GM 'mashed potato' revealed

The GM potato produces 19 times as much fructose as an unmodified potato

French scientists have developed a GM potato that releases sugars when it is cooked.

Two genes encoding enzymes capable of converting the starch stored in potatoes into fructose have been added to the plant. When the potato is heated and mashed, fructose is released, turning the humble spud into a miniature chemical factory.

The researchers believe the GM potato could revolutionise the food industry, enabling fructose to be produced more cheaply.

A variety of products, including some sweeteners, diabetic foods and soft drinks, contain fructose.

But the researchers warn that anti-GM feeling in Europe may delay future applications of the technology.

Food products

Current methods for producing the huge quantities of fructose syrup needed each year rely on large-scale industrial processes using starch from maize.

The starch is converted into fructose in a chemical plant using bacterial enzymes that can function at high temperatures.

The enzyme alpha amylase catalyses the breakdown of starch into glucose. Glucose is then changed to fructose by a second enzyme, glucose isomerase.

The French team, based at the Université de Picardie Jules Verne, Amiens, fused the genes encoding the two bacterial enzymes then inserted them into the potato.

When the GM potato is heated for 45 minutes at 65 °C (149 F), the added enzymes are activated, converting starch to fructose.

American interest

The GM potato produces about 19 times more fructose than an unmodified one, under the right conditions.

"This will completely change the potato-processing industries," Dr Rajbir Sangwan told BBC News Online.

"Using starch from potatoes is very cheap and it's very cost-effective. You just heat and mash the potato and you get the final product."

But he warned that the backlash against GM foods could delay progress towards commercialisation in Europe.

But he believes: "The US will jump on the technology."

The GM potato research is published in the journal Biotechnology and Bioengineering.