Inulin and that "gut" feeling: inulin, a prebiotic typically found in dairy yogurts to enhance calcium absorption, also can provide moisture in meat substitutes and trade spaces with carbohydrates to supplement dietary fiber

Prepared Foods, July, 2004 by Marcia A. Wade

Poly-dispersed inulin, which is the native inulin, is normally found in chicory root. "Typically, poly-dispersed inulin, a mixture of short-, medium- and long-chain inulin, is used in meat products," says Tungland.

The difference in the health benefits of the shorter and the longer chains are dependent on each supplier's studies. "There are a number of different ways you can look at it. Overall, they all do the same things. It's just a matter of how much you need to eat. As far as intestinal health is concerned, shorter chains are generally linked with better or faster growth in beneficial bacteria" says Veghte.

Low-carb Products

All fermentable dietary fibers have an effect not only on lipid metabolism but also on carbohydrate metabolism and inulin is no exception. Recently, inulin's popularity as a fat, starch and sugar replacer in U.S. weight-loss products has taken center stage over its original functionality as microflora chow. According to Izzo, inulin is being used in many low-carb baked goods, breads, cookies and muffins as an ingredient of choice for taste, functionality and nutritional reasons.

"Inulin is highly effective in low-carbohydrate food products because it provides elasticity to dough and baked products," states Tungland. It works with protein and hydrocolloids to reestablish the film or food structure that is lost when protein and starch is removed from flour.

It is important for consumers and manufacturers alike to know that low-carb foods provide a vehicle to help diabetics and people trying to gain control of their weight, says Tungland. "[However,] the ingredients such as the dietary fiber [like inulin] are really the keys to health. It's not that the food is low-carb or sugar-free. It's the fact that they contain higher levels of fermentable fiber in specific ratios that provide the keys to gastrointestinal health, heart health, increasing immunity and bone health," informs Tungland.

For instance, inulin, when fermented with resistance starch, results in high levels of butyric acid. Butyric acid is used almost exclusively by the lining of the large intestine and acts as a differentiating agent to convert pre-cancerous colon cells to normal cells. In regards to heart health, "Through the fermentation process, you have a reduction in the formation of glucose and the increase in the formation of glycogen with a reduction of LDL (bad cholesterol)," says Tungland.

Sugar Replacement

"In low-carb foods and sugar-free systems, polyols are often used in combination with inulin," says Izzo. Inulin is used in sweetener blends because it acts as a bulking agent during sugar replacement. "The mouthfeel that comes from the product is beneficial for bakery applications where you want a rich, thick, mouthfeel, especially when using it with sugar alcohols," says Veghte.

"Generally, you have to add a sweetener to an inulin or an oligofructose if you are going to use it as a sweetener. It is not sweet enough on its own," says Veghte. Also, inulin is not a non-nutritive sweetener. Depending on the supplier, the calorie content is usually around two calories/g as opposed to four calories/g of sucrose. "[The manufacturer should] look at each individual supplier's statement to obtain their calorie content," suggests Veghte.