In the mid-1980s, a Florida citrus growers’ organization offered $50,000 to anyone who could develop an analytical technique for detecting orange juice adulterated with cheap beet juice. Graduate student Nicholas Low, who was working on enzymes responsible for carbohydrate hydrolysis, thought he had a solution. 

As it turned out, no one, including Low, cracked the problem of beet-spiked juice. Years later, as a faculty member at the University of Saskatchewan’s Department of Food and Bioproduct Sciences, Low embraced the challenge again. This time, he would contrast the unique fingerprint of short-chain sugar molecules — oligosaccharides — found in both beets and oranges. 

Low was successful, and the experience gave him a taste for similar challenges, including how to detect diluted tequila. He drew the attention of the International Organic Agave Alliance (IOAA), which markets the syrup from the agave plant, which is the source of tequila as well as a valuable sweetener. It is sweeter than table sugar, allowing users to consume fewer calories while enjoying the same flavour. The IOAA’s concern is that the companies selling agave syrup, also used in cakes and cookies, are secretly adding cheap corn or starch syrup and beet or cane sucrose as a way of boosting their profit margin. 

Working with PhD student Jamie Willems, Low employed a pulsed and parametric detector designed to look specifically for carbohydrates. “With this system, we were able to see oligosaccharides at low concentrations quite easily,” Low says. “Couple that detector with column technology and stationary phase technology for chromatography and we were able to separate and identify oligosaccharides. Now we were able to see oligosaccharide patterns, where before they were masked.”

Low’s findings, published in the Journal of Agricultural Food Chemistry, outline the adulteration of various commercial agave syrup samples. He is now working on other food authentication initiatives for fish and juice extracts.