Page 11 - Major Gum Resin-E-Book

Introduction

water and form viscous dispersion or suspension. Other than plant exudates, some
commercially important gums like guar gum, tamarind gum, etc. are also obtained from
seeds. Gums are used in food, pharmaceuticals, textiles, cosmetics, ceramics, chemical
industries, lithography, inks, leather industry, adhesives and explosives. Plant gums, being
biocompatible, nontoxic and biodegradable, find direct applications in vital industries
from foods to pharmaceuticals and cosmetics to drug delivery. India is among the leading
producers of gums especially guar, karaya, ghatti, in the world, with an estimated output
of about 11.6 lakh tonnes per annum. In India, Rajasthan, Gujarat, Madhya Pradesh,
Chhattisgarh, Andhra Pradesh, Uttaranchal, Jharkhand, Maharashtra, Odisha and Tamil
Nadu are among major gum producing states.
Resins
Water insoluble and ethanol soluble exudates from plants are generally called as resins.
These are hydrocarbon secretions of many plants, especially coniferous trees, with an
exception of lac resin which is the only resin of insect origin. Besides their traditional uses
in medicines, worships, scents, varnishes, etc., they are also proving their potential as food
glazing agents, adhesives, polishes, in paints, perfumes, etc. Commercially important plant
exudate resins are obtained from Pinaceae (rosin, amber), Dipterocarpaceae (dammar) and
Leguminosae (copal) families.
Gum-resins
These are intermediate material where the exudates of certain plants comprise mixtures of
gums and resins in different proportions. These materials contain both water soluble and
alcohol soluble part giving rise to totally different materials as compared to gums or resins
as individuals. Some gum-resins are found with essential oils as one of components, and
are known as oleo-gum-resins. Commercially important gum-resins are guggul which is
obtained from Commiphora spp. and salai obtained from Boswellia spp.
Physiology of gum and resin production
Although many assumptions for the role of gum/
resins in their host plants are there, exact reason
for why these are secreted is not yet known. The
most popular justification would be, the gums are
produced as natural antibiotics by the plants to
protect themselves from infection due to injury or
to get relief from certain stress. Whereas, the resins
are secreted by particular plant either, to conserve
moisture or to protect themselves from freezing or Salai gum - resin exudating from Boswellia serrata
response to injury as an antibiotic.

Most of the NRGs are metabolic by-products of plant tissues either in normal course or
often as a result of disease or injury to the bark or wood of certain plants. Gummosis is the
process responsible for the production of the gums, in which gums are formed following

2 Major gum and resin plants of India