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

With the civil air travel industry under increasing pressure from increasing oil prices and environmental legislation, the race is on to find viable alternatives to traditional kerosene and these up until now seem to come down to different types of biofuel.

Not surprisingly, the first trials of alternative fuel were started by British aviation pioneer, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with limited biofuel usage in 2008. This was quickly followed by Lufthansa and Air New Zealand who each utilized different blends of regular fuel and bio derivatives consisting of some from made from jatropha curcas 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 pointed out Jatropha curcas as one of the 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 aerial major Embraer and the Sao Paulo state Research Support Foundation transferred to perform research and development into making use of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would serve as for the job.

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

One truly motivating advancement has been the relocation far from biofuels which contend head on with food consumers thereby avoiding a cost spiral. Not so long ago, a rise in use of biofuels in cars and trucks caused a spike in maize costs as US farmers diverted too much corn to fuel processing.

Hopefully in the future, airline companies and drivers will focus biofuel intake on non-food sources such as jatropha curcas and algae. It would be a blended true blessing undoubtedly if some individuals wound up starving just to satisfy somebody else's green qualifications.