It's bad enough for some propeller airplanes to be referred to as being powered by rubber bands. Now the skeptics might begin having a dig at industrial airplane flying on everything from cooking oil to melted algae.

With the civil air travel industry under increasing pressure from increasing oil costs and ecological legislation, the race is on to find practical options to traditional kerosene and these so far seem to come down to different types of biofuel.

Not surprisingly, the very first trials of alternative fuel were initiated by British air travel pioneer, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with restricted biofuel use in 2008. This was rapidly followed by Lufthansa and Air New Zealand who each utilized various blends of routine fuel and bio derivatives consisting of some from made from jatropha which can grow in soil thought about 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 household Euphorbiaceae.

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

Recently, US aerospace giant Boeing, Brazilian aerial major Embraer and the Sao Paulo state Research Support Foundation to perform research and advancement into the use of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would serve as strategic consultants for the job.

The most current airline company to begin try out new fuels is the Alaska Air Group which has 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 truly motivating development has been the move far from biofuels which complete head on with food consumers thus preventing a price spiral. Not so long earlier, a surge in usage of biofuels in cars 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 curcas and algae. It would be a blended blessing indeed if some people ended up starving simply to satisfy someone else's green credentials.