Let's do lunch: your 21st century lunchbox

Wednesday 23 February 2011, 12.30-1.15pm
The Chemistry Centre

Why do tinned peas look so unappetising? How can you have "natural" blue food colouring? What do chorizo sausage, Leicester cheese and some baked goods have in common? 

Substances used to add colour in food have changed over time. In the 19th century they were lethal. Unsuprisingly they were replaced. However, in the 20th century many of these replacements turned out to be carcinogenic. 

So food production companies abandoned these and turned to what should be a safer option: "natural" colours. But this brings a new set of problems. The main natural green pigment, chlorophyll, degrades when cooking. Some red pigments change colour in certain foods, others degrade on heating, and one is even made from beetles. 

Tom Coultate, food scientist, discussed the dangerous food colourings of the past and the "natural" versions of the present.