Studies On The Quality Characteristics Of Hot Water Dough And The Processing Technology Of Chinese Steamed Spring-rolls

This subject was to find the best process conditions for making Chinese steamed spring-rolls and studied on the qualities of hot water dough and Chinese steamed spring-rolls, and preliminarily established a method to evaluating the quality of the rolls by the quality indexes of hot water dough.It researched the effect of water addition to toughness and firmness and sensory score of Chinese steamed spring-rolls made with water temperature of 25℃、70℃、75℃、80℃、85℃、90℃、95℃、100℃. It showed that toughness of steamed spring-rolls decreased with water addition increased and significantly decreased when water temperature was higher than 90℃. Firmness of steamed spring-rolls had a downward trend with water addition increasing, and decreased with rise of water temperature. Sensory evaluation would be the main judge for the optimum water addition for water temperature of 25℃、70℃、75℃、80℃、85℃、90℃、95℃、100℃, and the results were 45%、53%、55%、57%、57%、60%、60%、63%.Under the condition of the optimum water addition for different water temperature, it would be found that water content of rolls increased gradually, firmness and toughness decreased. NMR showed that the adsorption water content increased from water temperature 25℃to water temperature 90℃and then decreased. The sensory score of rolls made with water temperature 90℃and water addition 60% was the highest, which means its quality was the best. The correlation between quality results of Chinese steamed spring-rolls and sensory score results showed that the moisture loss quantity and firmness and toughness of Chinese steamed spring-rolls could be an instrument indexes to evaluate the quality of Chinese steamed spring-rolls.Electron- microscope scanning results showed that starch granules deformation gradually with the water temperature increased and exposure to the solidification of protein structure until blend with the solidification of protein, it began to appear rupture phenomena.Water content, loss of water content, degree of gelatinization, viscosity of hot water dough increased gradually and hardness decreased under the condition of the optimum water addition for different water temperature; the tensile strength of dough made with water in temperature 90℃and water addition 60% was maximum, and the extensibility was minimum, and color was the best; Wet gluten content of hot water dough was lower than the wet gluten content of cold water and dough made with water temperature 90℃and water addition 60% had the highest wet gluten content. The study on rheological properties of dough made under the condition of the optimum water addition for different water temperature between 25℃-100℃indicated that G’ and G " increased with frequency increasing and the modulus of elasticity were greater than the viscous modulus; loss tangent value of the dough made under the condition of water temperature 80℃and water addition 57% changed greatly with frequency increasing; G" of the dough made with water temperature 90℃and water addition 60% was minimum. Using(NMR) technology to detect the three kinds of water in the dough would found that the ratio of the three kinds of water was affected by water temperature and water addition. Electron- microscope scanning results showed that the influence of water temperature on microscopic structure of hot water dough was more significant than the influence of water addition when experimental condition changes. The internal structure of hot water dough changes constantly with starch gelatinization and gluten protein denaturation.The correlation between the qualities of hot water dough and the qualities of with the water temperature increased showed that the water content, degree of gelatinization, L*, b* and dough extensibility could be used to evaluate if it was suitable for making with the water temperature increased; Texture characteristics and water related parameters are greatly influenced by the quality of dough.