The History of Guar
A brief history of Guar Gum
THE GUAR PLANT
The guar plant ‘Cyamopsis Tetragonalobus’ is an annual plant. The legume is an important source of nutrition to animals and humans, it regenerates soil nitrogen and the endosperm of guar seed is an important hydrocolloid widely used across a broad spectrum of industries.
The ‘Guar’ legume plant is extremely drought resistant and thrives in semiarid regions where most plants perish. It grows best in sandy soils and areas of West, Northwest india and parts of Pakistan are the ideal areas for it’s farming. Jodhpur City in the North Western state of Rajasthan in India is the most ideal and important processing centre of Guar Gum and contributes approximately 40% of the worlds’ Guar Gum supply.
Guar requires reasonably warm weather and a growing season of 14 to 16 weeks. It needs moderate intermittent rainfall with plenty of sunshine. Too much precipitation can cause the plant to become more ‘leafy’, thereby reducing the number of pods and/or the number of seeds per pod which affects the size and yield of seeds The crop is generally sown after the monsoon rainfall in the second half of July to early August and is harvested in late October early November. The Guar is a naturally rain fed crop and the total size of Guar crop varies from year to year depending on the monsoon rainfall.
Once upon a time, ‘Guar’ was used as a protein rich cattle feed. In India, the tender green Guar is also used as a vegetable and cattle feed. A severe locust bean gum shortage, just after the second world war, adversely affected the paper and textile industries. Guar Gum was found to be the most suitable substitute for scarce locust bean gum. The technology of Guar Gum extraction was commercialized in 1953 in the USA and after approximately a decade in India.
After harvesting, when the pods become dry through sunlight, they are beaten off and during this process, the seeds come out of the pods.
Chemical structure of GEMPOLYM
As per IUPAC SYSTEM of nomenclature, GEMPOLYM is a galactomannan polysaccharide.
The molecular structure reveals that GEMPOLYM is a straight chain galactomannan with galactose on every other mannose unit. Beta 1-4 Glycosidic linkages couple the mannose units and the galactose side chains are linked through alpha 1-6. The mannose to galactose ratio has been estimated at 1.8 : 1 to 2: 1.
The molecular weight of Guar has reported as 1-2 x 10 6. Further studies indicate that GEMPOLYM is a rigid rod like polymer because of the beta linkage between the monomer units. The Guar hydroxyls are in the CIS positions. The CIS position is important since adjacent hydroxyl groups reinforce each other in hydrogen bonding reactions.
GEMPOLYM has excellent cold water solubility because of the high galactose : mannose ratio. The special properties of GEMPOLYM make it most suitable for various industrial applications.