Glucans, soluble

P-Glucan solubility increases with temperature, and lichenase works very well even at 50°C. 

Somewhat analogous to these rice products is Oatrim, a material based on oat flour. It was developed at the Northern Laboratory of the USDA and is offered commercially by several firms. Oatrim contains 5% proteia, 5% P-glucan, 2% pentosans, and 83% maltodextrias. Unique properties are claimed based on the P-glucan component, and preparation of Oatrim is disclosed ia USDA pubHcations and patents. Briefly, oat flour is broken down by a-amylase, then the water-soluble component is dried and is the product of commerce, aimed at ground meat product usage. 

PuUulan [9057-02-7] first described in detail in 1959, is a water-soluble extracellular a-D-glucan elaborated by the fungus yiureobasidiumpullulans (formerly Eullulariapullulans) (285). It is a linear polymer of maltotriose units linked from the reducing end of one trisaccharidic unit to the nonreducing end of the next trisaccharidic unit by a(l — 6) linkages (286) ... 

The technological troubles of barley j0-glucan and the health benefits of cereal j0-glucans result, in general, from their ability to form highly viscous solutions and gels. The gel formation is controlled by the molecular weight as well as the solubility of the polysaccharides in aqueous media, which... 

It may be that this fact was associated with the rather complex composition of fungal mycelium, consisting of chitin enclosed in a glucan matrix (Bowman, Free, 2006). Therefore, mature saprophyte mycelium are completely covered by difficult-soluble glucans and the fraction of chitin in the apical cell wall is not sufficient. As such, we supposed that these cationic isoforms bound with another major component of the fungi... 

Various strains of oral streptococci produce D-glucosyltransferases which utilize sucrose as a o-glucosyl donor in the production of soluble and insoluble D-glucans. Consequently, it may be expected that some deoxyfluoro derivatives of sucrose function as competitive inhibitors for the dextransu-crases of tooth bacteria, thus preventing decay, or at least may be used as active-site probes for the enzymes. Another aim of these researches is to find non-metabolizable sweeteners. 

In our study, consumption of rye bread or rye bread with phloem did not have an effect on serum lipids (total, LDL or HDL cholesterol or triglycerides) (Table 14.4). This is contrary to a recent finding suggesting that soluble fiber from rye bread decreased the concentrations of cholesterol (Leinonen et al., 2000). In that study ingestion of rye bread (220 g/d) with naturally high amounts of insoluble (18 g/d) and soluble fiber (4 g/d) decreased the LDL concentrations by 8% in hypercholesterolemic men. The researchers speculated that soluble fiber, maybe P-glucan, was responsible for the hypocholesterolemic effect. The amount of rye bread (70 g/d vs 220 g/d), the amount of total (5.9-11.8 g/d vs 22.1 g/d) and soluble fiber (0.6-1.3 g/d vs 4 g/d) ingested in this study was considerably less, and could explain the lack of effects on blood lipids in our study. 

Analysis of the products which become water-soluble after extrusioncooking showed that feroylated heteroxylans and glucans were solubilised from wheat bran (10), arabinans, heteroxyalans and pectins from pea hulls (11,12), and pectins from the other sources (13,14). 

Materials. Soluble PGG Glucan (Betafectin, Alpha-Beta Technology, Worcester, MA) was prepared from Saccharomyces cerevisae strain R4 cells (14). 

Native or processed cellulose (e.g., cotton, Avicel, filter paper) and its soluble derivatives (e.g., CMC, HEC3) are substrates most often used in the study of cellulases. The classification based on the use of these substrates (l,4-/ -D-glucan cellobiohydrolases (CBH), exo-cellulases, Avicelases and... 

The most spectacular solid catalyst reported in the literature is probably the sulfonated carbon. Indeed, in contrast to all other solid catalysts, sulfonated carbon was able to hydrolyze, in water, cellulose to soluble 1,4-p-glucan with high yield. The presence of hydroxyl groups on the carbon surface was found to be crucial and allows a better adsorption of cellulose on the catalyst surface. However, the amount of catalyst used is unacceptable for an industrial application and much effort is stiU needed. 

HV057 Sasatamoinen, M., S. Plaami, J. Kumpulainen, and O. Rantanen. Concentrations of water soluble and in- HV068 soluble beta-glucan and phytic acid in 6 row and 2-row barley. Cereal Res Commun 1991 19(4) 391-397. 

---