Digestion profiles and some physicochemical properties of native and modified borlotti bean, chickpea and white kidney bean starches

Native starches isolated from borlotti bean (Phaseolus vulgaris L.), chickpea (Cicer ariteninum L.), and white kidney bean (Phaseolus vulgaris L.) was modified by pyrodextrinization (PD), cross-linking with sodium trimetaphosphate (CL), heat–moisture treatment (HMT), and gelatinization–retrogradation (GR) process. The effects of these modifications on the nutritionally important starch fractions, namely rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS), were studied in both uncooked and cooked starches. Solubility, swelling power and gelatinization parameters of the native and modified starches were also studied. PD, CL, and HMT reduced the swelling power of all three legume starches. Significant increases in solubility were observed after PD and CL, where GR decreased the solubility of all starches. CL and HMT shifted the onset temperature of gelatinization (To) to a higher temperature and tended to decrease the gelatinization enthalpies (ΔH). PD and GR starches has the largest proportion of RDS (39–69%) among uncooked starches where the RDS percentage of uncooked native, CL and HMT starches were only between 2–7%. Compared with native starches, all the modifications applied tended to decrease the RDS percentage of cooked starches. The highest decrease in RDS was determined after GR treatment for all the legume starches studied. The total SDS + RS, the two starch fractions that have nutritional benefits, content of GR and HMT starches were notably higher than the CL and PD starches.