It's bad enough for some propeller airplanes to be explained as being powered by elastic band. Now the cynics could begin 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 environmental legislation, the race is on to find feasible alternatives to traditional kerosene and these up until now seem to boil down to different types of biofuel.

Not surprisingly, the first trials of alternative fuel were initiated by British air travel leader, 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 used various blends of regular fuel and bio derivatives consisting of some from made from jatropha which can grow in soil considered too poor for growing mainstream foods.

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

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

Recently, US aerospace giant Boeing, Brazilian aeronautical significant 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 function as tactical experts for the project.

The current airline to begin try out new fuels is the Alaska Air Group which has carried out 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 hazardous emissions by 10%.

One truly encouraging development has been the relocation far from biofuels which contend head on with food consumers consequently preventing a rate spiral. Not so long earlier, a rise in use of biofuels in vehicles triggered a spike in maize prices as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airlines and motorists will focus biofuel intake on non-food sources such as jatropha and algae. It would be a mixed true blessing indeed if some individuals ended up starving just to please somebody else's green qualifications.