Preliminary Application Study On Freeze Concentration Technology In Sugar Juice

Under the premises that the solute density is lower than the eutectic density in the aqueous solution, freeze concentration, which is based on the phase equilibrium between ice and water, makes the solution cool to the freezing point, part of water ice up because of exothermic. Then, separate the concentrated solution and the ice crystal can realize the concentration.This article made a preliminary reseach on sugar juice dealt with the method of suspension freeze-concentration.The single factor and the orthogonal experiment was reseached to optimize the freeze concentration technologies, thus the sugar juice freeze-concentration's best technological conditions were determined. Firstly using the ice nucleus active bacterium applied to the sugar juice freeze-concentration, the solution's undercooling point was enhanced. Through the heating evaporation concentrating and freeze-concentration, the feasibility of the freeze-concentration technology applied to the sugar manufacturing industry has been proved.The main conclusions were made as follows:1. The stirring rate, the coolant temperature and the dosage of ice crystal seed are the primary factors which affect the effect of freeze-concentration, stirring rate is the most primary control factor among them. The orthogonal experiment determined that the freeze-concentration's best technological conditions are: Stirring rate of 1200r/min, cold media temperature of -4℃, ice crystal seed addition amount is 15.00g, the final concentration reached 30.0°Bx.2. Using the multistage freeze-concentration method, the consistency of first-level concentration is from 14.2°Bx to 30.3°Bx,the concentration ratio decreased gradually,the consistency of four-level concentration is from 33.5°Bx to 34.0°Bx, which is the final concentrated solution.3. Taking ice nucleus active bacterium P.syringae as the experimental culture, using the method of immobilization by alginate, the P.syringae's embedding technology was established and applied to freeze-concentration experiment, from which it was found that adding ice nucleus bacterium and stirring at the same time could obtain the superior effect, the coring temperature can enhance about 1℃.4. The contrast experiment of suspension freeze-concentration method and the tradition vacuum evaporation concentration has been carried out, The research discovered that sugar juice quality obtained by the freeze-concentration method is better by analysising obtained syrup's each physics and chemistry target.This article about the research on sugar freeze-concentration technology is preliminary; it will be have certain reference value to the later further research.