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Discovering the science behind chocolate

7 July 2015 No Comment

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Malvern Kinexus Work Experience

My name is Thea Miksch and I recently visited Malvern Instruments for a six day work experience placement.  It was quite a big thing for me since I came from Germany to the UK for this placement. I was a little scared that I wouldn’t understand anything about the technology, but the Malvern employees were great at explaining it so even I got it!

One of the many things I learned is that there is science behind everything. I never thought of the particle size of chocolate or the viscosity of hand lotion before, but those parameters matter! Whether you can get the hand cream out of the bottle easily, or if you have to squeeze really hard is determined by the viscosity of the product. And the particle size of chocolate makes a difference in taste. Smaller particle size will give you a smoother mouth feel, whereas bigger particles make the texture rougher.

To control these parameters, you first have to measure them. I worked with Carolyn O’Grady in the applications lab to measure chocolate particle size with the Kinexus rheometer and with the Mastersizer 3000 particle size analyzer, which was really interesting.  First we had to load the sample into the Kinexus, which is basically putting a piece of chocolate on the bottom plate. Then the upper one slowly lowers and melts the chocolate between the two plates. Then the Instrument starts to measure by oscillating the top plate. In the end you just have to read the data you get. Sounds easy right? We compared dark chocolate to milk chocolate and that’s what we found out: Dark chocolate melts at a higher temperature, but is more fluid when melted. Milk chocolate melts at lower temperatures but has a higher viscosity when melted (see viscosity data below).

viscosity of chocolate

We also compared the particle size of cheap and higher quality chocolate by measuring it with the Mastersizer. The results of this measurement showed that cheaper chocolate has bigger particles than the higher quality chocolate (see particle size data below).

particle size chocolate

The labs are not the only part of Malvern. I also spent some time at the Helpdesk where they look after all the needs of the customers. If there is a problem with any of the instruments, or you have any questions, the Helpdesk is there for you.  I also saw a demo of an instrument for a customer, and found out about how Malvern use social media to communicate with users of their instruments. But the most interesting was to learn about the instruments themselves.

I want to say thank you to everyone who explained such complex technology to me in a way that I would understand it. It was really good to see science in action instead of just hearing about it in class. It was a week I really enjoyed and I want to thank everybody who took time to show me how your company or an instrument works.

Click here for more information about careers at Malvern.

Related Resources:

Particle size and rheology in the chocolate industry – recorded webinar

Analyzing chocolate with the Morphologi G3 automated image analysis system