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

With the civil air travel industry under increasing pressure from increasing oil costs and ecological legislation, the race is on to find practical alternatives to traditional kerosene and these so far seem to boil down to numerous kinds of biofuel.

Not surprisingly, the first trials of alternative fuel were initiated by British aviation leader, Sir Richard Branson, whose Virgin Atlantic began London to Amsterdam flights with restricted biofuel use in 2008. This was quickly 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 considered too poor for growing mainstream foodstuffs.

Jatropha 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 pointed out Jatropha jatropha curcas as one of the very best prospects for future biodiesel production. It is resistant to drought and pests, and produces seeds consisting of 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aeronautical significant 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 function as tactical specialists for the task.

The current airline to begin exploring with new fuels is the Alaska Air Group which has performed 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 really encouraging development has been the move far from biofuels which complete head on with food customers thus preventing a cost spiral. Not so long back, a surge in use of biofuels in vehicles triggered a spike in maize rates as US farmers diverted excessive corn to fuel processing.

Hopefully in the future, airlines and drivers will usage on non-food sources such as jatropha curcas and algae. It would be a mixed blessing indeed if some people ended up starving simply to satisfy someone else's green credentials.