New Garlic Sensor - Isis Project No 7513

A simple, effective and inexpensive means to determine the strength of garlic.

Garlic in the kitchen and medicine cabinet

Garlic is used worldwide as a cooking ingredient and is also consumed in a variety of forms for its medicinal properties. UN data indicates that in 2007 at least 15.7 million tonnes of garlic was produced worldwide. Like many other natural products, the flavour of different batches of garlic vary significantly in strength, which therefore needs to be assessed before use by the food industry.

What gives garlic its characteristic taste and smell?

It has been found that the majority of the volatile compounds are thiosulfinates, although the rich variety of compounds that contribute to the flavour and fragrance of garlic stem from the odourless precursor alliin. Rupturing of garlic’s cellular tissue (by processing) causes alliin to be converted enzymatically to allicin, which makes up the majority of the thiosulfinates present in freshly chopped garlic. Allicin is unstable and decomposes to form a variety of compounds, with the literature pointing to diallyldisulfide as the most overwhelmingly abundant extractant from processed, raw and cooked garlic and the best indicator of the strength of garlic.

Simple, inexpensive analysis

The Oxford invention provides a simple, effective and inexpensive means for the electrochemical detection and quantification of diallydisulfides. The measurement is carried out after shaking a pureed material in solvent, diluting it and carrying out the analysis using a cheap, disposable screen printed electrode. This is a one shot analysis that requires little training and can be made even easier by the use
of Oxford’s simple electronics module (Isis Project 3675). This has potential applications in monitoring the batch-to-batch variation and the stability of garlic during storage and also the garlic content of medicinal supplements.

Alternative approaches

Like other flavours in the food industry, garlic batches are often quantified by organoleptic testing, typically based upon the dilution of garlic in sour cream followed by taste testing. Extraction and chromatography are also used, but such techniques require relatively more expertise and complicated bulky equipment.

Supporting material

B. C. M. Martindale, L. Aldous, N. V. Rees & R. G. Compton, “Towards the electrochemical quantification of the strength of garlic,” Analyst, 2011, 136, 128-133

Patent Status

The Oxford invention of an electroanalytical quantification of the strength of garlic is the subject of a UK patent application. Isis would like to talk to companies interested in developing this into a commercial opportunity.

For further information please contact the project manager using the link below.

Request Further Information: Project Number 7513 - New Garlic Sensor