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 commercial airplane flying on whatever from cooking oil to melted algae.

With the civil air travel market under increasing pressure from prices and ecological legislation, the race is on to find practical alternatives to conventional kerosene and these so far appear to boil down to various kinds of biofuel.

Not remarkably, the first trials of alternative fuel were initiated by British aviation leader, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with minimal biofuel use in 2008. This was rapidly followed by Lufthansa and Air New Zealand who each utilized various blends of regular fuel and bio derivatives including some from made from jatropha which can grow in soil considered too poor for growing mainstream foodstuffs.

jatropha curcas is a genus of approximately 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 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 aerial major Embraer and the Sao Paulo state Research Support Foundation moved 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 act as strategic experts for the project.

The most recent airline company to start explore new fuels is the Alaska Air Group which has conducted internal US flights utilizing a mix of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mixture, it is declared, can cut hazardous emissions by 10%.

One truly motivating advancement has been the relocation far from biofuels which contend head on with food customers thus preventing a price spiral. Not so long back, a surge in usage of biofuels in cars and trucks caused a spike in maize rates as US farmers diverted excessive corn to fuel processing.

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