Question:hard
Inulin like fructans are used as prebiotics as they are non digestible. Resistance to digestion in the upper GI tract results from:
Inulin like fructans are used as prebiotics as they are non digestible. Resistance to digestion in the upper GI tract results from:
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Human amylases break alpha bonds only; inulin is linked in the beta form.
Updated On: Jun 24, 2026
- Absence of digestive enzyme in the upper GIT
- Beta configuration of anomeric C2
- Low pH of the stomach
- Presence of alpha-osidic linkages
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The Correct Option is B
Solution and Explanation
The key is the bond chemistry of a fructan. Inulin is built from fructose residues stitched together through their anomeric carbon, which in fructose is $C2$, and crucially these bonds are in the beta orientation, typically beta(2 to 1). Our digestive machinery, the amylases of saliva and pancreas plus the small-intestinal brush-border enzymes, is specialised for alpha glycosidic bonds like those in starch and cannot touch beta linkages. Because every internal bond in inulin sits in that beta configuration at the anomeric C2, the molecule slips through the upper gut intact and only the colonic bacteria can ferment it, which is exactly what makes it a prebiotic. Stomach pH does not cleave these bonds, the alpha-linkage option is the opposite of the truth, and merely saying an enzyme is absent skips the actual chemical reason. The precise cause is the beta configuration at the anomeric C2.
\[\boxed{\text{Beta configuration of anomeric C2}}\]
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