Inulin and Fructooligosaccharides

Inulin is a fructose polymer extracted from plants. If we think of these polymers as molecules with different lengths, then we can pick out small molecules with a length between 2 and 10, which we can call fructo-oligosaccharides (or short chain inulin). Macromolecules with a length of >10-60 can be called polyfructose (or long-chain inulin).

The length mentioned above is a term that is easy for everyone to understand. Academically, this length is called the degree of polymerization (DP). The fructose molecules of inulin are linked by β (2→1) bonds. Inulin extracted from natural plants (Jerusalem artichoke or chicory) contains both short-chain, medium-chain and long-chain structures and is called natural inulin. Both short-chain inulin and natural inulin contain certain monosaccharides and disaccharides, so they are slightly sweet, and their sweetness is approximately equivalent to 10% to 30% of sucrose; long-chain inulin does not contain monosaccharides and disaccharides. Sugar has no sweetness. In the actual production process, artificial synthesis methods can be used to control the degree of polymerization of inulin. For example, synthetic enzymes can be used to produce short-chain inulin with different degrees of polymerization, and endonucleases can be used to hydrolyze inulin to obtain fructooligosaccharides with a DP range of 2-7 and an average DP of 4, using physical separation technology (crystallization and membrane separation) to produce long-chain inulin with an average polymerization degree of not less than 23.

1. The difference in physical characteristics between inulin and fructooligosaccharides.

The higher the degree of polymerization of inulin, the stronger its water retention and viscosity will be, and the worse its relative solubility will be.

For example, inulin with a low degree of polymerization can be dissolved in warm water, but inulin with a high degree of polymerization cannot be completely dissolved in warm water and may crystallize.

Conclusion: Fructooligosaccharides are more soluble in water than natural inulin, but their water retention and viscosity are not as good as inulin.

2. The taste characteristics of inulin and fructooligosaccharide are different.

The higher the degree of polymerization of inulin, the lighter its sweetness. Long-chain inulin has almost no sweetness, while fructooligosaccharides are slightly sweet because they contain monosaccharides and disaccharides.

Conclusion: Fructooligosaccharides are slightly sweeter than natural inulin.

3. Differences in physiological characteristics between inulin and fructooligosaccharides.

When inulin enters the intestine, short-chain inulin (fructo-oligosaccharides) will be quickly fermented by bifidobacteria (beneficial bacteria) in the front colon, while long-chain inulin (polyfructo-oligosaccharides) will be fermented slowly due to the long chain. It cannot be fermented by bifidobacteria until it reaches the back end of the colon.

Conclusion: Fructooligosaccharides are converted by intestinal microflora faster than natural inulin.

4. Is it better to buy fructooligosaccharides or inulin?

The answer is more likely to be inulin.

People who buy these two products basically buy them for the purpose of improving the intestinal tract and constipation, so for this purpose, using inulin will be more suitable. Because inulin contains fructo-oligosaccharides, and the long-chain molecules in inulin are relatively few pure fructo-oligosaccharides, this as dietary fiber is very important for promoting intestinal peristalsis and defecation!