Bet you can’t research just one
Patchen Barss | March 25, 2014
We’re standing in an unconventional laboratory in a campus research facility – the kind of place you’d never imagine anything unusual happens.
A technician lowers a sample of experimental material F07026 into a bath of heated triglyceride compounds.
Several molecular changes happen at once. A process called the Maillard reaction causes the sugars in F07026 to caramelize and darken. The triglycerides – also known as vegetable oil – displace the water in the material. The evicted water causes the bath to roil and spit.
As soon as the water has boiled away and the oil is calm again, the technician removes the samples, spreading them out to cool.
The experiment requires one more step to complete: the addition of sodium chloride crystals.
Salted potato chips, ready to eat.
The University of Guelph has had a frying lab since the 1980s. Those were heady days for potato research at the university, the pinnacle of which was the development of the Yukon Gold potato.
There’s a new quest now: the race is on to find an even greater tater.
What does this wonder spud of the future have that today’s tubers do not? For one thing, plant breeders are looking for a strain of potato that can be stored at cooler temperatures without its starches turning to sugar.
“The industry is always interested in knowing whether varieties will produce good quality chips when stored at a lower temperature because they can reduce sprout inhibitors and maintain dormancy longer, says Vanessa Currie, the research technician who has been frying sample batches for me.
Currie laid out two portions of chips on the table. Both were made from F07026 potatoes, which had been grown, harvested sliced and fried exactly the same way. But the differences were stark: one pile was tawny and delicious, while the other dark brown stack tasted burnt and bitter.
The difference was in how they had been stored after harvest. The burnt chips came from spuds stored at 4 degrees, while the tastier snack had spent the winter at 10-12 degrees. In the cooler storage area, more starch turned to sugar, and that made all the difference.
“The Maillard reaction causes sugars to brown when frying,” said Alan Sullivan, a Guelph researcher and plant breeder who oversees potato research at the university. “The sugars combine with amino acids and cause a dark colour. In a lot of foods that’s fine. In fact, it’s what gives bread and seared meat their appealing colour.”
But in the deep fryer, too much sugar spoils the chip.
Chip producers want a spud that keeps its starch at 4-8 degrees: If they could store them at that temperature, they could reduce their use of sprout inhibitors and anti-pest chemicals. They could store the potatoes for longer, which would lead to major cost savings.
Cold storage is just one issue of concern for the Guelph researchers. Another desirable quality is rapid maturation (which would allow for a longer harvesting season and less storage time).
“Potato chip producers want product 12 months of the year,” Currie says. “There’s a significant part of our season in Ontario where they don’t have local potatoes. At that time they have to import them from the States at considerable expense.”
And of course, what’s good for the chip bag is different than what’s good for the mash or the fry. Breeders aren’t seeking a single superpotato, so much as they are a variety of new strains, each optimized for starch content, water content, robustness in the face of rain and drought, yield, disease and pesticide resistance, and many other factors.
Of course, private companies like Frito Lay have their own fry labs. But Sullivan thinks there is great value in having such research take place at a university.
“We are publicly funded, and everything that we do is public,” says Sullivan. “We produce reports that are disseminated to the industry – not just potato growers but on the table stock side there are chefs who want to know what the latest is. Loblaws is also interested.”
Breeding and cross breeding is a lengthy process with many factors – sometimes you get a potato that’s great in cold storage, but the yield is inadequate. In fact, species F07026 is one of hundreds that have been researched at the university. Hope, of course, sprouts eternal.
“Everybody is looking for the next Yukon Gold,” Sullivan says.
The Research Matters blog periodically publishes a range of stories centred around a specific theme. This story is part of a series on Food and Drink.
The whole package
Teresa Pitman | September 26, 2014If you’ve ever bought ready-to-eat sushi, you may have noticed a blob of wasabi on the tray. It’s a convenient way to add pungent flavour to your lunch, but it also serves another purpose: it protects your food from micro-organisms. As food science professor Loong-Tak Lim explains, wasabi contains allylisothiocyanate, (AITC) a natural and potent anti-microbial that kills yeast and bacteria. Of course, not every food is enhanced by the strong flavour of wasabi, so Lim has developed a packaging system that offers the same antimicrobial benefits . Lim derives his AITC from ground mustard powder, and uses a patented nanotechnological process to spin tiny fibres that encapsulate the naturally sourced agent in the packaging. “The conventional approach to adding preservatives has been to add them to the food,” says Lim's research colleague Suramya Mihindukulasuriya. “But processing the food may break down the preservative. By having the preservative in the packaging, we don’t need as high a concentration to enhance the shelf-life, safety and quality of the food.” So-called “active packaging,” responds to changes in the environment and the food itself, Lim says. In this case, the membrane responds to a certain level of moisture and releases a preservative to prevent spoiling. Other active packaging materials respond to heat and light. Mihindukulasuriya works with a preservative called hexanal, the volatile organic compound you smell when you cut grass or slice a cucumber. Hexanal helps preserve cell membranes of fruits and vegetables so they don’t become soft or soggy as they ripen. The preservative also has some anti-microbial properties, which are activated by heat and humidity. Mihindukulasuriya calls her technique of enclosing the preservative using ultra-high electrical forces “electrospinning.” Lim jokes that “we are like Spiderman, spinning tiny fibres.” And the fibres are tiny – about 400 times smaller than a human hair. When exposed to humidity or water, these fibres become permeable and release the hexanal. During her PhD studies, Mihindukulasuriya also developed an oxygen indicator that is activated by ultraviolet radiation. When there is little or no oxygen in the package, the indicator is white, but if the package is damaged or torn, allowing oxygen to enter, the indicator turns blue. This matters because oxygen causes rapid deterioration of some foods, and higher levels of oxygen encourage the growth of more micro-organisms. These foods are sealed in vacuum packs or in packages flushed with nitrogen to remove the oxygen, but if the package becomes damaged at some point, oxygen can get inside. That’s where Mihindukulasuriya’s product comes in: a label with a blue line would indicate that the package should not be purchased. What’s next in active and intelligent packaging? Mihindukulasuriya is planning to develop a compound that will detect the volatile compounds produced by food when it spoils and indicate to consumers that the food should not be eaten. The technique would supplement expiry dates, which are only estimates based on typical situations. Not only would such packaging warn people that food had spoiled, it could also reassure them when it was safe to eat – even if the expiry date had passed. “People throw away lots of food that has expired but is still perfectly good to eat,” says Lim. This article was originally published by the University of Guelph. It has been edited for brevity, clarity and style, and is republished here with permission.