It's bad enough for some prop planes to be referred to as being powered by rubber bands. Now the cynics could start having a dig at industrial airplane flying on everything from cooking oil to liquefied algae.

With the civil aviation market under increasing pressure from increasing oil rates and ecological legislation, the race is on to discover practical alternatives to traditional kerosene and these so far seem to boil down to various kinds of biofuel.

Not surprisingly, the first trials of alternative fuel were started by British air travel leader, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with minimal biofuel use in 2008. This was quickly followed by Lufthansa and Air New Zealand who each used various blends of routine fuel and bio derivatives consisting of some from made from jatropha which can grow in soil considered too bad for growing mainstream foodstuffs.

Jatropha 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 cited Jatropha curcas as one of the best candidates for future biodiesel production. It is resistant to dry spell and pests, and produces seeds including 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aerial major Embraer and the Sao Paulo state Research Support Foundation relocated to perform research and advancement into making use of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would function as strategic consultants for the job.

The most current airline to start experimenting with new fuels is the Alaska Air Group which has carried out internal US flights utilizing 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 motivating development has actually been the move away from biofuels which compete head on with food consumers consequently preventing a rate spiral. Not so long back, a rise in usage of biofuels in cars and trucks triggered a spike in maize prices as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airline companies and motorists will focus biofuel usage on non-food sources such as jatropha curcas and algae. It would be a combined blessing undoubtedly if some people ended up starving simply to please somebody else's green credentials.