Resistant starch from processed cereals: the influence of amylopectin and non-carbohydrate constituents in its formation

The effect of removal of protein and lipids on the resistant starch (RS) content of processed rice and ragi has been studied. The percent recovery of RS increased significantly (over 2–3-fold) after defatting and autoclaving. However, deproteinization did not show any major difference. Prolonged storage of gelatinized starch suspensions showed considerably more undigested mass even after extended α-amylolysis, probably due to the involvement of long unbranched chains of amylopectin in the formation of RS. Thermal characteristics of these processed flours/starches showed variable enthalpy values. X-ray diffraction data revealed both B- and V-type diffraction patterns for the isolated RS.