The Studies And Designs Of Cooling Process On Steamed Bread

This study discusses the impact of different cooling conditions on steamedbread quality. Firstly, by laboratory test, to grasp the variation of steamed breadquality in different cooling conditions. Then pilot in the factory. By orthogonal testdesign, the impact of various factors which under the actual production environmenton steamed bread quality was ordered. According to the conclusions reached by theexperiment, preliminary designed cooling process. The main conclusions are asfollows:In the laboratory test, with the extension of the cooling time, the hardness of thevarious parts of steamed bread are showing rising trends, during40min to50min thenear the skin part of steamed bread slightly softened. The whiteness of each part ofsteamed bread with the extension of the cooling time showing decreases and thenincreases and then decreases, and showing high value at30min to40min. thetemperature of various parts are declining with the extension of the cooling time,after40min the steamed bread core temperature close to35℃. The moisture content,quality, height and diameter of steamed bread with the extension of the cooling timecontinue to drop. Considering all the quality changes, the cooling time is40min.With the cooling wind speed increases, the hardness of the steamed bread nearthe skin part showing gradually increased trend after the first slight decline; with thecooling wind speed increasing whiteness first increases and then decreases. Coolingwind speed increase based on8m/s, the bread core temperature is not obvious. Thesteamed bread stand embodied by height and diameter changes performance better inthe cooling wind speed of8m/s. Finally, cooling wind speed is8m/s.As the cooling temperature rise, hardness of steamed bread various partgradually decreases, whiteness of steamed bread of various parts increasing, watercontent showed a decreasing trend, the various parts of the temperature increases, therate of steamed bread quality decreases gradually increases, height and diameterfluctuations change, but at25℃the stand is best. Consider various indicatorschange, the cooling temperature is25℃.With the cooling humidity gradually increases, the hardness of steamed breadnear the skin part rising; whiteness trends first decreased and then slightly upward.The steamed core temperature is gradually rising. The moisture content of each part of steamed bread was first decrease and then increase. The rate of mass loss showeda decreasing trend after the first increases as the humidity increases. Height decreasewith increased cooling humidity decreases first and then increasing. Diameterdecrease trends first increase and then decrease and then increase. Therefore, coolinghumidity selected50%.Pilot accordance with the laboratory test results, to identify the different coolingconditions impact on steamed bread quality by orthogonal experiment. The coolingtime impact on the steamed bread temperature greater; hardness and whiteness of thesteamed bread impact by the cooling temperature, then followed by cooling humidity;relative to the other quality, the height and diameter of the steamed bread impact bycooling wind speed. Therefore, to finalize the cooling process: the coolingtemperature is25℃, cooling humidity is50%, cooling wind speed is6m/s, thecooling time is40min.