Good-for-You Baked Goods & Chocolate: A #hogsabroad Student Internship in Belgium

Imagine reaching for a piping hot biscuit or taking a forkful of crisp, flaky piecrust, knowing that each delicious bite will lower your bad cholesterol, raise your good cholesterol, and maybe boost your metabolism to burn more calories. Sound too good to be true? It gets better: how about savoring a chocolate bar that promotes heart health and combats fat? Sarah Mayfield, an honors food science senior with a second major in biochemistry, is working with Andrew Proctor, University Professor of Food Science, to make this dream a reality.

Sarah Mayfield uses a texture analysis machine to check consistency of CLA-rich shortening

She has spent more than five months making shortening and, more recently, chocolate with a new soy oil that Proctor produced that contains conjugated linoleic acid (CLA).

“The CLA-enriched soy oil has anti-obesity, anti-carcinogenic, anti-diabetic, and anti-arthritis properties, and it’s cholesterol-free and low in saturated fat,” Sarah Mayfield said.

A recent University of Arkansas System Division of Agriculture study that fed CLA-enriched feed to obese rats demonstrated its health benefits: in 30 days, total serum cholesterol and LDL (“bad”) cholesterol were reduced by 50%, and a fat-burning gene was activated.

Given today’s obesity epidemic and the economic potential – soybeans are a $2-billion-a-year-crop in Arkansas – the search is on at the university to produce CLA-rich food products with soy oil. And that’s where Sarah Mayfield comes in.

In the lab, Mayfield assembles the ingredients for her latest batch of shortening. The recipe is simple: melt together the fats, which include regular and CLA-enriched soy oils, then cool them in a cold-water bath while stirring with a kitchen hand beater. The combination of cooling and stirring causes the fats to crystallize and form a semi-solid substance that looks exactly like the shortening in your kitchen pantry. “So crystalline structure, rather than a high concentration of saturated fats, is responsible for the texture,” Mayfield explained.

Nearby, a tray is filled with more than 70 shortening samples in plastic containers, each marked with different percentages of CLA-enriched and regular soy oils. Later in the afternoon Mayfield will ship them to the University of Ghent in Belgium, where she will spend the summer subjecting the samples to a battery of tests.

“We’ll be looking at viscosity, hardness, color, and we’ll use X-ray crystallography to look at the crystal structure,” Mayfield said. “We’ll also use the DSC – differential scanning calorimetry – to see how much solid fat is in there. You don’t want it to be too low, or it would melt at room temperature.”
In addition to testing her shortening samples, Mayfield will work in the University of Ghent’s Cacaolab to develop chocolate bars and a chocolate paste that use a combination of CLA-enriched soy oil and the customary palm oil to provide the fat.

Once Mayfield returns to campus in fall 2014, she will study the oxidative stability of the shortening and chocolate over time.

“Fats go bad because they oxidize,” she said. “This leads to rancidity and off odors and flavors.”
Unsaturated fats oxidize faster than saturated fats, so this test will be an important final step. Mayfield also plans to start baking with the CLA-enriched shortening and regular Crisco, then compare the baked goods for crispiness and hardness.

“I’ll probably start with something simple, like pie crusts, that are easy to analyze,” she said. It’s a good bet that when Mayfield’s ready to taste test her baked goods and chocolates, she’ll have no problem finding volunteers.

Mayfield received an Honors College International Research Grant, a State Undergraduate Research Fellowship, a Bumpers College travel grant and support from the University of Ghent.

Photo by Russell Cothren
Article courtesy of the Honors College A+ Magazine: http://honorscollege.uark.edu/A+.php