Measuring heat
In recent years the chilli pepper has inspired some unusual lifestyle trends, such as the sale of chilli chocolate in supermarkets. Now there is the science of the chilli pepper. Professor Richard Compton and his team at Oxford University have developed a method of measuring the ‘heat’, the spiciness, of chillies.

The journey from science to chilli technology is not as odd as it may seem, as Compton explains, ‘I am an electro-chemist. In recent years we have been addressing issues of  “sensing”, both generically and specifically.' In 2006 Compton developed a company based on the research he was conducting for roadside drug testing. ‘We have an interest in chemical sensors,’ says Compton, ‘our interest in chilli peppers came about as we were looking at the properties of carbon nanotubes as electro-chemical sensors.’

Chilli tasters versus nanotubes
The food industry currently uses the ‘Scoville Method’, where the chilli is diluted until a team of trained chilli tasters can no longer detect any heat. What makes chilli peppers hot are ‘capsaicinoids’. To get a sense of the scale of spiciness, the Jalapeno chilli has a rating of between 2,500-8,000, while the ‘Naga Jolokia’ has a rating of 1,000,000. Compton and his team use an ‘adsorptive stripping voltammetry technique’ (ASV) involving nanotubes and an electrochemical reaction, which allows them to measure precisely the level of ‘capasaicinoids’ in the chilli. They have applied a relatively simple method to an unusually fiery food.

Compton compares it in some ways with a diabetes testing device, ‘In the coming months we hope to develop some handheld electronics, which would then drive the chemical end. Like the diabetes test where you prick your thumb, a disposable electrotrode is plugged into a metre and a number comes up to see what your blood-sugar is. That is an electro-chemical sensor.’

Personal chilli meters?
‘We have applied for a patent. We are currently talking to an Indian company that extracts chilli from chilli peppers and they are quite keen on our potential methodology. There are people who may even want their own personal chilli meter, to test how hot their chilli con carne is!”