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

With the civil air travel market under increasing pressure from rising oil rates and ecological legislation, the race is on to find feasible alternatives to standard kerosene and these so far seem to boil down to various kinds of biofuel.

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

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

In 2007 Goldman Sachs cited Jatropha curcas as one of the very best prospects 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 aerial major Embraer and the Sao Paulo state Research Support Foundation transferred to bring out research study and development into using biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would act as strategic experts for the job.

The most recent airline company to start try out new fuels is the Alaska Air Group which has carried out internal US flights using a mix of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mix, it is declared, can cut damaging emissions by 10%.

One truly encouraging development has actually been the move away from biofuels which compete head on with food customers thereby preventing a rate spiral. Not so long back, a rise in usage of biofuels in vehicles triggered a spike in maize prices as US farmers diverted too much corn to fuel processing.

Hopefully in the future, airlines and motorists will focus biofuel consumption on non-food sources such as jatropha and algae. It would be a mixed blessing undoubtedly if some individuals wound up starving just to please another person's green credentials.