It's bad enough for some prop planes to be described as being powered by elastic band. Now the cynics might begin having a dig at business aircraft flying on everything from cooking oil to liquefied algae.

With the civil aviation industry under increasing pressure from rising oil prices and ecological legislation, the race is on to discover viable alternatives to conventional kerosene and these up until now appear to come down to various kinds of biofuel.

Not remarkably, the first trials of alternative fuel were started by British aviation pioneer, Sir Richard Branson, whose Virgin Atlantic started London to Amsterdam flights with minimal 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 including some from made from jatropha which can grow in soil considered too poor for growing mainstream foods items.

Jatropha is a genus of around 175 succulent plants, shrubs and trees (some are deciduous, like Jatropha curcas), from the family Euphorbiaceae.

In 2007 Goldman Sachs pointed out Jatropha curcas as one of the finest prospects for future biodiesel production. It is resistant to drought and insects, and including 27-40% oil.

Recently, US aerospace giant Boeing, Brazilian aerial major Embraer and the Sao Paulo state Research Support Foundation transferred to carry out research and development into the usage of biofuels to power jet airliners. It was reported that Brazilian airlines Azul, Gol, TAM and Trip would act as strategic specialists for the task.

The latest airline company to begin try out brand-new fuels is the Alaska Air Group which has performed internal US flights using a blend of 80 % petroleum based fuel and 20% biofuel made from cooking oil. This mixture, it is declared, can cut harmful emissions by 10%.

One actually encouraging development has been the relocation far from biofuels which complete head on with food customers therefore avoiding a cost spiral. Not so long ago, a rise in usage of biofuels in cars and trucks caused a spike in maize costs as US farmers diverted excessive corn to fuel processing.

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