It's bad enough for some propeller planes to be described as being powered by rubber bands. Now the cynics could start having a dig at industrial aircraft flying on whatever from cooking oil to melted algae.

With the civil aviation industry under increasing pressure from increasing oil prices and ecological legislation, the race is on to find practical alternatives to traditional kerosene and these so far appear to boil down to numerous kinds of biofuel.

Not remarkably, the first trials of alternative fuel were initiated by British aviation leader, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with limited biofuel use in 2008. This was quickly followed by Lufthansa and Air New Zealand who each utilized various blends of regular fuel and bio derivatives consisting of some from made from jatropha which can grow in soil considered too bad for growing mainstream foods.

Jatropha is a genus of approximately 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas), from the family Euphorbiaceae.

In 2007 Goldman Sachs pointed out Jatropha jatropha curcas as one of the very best for future biodiesel production. It is resistant to dry spell and pests, and produces seeds consisting of 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aerial major Embraer and the Sao Paulo state Research Support Foundation moved to bring out research and advancement into making use of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would act as strategic experts for the project.

The most current airline to start exploring with new fuels is the Alaska Air Group which has actually conducted internal US flights using a blend of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mixture, it is declared, can cut harmful emissions by 10%.

One actually motivating advancement has been the move far from biofuels which contend head on with food customers therefore preventing a price spiral. Not so long ago, a surge in use of biofuels in cars caused a spike in maize costs as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airline companies and motorists will focus biofuel usage on non-food sources such as jatropha and algae. It would be a blended blessing undoubtedly if some people ended up starving just to please somebody else's green credentials.