Sources of Inulin

The term inulin first appeared in the literature in 1818 (Thomson, 1818), predating the discovery of fructose by about 30 years. It was ascribed to a substance, first isolated from elecampagne (Inula helenium L.) in 1804 (Rose, 1804). Jerusalem artichoke was first recorded as a source of inulin in around 1870. The actual linear structure of the molecule was not elucidated until the 1950s, and the small degree of branching that can occur only in the mid-1990s (De Leenheer and Hoebregs, 1994). As a polymer of fructose, inulin is classified as a fructan of which there are several types... 

A model of crop growth, development, and yield formation was used to compare Jerusalem artichoke and chicory — the two main agricultural sources of inulin (Meijer et al., 1993). The pattern of assimilation in the two crops was very different. Chicory is a biennial, with only vegetative growth in the first season and dry matter distributed to the storage roots during the second season. A greater fraction of total production is diverted to structural stem matter in Jerusalem artichoke. Most dry matter is allocated to the stem until the reproductive phase of Jerusalem artichoke, mainly in the form of structural stem material, but also as stored carbohydrates. 

A unique plant on many levels, the distinctive properties of the Jerusalem artichoke (Helianthus tuberosus L.) present novel answers to some of today s most pressing problems. Jerusalem artichoke is potentially a major source of inulin, a fructose polymer that provides dietary health benefits as a prebiotic that promotes intestinal health and as a low-calorie carbohydrate to combat obesity and diabetes. Inulin also has myriad industrial applications, including ethanol production — making Jerusalem artichoke a potential source of biofuel. With its ready cultivation and minimal pest and disease problems, Jerusalem artichoke is an underutilized resource that possesses the potential to meet major health and energy challenges. 

Fructans occur naturally, are predominantly found in plants, fungi, and are produced extra-cellularly by bacteria such as Streptococcus mutans [13]. Plants are the most likely source of inulin for the production of material to be incorporated into foodstuffs due to its abundance in plants and also from a safety perspective. Inulin is found in the tubers and roots of the plant family Compositae which includes aster, dandelion, dahlias, comos, burdock, goldenrod, chicory, lettuce, and Jerusalem artichoke [14,15]. Van Loo et al. [16] identified the quantity of inulin in various plants as well as their degree of polymerization (O Table 3). An extensive review of occurrence and distribution of fructans in nature is provided [16,17,18]. 

Inulin is a recognized prebiotic carbohydrate in its own right but is also used as a source of fructo-oligosaccharides by hydrolysis. Inulin, a fructan polymer is widely distributed in plants [264] and chicory Cichorium intybus) is extensively used as a source of inulin for commercial purposes [265]. The roots of chicory contain 15 to 20% inulin and 5 to 10%... 

Raccuia SA, Melilli MG (2004) Cynara cardunculus L., a potential source of inulin in the Meditenanean environment screening of genetic variability. Aust J Agric Res 55 693-698... 

The addition of prebiotics in food may offer other benefits by improving host absorption of minerals (like calcium or magnesium). Recent advances in this field show that inulin-type fructans enhanced calcium absorption primarily via the colonic mucosa in humans (Abrams et al. 2007). This effect may be partially due to the interaction of inulin type fmctans with the Fok 1 gene, a genetic modifier of calcium absorption, as well as due to the acidic environment caused by the production of SCFA, which may increase the solubility of minerals and thus enhance their absorption (Abrams etal. 2005). Crude fractions of chicory (a source of inulin) have shown improved bone parameters relative to native or reformulated inulin in rats, suggesting possible synergies between inulin-t5 e fructans and other nutrients (Demigne et al. 2008). 

It has been suggested that a rich source of inulin, such as Jerusalem artichokes, might be a source of D-fructose for use as a sweetening agent. However,... 

Promising higher-plant sources of inulins are chicory Cichorium sp.) and Jerusalem artichoke (- to-pinambur). 

Jackson and McDonald13 analyzed samples of inulin from various sources. They obtained a uniform product by recrystallization from water, irrespective of the source. Since they determined total solids by refractive index and density measurements on the hydrolyzed inulin, they were not concerned with its crystalline form nor with its moisture content. 

