Impact of γ-irradiation, CIPC treatment, and storage conditions on physicochemical and nutritional properties of potato starches

In the present study, three potato varieties were treated with chlorpropham (CIPC, 35 ppm), γ-irradiated (0.1 kGy) and stored for up to 5 months at 8 °C, and the physicochemical properties and in vitro starch digestibility of native and cooked starches were investigated. Sprouting was found to be satisfactorily suppressed by γ-irradiation and CIPC treatment. However, irradiation increased total free glucose content in two potato varieties, and decreased the thermal transition and pasting temperature of starch. The crystallinity of starch in irradiated potatoes decreased significantly (p ⩽ 0.05) which may explain its decreased resistant starch content. Sprout inhibiting treatments and storage had no effect on in vitro starch digestibility in cooked starches, but cooling cooked starch significantly (p ⩽ 0.05) increased its resistant starch content.