真空冷冻干燥芒果片的工艺研究

目的]优化芒果片冷冻干燥的工艺条件。方法]差示扫描量热法测量芒果共晶点和共熔点,设计4因素3水平正交试验,按国标法测量的Vc含量为指标,并进行感官分析。结果]芒果片的共晶点为-16.59℃,共融点为-4.61℃。正交试验得到芒果片冻干的最佳工艺条件是切片厚度3mm,预冻时间3h,一次干燥温度-5℃,二次干燥温度30℃。在此最佳冻干工艺条件下,芒果片的Vc含量达到618.299mg/kg,明显高于热风干燥。冻干芒果片基本能保持原有的色泽、香味和形态。组织呈多孔海绵状,复水性能好。结论]芒果冻干工艺流程合理有效,最佳工艺条件下的冻干芒果片Vc含量高,感官评价优良。该工艺条件有较高的工业生产应用价值。

Study on Freeze Drying Technology of Mango Slice

Objective]The paper aimed to set up the optimal freeze drying technology of mango slice.Method]The freezing end temperature and the thawing end temperature were measured by differential scanning calerimetry.The orthogonal design experiment was of 4 factors and 3 levels.The indexes were the Vc content and the sensory evaluation.Result]The freezing end temperature of mango was-16.59 ℃ and the thawing end temperature was-4.61 ℃.The optimization technological parameters of mango slice freeze drying were gotten as follows the thickness was 3 mm,Pre-freezing time was 3h,primary drying temperature was-5 ℃ and the secondary drying temperature was 30 ℃.The Vc content was 618.299 mg/kg of dried mango slice under the optimization parameters which is more than that of convection heat drying.The color,flavor and shape of dried mango slice can be basically retained and the texture of which was porous spongy tissue.Conclusion] The freeze drying technique procedure of mango slice in this experiment was reasonable and effective.The Vc content of dried mango slice was high and the sensory evaluation was good under the optimization parameters,which was more than those of convection heat drying.The optimization technological parameters were suitable for industries.