29 September 1995

Rethink on fry colour

POOR FRY colour in crisping and chipping potatoes can result from excessive carbon dioxide levels during storage, Dutch researchers confirm.

Even where temperatures have been controlled, dark colouring can develop if CO2 levels creep up, particularly above 0.5%. Gas burner fumes produced during tuber warming prior to unloading can be a big problem, warns Adrian Veerman, senior potato scientist at the Lelystad AGV research station.

Ventilating to flush the store or low volume aeration to keep levels nearer 0.2% avoid the problem. But growers must have CO2 levels checked first to avoid unnecessary ventilation which risks weight loss and extra cost, he says.

"We used to blame crop senescence for these effects. Perhaps we now need a rethink," adds Mr Veerman.