A European group of researchers have successfully expressed genes from the Snapdragon flower in tomatoes, resulting to deep-purple colored tomatoes with unprecedentedly high anthocyanin content at concentrations comparable to the anthocyanin levels found in blackberries and blueberries. The expression of the two transgenes increased the hydrophilic antioxidant capacity of tomato fruit threefold and a pilot animal study demonstrated that cancer-susceptible Trp53-/- mice fed a diet supplemented with the high-anthocyanin tomatoes showed a significant extension of life span.

See news release from the John Innes Center and the study published in Nature Biotechnology, doi:10.1038/nbt.1506.

Note: Two years ago, I reported on the work of a group of scientists from Oregon State University also working on purple tomatoes.