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R & D Area > Natural Product Development - Phytochemistry

Phytochemistry

Group Leader	Contact
Group Leader	Work	Home
Dr. G. I. Khan Sci 'EII'	91-522- 2205835	91-522- 2606203, 2708434

Other Scientists of the Group

Dr. Mahesh Pal, Scientist B

Group works on

The gums chemistry activity involved in R and D on seed gums, Exudates gum and Resins from Non wood forest products. The group is involved in R & D work on seed gums and other natural polysaccharides from existing and new sources with special reference to their physico-chemical, structural, X-ray diffraction, rheological, interaction and modification studies. Besides biopolymers, the group is engaged in development of extraction profiles of natural dyes from existing and new sources and their application work for coloring fibers, cosmetics, herbal formulations, food etc. The gums activity group is involved in R & D of eco-friendly, non-toxic, low cost and abundantly avaliable. Non wood forest products, seed gums, Exudate gums and Resins. These Polysaccharides from existing and new sources are subjected for their Physico-chemical, Structural (Isolation, sugars detection, Methylation, per iodate oxidation, oligosaccharide determination), Rheology, Viscosity and Interaction, studies , 13 C- NMR studies, X-Ray diffraction, HPLC and Modification by different derivatives and molecular weight determination for their applications in various important industries like Pharmaceuticals, Food, Cosmetics, Explosives, Toileteries, Paper, Textile, Paints and Petroleum etc. As these gums are vegetable hydrocolloids they are excellent additives for various purposes like binding, emulsifying , sizing , stabilizing , thickening, film- forming, flocculating and to provide texture to the end products. The galactomannan is a branched Polysaccharide consisting of the main chain of D-mannose units linked through b-(1->4) to which are attached single D-galactose units through α-(1->6) linkages. Basically these hydrocolloides are water soluble.Because of this water solubility, they improve mouthfeel and pourability, extend life, encapsulates flavors, emulsify beverages, build viscosity, retain moisture and provide elasticity and freeze-thaw stability. The properties of gums for various industrial uses are effected by many factors such as orientation and molecular association, water binding and swelling, concentration, particle size, degree of dispersion and interaction with other gums. Scanning Electron Microscopic Studies (SEM) were used to examine the characteristic distinct crystalline morphology of some commercial gums at various magnifications from (x200) to (x6000). Above this magnification decaying of sugar particles started. The observations recorded have revealed that SEM studies of various Polysaccharides could be used for finding out the purity of the substance e.g. in food and medicinal applications.

Background and Importance of Hydocolloids:

Vegetable gums are important food additives used in food processing. These gums are the natural food hydrocolloids that possess excellent thickening, binding, emulsifying, suspending, water-holding, gelling and viscosity properties and used in a variety of food applications. Some of these are guar gum, gum arabic, gum tragacanth, alginic acid, carrageenan, locust bean gum etc. Semi synthetic hydrocolloids such as methyl cellulose, sodium carboxymethyl cellulose, etc. have also been used. NBRI has contributed significantly on the R and D on vegetable gums and become an important centre in the country for their application work in industries like food, Pharmaceutical, cosmetics etc. More than one-thousand seeds have been screened for their water soluble gums, protein etc from various families. Family leguminosae have been found rich in gum percentages.

Plants are the main sources of natural gums. India is a rich centre of biodiversity and offers great potential for the sustainable utilization of these natural resources by converting plant wealth into economic wealth through biotechnology. Plant gums yield low to high viscosity depending upon different concentrations and conditions of time, temperature, pH, shear rate, shear stress etc. and possess excellent thickening and binding properties that are traped for their Vast Industrial applications.

Objectives

To explore and identify new sources of seed gums from Indian flora, particularly from Leguminoseae family. Seed gums from the genera like Cassia, Crotalaria, Sesbania, Caesalpinia, Indigofera, Gleditsia have been studied for their detailed chemical investigations.
Exploration of new galactomannan combinations.
Rheological, structural and interaction studies of seed gums.
Evaluation of inheriting properties of seed gums and value addition of seed gums through physical and chemical modification to enhance their properties for their application in food industry.
Toxicological and safety trials of gums and gum derivatives.
Application trials of natural gums for food processing and other industry like Pharmaceutical and cosmetics for their technical feasibility, extraction processes and processing technologies.
Commercial utilization of vegetable gums as food additives for the following reasons:
(i) To maintain product consistency.
(ii) To improve or maintain nutritional value.
(iii) To maintain palatability and wholesomeness.
(iv) To control acidity/alkalinity.
Seed gums are the preferred hydrocolloids since these are comparatively cheap, non-toxic, eco-friendly and non polluting during production and application.
Evaluation of the structure of the molecules by UV, IR, 13C-NMR, Gc-Ms etc.
Studies of the constituents sugars through PC, TLC, GLC, HPLC and HPTLC etc.
Modification of the polymer through thermal procedure and chemical derivatization by the preparation of hydroxyl ethyl, hydorxyl propyl, carboxymethyl and oxidized derivatives.
Establishing the use of seed gums specifically cassia species as natural additives in medical preparations.
Identification of important resins by certain simple and relevant tests so as to remove confusion in their identity.
CMC derivatives of the gum with varying levels of degree of substitution. They showed good solubility in water.

