Tomatoes carotenoid contents

Lycopene is well known as the predominant carotene in tomatoes, accounting for 65 to 98% of the total colored carotenoid content, depending on the cultivar (Table 4.2.3). The levels of lycopene in fresh tomatoes for salad varied from 21 to 79 g/g 34,35 jjj tomatoes for processing and deep-red tomatoes, the level of lycopene can be as high as 623 More than 80% of the tomatoes produced are... 

Tonucci, L.H. et al.. Carotenoid content of thermally processed tomato-based food products, J. Agric. Food Chem., 43, 579, 1995. 

Over-expression of bacterial phytoene synthase led to only modest increases in pigment accumulation (except in the case of chloroplast-contaiifing tissues). Attention turned to CrtI, one gene that might control flux through the entire four desaturation steps from phytoene to lycopene (discussed in Section 5.3.2.4). Only a modest increase in carotenoid content in tomatoes and a variety of changes in carotenoid composition including more P-carotene, accompanied by an overall decrease in total carotenoid content (no lycopene increase), resulted when CrtI was over-expressed under control of CaMV 35S. Apparently, the bacterial desaturase... 

Association of pigment accumulation with DNA features can inform systematics and applied breeding in crop plants. For carotenoid content among crop plants, maize and tomato are best studied by this technique. Because there is interest in accumulation of various intermediate products in the pathway as well as end products, QTLs were developed for genetic determinates that are not independent of each other. Some QTLs affect multiple pigment contents. 

As shown, tomatoes contain solely carotenes - lycopene (95 % of the total carotenoid content) and (3-carotene (5 %). The good resolution and shape of the separation is due to the enhanced shape selectivity of C30 stationary phases in comparison to Cis phases [33,34], Furthermore, C30 phases have a higher loading capacity, and therefore are preferably suitable for LC-NMR experiments [35-37]. 

Higher amounts can be found in certain varieties. In L. pimpinellifolum, levels as high as 40 mg per 100 g of fresh tissue have been reported, accounting for more than 95% of the total carotenoid content of these tomatoes (Porter and Lincoln, 1950). Nitrogen fertilizers and calcium sprays (0.2%) were reported to increase the lycopene content of tomatoes. Potassium deficiency may lower lycopene concentration however, very high potassium applications (>800 kg/ha) would cause a marked decrease in color uniformity disorders (Grolier, 2000). 

Literature is scarce on the effects of controlled atmosphere (CA) and modified atmosphere (MA) storage on carotenoid content and colonr retention in yellow and red vegetables. Sozzi et al. (1999), reported a lower content in total carotenoids and lycopene in tomatoes, which had been stored in 3% O2 or 20% CO2 than after storage in air (control). No differences were fonnd after storage in low O2 and high CO2. When the samples were transferred to air, the total carotenoid and lycopene contents were lower in the tomatoes, which were subjected to different storage treatments from those stored in air all the time. 

There are other preconditioning techniques in addition to heat that could lead to chilling tolerance. Irrigation with saline water (0.25% NaCl w/v) improves carotenoid content and antioxidant activity of tomato (De Pascale et al. 2001) and may lead to enhanced chilling tolerance. In sweet potato cultivars, enhanced coloration as a result of soil condition and water availability also led to high antioxidant potential (Philpott et al. 2003). 

De Pascale, S., A. Maggio, V. Fogliano, P. Ambrosino, and A. Ritieni. 2001. Irrigation with sahne water improves carotenoids content and antioxidant activity of tomato. J. Hort. Sci. Biotechnol. 76 447 53. 

Lycopene (T, T -carotene) is a red, acyclic carotenoid found in high concentrations in the tomato (Fig. 1), its high microcrystalline deposition in chromoplasts of the peel and flesh being responsible for their characteristic red color. Lycopene contributes about 80% to the total carotenoid content of tomatoes the remainder includes carotenoid precursors. 

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