Did science just zap the fat out of chocolate?

July 15, 2016

Love chocolate but also trying to watch your waistline? Well, you may be in luck as a group of researchers say they were recently successful in removing up to 20% of the fat that you usually find in your favorite chocolate bar.

Better yet, the scientists says, the chocolate still tastes good, too.

The researchers, led by Rongjia Tao of Temple University, were literally able to “zap” the fat of out chocolate in their lab by running liquid milk chocolate through an electrified sieve. Liquid chocolate is actually how many of the foil-wrapped bars of goodness get their start in the factory.

Liquid chocolate is made up of particles of cocoa solids (which give chocolate its characteristic flavor) sugar and mixed solids, suspended in melted fat and oil, mostly cocoa butter (typically, up to 40% by volume). The cocoa butter is essential for keeping the liquid chocolate flowing smoothly through factory pipes and creating the end product.

The researchers first started studying liquid chocolate in 2012 as part of a project they were working on to help improving the viscosity of liquid milk chocolate. Tao's team worked out a method of making the chocolate flow even better than normal through the pipes — without adding any more cocoa butter. It was at the point that it dawned on the researchers: If they could make liquid chocolate flow better without any extra cocoa butter, they could also slash the fat in it — by 10 to 20% — and still make it flow well enough not to jam the pipes.

Tao background includes studying smart fluids — liquids whose properties can be transformed by applying an electric field. For example, a smart fluid may thicken rapidly upon receiving an electric shock. Most smart fluids are machine oils, but, curiously, liquid chocolate is also a smart fluid.

An article explains that when you look at liquid chocolate at the microscopic level, the cocoa solids are circular, suspended in the fat and oil of the cocoa butter. These circular particles can pack together and get jammed (like a glass full of golf balls). Adding cocoa butter helps get the cocoa solids moving again.

But Tao and his team figured out how to use electricity to get the flow going and inserted an electrified sieve into the liquid chocolate. When the cocoa particles passed through the sieve, they receive an electric shock. That makes the cocoa solids flatten and start behaving like little bar magnets, lining themselves up into long chains. This chain formation allows more room for the liquid chocolate to flow.

Previously, manufacturers trying to lower the fat content in their chocolate could only reduce fat content to about 36%. However, Tao and his colleagues say their method allows them to slash fat content down to 28%, and leads to healthier and tastier chocolate.

But, John Hayes, a food scientist and the director of the Sensory Evaluation Center at Penn State University, says he is skeptical.

"Part of what makes chocolate so unique is the melting properties of the cocoa butter," Hayes said in the article. "It just melts exactly at body temperature." That's part of the pleasure we experience when a chocolate square melts in our mouth. Presumably, changing the amount of cocoa butter in chocolate would also change this experience. "Less butter would mean more powdery, more brittle, more stringent" chocolate, he added.

Since the researchers didn't include tests for taste and texture, however, it's hard to know how the zapped chocolate measures up, Hayes notes.

So is electrified, low-fat chocolate coming to a store near us? Tao says he is working with a "major chocolate company" to give his electric-field technology a real-world test run. Until then, us chocoholics can only hope.

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Category: Food Safety