Egg-cellent Enzymes: Science in Chocolate Eggs

With Easter just around the corner, we are taking a look at one of our favourite Easter treats: Easter eggs. As an ancient symbol of new life and rebirth, it became associated with Jesus’ crucifixion and resurrection in Christianity. The decoration and exchange of eggs as gifts has become part of our Easter tradition.

With Cadbury’s Crème Eggs being a particular favourite amongst BioLabTests team members, we decided to take a closer look at this sweet treat from a scientific view point (and we might have sampled some Crème Eggs in the process…all in the name of research of course). These popular treats consist of a thick chocolate egg-shaped shell and are filled with white and yellow soft fondant that mimics the yolk and albumen. But did you know that microorganisms play a crucial role in making them?

The Sweetest Thing

Yeasts are microorganisms that belong to a group called fungi. Saccharomyces cerevisiae (S. cerevisiae) is a strain of yeast commonly used in commercial settings for the production and purification of an enzyme called invertase by using sucrose as a nutrient. Enzymes participate in a reaction by lowering the energy needed for said reaction to occur, without being consumed. Invertases catalyse the hydrolysis of sucrose, cleaving the glycosidic bond between fructose and glucose, producing a mixture of both monosaccharides called invert sugar. This mix of glucose and fructose is beneficial, as it is sweeter than sucrose and does not crystallize as easily, keeping the fondant soft and smooth. This process is useful in making syrups, soft centred sweets, fondants and alcoholic beverages.

That Irresistible Soft Centre

So what is the science behind mouth-watering liquid centre chocolate treats? Well, the liquid centre starts out as a solid fondant, a mixture of sugar and water wrapped in chocolate. Over several weeks, water is supersaturated with sucrose by heating water to its boiling point, as it is able to dissolve twice as much sugar. During the heating process, sucrose is broken down by invertases, making the resulting glucose and fructose more water soluble and being able to dissolve in the water present. This is how you get the classic centre of liquid filled chocolates such as cherry cordial chocolates. Many companies use different concentrations of sucrose and invertase to get the desired consistency, this is because the higher the sucrose concentration the more viscose the liquid. Crème Eggs use invert sugar syrup, which has a straw like colour and is a mixture of fructose and glucose that was made using invertase. Thanks to the fondant, these Cadbury eggs contain so much sugar that just one of them makes up to 29% of the total recommended daily sugar intake.

Although there is an art to making chocolate, there is also a lot of science behind it. Invertase is only one of many processes that go into making these fascinating chocolates, showing the crucial role science plays in developing chocolate.

While enjoying your chocolate eggs this Easter, take a moment to appreciate the amazing role microorganisms and enzymes have in developing confectionary treats.

From everyone here at BioLabTests, we wish you a very happy Easter!