Effect of processing on starch fractions in different varieties of finger millet

The effect of processing on starch fractions in finger millet (ragi) was studied in a standardized system and convenience mixes. In raw varieties, rapidly available starch (RDS) was 8.3% to 11.1% with slowly digestible starch (SDS) of 26.4% to 35.3%, and total available starch (TAS) 39–53%. The changes in the SDS and TAS were statistically significant. Puffing resulted in an increased RDS and decreased SDS. The changes were more prominent in hill grown varieties as compared to base varieties. Resistant starch (RS) ranged from 0.9% to 1.0% among raw varieties and decreased during puffing. The effect of puffing on gelatinisation of ragi flour was investigated, MR-1 variety showed a single phase transition with gelatinisation temperature of 64 °C, the same was found to be absent in puffed flour reflecting the gelatinisation during puffing. RS formation was influenced by the processing methods, increased during pressure cooking and roasting while dietary fiber increased during cooking and both decreased in all other processing methods. However, its implication in the convenience mix has shown that other ingredients also play a role in the RS content.