The first encounter with (3R, 4R, 5R) -1,3,4,5,6-pentahydroxyhexane-2-one (not officially known as “psicose” or “allulose”) It goes back to graduate school. I was studying the molecular structure of monosaccharides, the carbohydrate category to which allulose belongs. I wasn’t interested in its biochemistry or sweetness. My focus was to distinguish it from fructose by a relatively new technique at the time of carbon-13 nuclear magnetic resonance spectroscopy (C-13NMR). Allulose is a stereoisomer of fructose. In other words, the two compounds differ only in the spatial arrangement of the atoms, and have subtle characteristics that make them difficult to distinguish. In any case, it turns out that C-13 NMR can distinguish allulose from fructose, and for me it was.
Now, fast forward for about 50 years, I will meet Arrose again. This time at a grocery store, not at a lab. Well, it’s not exactly a grocery store, but it’s a photo of a grocery store product label sent by someone in Florida. The label says “Zero carbs, zero calories, zero glycemic index, sugar-like taste, and a sugar-like granulated sugar alternative.” The only ingredient listed was allulose. This looked pretty interesting. As far as I’m concerned, as long as it comes from a laboratory bottle, I’ve never thought about where Allose is. But now I had to look further into this simple carb.
We have found that wheat, figs, raisins, maple syrup, and molasses produce small amounts of allose naturally. First identified in 1940 was about 70% sweetness of sucrose, which, interestingly, unlike other sugars, was not metabolized and was excreted as is. This has increased interest in compounds as potential non-nutritive sweeteners, but at the time it was not feasible to separate them from natural resources. Then, in 1994, Ken Izumori of Kagawa University discovered a method of converting fructose to allulose using an enzyme. Fructose is easily produced from corn, allowing commercial production of allulose. Studies in humans have shown that it was actually poorly absorbed and did not raise insulin levels. However, it suppressed to some extent the effects of intestinal enzymes that normally break down starch and sugar. As a result, they enter the colon, where they are fermented by bacteria, and the products of such fermentation can cause abdominal discomfort, flatulence and diarrhea.
In 2012, South Korean allulose producers requested the US Food and Drug Administration to classify the substance as “generally recognized as safe” based on its natural occurrence. No serious side effects were expected when used as a sugar substitute at the intended dose. The petition was accepted and the FDA also exempted it from being listed as an additive sugar on food labels because allulose is absorbed and metabolized differently than other sugars. This paved the way for allulose to be sold as a bulk sweetener and used as an additive in pastries, gums, candies, ice cream, beverages, yogurt and cereals.
Allulose is not approved in the European Union or Canada. Health Canada’s Food and Drug Regulations consider it a new food ingredient due to its limited history of use in food. Novel foods must first undergo a pre-marketing safety assessment before being sold in Canada. That doesn’t mean that Allrose is banned, and it’s not illegal to buy online from the United States.
Almost everyone agrees that overdose of sugar can lead to weight gain and other health problems. And there is no doubt that we are over-consuming. The average North American consumes 19 teaspoons of sugar daily. This is three times the recommended maximum amount. It’s easy to see why non-calorie sugar alternatives are attractive, but so far all sugar alternatives introduced to the market have caused some controversy. It is not yet known if Allrose will prove to be an exception.
