Effects of different gelatinization degrees of potato flour on gluten network integrity and dough stickiness
Xu Wang, Li Cheng, Zhengbiao Gu, Yan Hong, Zhaofeng Li, Caiming Li, Xiaofeng Ban
Abstract
Potato flour with different gelatinization degrees was prepared and the properties of potato flour - wheat flour dough were compared to investigate the reason why dough with more than 30 g/100 g potato flakes becomes sticky. The results showed that the water absorption capacity of potato flakes was the highest, which was 2.2-fold higher than that of gluten and 3.4-fold higher than that of wheat starch. Dough microstructure analysis indicated that competitive water absorption of potato starch and gluten protein led to the discontinuous gluten structure and more exposed gliadin which is responsible for dough stickiness. The gliadin content (obtained at a single elution) in potato flakes-wheat flour dough was 200–400 g/100 g higher than that of others. Two-step kneading method was applied to increase the gluten integrity and reduce gliadin leaching, which reduced the dough stickiness from 31.86 g to 23.07 g. This study demonstrated that the content of gliadin was more responsible for stickiness of the dough than gelatinized starch, and two-step kneading method can be employed to improve the properties of food prepared with potato flakes.