Mechanism For Effects Of Potato Granules And Its Main Components On Potato Noodle Quality

Potatoes are rich in necessary nutrients for human body, so adding a certain proportion of potato granules to wheat flour to process a new potato noodles is expected to enhance the nutritional value of noodles and would largely meet the requirement of people for nutritional staple food. However, addition of potato granules would result in quality decrease of potato noodles. In order to provide theoretical basis and technical support for the application of potato granules in noodles, the effect of potato granules on the edible and nutritional characteristics of noodle and the interaction between potato starch and wheat gluten were investigated in this study.Firstly, it was clearly indicated that the addition of different ratios of potato granules affected the rheological properties of dough systems. The addition of potato granules could increase the apparent viscosity but decrease the deformation of doughs. With the increase of the frequency, the dough viscoelasticity increased and gelling gradually. Compared with the control sample, the potato granule blended dough showed a delay in the gelatinization. There was an obvious structural deterioration of the dough samples as result of the addition of potato granules.The effects of wheat protein, peanut protein and soybean protein on the edible quality of potato noodles were investigated. Results showed that the brightness of potato noodles with soybean protein addition were the highest. All the three kinds of protein can significantly improve the edible quality of potato noodles, such as reducing the cooking loss, increasing the tensile resistance, hardness, cohesiveness and chewiness. And the effect of wheat protein on noodle quality was most significant followed by soybean protein. The scanning electron microscopy(SEM) results showed that wheat protein addition could make the gluten network more compact with less porosity. According to the electronic nose analysis results, it was found that soybean protein would increase the beany flavor in potato noodles as a result of nitrogen oxygen compounds increasing.Potato granule varieties have a significant effect on edible quality of noodles. The brightness of noodles made from Zhongshu 5 potato was the lowest. The cooking water turbidity and cooking loss of noodles made from Zhongshu 19 potato were much lower than other varieties. The tensile resistance, hardness, and chewiness of noodles with Zhongshu 19, Zhongshu 18, and 948 A potatoes was better than other varieties and gluten network of these potato noodles were more compact with less porosity from SEM observation. Electronic nose analysis results showed that the flavor of 948 A potato noodles were significantly different from wheat noodle. In conclusion, Zhongshu 19 is most suitable for processing potato noodles followed by Zhongshu 18, Atlantic, and shepody potatoes.In this study, three kinds of noodles, namely, wheat, Shepody potato, and Atlantic potato noodles, were produced with blended powder consisting of wheat flour and certain amount of various potato granules. The nutrient composition of four types of noodles was analyzed: fresh noodle, dried noodle, fresh noodle after boiling, and dried noodle after boiling. Results showed that the contents of protein, crude fiber, total ash, reducing sugar, vitamins, most mineral elements, dietary fiber, and amino acids in potato noodles were higher than those in wheat noodles. Results of the index of nutritional quality(INQ) showed that the nutritional value of Shepody potato noodles was the highest, followed by that of Atlantic potato and then wheat noodles.The viscosity, thermal, thermomechanical, and microstructural properties of potato starch–wheat gluten composite systems were investigated under mechanical shear and heating conditions using Mixolab. Results showed that the viscosity increased with the potato starch proportion increase. The water absorption capacity and gelatinization temperature of the samples increased significantly as the gluten proportion increased, while the endothermic enthalpy decreased. The addition of the potato granules weakened the network structure of the dough. The starch granules were distributed in gluten network and water absorption rate was lower than the gluten protein, resulting a competitive hydration between starch and gluten which might primarily explain the delayed gelatinization temperatures.