Isolation and characterization of yam (Dioscorea alata L.) starch from Brazil

Abstract

The aim of the present study was to isolate and characterize yam's (Dioscorea alata L.) starch in terms of its physicochemical, technological and structural properties. The starch isolated in the present study showed 96.58% of total starch (25.77% of amylose and 74.23% of amylopectin). Yam starch (YS) showed a higher proportion of long chains of amylopectin, 23.97% ± 1.10 of relative crystallinity, type B crystallinity pattern, and marked amylose leaching in the range of 75–95 °C. The onset and peak temperatures were at 69.62 °C ± 0.16 and 74.81 °C ± 0.11, respectively, and the gelatinization enthalpy was 12.15 J g−1 ± 0.25; the pasting temperature was 72.47 °C ± 0.41, the peak viscosity was 2031 cP ± 12.19, the breakdown viscosity was 1193.75 cP ± 41, the setback viscosity was 755.75 cP ± 34.71, and the final viscosity was 1554 cP ± 90.46. The starch texture profile showed 1.96 N ± 0.28 of hardness, 1.01 ± 0.04 of springiness, and 0.322 ± 0.04 of cohesiveness. The results indicated that YS can be a very important source in food production, and can be applied to crunchy foods, salad dressings, and ready-made desserts.