What it is
- A white, colorless polydisperse carbohydrate mainly, if not exclusively, made of fructosyl-fructose bonds
- Inulin from plants is linear with degree of polymerization (DP) ~10-12
- Inulin of bacterial origin is ~15 percent branched and has a high DP (106 to 107 Dalton)
Where it’s found
- Inulin was first isolated in 1804 from the herb Inula helenium by German scientist Rose
- Fructans are nature’s second-most abundant nonstructural polysaccharides, starch is the first
- In leek, onion, garlic, and asparagus (Liliaceae) & Dahlia, Jerusalem artichoke, chicory, and yacón (Compositae)
- Bacterial sources: Streptococcus mutans, the spores of Aspergillus sydowi and Lactobacillus reuteri
- Leading producers: Beneo GmbH (Belgium)—Orafti®, Cosucra (Belgium)—Fibruline®, Sensus (The Netherlands)—Frutafit®
Food or medicine?
- Legally classified as food or food ingredient; declared “Generally Recognized As Safe (GRAS)” in 1992 in the US
- Classified as “dietary fiber” in Europe and in most other countries
- Complies with the Codex Alimentarius definition of Dietary Fiber (Codex Guidelines on Nutrition Labelling CAC/GL 2-1985, Rev. 1, 1993).
Manufacturing pluses (+) and constraints (–)
+ Can improve the organoleptic characteristics of food and drinks significantly
+ Increases the stability of foams and emulsions
+ Exhibits fatlike behavior when used as a gel in water
+ Special “instant” qualities, which do not require shearing to form stable homogeneous gels
– Its subtle sweet taste may limit its application in savory food products
– At doses greater than 20g/day may cause gastrointestinal symptoms such as flatulence
– Properties may fluctuate with crop, weather and variety
- Growing consumer preference for “invisible” dietary fiber
- Consumers understand the value of prebiotics in their daily dose of probiotics
- Growing consumer preference for reduced fat, reduced calorie, and natural ingredients
- Advances in processing technologies to customize inulin fractions for specific functionality
- Strong evidence: Nondigestibility and low caloric value (1–1.5kcal/g) soluble dietary fiber
- Suitable for people with diabetes
- Stool-bulking effect: increase in stool weight and stool frequency, relief of constipation
- Modulates gut flora composition; stimulates beneficial bacteria (Bifidobacteria); represses harmful microbes (Clostridia); prebiotic/bifidogenic effect
- Improves calcium and magnesium bioavailability
Surprising fact: The alcoholic drink tequila is produced by the digestion and fermentation of inulin from Agave Azul Tequila Weber (Liliaceae)
Glenn R. Gibson & Marcel B. Roberfroid, Handbook of Prebiotics, Taylor & Francis Group, CRC Press, 2008.
Susan Sungsoo Cho & E. Terry Finocchiaro, Handbook of Prebiotics and Probtiotics Ingredients | Health Benefits and Food Applications, Taylor & Francis Group, CRC Press, 2010.
Kantha Shelke, PhD Kantha Shelke is a principal at Corvus Blue LLC, a Chicago-based food science and nutrition firm that specializes in competitive intelligence and expert witness services. Contact her at email@example.com or 312-951-5810.