The commercially available galactomannans are derived from the seed endosperms
of carob (Ceratonia siliqua), guar (Cyamopsis tetragonolobus) and to a lesser extent tara
(Caesalpinia spinosa) (Dea and Morrison, 1975; Neukom and Nittner, 1980). These
galactomannans all give solutions of high viscosity at low polymer concentration, but each as its own
unique characteristics. Guar gum hydrates rapidly in either hot or cold water, whereas complete
dissolution of carob galactomannan requires cooking at elevated temperatures (Hui and Neukom,
1964). Carob galactomannan interacts strongly with a number of polysaccharides including agar,
carrageenans and xanthan (Dea and Morrison, 1975), and these interactions are exploited
commercially. The interesting and novel chemical and physical properties of other galactomannans
such as those from Caesalpinia spinosa (tara gum) and Leucaena leucocephala seeds (McCleary,
1979a) are currently being realised.
The traditional source of galactomannan is from seeds of the carob tree which was cultivated many
centuries before the Christian era. The ancient Egyptians prepared the strips with which they bound
their mummies, using carob paste. Carob is a native of Southern Europe and the Near East and the
best quality seeds come from Sicily, where the trees were probably planted in the 16th-17th century.
Guar emerged as a commercial source of galactomannan in response to the limited supply of carob
to the U.S.A. during World War II. The guar plant is native to north-west India and Pakistan where
it has been grown for thousands of years for use as cattle fodder and as a green vegetable. World
demand for guar gum has increased rapidly in recent years and is reaching a point where traditional
suppliers such as India, Pakistan and the U.S.A. are hard pressed to meet the demand. Consequently,
considerable effort is being expended to develop guar as an economic agricultural crop in other
countries, including Australia.
Galactomannans are present in a wide range of legume seeds in amounts varying from 0.1 to about
35% of seed weight (Dea and Morrison, 1975). The viscosity and thickening properties of most of
these galactomannans are similar to those of carob and guar galactomannans. With the current
shortage and high price of carob seeds, the possibility of economically producing, from another seed
source, a mannan, becomes more attractive. To some extent tara gum will help fill this requirement.
However, other legumes which produce a similar galactomannan may prove economically viable,
eg: Crotalaria mucronata and Caesalpinia vesicaria. Caesalpinia vesicaria produces copious
quantities of seeds which contain 28.5% galactomannan (galactose/mannose = 28:72). This
galactomannan (limiting viscosity number, 1330 mL/g) has similar solution properties to guar
galactomannan, but interacts with xanthan to an extent intermediate between that of guar and tara
galactomannans (McCleary, unpublished data). Sesbania cannabina seeds contain 17.5% of a high
viscosity galactomannan (limiting viscosity number, 1440 mL/g) but the polymer has a high
galactose content (39%) and the degree of interaction with xanthan is low.
1. Guar Gum for Bakery : One of the major applications for Guar Gum Powder is
the production of bread. Even small quantities of Guar Gum powder added to the dough
increase the yield, give greater resiliency, improve texture and give longer shelf life.
2. Guar Gum for Dairy : In this field Guar Gum is used as an excellent binder of
water and a stabilizer. It is used in the production of ice-creams, sherbets, cheese, liquid
milk products, and others. It is also widely used as a gelling agent.
3. Guar Gum for Meat : Guar can be used as lubricants and excellent binder for
various meat products. It allows storing with less loss of weight and can decrease the
filling time for cans.
4. Guar Gum for Dressing and sauces : Guar can be used as lubricant and excellent
thickener to improve the stability appearance of salad dressings, barbecue sauces, relishes,
ketchups and others. It is quite compatible with highly acidic emulsions.
5. Guar Gum for Beverages : Guar can be used as stabilizer for chocolate drinks,
fruit nectars, and juices.
1. Guar Gum for Miscellaneous food applications : Dry soups, sweet dessert,
canned fish in sauce, frozen food item and others.
2. Guar Gum for Pharmaceutical & cosmetics : Guar Gum can be used as a
thickener for various cosmetics and pharmaceutical. In compressed tablets Guar
Gum can be used as a binder and disintegrator.
Several studies have found significant decrease in cholesterol levels after
administration of Guar Gum in human consumption.
Further important applications
• Textile printing • Mining
• Water treatment • Oil-drilling
• Tobacco Industry • Explosives and others