用不同浓度的蔗糖溶液制备不同黏度梯度的溶液,考察了黏度对谷氨酸结晶晶习及粒度分布的影响,并通过测定不同黏度条件下谷氨酸结晶诱导期时间及生长速率的变化,探寻了黏度对谷氨酸结晶的影响机理。实验表明,在实验所测的黏度范围(1.00～10.30mP·s)内,黏度对谷氨酸的晶习基本没有影响,在相同过饱和度下,黏度增加,谷氨酸结晶诱导期时间延长,结晶成核速率减小,谷氨酸晶体的生长速率减小,使得谷氨酸晶体的颗粒直径减小,但晶体粒度分布均匀性略有增加。在工业生产上可以适当地提高结晶温度,以降低溶液的黏度,缩短结晶的诱导期时间,提高晶体的生长速率,使其更有利于谷氨酸的结晶。

The monosodium glutamate solutions with different viscosity gradient was prepared by different concentrations of sucrose solution.The effect of viscosity on glutamic acid crystal habit and particle size distribution was investigated in this study.Meanwhile,the effect mechanism of viscosity on glumatamic acid crystallization was also probed through measuring glutamate induced crystallization time and the changing of growth rate at different viscosity.Experimental results showed that the viscosity has no effect on the crystal habit of glutamate in the measured viscosity range(1.00~10.30 mP·s).At the same supersaturation,the increasing of the viscosity resulted in the prolong of the crystallization induction time of glutamate,the decrease of the rates of crystal nucleation and crystal growth.Consequently,the particle diameter of glutamic acid crystals was decreased,while the uniformity of crystal size was slightly increased.Therefore,through appropriately improving the crystallization temperature in industrial production,the reducing of the viscosity of the solution could result in the shorten of the crystallization inducing time and improvement of the crystal growth rate,and ultimately making it more conducive to the crystallization of glutamic acid.