正交试验优化蜜柚真空冷冻干燥工艺

Optimization of Vacuum Freeze-drying Process of Honey Pomelo by Orthogonal Test

利用正交试验对蜜柚真空冷冻干燥工艺参数进行优化。研究预冻温度、升华干燥温度、解吸干燥温度对蜜柚含水率、色差、复水性及干燥速率的影响;采用综合评分法对这4个指标数据进行归一化处理并计算,确定干燥工艺的最佳参数组合。结果表明:预冻温度和解吸干燥温度对干燥综合效果影响显著,升华干燥温度对干燥综合效果影响不显著;3个因素对干燥综合效果影响的主次顺序为预冻温度>解吸干燥温度>升华干燥温度;最佳工艺参数组合为预冻温度-25℃、升华干燥温度50℃、解吸干燥温度60℃,在此条件下,产品含水率为1.62%、总色差值为11.73、复水比为4.29、干燥速率为5.90%/h。该研究结果可为蜜柚的实际生产提供一定的参考。

The orthogonal test was employed to optimize the parameters of vacuum freeze-drying of honey pomelo.The effects of pre-freezing temperature,sublimation drying temperature,and desorption drying temperature on the moisture content,color difference,rehydration property,and drying rate of honey pomelo were studied.Comprehensive scoring method was used to normalize the four indexes and determine the best combination of parameters for the drying process.The results showed that pre-freezing temperature and desorption drying temperature had significant effects on the comprehensive drying effect,while the sublimation drying temperature had no significant effect.The effects of the three factors on the comprehensive drying performance followed the order of pre-freezing temperature>desorption drying temperature>sublimation drying temperature.The optimal combination was pre-freezing at-25℃,sublimation drying at 50℃,and desorption drying at 60℃.The product dried under these conditions had the moisture content of 1.62%,the total color difference of 11.73,the rehydration ratio of 4.29,and the drying rate of 5.90%/h.The research results can provide a reference for the practical production of honey pomelo.