Tomatoes total antioxidant activity

Dewanto, V. Wu, X. Adorn, K.K. Liu, R. 2002. Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. J. Agric. Food Chem. 50 3010-3014. 

Different tomato phenotypes were analysed for the content of total polyphenols, selected flavonoids, including flavonols (rutin and a rutin-derivative), flavanones (naringenin and the related chalcone) and carotenoids (lycopene and P-carotene). The identity of these conoponents was based on their chromatographic, ultraviolet and mass spectrometric behavior. All phenotypes were surveyed for dieir total antioxidant activity (TAA), and correlations betweens TAA values and the content of each group of constituents. 

Furthermore, the total antioxidant activity (TAA) of the selected cultivars was assayed, and the obtained TAA values were correlated with the content of tomato components. 

Table IV. Total antioxidant activity of selected tomato cultivars...

Based on the results, it may be concluded that total antioxidant activity (TAA) of the examined tomato cultivars is mainly correlated to the content of total polyphenols, and this reinforces the need for further studies on the chemical identity of all phenolics present in tomatoes (as well as in other common vegetables). 

SFE is widely used for the extraction of phenolic compounds from grapes or derivatives [48,67,68] (Table 16.4). Furthermore, this technique has been applied in other matrices such as pepper, tomato, and eggplant by Helmja et al., who compared SFE and UAE. This study indicated that SFE provided the poorest results in ctxnparison with the data obtained by UAE [28]. SFE was also compared with traditional techniques such as Soxhlet extraction using ethyl acetate and ethanol as solvents in guava The best results, in terms of extraction yield (total and fraction) and product quality (antioxidant activity and total phenolic content), were obtained when SFE was tqrplied using ethanol as an organic modifier [66]. The effect of pressure and temperature on the SFE was also evaluated, observing that the most appropriate conditions for the extraction of phenolic compounds was an extraction temperature of 60°C and pressure of 102 bar [66]. 

Tomato (Solarium lycopersicwn L.) is extensively cultivated worldwide, and its fruits have assumed the status of functional foods as a result of epidemiological evidence of reduced risks of certain types of cancers and cardiovascular diseases [180,181]. They are a reservoir of diverse antioxidant molecules, such as lycopene, ascorbic acid, vitamin E, carotenoids, flavraioids, and phenolics, and may provide a significant part of the total intake of beneficial phytochemicals, as a result of then-high consumption rates. Among carotenoids, lycopene has a strong antioxidant activity and is able to induce cell-to-ceU communications and modulate hormones, immune systems, and other metabolic pathways [182]. 

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