Danish industrial enzymes maker Novozymes on Tuesday launched an enzyme that it said produces more ethanol from corn, addressing concern that growth in biofuels has come at the expense of food production.

The new enzyme, called Novozymes Avantec, can "squeeze an extra 2.5 percent of ethanol out of the corn," it said.

"It allows you to save a lot of corn and still produce the same amount of ethanol," said Peder Holk Nielsen, executive vice president at Novozymes.

Corn is the main raw material used in US biofuel production. Holk Nielsen said that "if all ethanol plants in the US started using Avantec, they would save 3 million tonnes of corn."

Claus Felby, professor of biomass and bio energy at the University of Copenhagen, said that technologically, the enzyme was not a revolution, but that it's "very smart to use the resources more efficiently."

"First generation bio ethanol is often criticised. But one tends to forget that just as much animal feed is produced when you produce ethanol from corn," he said.

First generation biofuels are made from the sugars and oils found in arable crops, while second generation biofuels are based on feedstocks that include crop residues, waste, algae and woody material.

Dan Belusa, a sustainable agriculture campaigner with Greenpeace in Copenhagen, suggested Novozymes focus on second generation biofuels instead, a process in which enzymes can be used to convert municipal waste into resources.

"There's a world of difference between worsening a food crisis and ... taking real waste and using that as a resource," Belusa said.

Earlier this month a UN official called for the European Union and the United States to abandon biofuels altogether as the land used to produce them was needed by farmers to grow food instead.

Food security has emerged as a top item on the international agenda and critics claim that biofuels have pushed out food production in some areas, contributing to a global rise in food prices.