Waste Not
The Many Benefits of This Cacao-Fruit Chocolate Make It Even Sweeter

Researchers at ETH Zurich — a public research university in Zürich, Switzerland — have developed a type of chocolate that makes use of an agricultural waste stream and is more sustainable and nutritious than conventional varieties. The team has also joined forces with the chocolate industry to investigate the potential for making maximum use of the cocoa fruit, which would increase the profitability of cocoa cultivation while making chocolate a healthier indulgence.

The main components of conventionally produced chocolate are cocoa mass (beans) and cocoa butter, which are extracted from the cacao fruit. But cacao fruit is a superfood that contains additional, valuable ingredients that have been largely underutilized until now — in producing conventional chocolate, the industry wastes 70 percent of the cacao pod. And while brands such as Barry Callebaut and Blue Stripes are exploring the many potential uses for the rest of the fruit, efforts to make use of these nutritious waste products have yet to scale.

So, as part of an Innosuisse project, a research team led by emeritus ETH professor Erich Windhab, worked together with Koa — a Swiss-Ghanaian startup that upcycles cacao fruit, especially the typically discarded pulp, into value-added ingredients to improve the resilience of cocoa farms and reduce the carbon footprint of the West African cocoa industry — and Swiss chocolate manufacturer Felchlin to develop their own recipe for cocoa-fruit chocolate.

Image credit: ETH Zurich

The ETH researchers used the flesh and parts of the cacao fruit shell (called the endocarp) for their cocoa-fruit chocolate recipe — processing it into powder and mixing it with part of the pulp to form cocoa gel. The resulting sweet, gel substance can replace the added powdered sugar that is normally part of the chocolate recipe.

However, landing on the perfect cocoa-fruit chocolate recipe was a challenge: Too much fruit juice extracted from the pulp made for a clumpy chocolate (an issue usually solved by adding powdered sugar), but too little resulted in an insufficiently sweet product. In the end, the experiments showed that chocolate may contain up to 20 percent gel, which equivalates to the sweetness of chocolate with 5 to 10 percent powdered sugar — in comparison, conventional dark chocolate can easily contain between 30 and 40 percent powdered sugar.

Healthier, more sustainable and more lucrative for farmers

According to Kim Mishra — former postdoc researcher at ETH and main author of the Nature Food study on the project — ETH’s cocoa-fruit chocolate was then vetted by a panel of taste-testers from the Bern University of Applied Sciences, with some containing various amounts of powdered sugar and others containing the new variety sweetened with cocoa gel: “This allowed us to empirically determine the sweetness of our recipe as expressed in the equivalent amount of powdered sugar,” he explains.

In addition to meeting expectations for flavor, by using cocoa gel as a sweetener, cocoa-fruit chocolate boasts about 20 percent higher fiber content than your average European dark chocolate (15 grams versus 12 grams per 100 grams) — which prevents blood sugar levels from rising too rapidly when consuming chocolate — and only 23 grams of saturated fat, as opposed to the usual 33 grams (a reduction of 30 percent).

Planting seeds for added value

The biggest opportunities here could be for smallholder cocoa farmers — the majority of whom struggle to earn a living income from their work. By scaling demand and processing capacity for more parts of the cacao pod, farmers can eliminate waste, diversify their product offerings and increase their income. And if most of the fruit can be used to produce cocoa-fruit chocolate, only the shell remains — which is traditionally used as fuel or composting material.

“This means that farmers can not only sell the beans, but also dry out the juice from the pulp and the endocarp, grind it into powder and sell that, as well,” Mishra says. “This would allow them to generate income from three value-creation streams. And more value creation for the cocoa fruit makes it more sustainable.”

And while this could be a win on many fronts, ETH’s cocoa-fruit chocolate won’t be hitting store shelves anytime soon.

“Although we've shown that our chocolate is attractive and has a comparable sensory experience to normal chocolate, the entire value-creation chain will need to be adapted — starting with the cocoa farmers, who will require drying facilities,” Mishra says. “Cocoa-fruit chocolate can only be produced and sold on a large scale by chocolate producers once enough powder is produced by food-processing companies.”

The first step has been taken: ETH has filed a patent for its cocoa-fruit chocolate recipe. The development of cocoa-fruit chocolate is a promising example of how technology, nutrition, sustainability and income diversification for small farmers can work in tandem to improve the entire value-creation chain of one of our most popular commodities.