PENENTUAN LAMA SANGRAI KOPI BERDASARKAN VARIASI DERAJAT SANGRAI MENGGUNAKAN MODEL WARNA RGB PADA PENGOLAHAN CITRA DIGITAL (DIGITAL IMAGE PROCESSING)
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 (195oC – 250oC). 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).
Penulis: Bambang Marhaenanto
Kode Jurnal: jppertaniandd151042
