利用聚焦光束反射分析仪（FBRM）分析测定了淀粉颗粒粒径分布，可实现了对淀粉在物理或化学处理过程中粒径变化的在线监测。考察了淀粉乳浓度、搅拌速率和介质等因素对FBRM测定淀粉颗粒粒径大小分布的影响以及不同种类淀粉颗粒的粒径分布曲线。结果表明：随着淀粉乳浓度的增加，FBRM测得的淀粉颗粒粒径呈现先增加后减小的趋势，当浓度达到10%时，粒径大小趋于稳定；在高浓度淀粉乳中，搅拌速率对淀粉颗粒粒径的影响较为显著，在低浓度淀粉乳中，则没有显著的影响；采用浓度小于50%的乙醇和异丙醇以及高于75%甘油作为介质时，可以得到较为稳定的粒度分布；不同种类淀粉颗粒的粒径分布曲线趋势不同。

In order to monitor the diameter change of starch granules in physical or chemical process on line,the influences of the starch slurry concentration,stirring rate and medium on the distribution of the granule diameter were investigated by means of FBRM.Moreover,the granule diameter distribution curves of different starches and the granule diameters of the same starch measured by different methods were analyzed.The results show that（1） with the increase of starch slurry concentration,the granule diameter measured by FBRM first increases and then decreases,and it reaches its maximum at a slurry concentration of 1%;（2） the stirring rate slightly affects the measurement of the granule diameter;（3） the granule diameter distribution becomes stable when ethanol and isopropanol with a concentration of lower than 50%,or glycerol with a concentration of higher than 75%,is used as the medium;（4） the distribution curves of the granule diameter vary with the starch type;and（5） even for the same starch granule,the measured diameter is inconstant due to different measurement methods.