Achievements

The group has introduced some potential sources of seed gum, which posses useful non-ionic and solution properties to be utilized for various industrial applications. It include Dhaincha gum from Sesbania bispinosa and cassis gum from Cassia tora and Cassia Siamea. These gums have been produced in India in handsome amount for varied industrial applications and export.
The group has developed a process for the preparation of Herbal Dry Color Composition for direct skin applications. The invention relates to the blending of natural dyes with natural ingredients at specific proportions and conditions. The resultant color powders thus prepared have good sticking capacity to skin and can be easily removed by soft mop. The preparation of Herbal-Gulals provides an option/alternative to replace synthetic dye bases dry powers for Holi playing. The complete specifications of process are under patenting process at Indian Patent Office.
Lab Scale Technologies regarding extraction and application of seed gums and natural dyes is
available, which can be upgraded to large scale, whenever required by any entrepreneur.
Lab Scale Technologies regarding the preparation of semi-synthetic gums have been developed.
The group has generated useful information regarding the availability of numerous sources of seed gums and their physico-chemical properties, structural aspects, viscosity behavior and interaction capabilities for the benefit of basic researchers and industries.
More than 200 research papers have been published in National and International journals.
The group has collaboration with Research Center for Vegetable Macromolecules (CERMAV-CNRS), Grenoble France for advanced researches on food hydrocolloids.
Value added processing in valves either chemical modification of the gum or blending with other gums to produce a final product with a range of physical and functional properties designed to suit the end users requirements.
Developmental potential of various Cassia gums like Cassia siamea, C.fistula, Cassia grandis, C.marginata, Cassia angustifolia through derivatisation like Carboxy methyl cellulose, Hydroxyethyl cellulose, Hydroxy propyl cellulose and oxidised methods.
Studies on classification of gums used in food products
1. Nonionic seed Polysaccharides - Guar, carob and Tamarind
2. Anionic (Negatively charged exudate Polysaccharides - Arabic, Karaya and Tragacanth
Through study on compatability with various salts like Sodium Chloride, Potassium Chloride, Aluminium Sulphate and many others.

Properties of Seed Gums

Seed gums are light to dark cream colored amorphous powder characterized by forming Viscous or clear solutions when dispersed or dissolved in cold or hot water.
They produce low to high viscosity 100 to 8000 cP depending upon the source and manufacturing process. They have property of forming high viscosity even at low concentration (4500-8000 cP at 1% w/v) where cP=centipoise, Measure scale of Viscosity.
Seed gums are stable over a wide range of pH(3-9). The nonionic nature of the polymer is responsible for almost constant viscosity of the solution.
They have excellent compatibility characteristic with organic, inorganic substance including certain dyes and various constituents of food.
They shows effective settling (flocculation) properties even at lower concentration.
They have strong hydrogen bonding properties due to the presence of cis-pair of hydroxyl groups in the b(1->4) linked main mannan chain of the polymer. In some cases, it is more preferable than other natural polymer like starch.
They behave excellent Surfactants in various cosmetic products with respect to ionic polysaccharides.

Resins

There is a large scale confusion while describing resins. Several samples of market resins sold under the name of Luban and Kundur and dammar samples under the name of chundurus and Ral were analysed. The Luban was essentially gum benzoin from styrax species and not the true olibanum from Boswellia species. However Kundur was the product of Boswellia Serrata, and therefore could be termed Indian oliba num. The dammars sold in the Indian market as Ral originated from Shorea species and those under the name of chundurus originated from Vateria indica Linn. or some other species of vateria and vatica. A medicinally strong anti-oxidant resin styrax benzoin. Resin present a great variety of structural specifications. As potent antioxidant, benzoin is specially important for protection against human diseases. Gum benzoin is a natural source of benzoic acid and benzoic acid esters. Gum benzoin is obtained from Syrax benzoin trees indigenous to Sumatra and Thailand. The resinoid is prepared by
alcoholic extraction of the crude benzoin which is scraped directly from the trees. At normal use level, it should not impart an odor to the finished product.

Training Capabilities

Isolation and various mesh preparations of crude gums. Purification by Barium Carbonate method and various profiles for pH, shear rate, temperature, concentration and time. Degradation observations, SEM studies etc. Identification of gum exudates and resins. Value additions of native gum for new resources, by removing peculiar odour of the seed, hydration profiles, treatment with sodium hydroxide and other salts to enhance their capabilities to be used in stages of processes for preparation of final products. Like in ice cream preparations to slow the melt down process, to increase mouthfeel and reduction of ice crystals etc. Deformation of solution and their studies through Rheometer, helipath viscometer etc.