本論文探討在咖啡豆過程中的質傳行為，主要研究分為兩個部分，一是咖啡因萃取：對於部分人來說，咖啡的醇厚的風味及高度變化性，雖令人欲罷不能，卻因為攝入咖啡因導致心悸、緊張、頭痛……等作用，在這樣的市場需求下，去咖啡因製程因此產生，本篇論文提出半球體咖啡因萃取模型，探討一顆咖啡豆的咖啡因萃取現象，比現有的文獻更能簡單並精準描述萃取現象。並對實驗數據進行曲線擬合，探討咖啡豆微結構、咖啡因萃取、化學成分與活化能之間的關係。
第二部分是不同支咖啡豆所泡出的咖啡液在水中的擴散現象，我們將咖啡液滴入水中，記錄咖啡液半徑大小隨時間的關係，並探討咖啡液擴散與黏度的關係。

In this paper, caffeine extraction and coffee diffusion in water have been discussed.
For some people, caffeine can bring about unpleasant symptoms such as nervousness, headache, and palpitation. The decaffeination processes were therefore developed to remove caffeine and keep the flavors locked in the coffee beans simultaneously. The model of caffeine extraction for hemispherical beans was derived, and the data were curve fitted. Then the results of extraction of caffeine from green beans and roasted beans were discussed.
In the second part, the different roasted coffee beans were ground and brewed for experiments. The coffee was dripped in the center of flat disk which was filled with water to a depth of 0.5 cm. The fronts of three different kinds of coffee at different temperatures were plotted as functions of time, respectively. After these data were curve fitted, the Arrhenius plots of diffusivity could be obtained. The relation between diffusivity and viscosity of different coffee samples were compared and discussed.

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