Researchers at ETH Zurich have produced a healthier alternative to chocolate. They say it could help increase the value creation of cocoa farming.

Chocolate is mainly made up of cocoa mass and cocoa butter extracted from the cocoa fruit. However, it is less known that the fruit contains additional valuable ingredients that have been historically underutilised.

Researchers at ETH Zurich have joined forces with start-up Koa and Swiss chocolate manufacturer Felchlin to investigate the potential for maximising the use of cocoa fruit. They sought to create a product that would increase the cultivation's profitability while making chocolate a healthier indulgence.

Finding the perfect recipe

Kim Mishra, lead author of the study, compared the cocoa fruit to the honeydew melon. She said, “These fruits have similar structures. Both have a hard outer shell that reveals the flesh of the fruit when cut open, as well as the cocoa beans or melon seeds and pulp in the interior.”

Conventional chocolate only uses beans, but the researchers used the flesh and parts of the endocarp (the fruit shell) for their cocoa-fruit chocolate recipe. They processed the flesh into powder and mixed it with part of the pulp to form cocoa gel. This gel substance is extremely sweet and can replace the added powdered sugar that is normally found in chocolate.

However, the team said finding the perfect recipe was not easy. They systematically tested the texture of various compositions in the lab. Too much fruit juice extracted from the pulp made for a clumpy chocolate, but too little resulted in an insufficiently sweet product. The clumping issue does not arise when using powdered sugar. However, the team endeavoured to find the perfect balance between sweetness and texture.

Sugar vs gel

Conventional dark chocolate can contain between 30 and 40 per cent powdered sugar.

This experiment showed that the chocolate may contain up to 20 per cent of the gel, which equivalates to the sweetness of chocolate with five to 10 per cent powdered sugar.

To test the recipe’s sensory experience, trained panellists from the Bern University of Applied Sciences taste-tested pieces of chocolate weighing five grams each. Some contained various amounts of powdered sugar and others contained the cocoa gel.

Kim explained, “This allowed us to empirically determine the sweetness of our recipe as expressed in the equivalent amount of powdered sugar.”

Healthy, sustainable and good for farmers

Using cocoa gel as a sweetener, cocoa-fruit chocolate boasts a higher fibre content compared to the average European dark chocolate (15 grams versus 12 grams per 100 grams). Also, it contained just 23 grams of saturated fat as opposed to 33 grams in average European dark chocolate. This means that ETH researchers were able to increase the fibre content by around 20 per cent while reducing the saturated fat percentage by around 30 per cent.

Kim explained, “Fibre is valuable from a physiological perspective because it naturally regulates intestinal activity and prevents blood sugar levels from rising too rapidly when consuming chocolate.

“Saturated fat can pose a health risk when too much is consumed. There’s a relationship between increased consumption of saturated fats and increased risk of cardiovascular diseases.”

According to the researchers, small-scale farmers can diversify their product offerings and increase their income if they market other components of the cocoa fruit instead of just the beans for chocolate production.

Kim said, “This means that farmers are not only able to sell the beans, but also dry out the juice from the pulp and the endocarp, grind it into powder and sell that as well.

“This would allow them to generate income from three value-creation streams. And more value creation for the cocoa fruit makes it more sustainable.”

However, the researchers said that the cocoa-fruit chocolate will not be available to buy anytime soon.

Kim said, “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.

“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.”

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