It's bad enough for some prop airplanes to be explained as being powered by rubber bands. Now the cynics could start having a dig at business aircraft flying on whatever from cooking oil to liquefied algae.

With the civil air travel market under increasing pressure from rising oil costs and ecological legislation, the race is on to discover feasible options to standard kerosene and these up until now appear to come down to different types of biofuel.

Not surprisingly, the first trials of alternative fuel were initiated by British air travel leader, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with restricted biofuel usage in 2008. This was quickly followed by Lufthansa and Air New Zealand who each utilized different blends of routine fuel and bio derivatives including some from made from jatropha which can grow in soil considered too bad for growing mainstream foodstuffs.

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

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

Recently, US aerospace giant Boeing, Brazilian aeronautical major Embraer and the Sao Paulo state Research Support Foundation moved to perform research and development into using biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would function as tactical specialists for the project.

The newest airline to start try out brand-new fuels is the Alaska Air Group which has actually performed internal US flights using a mix of 80 % fuel and 20% biofuel made from cooking oil. This mix, it is declared, can cut hazardous emissions by 10%.

One actually encouraging development has been the relocation away from biofuels which complete head on with food consumers consequently preventing a price spiral. Not so long ago, a surge in use of biofuels in cars triggered a spike in maize prices as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airline companies and vehicle drivers will focus biofuel usage on non-food sources such as jatropha and algae. It would be a blended blessing certainly if some people wound up starving just to please another person's green credentials.