It's bad enough for some prop aircrafts to be described as being powered by rubber bands. Now the cynics could begin having a dig at business airplane flying on whatever from cooking oil to melted algae.

With the civil air travel market under increasing pressure from increasing oil prices and environmental legislation, the race is on to discover practical alternatives to standard kerosene and these up until now appear to boil down to various types of biofuel.

Not remarkably, the very first trials of alternative fuel were started by British air travel leader, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with restricted biofuel usage 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 curcas which can grow in soil considered too poor for growing mainstream foods items.

jatropha curcas 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 curcas as one of the finest candidates for future biodiesel production. It is resistant to dry spell and insects, and produces seeds including 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aeronautical significant Embraer and the Sao Paulo state Research Support Foundation transferred to bring out research study and development into using biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would serve as strategic consultants for the task.

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

One truly encouraging development has been the move away from biofuels which complete head on with food customers therefore preventing a rate spiral. Not so long ago, a rise in usage of biofuels in cars and trucks triggered a spike in maize costs as US farmers diverted excessive corn to fuel processing.

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