茯苓采后不同预处理方式对其品质及干燥特性的影响  

Effects of different pretreatment methods on quality and drying characteristics of Poria cocos after harvest

作　　者：张平[1,2] 郑志安[1,2] 江庆伍[3] Zhang Ping;Zheng Zhian;Jiang Qingwu(College of Engineering,China Agricultural University,Beijing 100083,China;China Research Center for Agricultural Mechanization Development,China Agricultural University,Beijing 100083,China;Anhui Jinzhai Qiaokang Yao Ye Co.,Ltd,Liu’an 237000,China)

机构地区：[1]中国农业大学工学院,北京100083 [2]中国农业大学中国农业机械化发展研究中心,北京100083 [3]安徽金寨乔康药业有限公司,六安237000

出　　处：《农业工程学报》2018年第20期294-304,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：现代农业产业技术体系建设专项资金资助(CARS-21)

摘　　要：为进一步优化茯苓加工工艺,降低茯苓品质劣变风险,该文以传统"发汗"、水蒸气蒸制、鲜茯苓直接切制(无预处理)处理的茯苓为研究对象,对不同预处理方式下的茯苓品质、干燥动力学展开了系统研究。结果表明:1)预处理方式是影响茯苓品质的重要因素。(1)传统"发汗"处理茯苓的水溶性多糖质量分数是鲜茯苓直接切制的1.5倍、水蒸气蒸制的1.7倍,水蒸气蒸制处理茯苓的水溶性多糖质量分数显著低于鲜茯苓直接切制。(2)传统"发汗"处理茯苓的三萜质量分数显著低于鲜茯苓直接切制及水蒸气蒸制,水蒸气蒸制与鲜茯苓直接切制间无显著差异;通过适当控制"发汗"时间、"发汗"温度,可保持茯苓三萜含量不发生显著降低。(3)受传统"发汗"过程中物质迁移积累现象的影响,传统"发汗"处理茯苓的成品显著变白,色泽改善;水蒸气蒸制处理茯苓的成品显著变黄、变红,色泽变差。2)预处理方式是影响茯苓干燥特性的重要因素。与鲜茯苓直接切制相比,茯苓经传统"发汗"、水蒸气蒸制处理后,物料组织状态(硬度、孔隙率等)、化学成分(含量等)发生改变,从而使得毕渥数Bi显著增大(表明干燥过程中物料内部导热热阻的作用增大),形状参数β在0.3～1的区间内显著减小(表明干燥过程始终为内部水分扩散控制),有效水分扩散系数与传质系数显著增加,最终表现为干燥速率升高,干燥时间缩短。水蒸气蒸制处理在提升干燥速率方面的效果更优。研究结果可为进一步优化茯苓加工工艺,降低品质劣变风险,研究不同预处理方式对茯苓品质形成及干燥动力学变化的作用机理,研究中药材发汗的机理与作用机制,促进中药材产地初加工的规范化提供试验参考与依据。In order to optimize the drying process and to make the quality of Poria cocos under control,in this study,the traditionally sweated,steamed,and directly peeled and cut Poria cocos(without pretreatments)were evaluated through quality and drying kinetics to examine the relevance between pretreatments and the quality of Poria cocos and drying.Results showed that:1)pretreatments played a dominant role in the quality control of Poria cocos.①By comparing the mass fraction of water-soluble polysaccharides,Poria cocos after traditional sweating were 1.5 times higher than those without pretreatment and 1.7 times higher than those after steaming.The mass fraction of water-soluble polysaccharides of Poria cocos after steaming was significantly lower than that of those without pretreatment.②The mass fraction of triterpenes of Poria cocos after traditional sweating was significantly lower than that of those after other two pretreatments.No statistical difference was found between steaming and no pretreatment.By controlling the sweating time and sweating temperature to maintain the mass fraction of tritrpenes.③Because of the material migration and accumulation during traditional sweating,Poria cocos after traditional sweating were whiter with better lustre compared with those after steaming(turned yellow and red).2)Pretreatments is the key factor to affect the drying process.Compared with those with no pretreatment,Poria cocos after traditional sweating and steaming has a different the structure of material(hardness and porosity)and chemical composition(content),which made Bi significantly increased(indicating the increase of heat resistance within the material during the drying process).The shape parameterβwas significantly reduced in the range of 0.3-1(indicating that the drying process was always controlled by the internal water diffusion).The effective water diffusivity and mass transfer coefficient increased significantly,the drying rate increased and the drying time shortened.The steaming pretreatment is more eff

关 键 词：干燥 水分 品质控制 传统发汗 水蒸气蒸制 直接切制 茯苓 

分 类 号：S567.32[农业科学—中草药栽培] TS959.9[农业科学—作物学]