Studies on physico-chemical and functional properties of some natural Indian gums
Natural gums, which have a polysaccharide backbone, are widely used in the food processing industry as binders, thickeners and texturizing agents. Although all are hydrocolloids and physico-chemical properties of various gums have been described by various workers, there appears to be lack of detailed studies on their functional properties, which show appreciable differences. The present study was carried out to determine the key functional characteristics of commercially important natural gums. These included flow, solubility, water holding capacity and oil holding capacity, angle of repose, bulk and true density, and coefficient of friction. The bulk density of various gums ranged from 0.95-1.20 g/mL, the lowest densities was that of Babool gum and the highest was of Piyar gum. The compressibility index of various gums ranged from 1 to 38.75%. Khair gum showed the highest solubility (83.65%) and Karaya gum showed the lowest solubility (60.06%). Psyllium gum showed the highest water holding capacity whereas gum Acacia showed the lowest value. Oil holding capacity of different gums varied from 114.66 to 214.66 (g oil/100 g gum). Ghatti and Piyar gums (38.13°) showed comparative decrease in angle of repose, whereas Guar gum showed an angle of repose of 39.80°.