Water-extracted polysaccharides of selected cereals and influence of temperature on the extractability of polysaccharides in sorghum

Non-cellulosic and non-starchy (I2-KI negative) glucose-rich polysaccharides from wheat, ragi, rice and sorghum were extracted with water at ambient temperature (25°C). Ethanolic fractional precipitation of the polysaccharides yielded a number of fractions containing varying proportions of hexoses (0.7–98%) and pentoses (1–56%). Polysaccharides from sorghum were also extracted at 4, 55°C and at boiling water temperature. Prior amylolysis of the sorghum flour followed by extraction at boiling water temperature was found to give a better yield of non-starch glucose-rich polysaccharides.