The preparation of carboxymethyl (CM)-Cassia tora gum (CTG) with monochloroacetic acid and sodium hydroxide was investigated under different reaction conditions. The carboxymethylation reaction was studied with respect to the degree of substitution of CM-CTG. The variables studied were the concentration of reactants, methanol-water ratio (solvent), reaction time, and reaction temperature. Carboxymethylation of CTG increased its solubil-ity in cold water and the stability of its paste to microorganisms. Regardless of the degree of substitution of these products, their aqueous solutions were characterized by non-Newtonian pseudoplastic behavior. Determination of the rheological properties of CM-CTGThe rheological properties were determined with a Brookfield digital viscometer (model RVTD, Stough-Correspondence to: V. Kumar (vineetkmadan@yahoo.co.in) or P. L. Soni (sonipl@icfre.org).

Starch from the seeds of Quercus leucotrichophora was isolated, purified and its physico‐chemical properties were determined. Scanning electron microscopy of the granules show that they are oval to eliptical in shape. Its has high contents of ash, lipids, proteins and lower content of amylose. Its gelatinization temperature is 80–85°C and displays high water binding capacity. It has low swelling power but high solubility. Amylograph study shows 425 B.U. paste viscosity and no thinning inspite of 3 h heating. On cooling starch retrogrades to paste viscosity of 1200 B.U.

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Graft copolymerization of acrylamide onto Cassia tora gum was studied in an aqueous medium using ceric ammonium nitrate-nitric acid as the redox initiator. To optimize the reaction conditions for obtaining maximum percent grafting, the concentrations of Cassia tora gum, ceric ammonium nitrate, acrylamide, and nitric acid, time, and temperature were varied. Results are discussed and a reaction mechanism is proposed.

ABSTRACT:The seeds of Cassia occidentalis, an annual weed occurring throughout India, are a rich source of galactomannan gum. The gum derived from seed endosperm can be utilized in a number of industries to replace conventional gums. With a view to utilize the gum for broader applications, carboxymethylation of Cassia occidentalis seed gum was carried out. The reaction conditions were optimized with respect to concentration of monochloroacetic acid, sodium hydroxide, solvent ratio, reaction time, and reaction temperature. Rheological studies of carboxymethyl gum exhibited relatively high viscosity and stability vis-a-vis unmodified Cassia occidentalis gum.