摘要
为了探讨黑毛茶的陈化及成品茶的安全贮存特性,本研究通过静态称质量法测定了湖南黑毛茶在20、30、40℃,水分活度为0.010 3~0.981 8条件下的吸湿特性,建立不同温度下黑毛茶的吸湿曲面响应模型及等温吸湿曲线;对等温吸湿曲线进行了非线性回归拟合,并在温度25℃和相对湿度85%、87%、90%的条件下进行模拟仓储。结果显示:湖南黑毛茶等温吸湿曲线为Ⅱ类曲线,不同温度(20、30、40℃)条件下,黑毛茶吸湿平衡时间随着温度的升高而缩短,分别为14、10、6 d,并随着温度的升高而呈现平衡含水率降低的规律;3个温度条件下黑毛茶的曲面响应模型呈现一定的规律特性,GAB及Osiwin模型较优地拟合了黑毛茶的等温吸湿曲线,特定条件下模拟仓储10 d,相对湿度85%的条件下未见生霉现象,相对湿度87%的条件下出现局部霉变,相对湿度90%的条件下霉变严重。
The aim of this paper was to discuss the aging characteristics of raw dark tea and the safety of dark tea during storage.The moisture absorption characteristics of Hunan raw dark tea at 20,30 or 40℃over the water activity range of 0.010 3–0.981 8 were evaluated using the static gravimetric method and response surface models were developed.Moisture absorption isotherm curves were plotted and fitted to a nonlinear model.Furthermore,the mildew degree was examined during storage under simulated storehouse conditions:25℃and 85%,87%or 90%relative humidity.The results showed that the moisture absorption isotherms of raw dark tea exhibited the characteristics of a type II isotherm and the equilibrium time(14,10 and 6 days)was shortened with increasing temperature(20,30 and 40℃).Equilibrium moisture content was reduced with increasing temperature.The response surface models at all three temperatures showed regular patterns.Among 8 classical mathematical models,GAB and Oswin models were the best ones to describe the isothermal moisture absorption process.During 10 days of storage under simulated storehouse conditions,the dark tea did not mildew at 85%relative humidity(RH),mildewed partially at 87%RH,and mildewed seriously at 90%RH.
作者
胥伟
赵仁亮
姜依何
吴丹
朱旗
XU Wei;ZHAO Renliang;JIANG Yihe;WU Dan;ZHU Qi(Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients,National Research Center of Engineering Technology for Utilization Ingredients from Botanicals,Key Laboratory of Tea Science,Ministry of Education,Hunan Agricultural University,Changsha 410128,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2018年第7期27-32,共6页
Food Science
基金
国家自然科学基金面上项目(31571802)
湖南省教育厅重点项目(14A066)
湖南省研究生科研创新项目(CX2016B283)
关键词
黑毛茶
等温吸湿曲线
霉变安全
模型拟合
raw dark tea
moisture absorption isotherms
mildew degree
model fitting
