Want to gauge how hot a chilli is? Nanotechnology can help, says a new study.

Scientists have turned to carbon nanotubes to accurately gauge the hotness of chillies - hitherto the job of professional food tasters.

The technology might soon be available commercially as a cheap, disposable sensor for use in the food industry.

Richard Compton of Oxford University has developed a sensitive technique to measure the levels of capsaicinoids, substances that make chillies hot, in samples of chilli sauce.

The new method is expected to be quicker and cheaper than tasters and also more reliable for purposes of food standards; tests could be rapidly carried out on the production line.

They tested a range of chilli sauces, from the mild 'Tabasco Green Pepper' sauce to 'Mad Dog's Revenge', which sports an extensive health warning and liability disclaimer.

The Scoville method, currently the industry standard, involves diluting a sample until five trained tasters cannot detect any heat from the chilli, reports Sciencedaily.

The number of dilutions is called the Scoville rating; the relatively mild Jalapeno ranges from around 2,500 to 8,000, whereas world's hottest the Naga Jolokia of Nagaland, has a rating of one million.

High performance liquid chromatography (HPLC) can also be used, but this requires bulky, expensive equipment and detailed analysis of capsaicinoids.

In Compton's method, the capsaicinoids are adsorbed onto multi-walled carbon nanotube (MWCNT) electrodes. The team measures the current change as the capsaicinoids are oxidised by an electrochemical reaction, and this reading can be translated into Scoville units.

The technique is called adsorptive stripping voltammetry (ASV), and is a relatively simple electrochemical method.

These findings have been reported in The Analyst.