Effect On Sodium Carboxymethyl Cellulose With Different Structures On Quality Of Frozen Dough And Its Mechanism

With the peace of life accelerated and the popularity of the cold chain,frozen food industry has been rapid development.However,the freezing process inevitably reduces the quality of food,such as destruction of microstructure,increase of freezable water,reduction of the specific volume of bread.In this study,effect of CMCNa with different structures on frozen dough was studied.We also focused on the CMCNa on properties of frozen wheat gluten and wheat starch.This research could provide supportive date for the development of better food additive of frozen dough.The main results of this study are as follows:The study of different molecular weights of CMCNa on properties of frozen dough:the freezable water increased by 17.0%after the dough was frozen for 8 weeks.Addition of CMCNa could inhibit the increase of the freezeable water content of frozen dough,but there was no obvious difference when addition of different molecular weight of CMCNa.Addition of CMCNa reduced the content of T₂₁1 and increased the content of T₂₂.The smaller the molecular weight of CMCNa,the greater change in the moisture state of the dough,and the more homogeneous of moisture in the frozen dough during storage.Rheology experiments showed that addition of CMCNa could suppress the increase of tan?of frozen dough,maintained the rheological properties of the dough.CMCNa could increase the specific volume and decrease the hardness of bread baked from frozen dough.There was little effect on bread baking quality between different molecular weight of CMCNa.The influence of different DS of CMCNa on freeze storage stability of frozen dough were investigated:The addition of CMCNa slowed the increase of freezable water content and tan?of dough.CMCNa with high DS had more beneficial effects on inhibition the change of freezable water content and tan?.The CMCNa weakened the deterioration of the frozen treatment on the water mobility and stabilized the microstructure.The bread made from frozen dough possessed larger specific volume and smaller hardness with addition of CMCNa.And the high DS of CMCNa showed the most positive effect on baking quality of frozen dough during the frozen storage from 0 to 8 weeks.The influence of different molecular weight and DS of CMCNa on frozen gluten:The addition of CMCNa could inhibit the change of surface hydrophobicity and free sulfhydryl content of gluten protein during freeze storage and could also protect the protein network microstructure during frozen storage.CMCNa with high DS?DS1.2?was more beneficial in minimize the change of microstructure after frozen storage.There was no obvious difference between the groups of high and low molecular weight of CMCNa.Rheological experiments showed that addition of CMCNa improved the G'and G''of gluten and CMCNa with high DS was more effective in improving the viscoelasticity of gluten in the FT process.The content of T₂₁1 in gluten protein decreased from 23.9%to 22.5%after FT cycles,and the content of T₂₂2 increased from 75.3%to 77.1%.Addition of CMCNa could increase the content of T₂₁1 and decrease the content of T₂₂.However,CMCNa with different DS have little different effect on the water state of gluten.The effects of different DS of CMCNa on starch properties during freeze storage were investigated:addition of CMCNa inhibited the decrease the size of starch granule after FT cycles,but it had little influence on the microstructure of frozen starch.CMCNa with DS of 0.7 and 0.9 could inhibit of the decrease of crystallinity.CMCNa could reduce the peak viscosity,final viscosity and attenuation value of the starch system.The viscosity of DS of 1.2 groups was lowest.Addition of CMCNa reduced the relative starch crystallinity,formed smaller and less well-defined pores and more uniformity of water distribution.Addition of CMCNa with DS 1.2 induced an increase of T₂₁1 compared to control group.The rate of syneresis and hardness of starch gel increased by 55.2%and 385.8%during FT cycles,respectively.CMCNa with High DS could effectively reduce the syneresis rate and hardness.