Galactomannan control

Guar gum is a galactomannan used like locust bean gum and at approximately the same levels. However, unlike locust bean gum, it swells in cold solution and requires no heat for complete hydration. It also induces mix separation which may be controlled with carrageenin. It is well suited for use in HTST systems. 

Delayed Crosslinking Additives. Glyoxal [458,460,461] is effective as a delay additive within a certain pH range. It bonds chemically with both boric acid and the borate ions to limit the number of borate ions initially available in solution for subsequent crosslinking of a hydratable polysaccharide (e.g., galactomannan). The subsequent rate of crosslinking of the polysaccharide can be controlled by adjusting the pH of the solution. 

Assay and Purification of p-Mannanases. p-Mannanase can be specifically measured in crude enzyme mixtures with a dye-labelled carob galactomannan substrate (6), This substrate has a galactose content high enough (23%) to impart solubility to the substrate, but sufficiently low as not to interfere with the action of p-mannanases on the D-mannan backbone. The soluble dye-labelled substrate is incubated with enzyme preparation under controlled conditions and the reaction is terminated and unreacted dyed polysaccharide precipitated by ethanol addition. 

A method for purifying certain neutral polysaccharides by precipitation in borate buffer with cetyltrimethylammonium bromide was developed by Stacey and coworkers,118 but it does not appear to have been used for the isolation of galactomannan gums. It has, however, been claimed119 that guar gum and locust-bean gum can be separated by carefully controlled precipitation of the cetylpyridinium bromide complexes by 0.1 M sodium hydroxide. Guar gum is precipitated between pH 7.0 and 8.3, and locust-bean gum between 8.6 and 9.3. 

K. Lehmann, and K. D. Dreher, Methacrylate-galactomannan coating for colon-specific drug delivery, Proceed. Intern. Symp. Control. Rel. Bioact. Mater. 78 331-332 (1991). 

Vendruscolo CW, Andreazza IF, Ganter JLMS, et al. Xanthan and galactomannan (from M. scabrella) matrix tablets for oral controlled delivery of theophylline. Int Pharm 2005 296 1-11. 

Since crystalline mannan I is not hydrated, it seems clear that the role of the (l- -6)-a-D-gal actose substituent is to encourage hydration and plasticity. In wood cells where the galactoglucomannan (glucose present in the backbone) is a matrix substance, plasticization is probably the desired property. In seeds where galactomannan is a constitutent of an endosperm, controlled hydration to facilitate attack by some enzyme is probably the important feature. The facility of hydration can control the specific time of germination of seeds especially in a desert enV i ronment. 

Nakamura et al. (1992b) also reported that the antioxidative effect of ovalbumin was remarkably enhanced by covalent binding of dextran or galactomannan through a controlled Maillard reaction (Table 9). From the above results, it can be considered that conjugates formed by the interaction between protein and polysaccharide at mild conditions are very useful for the food industry in terms of their emulsifying, antioxidative and antimicrobial activities. 

Chitosan-Xanthan Gum starch-xanthan gum galactomannan from Schizolobium parahybae and xanthan Liposomes Pulmonary Delivery of Rifampicin for controlled dmg delivery [5]... 

H. Jian, L. Zhu, W. Zhang, D. Sun, and J. Jiang, Galactomannan (from Gleditsia sinensis Lam.) and xanthan gum matrix tablets for controlled delivery of theophylline In vitro drug release and swelling behavior, Carbohydr. Polym., 87,2176-2182,2012. 

The chemical structure (particularly M/G ratios for galactomannans and alginates acetyl and pyruvyl substituents for xanthan degree of acetylation for chitosan ) of the purified polysaccharides is controlled using NMR. The samples are dissolved in D2O (eventually with added DCl for chitosan) with a concentration around 6 mg/mL. NMR experiments were performed using Bruker AC-300 or an Avance 400 spectrometer (Germany). The delay adopted was 10 to 20s. Chemical shifts are given relative to external tetramethylsilane (IMS = 0 ppm). Deuterium oxide is obtained from SDS (Vitry, France). 

Lack of biocompatibility [39] was mentioned but seems to be now reconsidered there is few applications in biomedical domain. The main applications are in food [40] as a thickener or stabilizer of emulsions. They are also used in personnal care, cosmetic and pharmaceutic compositions and household care products for which there are many patents [37, 41,42]. Low molecular weight sulphated derivatives of galactomannan have anticoagulant activity[28]. Different pharmaceutical applications are mentioned in the literature as example for blood glucose-lowering effect[43], or to produce tablets by compression and control the release of drugs [44-46]... 

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