Development of Novel Hydrocolloids using Radiation Processing Technology

Abstract

Hydrocolloids are a class of materials that dissolve, disperse or swell in water, newlinethereby modifying the physical properties of aqueous systems by causing newlinegellation, thickening or emulsification / stabilization. They have the major newlineadvantages of being biodegradable and have found usage in several newlineindustrial applications. They also have the disadvantage of being susceptible newlineto microbial attack and have poor thermal resistance, which limits their usage. newlineWith the exploitation of hydrocolloids, such as polygalactomanans, for newlineindustrial applications alongwith their use as a feed-stock, their importance as newlinea crop gained more significance from economic point of view for the farmers. newlineThe derivatizedpolygalactomannan, such as guar gum exhibits various newlinecharacteristics needed for the high-end applications. Thus, all efforts to have newlinean indigenous technology for derivatization have been in focus for quite some newlinetime now. newlineThe derivatization of polygalactomannan such as guar gum is conventionally newlinecarried out by either etherification of the hydroxyl groups or by grafting of newlinefunctional moieties on the backbone of the polymer chain by chemical route newlineinvolving a cumbersome process. Also, in order to obtain guar gum of newlinedifferent viscosities, its depolymerisation is carried out by adopting a chemical newlineprocess. Thus, for both depolymerisation and derivatization of guar gum, newlinechemical processes have been adopted by the industry, which involve the use newlineof hazardous chemicals and several steps, which are quite cumbersome. newlineThe present thesis describes the depolymerisation of guar and its newlineconventional derivatives to desired viscosity by following the irradiation newlinetechnology. The grafting of monomers on guar gum has also been detailed newlineout using radiation processing technology. The increase in elastic modulus newlineand the viscosity of grafted guar gum has been observed as compared to newlineguar gum as such, which directly indicates that grafting has taken place...