组合干燥方式下胡萝卜真空脉动蒸汽烫漂工艺优化

Optimization of carrot vacuum pulsating steam blanching process under combined drying method

为探究新型的果蔬干燥前预处理工艺,提高干燥速率和干燥产品品质,采用真空脉动蒸汽烫漂预处理工艺,在热风真空组合干燥方式下对胡萝卜切片进行试验研究。分别进行蒸汽烫漂单因素试验和四元二次回归正交试验,通过响应面法分析烫漂温度、烫漂真空度、烫漂时间和循环次数与样品维生素(V_(C))含量、复水比、色差的关系,建立相应的数学模型,并对真空脉动蒸汽烫漂工艺参数进行优化。结果表明,烫漂强度的增加会对胡萝卜干制品中的V_(C)造成一定的破坏,但却有利于复水。对工艺进行优化后,得到的最优参数为烫漂温度110℃,烫漂真空度0.08 MPa,烫漂时间3 min,循环次数2次。研究结果可为真空脉动蒸汽烫漂预处理技术在果蔬干燥中的应用提供借鉴。

In order to improve the drying rate and the quality of dried products,a new pretreatment process of fruits and vegetables before drying was explored.The new pretreatment process of vacuum pulsating steam blanching was applied on carrot slices under the hot-air vacuum combined drying method.Single factor experiments and regression orthogonal test were carried out.The relationship among blanching vacuum degree,blanching temperature,blanching time and cycle times with vitamin C(V_(C))content,rehydration ratio and color difference of carrot was analyzed by response surface methodology,corresponding mathematical models were established,and the parameters for vacuum pulsating steam blanching were optimized.The results showed that the increase of blanching intensity would damage V_(C) to some extent,but it was beneficial for the rehydration ratio of dried carrot products.The optimized parameters for carrot vacuum pulsating steam blanching were as follows:blanching temperature of 110℃,blanching vacuum degree of 0.08 MPa,blanching time of 3 min,and cycle times of 2 times.The research results could provide reference for the application of vacuum pulsating steam blanching as pretreatment technology in fruit and vegetable drying.