Xanthan gum fermentation is probably the most complex fermentation process in terms ofrheological property variations and associated mixing,power consumption,mass and heat transferproblems.In order to obtain these dat...Xanthan gum fermentation is probably the most complex fermentation process in terms ofrheological property variations and associated mixing,power consumption,mass and heat transferproblems.In order to obtain these data,fermentations of Xanthomonas campestris were carried outon pilot scale bioreactor with different D/T ratios and different feeding strategies(batch andfed-batch).It was discovered that the rheology of xanthan fermentation broth is of paramountimportance to the above characteristics.The aerated power consumption and power number are both afunction of aeration rate during the initial stage of the fermentation when the viscosity is low andthe Reynolds number high.However when the becames viscous and Reynolds unmber≤10~3,thegas velocity does not show any effect on the power number.The oxygen mass transfer coefficientsand the overall heat transfer coefficients are both dependent on the impeller speed,the apparentviscosity of the broth and the D/T ratio.These data taken from practical展开更多
以苹果渣多糖(apple pomace polysaccharide,APP)、酒渣多糖(cider apple pomace polysaccharide,CAPP)、醋渣多糖(cider vinegar apple pomace polysaccharide,CVAPP)为研究对象。通过APP、CAPP、CVAPP质量分数、温度、放置时间对表观...以苹果渣多糖(apple pomace polysaccharide,APP)、酒渣多糖(cider apple pomace polysaccharide,CAPP)、醋渣多糖(cider vinegar apple pomace polysaccharide,CVAPP)为研究对象。通过APP、CAPP、CVAPP质量分数、温度、放置时间对表观黏度、剪切应力的影响对比,研究发酵对APP流变特性的影响。结果表明:APP、CAPP、CVAPP皆为假塑性流体,存在剪切变稀现象;CAPP、CVAPP表现出黏度明显降低、质量分数依赖性减弱、温度抗逆性增强以及存在一定的时间抗逆性;APP、CAPP、CVAPP放置3 d对流变特性影响较小;CAPP、CVAPP在一定程度上表现出优于APP的加工特性。展开更多
文摘Xanthan gum fermentation is probably the most complex fermentation process in terms ofrheological property variations and associated mixing,power consumption,mass and heat transferproblems.In order to obtain these data,fermentations of Xanthomonas campestris were carried outon pilot scale bioreactor with different D/T ratios and different feeding strategies(batch andfed-batch).It was discovered that the rheology of xanthan fermentation broth is of paramountimportance to the above characteristics.The aerated power consumption and power number are both afunction of aeration rate during the initial stage of the fermentation when the viscosity is low andthe Reynolds number high.However when the becames viscous and Reynolds unmber≤10~3,thegas velocity does not show any effect on the power number.The oxygen mass transfer coefficientsand the overall heat transfer coefficients are both dependent on the impeller speed,the apparentviscosity of the broth and the D/T ratio.These data taken from practical
