In vitro hydrolysis and estimated glycemic index of jackfruit seed starch prepared by improved extrusion cooking technology.

The effect of improved extrusion cooking technology (IECT) on jackfruit seed starch (JFSS) digestion properties was investigated by the in vitro starch hydrolysis, hydrolysis index (HI) and glycaemic index (GI). The IECT markedly increased the content of rapidly digestible starch (RDS), slowly digestible starch (SDS), equilibrium concentration (C∞), HI, GI, and the rate of starch digestion but decreased in resistant starch (RS). Increasing the temperature and screw speed resulted in significant increases in SDS, C∞, HI, GI, and decreases in RDS, RS content. The scanning electron microscope demonstrated the digestion result that the JFSS changed from more compact structure to more loose polyhedral and from fewer pits to number of hollows. However, the opposite results were observed for increasing moisture content. All these results suggested that the in vitro digestibility of the high amylose and small granules JFSS can be efficiently enhanced by the improved extrusion cooking treatment.