Bakers Journal

Features Technical
From Lab Bench to Bakery


November 7, 2007
By Rob McMahon

Topics

Rob McMahon discovers scientists are tools for the baker’s trade.

scienceBakers use literally hundreds of tools, from mixing bowls to baking pans. But beyond the daily essentials, scientific laboratories are revolutionizing both the way tools are used and the way we think of ingredients, from dough to fats.

Engineers, chemists, food scientists and others pull products from ovens and pick them apart under microscopes. By isolating different aspects of baked goods, from the gluten holding bread together to the cocoa butter used in chocolate, researchers are uncovering the science behind the art of baking. This is a relatively recent idea, according to Dérick Rousseau, a professor and research chair at Ryerson University’s School of Nutrition.

“Baking, along with chocolate, wine-making and brewing, is a combination of art and science,” said Rousseau. “It takes age-old techniques that have been developed over centuries. In the last 40 or 50 years, science has been catching up with those techniques.”

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Previously, bakers used intuition, and trial and error to create their products rather than standardized operations, said Rousseau. This has been largely replaced by scientific and technological precision, as companies involved in the industrial manufacturing of bread and other food products work to optimize and standardize their production. Science now allows manufacturers consistent product quality and shelf life.

In his research, which focuses in part on chocolate, Rousseau drew inspiration from a variety of fields — from engineering and physics to geology. He noted that in many ways, the surface of a chunk of chocolate resembles geological formations like mountains and plateaus.

“You can see domes and mountains jutting out of the surface of chocolate,” he said. “There’s a region in the Philippines called ‘Chocolate Hills,’ and the similarities with the surface of chocolate are astounding.”

Though publicly available, chocolate research is a relatively new field, when developments in microscopic technology during the 1980s allowed scientists like Rousseau to peer at changes in the structure of fats as they occurred. Rousseau’s research focuses on fat bloom — a white or greyish coating on the surface of chocolate. Fat blooms appear when the crystals that compose cocoa butter, a key ingredient in chocolate, change their structural form. These changes are due to fluctuations in temperature, or when different kinds of fats interact (for example, when a hazelnut filling mingles with its chocolate coating).

“In the hands of consumers, more often than not, chocolate is subjected to large variations in temperature,” said Rousseau.

To illustrate, he described a common summertime scenario. Imagine a chocolate bar traveling from a cool store to a sunny park to a consumer’s fridge.  Temperatures might vary between 32 and 10 C in 30 minutes, accelerating the development of fat bloom. If a consumer reached for the chocolate later, it might seem less appetizing due to the bloom. By managing shifts in the structure of cocoa butter at the microscopic level, Rousseau’s work aims to determine how temperature fluctuations affect the development of fat bloom by experimenting with different storage conditions.

“Globally, this is a very expensive problem, as it shortens the shelf life of chocolate,” said Rousseau. “I’m trying to understand the factors in foods that affect their shelf life so that we may better control them.”

Massachusetts Institute of Technology (MIT) researcher, Trevor Shen Kuan Ng, shares Rousseau’s belief that science can devise standardized ways to improve the art of baking. Ng said that since baking incorporates such a massive number of variables — from ingredients and baking time, to temperature and hand-kneading techniques — it is an art. However, isolated parts of that art can be reduced to a science.

“Looked at as a whole, there are so many aspects to baking, it’s an art,” said Ng. “However, if you concentrate on one small part of it, it becomes a science. The whole point of science is reducing things to different aspects of their systems in order to understand them.”

Ng is a mechanical engineer in MIT’s non-Newtonian fluid dynamics research group, which also studies how the slipperiness of saliva, tree sap and snail slime changes when applied with pressure. As the group’s dough researcher, Ng looks at bread dough as a mechanical system, examining how it behaves when subjected to forces.

Since bread is such a big part of the North American diet, Ng said it’s been a popular research product since in the 1930s. Despite a long history of research, however, the complexity of bread baking and the difficulty of working with gooey dough and its unstable nature (dough’s properties change as it is mixed and time passes), limits research.

“It’s a big issue — I’ve spent a lot of time working with how to get things consistent,” he said. “To make baking a science, you need a consistent method of testing.”

For his work, Ng modified lab equipment normally used to treat polymer substances such as molten plastic to work with dough. Using custom-designed tools, Ng worked to isolate the core of dough’s structural system, and found gluten defines a loaf’s texture, or in scientific terms, its mechanical properties. Noting how dough reacts under different mixing times, temperatures and levels of strain, he varied mixtures of water, flour and other additives to see how ingredients affect dough structure.

Many bakers agree hand-kneaded dough makes the tastiest bread. Ng’s work helps figure out why. He modified a regular mixing machine to measure the amount of torque exerted during the course of a mix.  By measuring the mix in this way, he discovered that the machine breaks up the dough’s structure more than hand-kneading does.  Simply put, it doesn’t have the intuitive “hands-on” feel.

“With hand mixing, you have a lot more control over things,” he said. “You can feel when the dough is about to break….The thing with machines is that they apply continuous strain.”

Despite this problem, Ng’s work is useful in uncovering a set of ingredients, environmental conditions and mixing methods that create a product that most closely resembles hand-kneaded dough. Ng said that hypothetically, a machine could be designed to take readings and adjust its mixing settings accordingly, to solve this problem; but at present, such a tool doesn’t exist.

Food chemist, Alex Marangoni, a professor at the University of Guelph, and  his business partner, Steve Bernet, have formed Fractec Research and Development Inc., to study substances like edible oils, biodiesel and chocolate.

While both said that science and art aren’t completely separate — that anyone struggling with a scientific problem has moments of intuition — baking is presently “80 per cent science and 20 per cent art.”

“Most baking products are manufactured by large corporations that are very scientific in their methods,” said Marangoni.
 “However, even when we try to be as scientific as we can, sometimes the great complexity of food systems forces us to rely on our intuition.”

Their research has uncovered a way to create a heart-healthy, trans fat-free shortening substitute made from soybean oil.  The product combines the solidity of lard, which imparts structure to baked goods, with the health benefits of non-saturated fat. By manipulating the properties of liquid crystals called emulsifiers, Marangoni coaxed the natural properties of liquid vegetable oil to solidify in the lab.

With a large soybean farming industry in Ontario and the U.S., the resulting product — a solid fat made from soybean oil — can be produced locally. Soybean oil also retains many of the vegetable’s healthful qualities, including high amounts of the essential fatty acid linoleic acid, claims Marangoni.

Like any baking product, soybean shortening doesn’t work well in all applications. Bernet explained that while it falls flat for croissants, it works very well in biscotti and muffins, among other baked goods. Presently, Touche bakery in London, Ont., uses the product in its line of biscotti.

The partnership with Touche illustrates Marangoni and Bernet’s view of the collaborative relationship between scientists and bakers. Laboratory work is a very abstract endeavor, explained Marangoni. Scientists discover the properties of a substance, figure out how it works, and, through controlled experimentation, define the variables to replicate the outcome. Once scientists make their discovery, others must utilize and further develop the concepts to create a finished product.

“We’re bakers, we are scientists,” said Bernet.  “We’re working closely with the industry to take the science and use it in product development.”

Without the expertise of bakers, the discoveries of scientists would remain pieces of abstract knowledge that are disconnected from the baking industry. Bakers, according to Marangoni, know where their product is best suited: whether in a muffin, cookie or biscotti.

“That’s the artistic part,” he said. “Making a product that tastes good.”