This technology may have a long way to go, but it appears to be having positive results. An interesting short read.
ISS astronauts to grow tomatoes and rice .... IN SPAAAAACE
Plutonian peas and cosmic capsicum already proven safe for human consumption
By Simon Sharwood, 31st January 2014
Plants grown aboard the International Space Station (ISS) have produced food that is entirely safe to eat, even after several generations of propagation, Russian scientists have revealed.
Reports from Russia suggest Margarita Levinskikh, a researcher at the Institute of Biomedical Problems who has form dating back to the MIR space station as an astro-veggie boffin, told a conference in Moscow this week that ISS astronauts have harvested peas, dwarf wheat and "Japanese leafy greens". All have checked out as fine for human consumption.
For more:
http://www.theregister.co.uk/2014/01/31/iss_astronauts_to_grow_tomatoes_and_rice_in_spaaaaace/