Study of Physical Properties of Post-Steaming Robusta Coffee Beans in Closed Steaming
Sapto Kuncoro, Lilik Sutiarso, Joko Nugroho, and Rudiati Evi Masithoh
University of Lampung
Abstract
This study aims to examine the relationship between temperature and length of steaming of coffee beans using a closed system method to change the physical properties of seeds such as moisture content, development of volume, color and hardness. The experiment was conducted using 750 g of each Robusta coffee beans are separately steamed in an autoclave (closed system) at temperatures of 100, 110 and 120 oC for 1, 2, 3, 4, 5, 6 and 7 hours, respectively. Changes in the physical properties of seeds after steaming were analyzed using the Avrami equation model with the Microsoft Excel program. From the results of this study it was found that the higher the temperature and the longer the steamed coffee beans can increase the volume of coffee beans and water content contained, and the degradation of the color of coffee beans that are getting darker. The opposite decreases the hardness of steamed coffee beans produced. The color of the coffee beans darkens is marked by a decrease in the average value of lightness (L) from 25.32 to 10.8.
Keywords: volume increase, color, hardness, Robusta coffee, Avrami equation
Topic: Other Agricultural and biosystems topic