Adu-Poku David, Saah Selina A, Agbenorhevi Jacob K
Department of Chemical Sciences, University of Energy and Natural Resources, Sunyani, Ghana.
Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Int J Food Sci. 2020 Nov 24;2020:1876463. doi: 10.1155/2020/1876463. eCollection 2020.
The diffusion of potassium in potato () at different leaching conditions was investigated. Two modes of pretreatment of potato samples (cubes and spheres) by preheating to 80°C and leaching at temperatures of 20-80°C were performed using a temperature- and agitation-controlled batch extractor. A Fickian model incorporating the effective diffusion coefficient ( ), partition coefficient () between the solute concentration in the potato and medium, and mass transfer coefficient (kl) was developed to simulate and predict the fraction of potassium leached from the potato at any temperature. Results showed significant reduction in activation energies from 92 to 25.02 kJ/mol for cubes and from 75.02 to 13.40 kJ/mol for spheres culminating in higher extraction rates when samples were preheated to 80°C. The , , and kl values obtained were in the range of 0.02 - 7.33 × 10 m/s, 0.63 - 8.00 × 10, and 0.01333.00 × 10 m/s, respectively. The kinetic parameters showed a change in slope or discontinuity in the gelatinization temperature range as a function of temperature, an indication of a change in the diffusional matrix. The optimum operating conditions were 80°C preheating and leaching at temperatures up to 50°C. The proposed mathematical model offered a satisfactory description of both dynamic and equilibrium mass transfers of potassium by adequately predicting the fraction of potassium from potato cubes and spheres. The present findings could be useful in the pretreatment of potato for renal patients.
研究了不同浸出条件下钾在马铃薯（）中的扩散情况。使用温度和搅拌可控的间歇式萃取器，对马铃薯样品（立方体和球体）进行了两种预处理方式：预热至80°C，并在20 - 80°C的温度下浸出。建立了一个包含有效扩散系数（）、马铃薯与介质中溶质浓度之间的分配系数（）以及传质系数（kl）的菲克模型，以模拟和预测在任何温度下从马铃薯中浸出的钾的比例。结果表明，立方体样品的活化能从92显著降低至25.02 kJ/mol，球体样品的活化能从75.02降低至13.40 kJ/mol，当样品预热至80°C时，最终浸出率更高。获得的、和kl值分别在0.02 - 7.33×10 m/s、0.63 - 8.00×10和0.01333.00×10 m/s范围内。动力学参数显示，在糊化温度范围内，斜率发生变化或出现不连续，这表明扩散基质发生了变化。最佳操作条件是预热至80°C，并在高达50°C的温度下浸出。所提出的数学模型通过充分预测马铃薯立方体和球体中钾的比例，对钾的动态和平衡传质提供了令人满意的描述。本研究结果可能对肾病患者马铃薯预处理有用。
