[關鍵詞]
[摘要]
目的 建立防己Stephaniae Tetrandrae Radix趁鮮切制熱風干燥的干燥動力學模型,測定其干燥特性參數(shù),研究其干燥過程中的成分變化規(guī)律,為闡明防己趁鮮切制熱風干燥機制及干燥工藝提供參考依據(jù)。方法 在60、70、80 ℃條件下建立防己趁鮮切制干燥過程中的干燥動力學模型,基于低場核磁共振技術研究防己干燥過程中的水分相態(tài),根據(jù)Fick擴散定律和Arrhenius方程計算出有效擴散系數(shù)(effective diffusion coefficient,Deff)和活化能(activation energy,Ea),采用HPLC法對防己干燥過程中指標成分粉防己堿和防己諾林堿的質(zhì)量分數(shù)進行動態(tài)監(jiān)測。結果 Page模型(MR=e−ktn,MR為水分比,k,n為模型參數(shù))可以準確地描述防己干燥過程中水分含量的變化,溫度越高,水分散失越快,模型中的參數(shù)k隨著溫度的升高而增大,參數(shù)n隨著溫度的升高而減?。?0、70、80℃熱風干燥條件下的Deff分別為8.13×10−7、9.97×10−7、1.04×10−6 m2/s,Deff隨著溫度的升高而增大;防己趁鮮切制熱風干燥的Ea為12.51 kJ/mol。橫向弛豫時間(T2)圖譜顯示,4 h之前水分相態(tài)發(fā)生顯著變化,自由水比例大幅下降,水的自由度逐漸降低;4 h之后水分含量和相態(tài)無明顯變化。防己在趁鮮切制干燥過程中,粉防己堿和防己諾林堿總含量無明顯波動。結論 采用干燥動力學模型和低場核磁共振技術可以直觀地描述防己趁鮮切制干燥過程中的水分變化規(guī)律;為闡明防己趁鮮切制干燥機制和干燥工藝提供參考。
[Key word]
[Abstract]
Objective To establish the drying kinetic model of Fangji (Stephaniae Tetrandrae Radix, STR) fresh-cut hot air drying, determine its drying characteristic parameters, and study the variation of its components during the drying process, so as to provide a reference for elucidating the drying mechanism of STR fresh-cut and optimizing the drying process. Methods The drying kinetics model of STR during fresh-cut drying was established at 60, 70, 80 ℃. The water phase in the drying process of STR was studied based on low-field nuclear magnetic resonance technology. The effective diffusion coefficient (Deff) and activation energy (Ea) were calculated according to Fick’s diffusion law and Arrhenius equation. The mass fraction of tetrandrine and fangchinoline in the drying process of STR was investigated by HPLC for dynamic monitoring. Results The Page model (MR = e−ktn, MR is water ratio, k, n are model parameters) could accurately describe the change of moisture content in the drying process of STR. The higher the temperature, the faster the moisture loss. The k in the model increased with the increase of temperature, and the n decreased with the increase of temperature. Deff were 8.13×10−7, 9.97×10−7, 1.04×10−6 m2/s at 60, 70, 80 ℃, and the effective diffusion coefficient increases with the increase of temperature. The Ea value was 12.51 kJ/mol. The T2 spectrum showed that the water phase changed significantly before 4 h, the proportion of free water decreased significantly, and the degree of freedom of water decreased gradually. There was no significant change in water content and phase state after 4 h. In the process of fresh-cut drying, the total content of tetrandrine and fangchinoline had no obvious fluctuation. Conclusion The drying kinetics model and low field nuclear magnetic resonance technology can intuitively describe the moisture change law of STR during fresh-cut drying process. It provides a reference for elucidating the drying mechanism and drying process optimization of STR fresh-cut.
[中圖分類號]
R283.6
[基金項目]
國家自然科學基金項目(82060724);國家自然科學基金項目(82460772);省重點研發(fā)計劃項目(20243BBI91015);江西省中醫(yī)藥標準化項目(2023A19);江西省高水平本科教學團隊(2252201013);校級虛擬教研室(2252300109)