Detecting coffee adulteration

Scientific American reports on a new method to detect coffee adulteration.

Coffee, like many high-demand crops, is subject to adulteration, especially as prices rise. Adulteration is the addition of different chemical and/or plant material to a sample, usually intentionally, which is not declared and should not be present. This is a common problem in the herbal raw materials trade, especially for high value herbal medicines, and has been for centuries. It is one of the reasons why stringent national regulations around quality control and quality assurance are so important in herbal medicines production.

This article from Scientific American reports on a new method using high-performance liquid chromatography (HPLC) to examine the proportion of various sugars in a coffee sample. One of the primary sugars present naturally in coffee is galactose, but higher proportions of other sugars such as glucose and mannose can indicate adulteration with cereal grains such as maize or triticale, or even plants such as acai. This method improves upon the microscopic examination of ground samples, which is subject to more error especially if the percentage of adulteration is low, and is more subjective.

HPLC is commonly used with the herbal medicines industry as one of the analytical procedures available to quantify various constituent levels, and the article reports that by using this method they can detect adulteration of coffee with an accuracy of 95%.

It will be interesting to see the results if and when this technique becomes more widely used within the coffee industry.

Image from Nathan/Flickr

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