Polysaccharides locust bean gum

It has been discovered that galactomannans interact with a number of bacterial polysaccharides.168 The most studied has been the interaction with the exo-polysaccharide from Xanthomonas campestris. Mixtures of this non-gelling polysaccharide with locust-bean gum form firm, rubbery gels at total-polysaccharide concentrations181 211 greater than 0.5%. The gels are firmest at a Xanthomonas polysaccharide locust-bean gum ratio of 1 3. 

Although most seeds contain starch as the principal food reserve, many contain other polysaccharides and some have industrial utility. The first seed gums used commercially were quince, psyUium, flax, and locust bean gum. However, only locust bean gum is stiU used, particularly in food appHcations quince and psyllium gums are only used in specialized appHcations. 

Like guaran, and the endosperm polysaccharides of other legumes, locust bean (carob)gum [9000-40-2] is also a galactomaiman. Like guaran, it has a linear backbone of (1 — 4)-1inked P-D-mannopyranosyl units. However, in locust bean gum, approximately one of every 3.9 P-D-mannopyranosyl units, on the average, is substituted with an a-D-galactopyranosyl unit attached at 0-6. 

Different polysaccharides change the perception of flavour, thus xanthan is superior to gum guar in the perception of sweetness. Mixtures of xanthan and locust bean gum have improved flavour release and texture when used in pies and pat s compared to starch. Many foods are emulsions, examples being soups, sauces and spreads. Exopolysaccharides are used to stabilise these emulsions and prevent the phases from... 

Locust bean gum is a polysaccharide (a long chain made of sugars) made of the sugars galactose and mannose. Some other familiar... 

Synthetic products, e.g., polyethylene oxides(104), polyacrylates, polyacrylamides, and polyetherglycols were in competition with natural polymers like starch, guar, cellulose derivatives, alignates, carrageenan, and locust bean gum. The basic physical and structural properties of the various polysaccharide thickeners have been compiled and reviewed by numerous authors and editors(105-109). 

Conventional improvers are not used in rye bread but additives are sometimes used to increase the water absorption of the dough. Examples are polysaccharide gums such as guar and locust bean gum as well as pregelatinised potato flour, rice starch or maize starch. 

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. 

As with agar and carrageenan, substitution in the Xanthomonas polysaccharide structure inhibits the interaction with galactomannan. Thus, removal of the acetyl groups by saponification yields a product that interacts much better with galactomannans.211 Less locust-bean gum is required to gel deacetylated Xanthomonas polysaccharide, and mixtures of locust-bean gum and deacetylated Xanthomonas polysaccharide form a gel at lower, total-polysaccharide concentrations. 

Gelling mixtures of Xanthomonas polysaccharide with locust-bean gum or tara gum do not give reproducible optical rotation results, possibly because of gel strain, but examination of non-gelling... 

Milk fat and milk solids-not-fat (MSNF) are most commonly obtained from cream and condensed skim milk, but may also be obtained from a combination of fluid milk, condensed whole milk, frozen cream, frozen condensed milk, nonfat dry milk, dry whole milk, and butter. Sweeteners used in the mix normally include a combination of liquid or dry sucrose, corn sweetener, high-fructose corn sweetener, and corn syrup solids. Ice cream stabilizers are formulated to contain one or more polysaccharide hydrocolloids, e.g., carboxymethyl cellulose, locust bean gum, carageenin, alginate, and other gums. Ice cream emulsifiers normally contain monoglycerides and diglycerides of palmitic and stearic... 

The results of a conductivity study on locust-bean gum (a neutral polysaccharide) in aqueous salt solutions led Barry and Halsey28 to conclude that there is no interaction between this carbohydrate and the many ions employed (H , Na , K , Ag , Ba2 , OAc , Cl , NO, , SO,2 , and HSO, ). Hydroxide ion was an exception. The electrolyte concentrations ranged from 0.0005 to 0.1 N, and the maximum concentration of polysaccharide was 0.0277 M (on a monosaccharide-residue bans). The specific conductivity of each polysaccharide-salt solution was identical to that of the corresponding salt solution containing no polysaccharide, strongly indicating the absence of significant adduct formation under the conditions... 

In addition to their role in primary stabilization related to viscosity increase, some hydrocolloids (particularly carrageenan) are traditionally used as secondary stabilizers. Many of the primary stabilizing hydrocolloids, including locust bean gum and carboxy methyl cellulose induce precipitation of the milk proteins in the mix. This phenomenon in ice cream mix is known as wheying-off, and may be due to direct protein-polysaccharide binding and/or protein-polysaccharide incompatibility in the water phase40. The latter phenomenon may be due to decreased solvent quality due to the competition between protein and polysaccharide for solubilisation. 

---