Handheld scanner tech can detect coconut water fraud

There has been an explosion of interest in the health and nutritional benefits of coconut water, with huge increases in sales volumes even as production volumes have been falling.

As ever, fraudsters have followed the trend and started peddling adulterated coconut water, for example by diluting it with cheaper liquids such as water, dairy products and vegetable oils and adding undeclared sweeteners such as cane sugar to alter its appearance, mouthfeel and taste.

Differentiating virgin coconut water from fraudulent versions has been difficult, but a research team from the University of Manchester in the UK have shown it can be achieved quickly and effectively using Raman spectroscopy.

In the journal Food Chemistry, they report that Raman plus chmometrics can be used to distinguish between unadulterated coconut water and samples that have been diluted with water or had sugars or high-fructose corn syrup added. The technique was highly effective spotting dilution and sugar adulteration even at very low levels (below 3%).

The research comes against a backdrop of numerous cases of coconut water adulteration in recent years which – anecdotally at least – seem to be on the increase. Last year, investigation by the UK’s National Food Crime Unit (UK) of 'pure' coconut drinks intercepted at the point of import, found that almost two-thirds contained undeclared added sugars from non-coconut sources.

Meanwhile, earlier this year, a vegan dairy-free coconut yogurt sold by CoYo, which had been promoted by celebrity cook Nigella Lawson – had to be recalled after testing revealed the presence of dairy ingredients. The company blamed “contaminated material” provided by a third-party ingredient supplier.”

That incident followed a number of cases in which coconut water drinks were recalled due to the presence of dairy proteins, in one case linked to a fatal case of anaphylaxis, according to the Food Fraud Advisors database.

Market research by Kaplan suggests that the global market for coconut water reached $2.2bn in 2016, up from $533m in 2011, and the Manchester team note that as immature coconuts of a specific age range and just five countries worldwide are the only source, rising demand “has the potential to outstrip supply [and] this can also lead to these supply networks becoming significantly more vulnerable to fraud.”

They believe their study is the first time that Raman has been shown to be effective in detecting coconut water fraud. It’s important to note that handheld Raman devices are available, and the technology works through packaging, making it an option for rapid screening of products in the field.

“It can be concluded that Raman spectroscopy has significant potential as a rapid accurate analytical method for the detection of adulteration in this product,” they write.