Inulin production

De Mastro, G., Manolio, G., and Marzi, V., Jerusalem artichoke (Helianthus tuberosus L.) and chicory (Cichorium intybus L.) potential crops for inulin production in the Mediterranean area, Acta Hort., 629, 365-374, 2004. 

Meijer, W.J.N., Mathijssen, E.W.J.M., and Borm, G.E.L., Crop characteristics and inulin production of Jerusalem artichoke and chicory, in Inulin and Inulin-Containing Crops, Fuchs, A., Ed., Elsevier, Amsterdam, 1993, pp. 29-38. 

Toxopeus, H., Dieleman, J., Hennink, S., and Schiphouwer, T., New selections show increased inulin productivity, Prophyta, 48, 56-57, 1994. 

Koops, A.J., Sevenier, R., Van Tunen Arjen, J., and De Leenheer, L., Transgenic Plants Comprising 1-SST and 1-FFT Fructosyltransferase Genes for a Modified Inulin Production Profile, European Patent 952222, 1999. 

Economic data for the production and utilization of Jerusalem artichoke are relatively scarce, because the crop is not currently grown on a large commercial scale. However, there are some economic analyses for crop production and the use of Jerusalem artichoke for bioethanol and inulin production that highlight its potential. Bioethanol is in demand as a gasoline additive and biofuel, while inulin is increasingly used as a food ingredient. The tops and tubers of Jerusalem artichoke also have many other potential applications. 

The price of inulin has been around 2.5 to 3.0 euros per kilo in recent years (2006) and has remained relatively stable because the producers have been successful in predicting the year-on-year increase in demand for inulin. Price rises for inulin products occurred in 2004 due to rising oil prices, which increased on-farm and processing production costs. Orafti raised the prices of its... 

Processes for making novel inulin products Patent number US6569488 (2003)... 

This obvious structural difference between plant and bacterial inulin has its origin in the individual synthesis related system. Feedstock for both inulins is sucrose. However, the plant inulin production is a two-step reaction, starting with a sucrose-1-fructosyltransferase (1-SST). One sucrose molecule acts as donor and a second one as acceptor of a fructosyl unit. This leads to the formation of the trisaccharide 1-kestose. Catalyzed by a fructan-fructan-1-fructosyltransferase (1-FFT), fructosyl units are shuffled between the 1-kestose and higher polymeric p-(2 1) linked fructan molecules in the second step. Repetition of this step results in inulin with (3-(2 1) linkages only [129-132]. 

Generally speaking, three types of inulin products can be distinguished and are commercially available as white powders. First of all is the native inulin with a mean DP of... 

Finally, the area is enlarged a bit by looking at larger surface-active molecules that one could describe as surface-active polymers or polymeric surfactants. Here mature types of products like cellulose derivatives and lignosulfonates, as well as the newer inulin products, are treated. 

D-fructose, C HijOo. Crystallizes in large needles m.p. 102-104 C. The most eommon ketose sugar. Combined with glucose it occurs as sucrose and rafftnose mixed with glucose it is present in fruit juices, honey and other products inulin and levan are built of fructose residues only. In natural products it is always in the furanose form, but it crystallizes in the pyranose form. It is very soluble in... 

The biosynthesis and degradation of fructans by microbial organisms has been reviewed in detail recently.35 Additionally, a review of the production of di-D-fructose dianhydrides from inulin and levan by enzymes has been published in Japanese.36 This account is therefore limited to a general overview. 

A mechanism was proposed31 for the formation of di-D-fructose dianhydrides from inulin and fructose. It was suggested that a-D-Fru/-1,2 2,1 - 3-D-Fru/ [difructose anhydride I (5)] formed first and then isomerized via ionic intermediates to produce the remaining products. Important support for the concept of the reversibility of the isomerization was the observation that ot-D-Frup-1,2 2,1 - 3-D-Frup (4) and p-D-Frup-1,2 2,1 - 3-D-Frup produced, upon treatment with HF, the same product mixture as did D-fructose. 

Thermal activation of sucrose and inulin in the presence of citric acid,93 and sucrose in the presence of acetic94 acid, yields caramels containing, among other products, di-D-fructose dianhydrides and glycosylated difructose dianhydrides, as described in Section V.6). Similarly, the thermal treatment of 6-0-ot-D-glu-copyranosyl-D-fructofuranose (palatinose) in the presence of citric acid87 has been shown to produce appreciable proportions of glucosylated di-D-fructose dianhydrides. 

Although the measurement of GFR with inulin is quite accurate, it is inconvenient because it requires the continuous infusion of this exogenous substance for several hours. More often, in clinical situations, the plasma clearance of creatinine is used to estimate GFR. Creatinine, an end-product of muscle metabolism, is released into the blood at a fairly constant rate. Consequently, only a single blood sample and a 24-h urine collection are needed. Measurement of the plasma clearance of creatinine provides only an estimate of GFR in fact, this measurement slightly overestimates it. A small amount of creatinine is secreted into the urine (about 10% on average). In other words, the concentration of creatinine in the urine is the result of the amount filtered (as determined by GFR) plus the amount secreted. 

The idea that inulin-type fructans are fermented by bacteria colonising the large bowel is supported by many in vitro (both analytic and microbiological) and in vivo studies, which, in addition, confirm the production of lactic and short-chain carboxylic acids as end products of the fermentation (Tanner, 2005). Furthermore, it was shown inhuman in vivo studies that this fermentation leads to the selective stimulation of growth of the bifidobacteria population, making inulin-type fructans the prototypes of prebiotics (Roberfroid, 1997 Roberfroid, 2001). 

Early reports on levan are obscured by incomplete descriptions of impure products.2 96 Greig-Smith found that Bacillus levaniformans(1) produced levan from sucrose96" in suitable nutrient solutions, but not from D-glucose, D-fructose, lactose or maltose.966 He therefore assumed that levan could only be formed from the nascent D-fructose and D-glucose resulting from the inversion of sucrose. Hydrolysis of levan yielded D-fructose only, and analysis of levan agreed with the empirical formula (C HiriOi) it was noted that levan was closely related to inulin but was not identical with it. 

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. 

Inulin Acetate. Stir 100 g. of inulin in 1,000 ml. of pyridine at 80° for forty-five minutes. Cool, while continuing the stirring, and to the clear solution add dropwise 180 ml. of acetic anhydride. After six hours more of stirring, pour the clear solution into 10 liters of water. The inulin acetate separates as a white solid. Filter and wash repeatedly with distilled water to remove the pyridine and acetic anhydride. Purify the dried crude product by dissolving in ten times its weight of hot methyl alcohol and filtering. Inulin acetate separates from the cold solution as a fine white powder [ajj20 = — 34° (c = 1.5, chloroform), [o ]d20 = — 43° (c = 1.8, acetic acid). 

They prepared the acetate by means of acetic anhydride in dry pyridine and purified it by separation from an acetic acid solution to which warm methyl alcohol had been added n ]n2 = — 22.70° (c = 10, acetic acid), m. p. 206-208°. In the presence of barium hydroxide irisin formed an insoluble product whose composition was represented by 6(C6Hi0O6)-Ba(OH)2. In contrast to inulin, these authors found that Takadiastase at pH 5 to 5.5 did not hydrolyze irisin. 

J. W. Yun and D. H. Kim, Enzymatic production of inulooligosaccharides from inulin, in C. Bucke, (Ed.), Methods in Biotechnology—Carbohydrate Biotechnology Protocols, Humana Press, New Jersey, 1999, pp. 153-163. 

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