Quality Evaluation And Evaporation Characteristics In The Process Of Concentrating Pineapple Juice

In the paper, the dimpled vertical plate falling film evaporator was applied to concentrate and condense the heat sensitive pineapple juice. The kinetics of Vitaminc loss in the concentration process of pineapple juice was studied. And then based on the former, the quality evaluation criterion for concentration process of food liquid was established. The kinetic model of Vitaminc loss was both tested in evaporation and concentration process. The results indicated that the predicted values from the model pineapple juice concentration agree very well with the experimental data. In addition, the evaporation characteristics of dimpled vertical plate falling film evaporation was studied either. And then, the heat transfer model was put forward and the numerical value of which value accorded with the experimental data well. At the same time, the parameters such as evaporation temperature,temperature difference,liquid flux and liquid thickness were changed to analyze and study the hydrodynamics and heat transfer properties of the equipment under different operational conditions.The study indicates that Because the dimpled vertical plate falling film evaporator could enhance heat transfer, prevent and clean fouls and be operated at lower temperature difference, it was fit for the evaporation of heat sensitive foodstuff. So, it is feasible to be introduced in industry production, especially in food field.