IN APRIL 2008, the BioPotato Network, led by research scientists from Agriculture and Agri-Food Canada, brought together 11 organizations and 30 research scientists throughout Canada to develop bioproducts for health and the environment. For the past three years, the network has worked on the development of new biopotato products. Although its funding ends this March, researchers say there is still much work to be done. And the network of researchers are confident the work will continue through a combination of ongoing breeding selections being carried out by AAFC, future publicly- funded programs and private companies seeking to commercialize newly identified bioproducts.
Biopotatoes are potato varieties that contain compounds beneficial to human and animal health. Providing solid scientific evidence to support the benefits of consuming the potato varieties studied, which were developed by AAFC’s Potato Research Centre in Fredericton, has been a key driver of the network.
“One of the primary purposes of the BioPotato Network is to offer farmers a new crop that they can grow with more profitability for them,” says Bob Chapman, lead scientist of the network and director of research for the Institute for Nutrisciences and Health of the National Research Council of Canada. “First, there has to be a market established for the products, and there has to be evidence to support how these products function and what advantages they have over regular types of potatoes, before consumers will pick them up.”
The network has focused on four main streams of research: bioactives, functional food and nutraceuticals; low glycemic index and high-fibre functional food; new potato starch for functional food, pharmaceutical and bioplastic uses; and botanical insecticides and biopesticides for insect control. Benefits for Nutrition and Health
Development of potato varieties for use in the production of value-added functional food, nutraceutical and pharmaceutical products has been explored by the network. Potential therapeutic benefits of these products were examined in relation to a number of health conditions, including neurodegenerative diseases, stroke, autoimmune disorders, diabetes, allergies, infections, heart disease and obesity-related diseases.
For example, researchers investigated the nutritional value of purple-pigmented potatoes, which are rich in antioxidant compounds, and were found to have 25 to 50 per cent of the antioxidant capacity of strawberries or blueberries. “The idea is that you could have the same antioxidant potential that you get from a blueberry in a potato, but potatoes can be grown on a much larger scale and more economically—and still have the same impacts for human and animal health,” says Chapman, who recently led the research in this stream.
Identifying the potential links to health is the first step, but creating products that consumers will want to purchase, and that are easy for them to prepare and cook, is equally important if those products are ever to reach store shelves.
As a member of the network, the P.E.I. Food Technology Centre in Charlottetown, focused on evaluating the suitability of pigmented and coloured-flesh biopotato varieties for the production systems of food processors.
Researchers found that the biopotato products kept their colour and antioxidant properties throughout the production process, and they produced a potato flour that chefs at Canada’s Smartest Kitchen found was suitable for many breading and baking applications—and is also gluten free. From potato croquettes to potato chips, the potential is vast for healthier consumer products made from biopotatoes.
It’s in the Genes
Another area of concentration for the network was developing new potato germplasm for the food sector with low glycemic indices and high-fibre content—that is, high in slowly digestible or resistant starches and fibre content—emphasizing the health benefits of these traits. “In order to start a breeding program, we need to study the variation we have in our gene pool, and so that is where we have been focusing our efforts,” says Benoit Bizimungu, a research scientist at the Potato Research Centre and the stream leader for this area of study. “Once we identify that there is a natural genetic variation, we can use that to breed better varieties with additional health benefits.”
The multidisciplinary team involved in this area of research studied the genetics and agronomy, chemistry and biochemistry, and physiology of the germplasm they were investigating.
Here, researchers explored the genetic ability to provide more nutritional value to food products from biopotatoes, especially the glycemic index potential. Research shows foods with a low GI provide benefits with respect to a number of health-related areas. Diets made up of foods with a low GI can help manage diabetes, aid in weight loss, reduce the risk of heart disease and stroke, improve blood cholesterol levels, and prolong physical endurance.
“Some studies have portrayed potatoes as having a high-glycemic index,” says Bizimungu. “If we can identify potato varieties with a low GI potential, they will offer improved nutritional benefits that can be useful to the population in general, not just diabetics. Those varieties would definitely have an advantage in the marketplace.”
At the same time, the network has explored the agronomics of growing these varieties, such as the influence of environmental factors, growing conditions and storage ability, to ensure they can be easily and profitably grown by farmers.
Also, a large part of the research has focused on the biochemical factors that contribute to desirable traits like low GI and high-fibre content in potato germplasm.“In our research, for example, we aim at identifying germplasm with a starch that is resistant to digestion, which means it can be effective as another form of dietary fibre,” says Bizimungu. “This can be used in the traditional starch market and as a functional food ingredient, so it can become a part of many different food products.”
The final step in determining the potential health benefits of the germplasm of certain biopotato varieties included pig feeding trials and human clinical trials. This also involved studying the effects of cooking methods on the GI of selected germplasm.
Potato Starch Research Expands Uses
The development of novel potato starches for functional food, pharmaceutical applications and starch-based bioplastic as a packaging material was a priority for the network.
“We mainly focused on the modification of potato starch for resistant starch and pharmaceutical applications,” says Qiang Liu, stream leader and research scientist with AAFC’s Research Centre in Guelph, Ont. “We have developed several novel modified potato starches, and we are helping to understand the mechanisms that cause resistance to enzyme hydrolysis for these starches.”
The research conducted by the network has led to the development of some modified starch products that can be used as a binding agent by the pharmaceutical industry, and also in bioplastics for use in packaging.
“For packaging applications, the starches used in bioplastics commonly have weaker mechanical and water absorption properties than oil-based plastics,” says Qiang. “We have made efforts to improve those weaknesses—with good results, which could have good potential for other industrial applications that could use potato starch-based bioplastics.”
Breeding for Resistance
For over a decade, researchers at AAFC’s Potato Research Centre have been working on a breeding program to produce new potato varieties resistant to the Colorado potato beetle. They identified several wild Solanum species—a cousin of the potato—that had natural resistance to the beetle and were seeking to identify the specific compounds within this species that provided the resistance.
“We were looking to identify the chemical that is active against Colorado potato beetle, but also any other chemicals that could potentially have some insect-repellent properties in the Solanum genus,” says Yvan Pelletier, one of the network leaders and a research scientist at the Potato Research Centre.
The BioPotato Network focused on developing a technology called metabolomic profiling in order to identify the metabolites, or chemicals, in the plant’s foliage. Pelletier says they are just scratching the surface when it comes to identifying compounds that may be useful as biopesticides.
Although that area of research may be put on hold as the network’s funding ends, the expertise and technology developed by its participants will be of benefit to the ongoing development of new Colorado potato beetle-resistant varieties in the future.
As commercialization of new products developed through the work of the BioPotato Network and other research programs progresses, biopotatoes have the potential to become a highly sought-after food because of their value to our health and as a “green” alternative to industrial raw materials and agricultural inputs, to the benefit of our environment. All of which could lead to an increase in acres of these versatile varieties at a premium price for Canadian growers.