Fructan polymerization

Three enzymes, sucrose sucrose 1-fructosyl transferase (1-SST), fructan fructan 1-fructosyl transferase (1-FFT), and 1-fructan-p-fructosidase (1-FEH), appear to control fructan polymerization and depolymerization in the Jerusalem artichoke. Each is sequestered in the vacuole of the cells in which they are expressed and has a pH optimum in the acid range (pH 5.0 to 5.5), in keeping with a vacuolar origin (Frehner et al., 1984). 

Degree of polymerization distribution of a plant fructan (inulin) at increasing physiological age of the source remarkable performance of S-200 in the low dp range degree of polymerization distribution obtained from bad (P-6) and good (S-200 / P-6) resolution of high dp components... 

Some polysaccharides, for instance glucans, fructoglucans, or fructans, can be produced by either thermal or biocatalyzed polymerization.237 245,336 Such polysaccharides are complementary to all other natural or engineered polysaccharides for which a vast number of applications are known. Poly-... 

Praznik, W., Beck, R. H. F., and Nitsch, E. (1984). Determination of fructan oligomers of degree of polymerization 2-30 by high-performance liquid chromatography. /. Chromatogr. 303 417-421. 

Inulin was identified as a major (5.9%) component of the roots of E. angustifolia (Heyl and Stanley, 1914). Giger et al. (1989) noted that polymerization of fructans occurred over the course of winter as observed by the reduction in fructose from October and May. The rate of polymerization was faster in E. purpurea than E. angustifolia, suggesting that other polysaccharides may develop in a similar manner. Additional research is needed to identify the effects of harvest time on polysaccharide composition. 

To make flour, Jerusalem artichoke tubers are macerated, heated, and spray-dried. In the process, inulin is hydrolyzed to short-chain fructooligosaccharides (Yamazaki et al., 1989). Jerusalem artichoke flour is also used to supplement animal feed. In one study, the composition of a typical Jerusalem artichoke flour was 2.1% (of dry weight) nitrogen, 16.2% insoluble fiber, 4.2% ash, and 77.5% soluble carbohydrate. The carbohydrate comprised fructans with degrees of polymerization of 1 to 2 (33.3%), 3 to 4 (46.4%), and over 5 (20.3%) (Famworth et al., 1993). 

Fructans and fructose extracts, which can potentially be obtained from Jerusalem artichoke, have become attractive to industry for a number of food and nonfood applications because of their health benefits (e.g., Fleming and GrootWassink, 1979 Fontana et al., 1993 Fuchs, 1993 Roberfroid, 2005). Short-chain fructooligosaccharides (degree of polymerization of 2 to 5), for example, are increasingly used as low-calorie sweeteners in processed foods, and their utilization is anticipated to expand significantly in the future. 

Inulin biosynthesis in Jerusalem artichoke occurs via the combined action of two enzymes l-sucrose sucrose fructosyltransferase (1-SST) and l-fructan fructan fructosyltransferase (1-FFT). 1-SST catalyzes the synthesis of inulins of a low degree of polymerization, while 1-FFT catalyzes the synthesis of ffuctans of a degree of polymerization up to 50 (Sevenier et al., 2002a). High... 

A second enzyme, fructan fructan 1-fructosyl transferase (1-FFT EC 2.4.1.100) is responsible for chain elongation with 1-kestose and fructans with a degree of polymerization of >3 acting as... 

International classification C08B37/00, C12N9/96, C12N11/10 The invention relates to an auxiliary substance to accompany an active substance, such as a pharmacon. The auxiliary substance has a stabilizing action and a positive influence on the bioavailability of the active substance within pharmaceutical preparations. The auxiliary substance is based on a fructan (inulin of degree of polymerization (DP) over 6), obtained from Jerusalem artichoke or other sources. 

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]. 

Fructans are oligomers and polymers formed by polymerizing fructose from transport metabolite sucrose on one out of three possible starter trioses 1-kestose yields inulin-type (2 1)-p-D-fructans, 6-kestose yields levan-type (2 6)-p-D-fructans (Fig. 3A), and neo-kes-tose yields mixcD-type and/or branched (2 1), (2 6)-p-D-fructans (Fig. 3C). Pronounced fructan metabolism is found in composites (chicory, Jerusalem artichoke), Liliaceae (onion, chives, garlic), cereals (wheat, barley, rye, oat), Asparagaceae (asparagus), Amaryllidaceae (banana), and Agavaceae (agave). 

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]. 

Only the fructosyltransferase (FTF, EC 2. 4. 1. 9) is required in bacteria for the synthesis of bacterial inulin. The enzyme shuffles fructosyl units from one sucrose molecule (acting as druior) to another sucrose molecule, 1-kestose, and higher polymeric p-(2 1) linked fructan molecules, respectively (acting as acceptor). This enzyme partly leads to p-(2—>6) linkages, which results in branches within the inulin molecule [130, 133]. 

Fructans can occur as oligosaccharides and polysaccharides. This means that their degree of polymerization can vary from below 20 sugar units to well above 20 sugar units. As a food ingredient, fructans often have a degree of polymerization of 25 or less. Thus, they are discussed as oligosaccharides. 

For the production of bacterial inulin only the enzyme fructosyl transferase (FTF, EC 2.4.1.9) is required, which shuffles fructosyl units from the sucrose donor to another sucrose molecule or 1-kestose or higher polymeric p-(2- 1) linked fructan molecules acting as acceptor. The enzyme partly leads... 

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