The Study Of Control Parameters Of High Temperature Drying System Of Noodles And Its Qualities

The control parameters of high temperature noodle drying system and noodle qualities were studied in this paper. The wet noodles were dried under different temperature, wind speed and relative humidity in this paper. The water curve was measured at different conditions, then the drying characteristics of noodle was discussed. Combined with noodle drying characteristics, texture qualities of dry fine noodles obtained from tunnel drying method were analyzed. Through the comparison of the physical and chemical properties of high and low temperature drying noodles, the advantages of high temperature drying was demonstrated.The results showed that: temperature, wind speed, relative humidity and thickness of noodle had different influence toward the drying rate and equilibrium water content. The drying rate of noodles was positively correlated with drying temperature, negatively correlated with relative humidity, and there was a critical point between the drying rate and wind speed. A sclerotic film would be formed around the critical wind speed, which will affect the internal moisture migration of the noodle. When the drying wind speed was less than the critical wind speed, the dry rate was proportional to the wind speed, other wise the drying rate was inversely proportional to the wind speed. The drying rate deceases with the increase of the thickness of the noodle. The equilibrium water content was negatively correlated with drying temperature, positively correlated with relative humidity and had nothing to do with the wind speed and the thickness of the noodle.Various factors in the drying process had significant effects to the texture qualities of the dry fine noodle and the cooked qualities of the noodles. Though the important order was different, drying temperature, cooling down time and maintaining humidity were significant to all the texture qualities. The optium process was determined through orthogonal experiment and verified.Through the comparison of various qualities of the dry fine noodles prepared from high and low temperature, it was showed that: high drying temperature had no significant effect to the protein, the gelatinization degree of the starch, and the acid value; when the drying temperature was below 70℃, the gluten index would rise a little with the increase of the temperature, but when the temperature was higher than 70℃, the gluten index would decrease significantly; from the perspective of fatty acid, high temperature drying was favorable for the extension of the shelf life of the noodles; high temperature drying made a slight decline to the color of the noodle, and made the cooking loss of noodle increased. In addition, it was found that pests could be prevented when the flour was made into noodles. The sensory evaluation found that, sensory evaluation was highly relevant with the texture index and several physicochemical properties of the noodles. And noodles prepared under the temperature of 70℃got the best score. Through the comprehensive comparison of the texture qualities and the physical and chemical prosperities of the dry noodle obtained by high and low temperature drying process, it was thought that high temperature had greater advantages.