| dc.description.abstract | Roasting is one of the important stages in coffee processing to forming its aroma and taste.
The purpose of this study was to determine the level of relationships between RGB value from sample
image with the RGB value from roasting degrees standard image and predict the duration of roasting
based on the similarity of RGB value between both samples and roasting degrees standard. The
samples of roasted coffee were taken in various temperature (195
o
C – 250
o
C). Images of those
samples were taken using CCD camera and IC Capture software. The images then were evaluated
using Sharp Develop program to obtain RGB values. There were very strong relationships between
RGB value Arabica samples with roasting degrees standard of roast temperature 205°C, 225°C,
250°C, either with robusta samples, at temperature 195°C, 200°C, 205°C , 225°C, 250°C and
275°C. Based on analysis, the G value produced the best relationship, so the formula to predict the
duration of roasting build with this value. Using linier regretion all of the duration to achieved
various roasting degrees of Arabica and robusta can be predicted at every roast temperature from
the lowest degrees (cinnamon roast) to highest degrees (Italian roast) at every roast temperature.
The Result were: Robusta 200°C (101.7 minutes, 158.2 minutes); Robusta 225°C (56.9 minutes, 85.2
minutes); Robusta 250°C (30.2 minutes, 41.3 minutes); Arabica 205°C (31.6 minutes, 44.7 minutes);
Arabica 225°C (20.7 minutes, 28.9 minutes); and Arabica 250°C (21 minutes, 29.6 minutes). | en_US |
