Engineering Chocolate

From EngineeringUK, this engaging poster looks at the food industry engineering careers involved in the production of chocolate. Short descriptions are given for the jobs of: chemical engineer, environmental engineer, packaging engineer and biochemical engineer.

Four lesson activities accompany the poster:

Hot chocolate: This activity encourages students to investigate solubility. Using drinking chocolate as an example, students compare how sugar dissolves in warm water whereas drinking chocolate powder forms a suspension. They look at the different properties of solutions and suspensions.

Keeping cold: This activity sees students investigating the thermal insulation properties of different materials using the context of chocolate production. Students think about the properties of chocolate and how refrigeration is important during its manufacture. They learn that insulation is very important in aiding refrigeration, and also in keeping things cold in carrying frozen foods home.

Testing milk: These activities help students to think about hygiene, microorganisms and the spread of infections. Students use the resazurin test to observe the levels of bacteria in milk samples that have been stored in different conditions. Milk contains nutrients that make it a very good medium for the growth of many microbes. This is why dairy produce has to be processed carefully and has a limited shelf life. It deteriorates fast if storage conditions are not strictly controlled during delivery and, if strict hygiene procedures are not followed, bacteria would grow in the milk. Food manufacturers use the resazurin test to check incoming batches of milk before use.

Engineering colour: These activities introduce students to natural and synthetic dyes. Through a practical investigation, students prepare dyes and see how well they are taken up by different fabrics. It also links to the work of a packaging engineer because the materials used to package a product must be colour-printed or dyed. Students are challenged to produce attractive and innovative packaging for chocolates.

• URL: http://stem.org.uk/rx4ax