reference
In-Depth Information
Tomato Fruit Quality from Organic and Conventional Production
http://dx.doi.org/10.5772/58239
also contained the highest level of vitamin C (14.3 mg 100g
-1
) in comparison to the rest of the
examined tomato cultivars. The conventionally grown Amati and Robin tomato fruits
contained more vitamin C than their organically grown counterparts [38].
5. Lycopene content
The color of the fruits is an important consumer quality parameter. The typical color changes
during tomato ripening from green to red are associated with chlorophyll breakdown and the
synthesis of carotenoid pigments due to the transformation of chloroplasts to chromoplasts
[39]. Pigment synthesis in tomato is closely related to the initiation and progress to ripening
and red color of the fruit results from the accumulation of lycopene [40], so that lycopene has
been suggested as a good indicator of the level of ripening. Lycopene is considered the
predominant carotenoid of tomato fruit (80-90%), followed by β-carotene (5-10%) [41].
The lycopene level of tomato fruit is determined by the genetic potential of the cultivar. Most
commonly, lycopene levels range within 4.9 and 12.7 mg 100g
-1
[42] or between 3.5 and 6.9
mg100g
-1
fresh weight (f.w.) [43]. Lycopene content ranged from 4.3 to 116.7 mg kg
-1
on a fresh
weight basis, with cherry tomato types having the highest lycopene content [11].The distri‐
bution of lycopene in the tomato fruit is not uniform. The skin of the tomato fruit contains high
levels of lycopene, comprising an average of 37% of the total fruit lycopene content [45], or 3-
to 6-fold higher than in whole tomato pulp [44]. About 12 mg of lycopene per 100 g fresh weight
was found in tomato skin, while the whole tomato fruit contained only 3.4 mg 100g
-1
fresh
weight [47]. The outer pericarp constitutes the largest amount of total carotenoids and
lycopene, while the locule contains a high proportion of carotene [46].
The lycopene content of tomato fruit also varies due to growing and environmental conditions,
mainly temperature and light. In general, field-grown tomatoes have higher levels of lycopene
than greenhouse grown fruit [13].The lycopene content determined in 39 tomato genotype
varieties ranged from 0.6 to 6.4 mg/100 g and 0.4 to 11.7 mg/100 g for greenhouse and field-
grown tomatoes, respectively [11]. Similarly, different cultivar varieties have been shown to
possess varied lycopene concentrations [13; 48; 49; 45]. Fruits from the indeterminate tomato
cultivar Daniela grown in the greenhouse had a higher lycopene content than field grown fruit
[50]. Lycopene content also changes significantly during maturation and accumulates mainly
in the deep red stage [51].
Tomatoes grown organically contained substantial amounts of lycopene when ripened to firm
red or soft red stages. About half of the total lycopene found in soft red tomatoes was present
in pink tomatoes and 70 percent in light-red fruit. Fruit picked at unripe stages (breaker
through light red) gained as much or more lycopene as those picked at the firm or soft red
stages. Results indicate that fruit could be harvested well before full visible red color without
loss of lycopene [52].
Tomatoes grown by the conventional or organic agricultural practices did not show any
significant difference in the carotenoid content [23].Thus, the absence of any difference
