The Perfect French Fry – What Is It?

Soggy, chewy, slimy, pasty? How was your last french fry? Consumers are choosy about their fries, says Susie Thompson, North Dakota State University potato breeder, and that’s why fry testing is an important part of NDSU’s potato breeding project.

Thompson and her colleagues at NDSU and the ARS Potato Research Worksite in East Grand Forks, Minn. test french fries for factors such as high specific gravity, color and sugar content. High specific gravity is indicative of tuber solids. Generally, potatoes are about 80 percent water, but the industry prefers high percentages of dry matter.

In the frying process, the more water there is to be displaced, the more oil there is taken up, adding calories and costing the processor money. “The oil actually is a greater cost than the potatoes,” Thompson says. NDSU breeders work to develop potatoes that range from 20.7 to 22.4 percent solids.

Considering color, Susie says the lighter the better. Sugar analysis is closely linked to color, as lower sugar content usually results in whiter fries. The potatoes should fry acceptably light at storage temperatures of 45 to 48 degrees F.

Ultimately, Susie hopes that through improved breeding, they will be able to lower the temperatures to 38 to 42 degrees F. At such low temperatures, producers need not rely on chemical sprout inhibitors. Furthermore, low temperatures prevent or reduce activity by pathogens that cause breakdown.

Of course, panelists also judge for flavor and texture. More interesting is the test for limpness. Fries should be long, but they cannot droop. “People hate going to fast food restaurants and getting limp fries,” Thompson says.

The potato breeding project uses advanced selections and cultivars grown in test plots at various locations across the state. The data gathered from the testing procedures is used to determine which crosses to try in the future, and which selections to drop.

Selections that show promise are presented to growers and processors in publications, at commodity schools and field days. However, it can take as long as 10 to 16 years before a cross is released and named.

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Source: Susie Thompson, (701) 231-8160, asunta.thompson@ndsu.nodak.edu
Writer: Teresa Oe, (701) 231-8371, teresa.oe@ndsu.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu