Variation of Phenolics In Anthocyanin- and Nonanthocyanin- Fruit Tomatoes

Phenolic and flavonoid compounds are known to have biological activity with beneficial effects on human health. Fruit of cultivated tomatoes (Solanum lycopersicum L.) are a major source of phenolics and flavonoids in the U.S. diet because this crop is the second most widely consumed vegetable on a per capita basis, but actual levels are low compared to other fruits and vegetables.  Anthocyanins are an important class of flavonoid phytonutrients known for their antioxidant properties and novel purple color.  Tomato fruits do not normally posses anthocyanins, but we have developed lines which express up to 80 mg/100 g FW in the fruit peel.  We wished to quantify levels of total phenolics and anthocyanins in anthocyanin expressing tomato fruit in different production systems and compare to total phenolic content of normal tomatoes. Epidermis and pericarp tissue of three advanced breeding lines of anthocyanin-fruit tomatoes and three lines of nonanthocyanin-fruit tomatoes were assayed by Folin-Ciocalteu method for total phenolics and by pH differential using a spectrophotometer for total monomeric anthocyanin content.  A replicated set of the experimental lines were grown in organically and conventionally managed systems and were compared for total phenolics.  The mean phenolic concentration of the highest-ranking anthocyanin-fruit line was 73 mg/100g FW and significantly greater than that of the highest-ranking nonanthocyanin-fruit line at 43 mg/100g FW.  The highest anthocyanin concentrations were more than 10 mg/100g FW (whole fruit basis), with conventional tomato lines having no anthocyanin production.  Anthocyanin concentrations varied among the three anthocyanin-fruit breeding lines.  While higher, total phenolics in tomatoes from the organic production system was not significantly different from that of a conventional production system.