Physicochemical, functional properties, and digestion of isolated starches from pigmented chickpea (Cicer arietinum L.) cultivars.

This research was undertaken to study physicochemical, functional, and in vitro starch digestion properties of wet-milled chickpea starches obtained from an array of ten cultivars differing in seed coat color (black, brown, green, red, and cream). The yield of chickpea starches ranged from 19.22 to 30.06%, in which resulting starches varied in total starch and amylose contents from 87.14 to 96.02% and 25.05 to 35.26%, respectively. The DSC transition temperatures To, Tp, and Tc and gelatinization enthalpy ranged from 61.93 to 68.94°C, 66.47 to 72.57°C, 73.34 to 78.50°C, and 8.82 to 10.68 J/g, respectively, indicating large differences among the starches. Scanning electron micrographs of the starches showed lenticular-shaped granules with a smooth surface and different granule sizes. The rapidly digestible (RDS), slowly digestible (SDS), and resistant (RS) gelatinized starch fractions varied from 56.34 to 59.15%, 33.22 to 35.43%, and 6.42 to 9.22%, respectively. The predicted glycemic indexes (pGI) of native and gelatinized chickpea starches ranged from 65.52 to 66.10 and 74.39 to 75.74, respectively. A close correlation among the viscosity characteristics of isolated starches and the starch digestion fractions was found after PCA analysis. The properties of the starches were not dependent on the seed-coat coloration of the cultivars. Overall, the results suggest that the starches of the array of chickpeas studied may hold potential for the development of functional foods especially due to its functional properties, medium glycemic index, high SDS, and RS contents.