Hot potato

The potato is one of the world’s most versatile foods and its preparation methods are nearly end- less. In fact, it’s almost as versatile as it is productive. In Canada the potato is the most important vegetable crop, valued at just over $900 million, which accounts for 35% of all vegetable-farm cash receipts. What may be surprising is that roughly 55% of all potatoes grown in Canada are used for processing, mostly for making french fries.

One of the potato’s biggest downfalls is its tendency to discolour after cooking when it’s exposed to air, known as after-cooking darkening (ACD); it’s an unwanted problem for all processors. That’s where Dr. Gefu Wang-Pruski, a molecular biologist at the Truro, Nova Scotia–based Faculty of Agriculture, comes in. It has become her life’s work to improve potato-tuber quality and, more specifically, to rid the root vegetables of ACD.

French fry processors currently prevent ACD by adding a chemical called sodium acid pyrophosphate (SAPP) during blanching; however, Wang-Pruski believes that better solutions exist, including preventative measures. She proposes reducing or eliminating the use of SAPP during processing by finding the genetic and environmental factors that lead to it. Once she has identified those factors, she will be able to breed and select potatoes with a reduced response to ACD.

Wang-Pruski’s research is particularly intriguing to Canadian processors, especially environmentally conscious ones. “Environmental regulations require that processing plants use water-treatment systems to safely remove chemicals such as SAPP from the water before the water can be safely disposed,” says Wang-Pruski. “If we had a potato cultivar that didn’t show the ACD characteristic, there would be no need for the preservative or the water-treatment system, resulting in significant savings.”

Consumers will also benefit from the research. “Generally, people don’t want chemical additives in their food,” says Wang-Pruski. “By finding the genetic and environmental factors responsible for ACD, we can find ways to prevent the problem and reduce or eliminate the need for chemical treatments.”

In addition to identifying genic factors, Wang-Pruski and her team have also pinpointed important growing and storage factors that could reduce ACD prevalence, such as those related to fertilizer usage, soil conditions, and irrigation conditions. “We know ACD is not specific to any particular cultivar or variety, that it occurs in every type of potato and that it’s not related to skin or flesh colour,” says Wang-Pruski. “ACD is also controlled by multiple genes and metabolisms. Part of the next step is to identify potato cultivars with reduced ACD characteristics that will benefit industry and consumers.

Industry–based funding and a Natural Sciences and Engineering Research Council of Canada Discovery Grant are helping fund the research. David Fullerton, the Faculty of Agriculture’s industry liaison officer, says the potential to commercialize Wang-Pruski’s research looks positive.

“Atlantic Canadian provinces account for 42% of total Canadian potato production,” says Fullerton. “In this region alone, the technology could be marketed in many sectors, including plant breeders, potato growers, processors, and seed-potato vendors, as well as to agricultural-solution and life-sciences companies.”

Wang-Pruski has filed two patents with her technologies since 2005; recently, she received two Springboard Atlantic Patent and Legal Fund Awards to support those patent applications. (Springboard is a network of 14 Atlantic Canadian universities that provides funding and assistance for the commercialization of university research in the region.)

Wang-Pruski has launched the Potato Consumer Research Initiative (PCRI), a multi-disciplinary group of researchers working in consumer behaviour, research methodology, and marketing. “I hope that PCRI will identify factors influencing consumer purchasing needs in order to help the potato industry better design their products,” says Wang-Pruski. “I do research for the sake of discovery but also to benefit society.”

From an article by Erin MacPherson originally published in Performance Research & Development magazine.