摘要
该文研究了恒定湿度(10%、30%、50%)和阶段湿度(30%、50%保持20、30 min后降为10%)条件下的干燥动力学曲线,并结合Weibull函数进行分析;采用扫描电子显微镜和GC-MS分析花椒果皮微观结构和挥发油成分。结果表明,干燥存在恒速阶段,降低湿度能显著提高干燥速率,缩短干燥时间;干燥前期高湿有利于物料内部升温,湿度50%保持20 min后恒定10%所需干燥时间最短(206 min);Weibull函数能很好地描述各湿度条件的干燥过程,降低湿度可使尺度参数α值减小,对形状参数β的影响较小,估算水分扩散系数变化范围为1.30×10^(-7)~2.47×10^(-7)m^(2)/min;高湿干燥时间过长易使花椒果皮颜色褐变、破坏油苞结构,50%保持30 min后降湿(10%)干燥的花椒果皮硬化,出水孔隙出现收缩;大红袍花椒挥发油中鉴定出67种化学成分,其中D-柠檬烯含量最高(13.84%)。综上,合理的湿度控制策略能有效提升大红袍花椒热风干燥速率和品质,为后续研究花椒干燥过程中相对湿度的调控提供基础。
Taking Dahongpao Zanthoxylum bungeanum Maxim.(DZBM) as the study object,the hot air drying characteristics and quality were investigated under constant relative humidity(RH) and the step-down RH drying method.The drying kinetic curves under the conditions of constant humidity(10%,30%,50%) and the step-down RH(30%,50% kept for 20,30 min and then decreased to 10%) were studied and analyzed in combination with the Weibull function.Scanning electron microscope(SEM) and gas chromatography-mass spectrometry(GC-MS) were used to analyze the microstructure and volatile oil components of the DZBM epidermis.Results showed that there was a constant rate stage in drying.Reducing humidity could significantly increase the drying rate and shorten the drying time,high humidity hot air was beneficial to the internal warming of materials in the drying early stage.When RH 50% was held for 20 min and then decreased to 10%,the drying time was the shortest(206 min).The Weibull function could well describe the drying process under various humidity conditions,and reducing humidity reduces the scale parameters and has less effect on the shape parameters.It was estimated that the variation range of the moisture diffusion coefficient was 1.30×10^(-7)-2.47×10^(-7) m^(2)/min.The skin color of DZBM could be browning and the structure of the oil bud could be destroyed if the drying time was too long under high humidity conditions.When RH 50% was held for 30 min and then decreased to 10%,the skin of DZBM would harden and the pore of water would shrink.67 chemical constituents were identified from the volatile oil of DZBM,in which the content of D-limonene was the highest(13.84%).The rational humidity control strategy can effectively enhance the hot-air drying rate and quality of DZBM,and the results provide a basis for subsequent studies on the regulation of relative humidity during the drying process of Zanthoxylum bungeanum Maxim.
作者
薛韩玲
廖帮海
拓雯
陆泽华
王楠
牛婷婷
XUE Hanling;LIAO Banghai;TUO Wen;LU Zehua;WANG Nan;NIU Tingting(College of Energy and Engineering,Xi′an University of Science and Technology,Xi′an 710000,China;School of Architecture and Civil Engineering,Xi′an University of Science and Technology,Xi′an 710000,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2023年第22期149-155,共7页
Food and Fermentation Industries
基金
陕西省重点研发项目(2019NY-166)。
关键词
湿度
花椒
热风干燥
Weibull函数
微观结构
挥发油
humidity
Zanthoxylum bungeanum Maxim.
hot air drying
Weibull function
microstructure
volatile oil
