This is similar to what breweries do with barley—malted barley is simply barley that's been made to germinate/bud and then dried before the budding seeds grow into barley plants.
Germinated brown rice is a red-hot health food in Japan now because of its higher amounts of amino acids (the building blocks of protein) compared to ordinary brown rice.
But what really has people paying attention to germinated/malted brown rice is that it contains twice as much gamma-amino butyric acid (GABA) as ordinary brown rice and ten times as much as white rice. That's important because research is showing that GABA helps boost the immune system and inhibits the development of cancer cells.
The GABA content of germinated brown rice sold today would be even higher if so much GABA didn't leach out while the rice is soaking in warm water (which has to be changed at least once during the process because of bacteria growth).
After much trial and error, the Shimane Prefecture Agricultural Technology Center has found a solution to this problem. Their germinated brown rice has a whopping three times as much GABA as germinated brown rice currently on the market. This brown rice has gobs of GABA! The secret? Germinating the brown rice in green tea.
The researchers theorize that green tea prevents GABA loss in two ways: because of its higher osmotic pressure and because it naturally inhibits the growth of bacteria, thus eliminating the need to change the water during germination. One also has to surmise that the green tea also acts like a natural plant-growth stimulator—after all, many Japanese pour leftover green tea on their houseplants and use old tea leaves as a garden fertilizer. Finally, brown rice germinated in green tea obviously absorbs the tea's polyphenols and other good stuff.
In short, green-tea-germinated brown rice clearly has a lot going for it. Watch for green-tea-germinated brown rice (and products made from it) at a health food store near you.
Source: Nihon Nogyo Shimbun (Japan Agriculture Newspaper) [http://www.nougyou-shimbun.ne.jp/modules/bulletin8/article.php?storyid=336].