In the UK we are about to celebrate Easter, where we get the chance to spend a few days relaxing with family and friends and enjoying the start of spring. It is traditional at this time of year to give away chocolate Easter eggs, as a symbol of new life.
So, for me, the hunt is on for the perfect Easter egg for my family. As I do this, the questions I find myself asking are:
- What size is it?
- What shape is it?
- What does it contain?
Interestingly these are precisely the same questions the producers of the chocolate used to make the egg ask too!
What size is it?
In Easter Egg selection it is generally believed, by my family anyway, that the larger the egg is the better it is, as this will ensure that there is enough chocolate to share! However, although big is good for Easter eggs, this is not the case for the particles found in the chocolate. The presence of large particles of sugar or cocoa solids can cause the chocolate to have a very gritty mouth feel, making it less pleasant to eat. Large particles can also slow flavor release during eating too. So, producers usually mill the chocolate solids to a fine particle size in order to deliver a smooth, luxurious mouth-feel and the wonderful chocolate taste we all love.
What shape it is?
Despite my belief as a user of laser diffraction particle size analysis that all objects are spherical, I have to admit that when it comes to choosing Easter eggs spherical will not do! An Easter egg needs to be egg shaped. Shape is also important for the particles in the chocolate too. The presence of irregularly-shaped sugar crystals can contribute to a gritty mouth-feel. Their presence can also affect the rheology of the product, another important aspect in defining the mouth-feel of chocolate. Milling the particles to provide a fine, semi-spherical shape may helps improve product perception.
What does it contain?
One of the joys of receiving Easter eggs is to discover what is inside when the egg is cracked open. Although it is less common to find filled eggs these days, when I was young Easter eggs could contain toys or, in most cases, more sweets! Composition is also important within the chocolate too. At the moment, we do not know of any applications for component-specific particle size analysis for chocolate (write into us on this blog if you know of any!). However, particle size does have an effect on the final composition of chocolate. Milling to too fine a particle size can cause an increase in the amount of cacao butter required to disperse the chocolate solids during manufacture, leading to a mouth-feel which may be too sticky.
Manufacturers are also considering how to lower the fat levels in chocolate by defining the width (polydispersity) of the size distribution within the chocolate, as this provides another way of controlling the rheology of the product.
So – Easter egg hunting and particle characterization appear to be similar when it comes to chocolate. I hope you enjoy hunting for (and consuming) your perfect chocolate egg!