It's bad enough for some prop planes to be explained as being powered by elastic band. Now the cynics could start having a dig at commercial aircraft flying on everything from cooking oil to melted algae.

With the civil aviation market under increasing pressure from rising oil rates and environmental legislation, the race is on to discover practical options to conventional kerosene and these so far appear to boil down to various types 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 restricted 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 consisting of some from made from jatropha curcas which can grow in soil thought about too bad for growing mainstream foods.

jatropha curcas is a genus of approximately 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 best candidates for future biodiesel production. It is resistant to drought and pests, and produces seeds containing 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aeronautical major Embraer and the Sao Paulo state Research Support Foundation relocated to perform research and development into the use of biofuels to power jet airliners. It was reported that Brazilian airline companies Azul, Gol, TAM and Trip would serve as strategic consultants for the project.

The most recent airline to start explore 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 mixture, it is declared, can cut hazardous emissions by 10%.

One truly encouraging advancement has actually been the move away from biofuels which compete head on with food customers thus avoiding a rate spiral. Not so long back, a rise in usage of biofuels in vehicles caused a spike in maize prices 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 certainly if some people wound up starving simply to satisfy someone else's green qualifications.