Locust beans

A wide variety of plant exudates have been used ia foods and medicines for centuries, including acacia, karaya, and ghatti. Plant gums derived from seeds iaclude arabic, guar, locust bean, tamatind, and tara. AH play a role ia fat replacement either singly or ia mixtures. 

Locust bean (carob) is derived from the endosperm portion of seeds of a tree widely cultivated in the Mediterranean area. It is a polysaccharide built of mannose units with short branches of single galactose units, with an average molecular weight of 310,000. 

Locust Bean Gum. Locust bean gum [9000-40-2], also known as catob seed gum, is a galactomannan extracted from the endosperm of the catob tree seed which is cultivated in the Mediterranean area. The primary use of locust bean gum is in dairy appHcations such as ice cream. It is often used in conjunction with carrageenan because the chemical stmctures of the two enable them to cross-link and form a gel (85). 

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. 

Locust Bean Gum. Locust bean gum [9000-40-2] is produced by milling the seeds from the leguminous evergreen plant, Ceratonia siliqua or carob tree, which is widely grown in the Mediterranean area. Pods produced by the carob tree consist of a husk, embryo, and endosperm. The latter, the source of the gum, is separated from the tough outer husk and the yeUow embryo tissue by a variety of rolling and milling operations, and subsequently is milled into a fine powder (60). 

Locust bean gum is not completely soluble in cold water it must be heated to 80°C and cooled to attain a stable solution that has high viscosity at low concentrations. The gum is compatible with other plant gums and the viscosity of solutions is not appreciably affected by pH or salts. 

In the food industry, locust bean gum is used as a stabilizer in ice cream and in the preparation of processed cheese and extmded meat products. It is also used as an emulsifier and stabilizer of dressings and sauces and overall has similar properties to those outiined for guar gum. 

Locust bean gum and its derivatives are exceUent film formers and can be used either alone or in combination with starch as textile sizing agents and dye thickeners in textile printing, and as fiber bonding and beater additives in the papermaking industry. However, in most of these appHcations it has been replaced by guar. 

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. 

Commercial locust bean gum is the ground endosperm of the seeds of the locust bean (carob) tree. The general properties of locust bean gum are similar to those of guar gum. Differences are its low cold-water solubiUty and its synergistic gelation with kappa-carrageenan, furceUaran, and xanthan... 

Product Agar Algin Carra-g eenan Furcel-1 aran Arabic Xan -tha n Traga- canth Hydroxy- propyl cellulose Locust bean Guar cmD Methyl cellulose Karaya... 

Table 7.4 Comparative features of gel-systems evaluated for use in quick setting jelly products. CWS = cold water soluble, LBG = locust bean gum.

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... 

It has a high viscosity (thickness) even when very little is used. When mixed with xanthan gum or locust bean gum, the viscosity is more than when either one is used alone, so less of each can be used. 

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