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Not a piece of cake
The classical pound cake is made from equal parts of flour, sugar, eggs, and butter
© KU Leuven – Lomme Deleu

Not a piece of cake

The search for alternative cake ingredients is… not a piece of cake.

4 minutes
19 April 2021

Can you make a cake without sugar, butter, or eggs? The standard ingredients of cake have become controversial but replacing them is more difficult than one might expect. One thing is certain: this challenge cannot be addressed without a big serving of chemistry and biochemistry.

The food industry is currently focusing on consumer demand for healthy and sustainable products. “In ten years’ time, sugar will become the new tobacco, I sometimes hear”, says Professor Jan Delcour at the Laboratory of Food Chemistry and Biochemistry, who has been conducting research into cake and other foods for many years.

That means less sugar, fat, and E-numbers. And vegans do not eat products containing ingredients of animal origin, like eggs. But finding good substitutes is not simply a question of adjusting the recipe slightly. It requires an understanding of the science behind the cake, and this is what Delcour and his researchers help food companies to do.

Cake RS MG 0058
© KU Leuven - RS

Fundamental research

To research various kinds of cake, the Laboratory has spent years collaborating with Puratos, a Belgian multinational that supplies ingredients to bakeries and the pastry and chocolate sectors. “We conduct fundamental research into bread and cake. How do the raw materials work? How do they interact with one another during the kneading or mixing process? What happens during baking? The answer is different for each type of product: what works for a biscuit does not work for a pound cake.”

“Some ingredients are a victim of their own success, in a manner of speaking, because they serve so many purposes. An egg, for example, does wonders for a recipe”, Delcour says. An egg actually consists of two ingredients: the yolk and the egg white. The yolk is itself a mixture of water and a fat containing phase. This means that you can easily add a different kind of fat – butter or margarine – to it. But in addition to fats, egg yolk also helps retaining air and carbon dioxide in the batter during baking, so that you obtain a beautiful, airy cake.

Voeding lab RS MG 0023s web
© KU Leuven - RS

No egg, no crust

An amateur cook associates egg white with meringue. In a biscuit, the egg white does indeed ensure airiness. By contrast, in a pound cake, the egg white gives the cake a firm structure while it is baked. Egg white contains various proteins that connect to one another and other ingredients at high temperatures, thereby forming a solid network. In short, without egg white, your cake would be less firm and would collapse.

What about sugar, surely there are alternatives like stevia or aspartame? “Those are high intensity sweeteners. You might find them in soft drinks, in which you can easily replace sugar with water and a low quantity of sweetener. But if you take the sugar out of a pound cake recipe, you must compensate it either with more flour, more fat, or more eggs, and in many cases, you end up with something closer to bread. In cakes, sugar is far more than only a sweetener, and this makes the search for a good substitute very difficult.”


Sugar is an extremely multifunctional ingredient: it makes the batter syrupy, so it stays airy when you mix all the ingredients. Just like eggs, sugar also plays a prominent role in the structure of cakes. Without sugar, the batter solidifies in the oven before it has even risen. And sugar also ensures longer storability. Without sugar, mould can take over much more quickly.

There are alternatives, but they don’t all do the same things. “People want a lookalike of the cakes to which they are accustomed, but it is impossible simply to replace one component with another one that is equally versatile. The result is a recipe with several additives.”

Clean label

Although these additives – E-numbers – are strictly regulated, they are not popular among consumers. An example of an additive in cake is baking soda, which when combined with an acidifier forms the raising agent. In the past, such acidifiers often contained aluminium, but this has become undesirable. “Food companies now strive for clean labels: recipes and production processes based entirely or primarily on natural ingredients.”

“Know your raw materials”, is Delcour’s motto. “If you have a good understanding of the composition and reactions of your ingredients, you can get more out of them, and you might not need any extras.”


In other words, it is a balancing act. Ingredients cannot simply be replaced, production processes cannot easily be changed, and alternative ingredients are sometimes too expensive to be used on an industrial scale. But this is also partly up to us: we are probably too attached to foods that look and taste familiar. “We ought perhaps to have more courage in transitioning to delicious new products.”

With special thanks to Kristof Brijs, Lomme Deleu, Thibault Godefroidt, Nand Ooms and Sarah Pycarelle

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Summer 2021