Production;Quality Changes And Improvement Of Fermented Frozen Fried Bread Stick In Frozen Storage

Abstract: Twenty three kinds of wheat flours with the protein content of9.03%～14.81%were used as the main raw materials. The correlation between physicochemical properties of wheat flourd and textures, sensory characteristics of fermented frozen fried bread stick were analyzed. Moreover, the flour varieties which suited to fermented frozen fried bread stick were selected. According to the screening experiment, jinyuan high gluten flour was selected for the production of fermented frozen fried bread stick. The quality changes of frozen fried bread stick during the storage period were also researched. Finally, the qualities of fermented frozen fried bread stick were improved with additives, such as monoglyceride, sodium stearoyl lactylate, starch sodium octenyl succinate, alpha-amylase and xylanase.1. The physicochemical properties of23kinds of wheat flour were studied. The results showed that there were significant differences among RVA characteristic profiles in different wheat cultivars. The higher the protein content was, the smaller hot paste viscosity and peak time was. Besides, the higher the wet gluten was, the lower the cool paste viscosity was. Protein content had significant negative correlation with the hot paste viscosity and peak time. There was negative collelation with wet gluten content and cool paste viscosity.The seven characteristics of RVA parameters showed that there was a positive correlation between the peak viscosity and hot paste viscosity, cool paste viscosity, also peak time. There was a positive correlated to hot viscosity and cool paste viscosity, peak time. Breakdown viscosity was positively related with cool paste viscosity and peak viscosity. Pasting temperature was positively related with peak viscosity, hot paste viscosity and peak time.2. Twenty three kinds of wheat flours were used as the main raw materials to produce fermented frozen fried bread stick. The correlation between physicochemical properties of wheat flours and textures, sensory characteristics of fermented frozen fried bread stick were analyzed. The sensory scores showed obviously positive correlation with pringiness and resilience, and the correlation coefficients were0.685and0.569, respectively. Sensory scores were significantly positive related to cohesiveness and chewiness. Moreover, protein contents were significantly correlated with oil contents. The oil contents of fermented frozen fried bread stick were negative correlation with setback viscosity. Sensory scores had significant positive correlation with hot paste viscosity and has a significant positive correlation with peak viscosity and peak time.3. Based on the screening experiment, jinyuan high gluten flour was selected for the production of fermented frozen fried bread stick. The optimal process factors of producing fermented frozen fried bread stick were studies. The results showed that the optimum conditions for fermentation frozen fried bread stick were as follows:amount of yeast1.0%, amount of leavening agent3.0%, the fermentation time2.4h, frozen temperature-35℃, frozen time20min. Under these conditions, the specific volume was4.54mL/g.4. The quality changes of fermented frozen fried bread stick during frozen process were also researched. The results showed that the moisture content and water activity of fried bread stick reduced, and the characteristic parameters of RVA profiles showed that the highest viscosity, cool paste viscosity, hot paste viscosity and breakdown viscosity increased with the extension of storage time. Moreover, gelatinization temperature droped and starch retrogradation increased in the frozen storage. Using scanning electron microscopy to observe the microscopic structure of the fermented frozen fried bread stick and the results showed that surface structure and the state of the water closely integrated with the proteins and other macromolecules changed with the frozen storage time. Meanwhile, the gluten network structure was damaged. But the speed of oxidation and rancidity in fried bread stick was slow.5. The additives had significant effects on the textural properties and the specific volumes as well as improving the qualities of fermented frozen fried bread stick. The suitable amounts of monoglyceride, sodium stearoyl lactylate, starch sodium octenyl succinate A, starch sodium octenyl succinate B, alpha-amylase, xylanase were0.5%,0.4%,2%,3%,0.01%,0.001%, respectively. Additives could increase shear stress and reduce the viscous and hardness of the fermented frozen fried bread sticks, which resulted in better chew qualities and non-stick core for the fried bread sticks.