玛咖切片的微波真空干燥特性及品质特征

为缩短玛咖切片干燥时间,提升干制品品质,实验采用微波真空干燥技术对玛咖切片进行脱水处理,研究了其在不同干燥条件下的干燥及品质特征;通过逐步回归分析构建了干制品品质与干燥条件之间的数学模型;利用加权综合评价对不同条件下玛咖微波真空干燥过程进行对比研究。结果表明:微波密度对干燥速率及产品品质的影响更为显著(p0.05);Weibull分布函数能够高精度描述(R~20.99)玛咖切片微波真空干燥过程中水分比随时间的变化规律;玛咖切片微波真空干燥有效水分扩散系数在2.98×10~(-12)～5.08×10~(-12)m~2/s之间,且有效水分扩散系数受微波密度影响更明显;逐步回归分析能够准确构建(R~20.99)玛咖切片干制品品质与干燥条件之间的数学模型;当微波密度和干燥压强分别为1.5 W/g和300 Pa时,玛咖微波真空干燥过程综合评分值最高,该条件最适合应用于玛咖切片微波真空干燥。

Microwave Vacuum Drying Characteristics and Quality of Maca Slices (Lepidium meyenii)

In order to shorten the drying process of maca slices and improve the quality of dried products, microwave vacuum drying technology was used to dehydrate maca slices. The drying characteristics and quality of maca slices obtained under different drying conditions were studied. Mathematical models were established to predict the relationship between the dry product quality and drying conditions of maca slices by stepwise regression. Comparisons were made on the microwave vacuum drying processes of maca under different conditions by weighted comprehensive evaluation. The results showed that the effect of microwave power density on the drying rate and product quality was more significant (p < 0.05). The Weibull distribution function can describe the changing pattern of moisture ratio in maca slices as a function of time during microwave vacuum drying with high accuracy (R2 > 0.99). The effective moisture diffusion coefficients of maca slices subjected to microwave vacuum drying ranged from 2.98×10-12 to 5.08 ×10-12 m2/s, and were influenced more remarkably by the microwave density. Stepwise regression analysis can accurately build a mathematical model between the dry product quality and drying condition of maca slices (R2 > 0.99). The maca slices gained the highest comprehensive assessment score when the microwave power density and drying pressure were 1.5 W/g and 300 Pa, respectively. Thus, among the selected conditions for drying, such a condition was the most suitable for microwave vacuum drying of maca slices.