It's bad enough for some propeller planes to be referred to as being powered by elastic band. 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 market under increasing pressure from rising oil rates and environmental legislation, the race is on to find practical options to conventional kerosene and these up until now seem to boil down to various kinds of biofuel.

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

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

In 2007 Goldman Sachs mentioned Jatropha jatropha curcas as one of the best 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 aeronautical significant Embraer and the Sao Paulo state Research Support Foundation moved to carry out research and development into the use of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would function as strategic specialists for the project.

The current airline to begin experimenting with new fuels is the Alaska Air Group which has carried out internal US flights using a blend of 80 % fuel and 20% biofuel made from cooking oil. This mixture, it is claimed, can cut hazardous emissions by 10%.

One actually motivating development has actually been the relocation away from biofuels which compete head on with food customers thereby preventing a rate spiral. Not so long earlier, a rise 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 motorists will focus biofuel intake on non-food sources such as jatropha curcas and algae. It would be a blended blessing indeed if some individuals ended up starving just to satisfy somebody else's green credentials.