包装与食品机械
包裝與食品機械
포장여식품궤계
PACKAGING AND FOOD MACHINERY
2014年
1期
23-27
,共5页
南瓜%干燥模型%有效扩散系数%活化能
南瓜%榦燥模型%有效擴散繫數%活化能
남과%간조모형%유효확산계수%활화능
pumpkin%drying model%effective diffusivity%activation energy
研究南瓜片在不同温度（60℃、70℃和80℃）下的热风干燥特性。采用Fick扩散模型对南瓜片的水分质量传递进行描述，并计算水分扩散系数。结果表明，热风温度越高，干燥速率越快，干燥过程发生在降速阶段。水分扩散系数随温度的升高而增大，在试验温度范围内，有效扩散系数值在5．4150×10-10～1．0077×10-9 m2/s之间。温度对水分扩散的影响可用Arrhenius关系方程来表示，其决定系数为0．997。南瓜的活化能值为30．33kJ/mol。采用12种数学模型对南瓜片的薄层干燥过程进行描述，通过比较水分比的试验值和预测值之间的统计参数---决定系数（R2）、卡方（X2）和均方根误差（RMSE），发现Modified Henderson and Pabis模型最适宜于描述南瓜片的薄层干燥过程，该模型能较准确地表达和预测南瓜热风干燥过程的水分变化规律。
研究南瓜片在不同溫度（60℃、70℃和80℃）下的熱風榦燥特性。採用Fick擴散模型對南瓜片的水分質量傳遞進行描述，併計算水分擴散繫數。結果錶明，熱風溫度越高，榦燥速率越快，榦燥過程髮生在降速階段。水分擴散繫數隨溫度的升高而增大，在試驗溫度範圍內，有效擴散繫數值在5．4150×10-10～1．0077×10-9 m2/s之間。溫度對水分擴散的影響可用Arrhenius關繫方程來錶示，其決定繫數為0．997。南瓜的活化能值為30．33kJ/mol。採用12種數學模型對南瓜片的薄層榦燥過程進行描述，通過比較水分比的試驗值和預測值之間的統計參數---決定繫數（R2）、卡方（X2）和均方根誤差（RMSE），髮現Modified Henderson and Pabis模型最適宜于描述南瓜片的薄層榦燥過程，該模型能較準確地錶達和預測南瓜熱風榦燥過程的水分變化規律。
연구남과편재불동온도（60℃、70℃화80℃）하적열풍간조특성。채용Fick확산모형대남과편적수분질량전체진행묘술，병계산수분확산계수。결과표명，열풍온도월고，간조속솔월쾌，간조과정발생재강속계단。수분확산계수수온도적승고이증대，재시험온도범위내，유효확산계수치재5．4150×10-10～1．0077×10-9 m2/s지간。온도대수분확산적영향가용Arrhenius관계방정래표시，기결정계수위0．997。남과적활화능치위30．33kJ/mol。채용12충수학모형대남과편적박층간조과정진행묘술，통과비교수분비적시험치화예측치지간적통계삼수---결정계수（R2）、잡방（X2）화균방근오차（RMSE），발현Modified Henderson and Pabis모형최괄의우묘술남과편적박층간조과정，해모형능교준학지표체화예측남과열풍간조과정적수분변화규률。
Air-drying characteristics of pumpkin slices were investigated under air temperatures of 60℃, 70℃and 80 ℃.Moisture transfer from the test samples was described by applying the Fick’s diffusion model and the effective diffusivity was calculated.Results indicated that the drying rate increased with drying air tem-perature and drying took place in the falling rate period.The effective diffusivity was found to increase with the drying air temperature and ranged between 5.41 50 ×1 0 -10 ~1 .0077 ×1 0 -9m2/s.The effect of temperature on diffusivity could be expressed by an Arrhenius type relationship with a high R2 of 0.997.The activation energy of pumpkin was found to be 30.33 kJ/mol.Twelve mathematical models for describing the thin-layer drying process of pumpkin slices were investigated.The mathematical models compared according statistical parame-ters such as the coefficient of determination (R2 ),reduced chi-square (X2 )and root means square error (RMSE)between experimental and predicted moisture ratios.In conclusion,the Modified Henderson and Pabis model is the most suitable model for describing the thin layer drying process of pumpkin slices and could exact-ly describe and predict the moisture dynamics of pumpkin slices during hot air drying process.
