Gelatin hydrolysate offers promise of textural breakthrough for frozen foods

New 'antifreeze' proteins from gelatin could help improve the quality of a range of frozen food by reducing the growth of large ice crystals, according to researchers at the University of Wisconsin, Madison.

Srinivasan Damodaran, professor of food chemistry at the university and an expert in the enzymatic modification of proteins, expects to see a lot of commercial interest in the gelatin hydrolysates, which could be used in several frozen foods from meat to ice cream.

He said: "This could significantly increase the storage life of frozen foods. When they are stored and handled, you can get thermal fluctuations which lead to the formation of large ice crystals. These can really ruin texture.

"Although very small ice crystals bestow a smooth texture to ice cream, larger ones make it unacceptably coarse and grainy. We can tackle this by decreasing the rate at which the crystals form and altering their size and shape."

The proteins could also be injected into meat to improve its quality and texture and reduce the structural damage caused by ice crystals, he said.

Unlike Unilever, which has developed an antifreeze protein using genetically modified bakers' yeast, gelatin hydrolysates are not subject to the Novel Food Regulation.

The tasteless proteins are derived from the hydrolysis of gelatin by papain - a protein-cleaving enzyme derived from papaya and other plants.

Further research into the molecular interactions responsible for ice crystal growth inhibition by peptides from gelatin hydrolysates could lead to more targeted and tailored ingredients with even greater antifreeze activity, predicted Damodaran.