Black as a tomato: the anthocyanin-biosintesizing tomato genotype 'Sun BlackTM'

Tomato (Solanum lycopersicum L.) is one of the most cultivated vegetable in the world and it is a large source of bioactive compounds, including lycopene and other carotenoids, flavanols (quercetin) and flavanones (naringenin). However, the concentration of flavonoids in tomato is considered sub-optimal, particularly because anthocyanins are not generally present. Therefore this species has been the object of an intense metabolic engineering in order to obtain anthocyanin-enriched tomatoes by using either breeding or transgenic strategies. Some tomato-related wild species, such as S. chilense, S. cheesmaniae, S. lycopersicoides and S. habrochaites, biosynthesize anthocyanins in the sub-epidermal tissue, and some allneles from those genotypes have been introgressed into cultivated genetics backgrounds, resultig in a 'purple' skin color. The breeding activity pursued at Tuscia University (Viterbo, Italy), aimed at combining different alleles leading to anthocyanin production, have been lead to "Sun BlackTM , a trade mark-protected tomato line with deep purple pigmentation, due to the biosynthesis of anthocyanins in the peel. "Sun Black" is therefore a breeding product, not a GMO product. This aspect is considered an added-value for the market. In fact "Sun Black" tomato has been available in July 2015 on the Italian market, thanks to an exclusive agreement between the owner of the trademark and Unicoop Firenze. We report here the chemical characterization and structure elucidation of the unique anthocyanins found in the epiderm of "Sun Black" tomato, as well as other bioactive compounds (carotenoids, polyphenols, vitamin C) of the whole fruit. The results show the unique features of this tomato genotipe as a 'novel food' with functional properties. Keyword: tomato, anthocyanins, functional food