Inulin fructans: Fermentability in the human colon, health benefits and quantification

Inulin fructans are non-digestible polysaccharides of the fructan family that are composed of monomers of fructose joined by β-(2-1) glycosidic (fructosyl-fructose) linkages with varying degrees of polymerization. Inulin fructan has numerous functional and health benefits, which have fueled market demand remarkably as a functional food ingredient during the last several years. Recent human and animal clinical trials have revealed that inulin can enhance the saccharolytic fermentation over proteolytic fermentation in the colon, thereby increasing short-chain fatty acid and lactic acid production, which in turn deliver numerous health benefits, including gut microflora modulation, enhancing mineral absorption and reducing the risk of colon cancers. With the rising popularity and use of inulin, there has been increasing research interest in determining the quality and quantity of inulin fructans. Quantification of inulin has become challenging since plants contain inulin with a varying degree of polymerization in a range of 3-60. Various techniques have been used to quantify fructans, including diverse chromatographic and enzyme-involved spectrometric techniques. Despite there are many reviews on inulin as a functional food, few compiles accepted quantification methods of inulin. This review offers a concise guide on the theoretical principles behind the accepted analytical methods of quantification of inulin, in addition to the fermentability of inulin in the human colon and its potential health benefits.