It's bad enough for some propeller airplanes to be referred to as being powered by elastic band. Now the cynics could begin having a dig at industrial aircraft flying on everything from cooking oil to melted 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 so far appear to boil down to various types of biofuel.

Not remarkably, the first trials of alternative fuel were started by British aviation pioneer, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with limited biofuel use 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 poor for growing mainstream foods.

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

In 2007 Goldman Sachs cited Jatropha jatropha curcas as one of the finest prospects for future biodiesel production. It is resistant to drought and pests, and produces seeds containing 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aerial significant Embraer and the Sao Paulo state Research Support Foundation transferred to carry out research and development into using biofuels to power jet airliners. It was reported that Brazilian airline companies Azul, Gol, TAM and Trip would serve as tactical specialists for the task.

The most recent 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 mix, it is declared, can cut damaging emissions by 10%.

One actually motivating development has been the move far from biofuels which compete head on with food customers thus a cost spiral. Not so long ago, a surge in use 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 drivers will focus biofuel intake on non-food sources such as jatropha and algae. It would be a blended true blessing undoubtedly if some people ended up starving simply to satisfy another person's green credentials.