真空冷冻—热风联合干燥对甘肃紫斑牡丹品质的影响

The effect of vacuum freezing-hot air combined drying on the quality of purple-spotted peony in Gansu

目的:揭示干燥工艺对甘肃紫斑牡丹花冠茶品质的影响。方法:采用真空冷冻热风联合干燥(FHCD)、变温热风干燥(VHD)和真空冷冻干燥(VFD)对紫斑牡丹鲜花进行干燥,测定3种干燥工艺下紫斑牡丹花冠茶的活性成分(花青素含量)和质量属性(水分含量、皱缩率和复水性),结合干燥工艺的能量消耗和紫斑牡丹花冠茶的感官特性(外观、茶色、口味等)对3种干燥工艺进行比较。结果:3种干燥工艺下的紫斑牡丹花冠茶花青素含量分别为8.63%,4.68%,12.26%,复水性分别为491.52%,433.28%,531.75%。与VHD相比,FHCD的紫斑牡丹花冠茶花青素含量增加了3.95%、复水性增加了58.24%、皱缩率减小了13.82%;与VFD相比,FHCD的效率提高了1倍,且能耗降低了51.79%。花冠茶的花青素含量与复水性和含水量呈显著正相关,相关系数分别为0.741和0.738。花冠茶的颜色与花青素含量有关,花青素含量规律为玫红色花冠茶>粉色花冠茶>白色花冠茶。结论:FHCD的紫斑牡丹花冠茶优质、高效、节能,其花冠茶花青素含量、水分含量、皱缩率和复水性分别为8.63%,9.46%,52.85%,492.40%。

Objective:To reveal the effect of drying processes on the quality of Gansu purple-spoted peonycorolla tea,and to explain the drying mechanism of different drying processes.Methods:Vacuum freezing-hot air combined drying(FHCD),variable temperature hot air drying(VHD)and vacuum freeze drying(VFD)were used to dry the flowers of peony.The active ingredient(anthocyanin content)and quality attributes(moisture content,shrinkage rate and rehydration)of the purple-spotted peony corolla tea processed by three drying processes were determined,and the energy consumption of the drying processes and sensory characteristics(appearance,tea color,taste,etc.)of corolla tea were compared with three drying processes.Results:the anthocyanin content of the purple-spotted peony corolla tea processed by the above three drying processes were 8.63%,4.68% and 12.26%,and the rehydration of them were 491.52%,433.28% and 531.75%,respectively.Compared with VHD,anthocyanin content of the purple-spot peony corolla tea processed by FHCD increased by 3.95%,rehydration of it increased by 58.24%,and shrinkage of it reduced by 13.82%;Compared with VFD,the efficiency of FHCD process doubled,and it's energy consumption reduced by 51.79%.The anthocyanin content of corolla tea was significantly positively correlated with shrinkage rate,rehydration and water content,and the correlation coefficients were 0.749,0.741 and 0.738,respectively.The color of purple-spotted peony was related to the anthocyanin content.The anthocyanin content rule was:rose red corolla tea>pink corolla tea>white corolla tea.Conclusion:The purple-spot peony corolla tea processed by FHCD has high quality,high efficiency and energy saving.The anthocyanin content,moisture content,shrinkage rate and rehydration rate of corolla tea processed by this process were 8.63%,9.46%,52.85% and 492.40%,respectively.The test results provide a reference for improving the comprehensive quality and drying process of purple-spotted peony corolla tea.