A more economical way to give potato chips the light color that consumers demand could be in the bag within several years. The key is a wild South American relative of the potato plant, according to scientists with USDA’s Agricultural Research Service.

The potato chip industry now must warm potatoes taken from cold storage before they can be processed into chips. Without being warmed, the potatoes would yield dark brown chips because of accumulating sugars. Burnt-looking, dark chips are unacceptable to consumers. None of the commercial varieties now available can be processed directly from cold storage.

That’s where Solanum raphanifolium comes in. Tubers of this potato relative can be processed into light-colored chips directly from cold storage, according to studies by Robert E. Hanneman of the ARS Vegetable Crops Research Unit, Madison, Wis. Hanneman identified this trait of S. raphanifolium, a native of Argentina and Bolivia, in screening more than 80 wild potato species from around the world.

By crossing S. raphanifolium with relatives of commercial potato varieties, ARS scientists developed new breeding lines that can be stored between 34 and 36 degrees F. The hybrids from these lines were chipped directly from cold storage, cutting reconditioning time from one month to one week.

These breeding lines have been provided to state, federal and industry breeders who hope to develop new varieties early in the next century.

An added benefit of potatoes that can be chipped from cold temperatures is the reduced need for chemicals that inhibit sprouting in stored potatoes. This benefit comes just as many chemically based sprout inhibitors are being eliminated by the Environmental Protection Agency (EPA).

Scientific contact: Robert E. Hanneman, ARS Vegetable Crops Research Unit, Madison, WI 53706, phone (608) 264-5193 or 262-1399, fax 262-4743, rehannem@facstaff.wisc.edu.