Biomedical Engineering

It's happening. I honestly can't decide if I like the idea, and there is debate in our office about making chocolate healthy. But regardless of what I think, scientists have developed a technique which allows chocolate to maintain all of its chocolaty characteristics which containing half the fat.

The milk fats and cocoa butter (herein referred to as 'the good stuff') in the chocolate are what gives the treat its succulent and satisfying feeling, such as the smooth glossy surface, the satisfying snap when a piece is bit off, and the melt-in-your- mouth sensation (great, now I want chocolate). Clever chemists are now able to replace 50% of the fat content with fruit juice. A process called Pickering emulsion substitutes the good stuff with tiny droplets of juice measuring less than 30 microns in diameter.

^{Cocoa beans (left) and cocoa butter (right) Image Credit: BellyGlad}

The emulsion uses food-approved ingredients, and the technique prevents the small droplets from merging together and sinking to the bottom of the molten chocolate. Pickering emulsion combines fumed silica particles with chitosan under acidic conditions. A water-in-oil emulsion uses sunflower oil, molten cocoa butter, and either white, milk, or dark chocolate. The chitosan molecules are absorbed onto the surface of the silica particles and influence their wettability, making it an effective Pickering stabilizer. The molten chocolate acts like a gel so the droplets don't sink to the bottom.

^{Pickering Emulsion 24 hours after preparation. Image Credit: Beijing University of Chemical Technology}

The good stuff provides the chocolate with polymorph V content, which gives chocolate its glossy appearance, firm and snappy texture, and allows it to melt in your mouth. By maintaining the polymorph V content, the scientists are able to maintain the "mouth-feel" given by the good stuff in chocolate.

^{Image Credit: Wakeup-world.com}

Currently, the healthy chocolate will taste fruity due to the infusion of orange and cranberry juice. Scientists are working on a way to use water and small amounts of ascorbic acid (vitamin C) to maintain the chocolaty taste.

^{Dr. Bon and ingredients. Image Credit: University of Warwick}

The research was done out of the University of Warwick and led by Dr. Sefan Bon. The study was published in the Journal of Materials Chemistry. The next step is for the food industry to catch on and use the technique to create lower-fat chocolates, aka healthy chocolate. I'm all about making things healthier, especially when it's an easy transition (i.e. buying wheat bread instead of white). But just to be safe, I think I'm going to stock-up on chocolate filled with the 'good stuff'.

Resources

Fruity science halves fat in chocolate

Quiescent water-in-oil Pickering emulsions as a route toward healthier fruit juice infused chocolate confectionar