It's bad enough for some propeller aircrafts to be described as being powered by elastic band. Now the skeptics might begin having a dig at business 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 feasible alternatives to traditional kerosene and these so far appear to boil down to different kinds of biofuel.

Not surprisingly, the very first trials of alternative fuel were initiated by British air travel pioneer, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with minimal biofuel use in 2008. This was rapidly followed by Lufthansa and Air New Zealand who each used different blends of routine fuel and bio derivatives including some from made from jatropha 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 finest candidates for future biodiesel production. It is resistant to dry spell 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 perform research study and development into making use of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would act as strategic experts for the job.

The latest airline company to begin explore new fuels is the Alaska Air Group which has carried out internal US flights utilizing a mix of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mixture, it is claimed, can cut damaging emissions by 10%.

One actually encouraging development has been the move far from biofuels which contend head on with food thus avoiding 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 too much corn to fuel processing.

Hopefully in the future, airline companies and vehicle drivers will focus biofuel usage on non-food sources such as jatropha and algae. It would be a mixed blessing indeed if some people wound up starving just to satisfy another person's green credentials.