龙眼果肉微波真空薄层干燥数学模型研究

刘永富 谭安林 潘小莉 韦向成

摘要 为获得龙眼果肉的微波真空干燥特性，研究了固定真空度下不同微波强度对龙眼薄层干燥水分的影响。采用8个常用薄层干燥数学模型，建立了龙眼干燥水分比和时间的动力学模型。结果表明：微波强度是影响干燥过程的主要因素;分别对8种数学模型进行非线性回归分析，并确定模型参数，发现Page模型拟合效果最佳，能准确预测龙眼果肉干燥水分的变化规律。干燥过程大致分为升速、恒速和降速阶段;当微波强度较低时干燥过程由升速和恒速阶段控制;当微波强度较高时，干燥过程由降速阶段控制。

关键词 龙眼;微波真空;干燥特性;数学模型

中图分类号 TS255  文献标识码 A

文章编号 0517-6611（2021）04-0182-04

doi：10.3969/j.issn.0517-6611.2021.04.050

Study on the Mathematical Model of Microwave Vacuum Thin Layer Drying of Longan Pulp

LIU Yong-fu1，TAN An-lin2，PAN Xiao-li1 et al （1.Yulin Normal University，Yulin，Guangxi  537000;2.Yulin Institute of Inspection and Testing，Yulin，Guangxi  537000）

Abstract In order to obtain the microwave vacuum drying characteristics of longan pulp，the effects of different microwave intensities on thin layer drying moisture of longan at fixed vacuum degree were studied.Eight commonly-used thin-layer drying models were used to establish the dynamic model of the drying water ratio of longan and time.The results showed that the microwave intensity was the main factor affecting the drying process.The experimental data were used to make the nonlinear regression analysis on eight mathematical models，and the coefficients of models were determined.The results showed that Page model had the best fitting effect，and it could accurately predict the change rules of drying moisture in longan pulp.The drying process of longan pulp involved three stages：acceleration phase，constant-rate phase and deceleration phase.When the microwave power was low，the drying process was controlled by acceleration phase and constant-rate phase.When the microwave power was high，the drying process was controlled by deceleration phase.

Key words Longan;Microwave vacuum;Drying characteristics;Mathematical model

基金項目

国家自然科学基金地区科学基金项目（31960478）;玉林师范学院高层次人才科研启动基金项目（G2018003）;2018年度玉林师范学院校级科研项目（2018YJKY31）。

作者简介 刘永富（1978—），男，黑龙江哈尔滨人，讲师，硕士，从事机电一体化研究。通信作者，副教授，博士，从事农业机械化工程研究。

收稿日期 2020-07-14

龙眼是广西特色水果之一，因其兼具药用和食用价值而备受人们的喜爱，具有“果中圣品”“南方人参”等美誉[1]。因为收获季节为高温多雨的季节，龙眼多汁且含糖量高，不耐储藏，常采用干制法来延长产品的储藏期。《本草纲目》记载：“资益以龙眼为良”，研究表明龙眼具有抗氧化、抗焦虑、抗肿瘤、提高免疫力和改善睡眠等功效[2-4]。龙眼干制法由传统日晒、热风干燥向新型干燥或组合法转变，例如红外、微波、真空微波、冷冻干燥或几种方法组合干燥，许多学者对此进行了深入研究，并取得了显著成果[5-11]。……