Most contrast agents elicit nephrotoxicity because they are primarily excreted by the kidneys. However, when administered in small doses, they constitute a rich source of GFR markers. The two major classes of contrast agents that are finding clinical utility as GFR markers are iodinated aromatic compounds and metal complexes. lodinated aromatics such as iohexol and iothalamate (Fig. 13) are commonly used as contrast agents for computed tomography (GT). They also have pharmacokinetics similar to inulin and hence are useful indicators of renal status [215]. The iodinated molecules used for GFR measurements consist of a triiodo-benzene core and hydrophilic groups to enhance solubility in aqueous medium. 

Glucose syrups have been used in the food industry for a long time. Fructose is significantly sweeter than glucose. No effective chemical isomerisation methods are possible, and other sources of fructose, for instance by the hydrolysis of inulin, are not yet performed on large scale. Therefore an enzyme isomerisation technology has been developed (Jensen and Rugh, 1987 White, 1992 Pedersen, 1993). 

There is a growing interest in the inclusion of soluble fibre into the diet to help improve health. This is extending to drinks as well, with such fibre being added to milk- and fruit-based products such as smoothies . One source of soluble fibre which has attracted attention over the last few years is inulin or oligofiuc-tans. Inulin consists of oligosaccharides that are extracted from chicory or Jerusalem artichokes and that are claimed to improve colon function and to have prebiotic properties, enhancing the working of the gut. Inulin is a complex carbohydrate which can be assayed in a number of different ways. However, there are two published methods in the AO AC manual for its analysis (997.08 and 999.03). 

The polysaccharides cellulose and hemicellulose are two major components of lignocellulosic biomass and form an abundant, non-edible and renewable source of carbohydrates. Other sources include starch, chitin, inulin and smaller... 

Jerusalem artichoke tubers contain little or no starch, virtually no fat, and have a relatively low calorific value. Of the small amount of fat present, trace amounts of monounsaturated and polyunsaturated fatty acids have been reported, but no saturated fatty acids (Whitney and Rolfes, 1999). The polyunsaturated fatty acids linoleic (18 2 cis, cis n-6) and a-linoleic acid (18 3 n-3) have been recorded as present at 24 mg and 36 mg-100 g 1 of raw tuber, respectively (Fineli, 2004). The tubers are a good source of dietary fiber, because of the presence of inulin. 

Both the quantity and quality of inulin in various plant sources are of considerable importance in terms of its utilization. Both Jerusalem artichoke and chicory have inulin contents of >15% on... 

Currently the primary commercial plant-derived sources for inulin are Jerusalem artichoke and chicory. The former is grown more so in Eastern Europe and the latter in Northwestern Europe. There is increasing interest in the commercial production of Jerusalem artichoke in China and several other countries. At present, neither crop is grown to any extent in the U.S., although there is some fresh-market production of Jerusalem artichoke. 

With concern about the rising incidence of obesity and diabetes, increasing the dietary intake of Jerusalem artichoke, and inulin-containing products derived from it, could bring major health benefits. Historically, the average daily intake of inulin from all sources has been estimated to be around 25 to 33 g. However, by the 1990s, consumption was as low as 2 to 12 g per person per day (Roberfroid et al., 1993). The current estimated consumption in the U.S. is around 1 to 4 g per day, while in Europe it is 3 to 11 g per day wheat and onions mainly account for this inulin consumption (Moshfegh et al., 1999 Roberfroid and Delzenne, 1998 Van Loo et al., 1995). 

The patent discloses a suggested food additive composition, containing fiber, vitamins, and mineral substances. The suggested plant sources of pectin and inulin are dandelion... 

A method is presented for producing concentrate of dehydrated Jerusalem artichoke tubers. The novel product is characterized by a high content of micro- and macroelements (e.g., silicon, potassium, phosphorus, and magnesium). It provides a biologically active additive for foodstuffs, a base or component of food products, and can also be a source material for the production of inulin for use in the biotechnological, medicine, cosmetics, and pharmaceutical industries. 

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