Studies On The Application Of Hydrocolloid In Frozen Dough

Frozen dough has the advantages of improving product quality,reducing production costs and great convenience for consumers.It has a very wide range of application.Besides application to bread production,it also can be applied to the processing and production of steamed bread,buns and dumpling with Chinese characteristics.Due to the decrease of the textural quality of frozen dough during frozen storage phase of frozen dough,the finished product made of frozen dough has the drawback of rough texture,specific volume decreases,poor sensory quality and so on. So the frozen environment greatly limits the development of frozen dough technology.Hydrocolloid which is served as a food addictive can be used as antifreeze,water-retaining agent and anti-aging agent in the frozen flour food.The colloid reunite reduce the growth rate and size of ice crystal in dough,inhibit the destructive effects of ice crystals on the network structure of the gluten and yeast cells,and improve the low-temperature stability of frozen flour food.This paper discussed the effects of guar gum, carrageenan, carboxymethyl starch sodium(CMS) and konjac purified powder on the textural quality of frozen dough,in the same time,explored the effect of freezing treatment on frozen dough and the protective effect of hydrocolloid on frozen dough.Finally, the quality improvement of steamed bread was researched by adding preferred hydrocolloid addictive composition into steamed bread.The changes of hardness and adhesiveness of frozen flour food under the condition of different quantity was researched by respectively selecting5levels of the above hydrocolloids and carrying out single factor experiments.On the basis of single factor experiments,a superior combination of these four gels was obtained by4factors5levers orthogonal experiment.The results demonstrated that the hardness of frozen dough increased18.9%and adhesiveness reduced29.7%after adding complex hydrocolloids which contains1.2%guar gum,0.8%carrageenan,0.4%CMS,0.4%konjac purified powder (based on flour weight).It can improve the textural quality of frozen dough significantly through adding hydrocolloids.The freezing treatment effects on its textural quality was discussed through adding the optimal combination into frozen dough.Compared with the frozen dough, the hardness of frozen dough increased49.08%and the adhesiveness only increased2.53%after4freeze-thaw cycles.With the prolongation of the freezing time, the hardness of dough has been decreasing.The adhesiveness of frozen dough showed a trend of first decrease and then increase.After frozen for11days, the hardness of control dough decreased50.41%and the adhesiveness decreased19.94%.The hardness of frozen dough which had been added optimal combination decreased13.67%and adhesiveness only decreased0.84%.It can weaken the destructive effect of frozen environment on frozen dough significantly through adding hydrocolloids.Compared with the frozen steamed bread, all the quality of frozen steamed bread has been improved after adding hydrocolloids.The specific volume of optimized steamed bread increased1.89%.The expansion ratio increased3.91%.The sensory evaluation score increased4%.The results of TPA test showed that the TPA indicators of frozen dough can be improved greatly by adding optimal hydrocolloids combination;the hardness of frozen dough increased17.8%; the plastic viscosity increased21.7%.;the chewiness increased3.8%; the adhesion reduced18.6%.