samedi 3 octobre 2009

Pea-starch film protects foods against microbes

Researchers at the University of Manitoba have made bioactive edible films and coatings from the starch of yellow field peas to improve foods' quality and safety.

Dr. Jung Han of the U of M's Department of Food Science said in a release this week that his main goal was to make a bioactive material delivery matrix -- a neutral food-grade material -- that could contain or incorporate various kinds of bioactive components.

Making the pea starch film is easy because I used a regular extruder. It melts or gelatinizes the pea starch and rearranges the polymers' direction. The starch bundles that form are resistant to digestion by enzymes.

Starch-based plastic-like compostable containers can be made from potato starch, but Han said that product is mechanically weak. Adding pea starch to the mix helps increase its mechanical strength. Han says pea starch plastic is mechanically very strong.

He concluded that dried pea starch films can be used as a food wrapping or within the food, to separate food components. The resistance of the films to high relative humidity makes these films useful with moist foods.

"Pea starch film is strong, has intermediate stretchability and good barrier properties at high relative humidity, which make it applicable on intermediate and high moisture foods. It can be sprayed plain or carry functional ingredients on dried fruits, bread, chocolate and nuts," Han said.

A pea starch-based antimicrobial coating showed suitability to be used on raw chicken. The coating enhanced the antimicrobial activity of certain food preservatives.

Aucun commentaire: