Change Rules Of Glutenin During Storage At Room Temperature And Its Effect On Quality Of Dried Noodles

In order to provide a theoretical basis for further research on the technology of delaying the quality decline of dried noodles during normal temperature storage,two kinds of wheat with different gluten strength(Zhengmai366,AK58)were used as raw materials to make dried noodles,which were stored at constant temperature and humidity(25 ℃,50%)for 180 days.Through texture analyzer(TA-XT),scanning electron microscope(SEM),dynamic rheometer(DHR-2),Fourier transform infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR),the change mechanism of glutenin in dried noodles during storage at room temperature and its influence on the quality of dried noodles were studied.The conclusions are as follows:(1)Changes of quality indexes of dried noodles during storage at room temperatureWith the extension of storage time,the brightness value(L*)of the two kinds of dried noodles decreased,and the yellowness value(b*)increased;the water absorption increased and the broken rate increased;the texture properties decreased,and the hardness,elasticity,shear force,tensile distance and other indicators showed a downward trend,and their adhesiveness showed an upward trend;the sensory score decreased with the increase of storage time;SEM showed that the internal structure of dried noodles became more and more loose,the exposed area of starch granules became larger and larger,and the gluten content gradually decreased,indicating that the glutenin content also decreased.(2)Changes of physical properties of glutenin in dried noodles during storage at room temperature and its effect on noodle qualityWith the increase of storage period,the water holding capacity and oil holding capacity of glutenin in the two kinds of dried noodles decreased;the storage modulus and loss modulus of glutenin decreased in varying degrees,and the Tan tangent increased;NMR analysis showed that the content of bound water in glutenin decreased with the storage time,while the content of weak bound water and free water increased.(3)Changes of microstructure of glutenin in dried noodles during storage at room temperature and its effect on noodle qualityWith the extension of storage time,the microstructure of glutenin in dried noodles was destroyed,the pores gradually became larger,and the internal network structure of glutenin was broken to varying degrees,especially in the later stage of storage,which led to the decline of the elastic properties of glutenin,thus affecting the taste of dried noodles.(4)Changes of chemical components of glutenin in dried noodles during storage at room temperature and their effects on noodle qualityWith the increase of storage time,the content of free sulfhydryl group of glutenin in the two kinds of dried noodles showed an upward trend,the content of disulfide bond and GMP showed a downward trend;the content of β-fold of glutenin in dried noodles showed a significant downward trend,and the content of α-helix,β-corner and irregular coil showed an upward trend;the number of glutenin bands in dried noodles gradually decreased and the color became lighter,which indicated that the macromolecules degraded with the extension of storage time,and the glutenin macromolecules depolymerized.