Tomatoes ascorbic acid content

Giuntini, D., G. Graziani, B. Lercari et al. 2005. Changes in carotenoid and ascorbic acid contents in fruits of different tomato genotypes related to the depletion of UV-B radiation. J. Agric. Food Chem. 53 3174-3181. 

Yahia EM, Contreras M and Gonzalez G. 2001b. Ascorbic acid content in relation to ascorbic acid oxidase activity and polyamine content in tomato and bell pepper fruits during development, maturation and senescence. Lebensm Wiss u-Technol 34 452-457. 

Yahia EM, Soto G, Puga V and Steta M. 2001a. Hot air treatment effect on the postharvest quality and ascorbic acid content in tomato fruit. In Artes F, Gil MI and Conesa MA, editors. Improving Postharvest Technologies of Fruits, Vegetables and Ornamentals, Volume 2. Paris International Institute of Refrigeration, pp. 550-556. 

In a series of five studies of 14 days each, the effects of ascorbic acid on manganese utilization were investigated. The usual basal diet was modified to lower the ascorbic acid content by substituting apple juice for the usually-fed orange and tomato juices. 

Genetic Variation. The concentration of many individual nutrients in foods of plant origin is under genetic control. Baker (34) reviewed some examples of genetic manipulation that improved the quantity of )3-carotene in tomatoes, methionine in beans, and lysine in com. Variations of ascorbic acid content of different varieties of raw vegetables and fruits is notoriously high (35). Twofold variation in vitamin C concentration in different strains of a vegetable or a fmit is common and a fivefold variation can be found. Differences in ascorbic acid contents (35- to 300-fold) of different strains of a fmit were reported prior to 1950 (36). These reports have not been substantiated. 

Betancourt et al. (46) found that in two varieties of tomatoes, plant-ripened fruit accumulated more (22%) RAA than did fruit ripened off the plant. Unfortunately, these researchers did not measure the total ascorbic acid content of tomatoes in their study. Pantos and Markakis (47) found that two cultivars of tomatoes contained 25-33% more total vitamin C when they were ripened on the vine rather than artificially. Conversely, Matthews et al. (48) reported that RAA of Walter tomatoes harvested at the green-mature stage and ripened off the plant was essentially the same as in those ripened on the plant. Thus, there may be varietal differences in this regard. 

New varieties are being developed to withstand better mechanical harvesting. Burge et al. (43) reported that the ascorbic acid content of tomato varieties developed for this purpose contain as much ascorbic acid as do conventional varieties. 

From the data presented in Table III, the 95% confidence interval for the ascorbic acid content of vine-ripened tomatoes would be ... 

Again using the example given in Table II, the true difference between the ascorbic acid contents of vine-ripened and room-ripened tomatoes may be estimated from the point estimate and 99% confidence interval estimates ... 

Baqar MR, Lee TH (1978) Interaction of CPTA and high temperature on carotenoid synthesis in tomato fruit. Zeitschrift fur Pflanzenphysiologie 88 431 35 Brown GB (1954) The ascorbic acid content of tomatoes as related to Illumination. J Am Soc Hort Sci 65 342-348... 

As for natural antioxidants, irradiation treatments caused proportional decrease in the tocopherol and ascorbic acid content of tomato at both 1st and 2nd harvest (Table 4 ). In exception was that a treatment of 0.05 slightly improved ascorbic acid of 2nd harvest fruits. 

TABLE 4 Tocopherol and ascorbic acid content (pg/g fresh) of tomato irradiated at green stage ripeness... 

Ftintos, C.E., and P. Markakis, "Ascorbic Acid Content of Artificially Ripened Tomatoes,"/ouma/of Food Science, Vol. 38, 1973, p. 550. 

The important commercial feature of these juices, especially significant with blackcurrant and tomato juices, is their ascorbic acid (or vitamin C) content, of which loss by oxidation is known to be accelerated both by heat and by metal (particularly copper) contamination. The effect of copper has been carefully investigated for pure ascorbic acid", and more recently ascorbic acid in blackcurrant juice and model systems. There are, however, oxidation inhibitors of different kinds (which may themselves be heat-sensitive) present in various fruits, which give differing results. The presence of metals will also affect flavours", may cause discoloration, and may give rise to clouding effects, as in apple juice. ... 

Watada et al. (45) reported that RAA content was not significantly different in ripe or mature-green tomatoes. Ethylene-treated tomatoes were higher in ascorbic acid than untreated fruit but the differences could not be directly attributed to ethylene. The differences between cultivars were greater than those between maturity stages. 

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