United States food technologists have invented dried rations that a soldier can rehydrate by using dirty water or even his own urine, the British weekly New Scientist reports.
The ration is surrounded by a plastic membrane made of a nanofibre that, according to its inventors, can filter out 99.9 per cent of microbes and the most harmful toxic compounds, allowing only clean water to get to the preserved food.
http://www.abc.net.au/news/newsitems/200407/s1159190.htm
Sounds interesting