Disposition of Selected Flavonoids in Fruit Tissues of Various Tomato (Lycopersicon esculentumMill.) Genotypes

Abstract

Flavonoids have been studied extensively because they offer great potential health benefits. In this study, enzymatic hydrolysis of glycosylated quercetin, kaempferol, and naringin was used to obtain their sugar-free aglycones. The investigation also employed a validated HPLC method to obtain the chiral disposition of the aglycone naringenin enantiomers. These analyses were conducted on exocarp, mesocarp, and seed cavity tissues of field-grown tomato (Lycopersicon esculentum Mill.) mutants (anthocyanin absent, atroviolacea, and high pigment-1) and their nearly isogenic parent (cv. Ailsa Craig) at immature green, "breaker", and red ripe maturity stages. Concentrations of all flavonoids using enzymatic hydrolysis were significantly higher than previously reported concentrations using acid hydrolysis. Presumably, this occurred due to a more specific and rapid hydrolysis of the glycoside moiety by the beta-glucosidase enzyme. The glycoside S-naringin was the predominant enantiomer in all fruit tissues, although the aglycones free R- and S-naringenin were detected in both exocarp and mesocarp. Whereas there was significantly more quercetin than kaempferol in exocarp tissue, they were present in about equal concentrations in the mesocarp. Quercetin concentrations were higher in the exocarp and mesocarp of immature green and breaker fruit of the high pigment-1 mutant than in the other genotypes, supporting the observed photoprotection and potential health benefits of the high pigment-1 tomato genotype.

Response of wild-type and high pigment-1 tomato fruit to UV-B depletion: flavonoid profiling and gene expression

“…3d). Consistent with previous Wndings (Torres et al 2005), hp-1 peel had the highest concentrations of all Xavonoids analysed at TU stage and a dramatic reduction of naringenin chalcone at RR stage (Fig. 3d).…”

Flavonoid Profiling and Biosynthetic Gene Expression in Flesh and Peel of Two Tomato Genotypes Grown under UV-B-Depleted Conditions during Ripening

“…These data are at least 1 order of magnitude higher than those commonly reported for tomato whole fruits (35,36), but several authors already reported similar levels of phenolic compounds for tomato peel (37,38).…”

Simultaneous determination of main phenolic acids and flavonoids in tomato by micellar electrokinetic capillary electrophoresis

“…As expected, within the cultivated species "Cherry" tomatoes showed the highest levels chlorogenic acid (23.51 mg kg −1 fw), whereas "Canario" and "Pera" tomatoes did not reach half this value (8.74 and 5.89 mg kg −1 fw respectively). Since polyphenols are mainly accumulated in the surface of tomato (Torres, Davies, Yañez, & Andrews, 2005), smaller tomatoes have higher surface to volume ratio, consequently the accumulation of polyphenols would also be higher in this type of materials. In fact, the development of new tomato varieties with outstanding functional value are targeted to the combination of high pigment (hp) genes and the restoration of anthocyanin accumulation in the fruit, specifically in "Cherry" varieties (Sestari et al, 2014).…”