Chances are, you've never heard of xanthan gum. (And no, it's not another name brand of chewing gum.) But chances are good that you've had it before, especially if you've ever eaten salad dressing, ice cream or a smoothie. That's because they typically have xanthan gum in their ingredients.
So what in the world is xanthan gum? Simply put, it's a food additive with a strange name and even stranger origin.
Xanthan Gum and Its Uses
Xanthan gum is a hydrocolloid (think long chain polymers like polysaccharides and proteins) that stabilizes and thickens foods so that they have the flavor and mouthfeel you'd expect. Since its discovery in the 1960s, xanthan gum has been an ingredient in a variety of foods and beverages including sauces, dairy products, baked goods, confections and low-fat spreads. As we mentioned, it helps suspend spices in salad dressings and even gives toothpaste that smooth and consistent texture.
It's also a key ingredient in gluten-free foods. People with celiac disease and gluten-sensitivity can experience painful stomach cramps and diarrhea if they eat baked goods or other foods that contain flour. Foods made without gluten rely on xanthan gum (and other ingredients) to thicken and bind moisture so that gluten-free breads and pastries can have the same texture and flexibility of foods containing gluten.
It's pretty useful in commercial kitchens as well as household ones, says Shawn Matijevich, chef instructor at the Culinary Institute of Virginia in Norfolk. "I talk about it with [my students]. It's something I've been using for a long time," he says. "It's a really cool way to manipulate texture especially with sauces and baked goods."
Xanthan gum absorbs water in foods that don't purée well, like bell pepper so that it can be puréed into a smooth sauce, Matijevich explains. "The xanthan gum actually gives it a really nice texture."
Is Xanthan Gum Gummy?
Xanthan gum comes in a powder form that you can find in the grocery store. It's colorless and flavorless, and largely unremarkable. And that's the point. Unlike other thickening agents, like corn starch or flour, xanthan gum doesn't block the flavor of the food it's mixed with, Matijevich says.
And you need very little of it to create the thickening effect. "So, when we're using corn starch, we're using it in concentrations of like 1 percent," Matijevich says. "With xanthan gum, we're using it in like a quarter of a percent or even less than that."
Bob's Red Mill, which sells xanthan gum, recommends just a quarter teaspoon of xanthan gum per cup of flour for gluten-free cookies; and 1 to 1½ teaspoons per cup of flour (i.e., rice, buckwheat, almond flour) for gluten-free breads. You can also add about 1 gram (1/8 teaspoon) per liter (about 4 ¼ cups) to drip coffee and process it in a blender for a few seconds for a dairy-free latte.
But if you use too much xanthan gum, the effect is rather unappetizing, Matijevich cautions. When it's overused, it can turn things, well, rubbery. "I describe the texture sort of like mucus," he says. "It's very distinct, and not pleasant at all."
Xanthan Gum's Weird Beginnings
For such a cool and useful ingredient, the name "xanthan gum" is a bit offsetting, Matijevich admits. "It has a weird name, so people are a little scared of it. And when they find out how it's made, it gets even a little bit weirder."
Xanthan gum comes from the protective layer of the bacteria Xanthomonas campestris, which are found on the leaves of green vegetables such as broccoli, Brussels sprouts and turnips. It's the same bacteria blamed for some plant diseases such as black rot and bacterial wilt.
When Xanthomonas campestris are fed glucose derived from corn, soy or wheat, fermentation occurs and creates a coating that is then dried and ground into a powder to create xanthan gum.
"When you try to explain to people it's a natural product and then you explain what it is, they're like 'ew, that's kind of gross.'"
While xanthan gum has been around for decades, it's only made its way to grocery store shelves (check the baking aisle) within in the past decade or so due in large part to the rapid rise in celiac disease diagnoses. Matijevich also credits consumers' growing interest in avant-garde cuisine. "Once something gets used a lot by chefs, it takes a while but then it trickles down and becomes more mainstream," he says.
The Good, the Bad and the Ugly
Xanthan gum was approved as a food additive by the U.S. Food and Drug Administration (FDA) in 1969 based on a safety assessment by the federal agency. It is currently used in food products around the globe including countries such as Canada, Mexico, Brazil, the European Union, China, Japan and Korea. Even the World Health Organization and Food Agriculture Organization deem it safe for consumption.
Aside from its thickening and emulsion qualities, xanthan gum may also offer health benefits. Two studies, one in 2013 published in the journal Applied Physiology Nutrition and Metabolism and a second in 2016 published in Food Science and Technology Research, found that xanthan gum may have a positive impact on blood glucose levels. The 2016 study showed that it actually lowered the glycemic index of rice and the blood sugar levels of those who consumed it.
There's also evidence that xanthan gum binds moisture in the digestive tract and as such can act as a laxative, which can be a blessing for people who suffer from constipation but a pain in the butt — and the gut — for people with diarrhea, gastrointestinal issues, or a history of fecal incontinence.
And since xanthan gum is made from bacteria that lives on cruciferous plants, people with severe allergies to vegetables like broccoli and cabbage may experience adverse reactions to products made with xanthan gum.
For those who don't have issues with it, Matijevich suggests making it a staple. "I've had it in my house for a while. It stores well, like a spice in a spice cabinet," he says. "It's such a useful product."