Dekafeinasi kopi robusta dengan pelarut air pada berbagai suhu dan pH

RUSMANTRI, Dr.Ir. Sri Anggrahini, MS

2002 | Tesis | S2 Teknologi Hasil Perkebunan

Kopi Robusta mengandung kafein yang tinggi, hampir dua kali lipat diban ding yang ada dalam kopi Arabika. Kafein selain dapat menyegarkan syaraf sentral, menaikkan aliran darah diduga dapat menyebabkan penyakit jantung, tekanan darah tinggi,kanker, memperpendek umur, keguguran dll. Untuk mengurangi kekhawatiran tersebut, dilakukan penelitian penurunan kadar kafein dalam kopi yang disebut proses dekafeinasi. Penelitian dilakukan dengan cara memanaskan kopi biji pada suhu 70, 80, 90,100 “C dan pH 7,O; 8,O; 9,O;selama 15 menit; perbandingan kopi dan air 1: 7. Setelah pemanasan, air bekas pemanasan dipisahkan, kopi biji dicuci, lalu ditiriskan, kemudian dijemur selama 7 hari. Kopi biji kering disangrai, lalu digiling dan diayak dalam ayakan 75 mesh. Kopi bubuk dekafeinasi yang dihasilkan diuji kadar kafein, asam khlorogenat, trigonelin, profil aroma, nilai sensoris (aroma, cita-rasa, bodi), protein, lemak, karbohidrat abu,dan kadar air. Selain itu dihitung prosentase kopi biji yang “tumbuh”. Hasil penelitian menunjukkan perlakuan suhu 100 “C dan pH 8,O menghasilkan penurunan kadar kafein paling besar sebanyak 70,1% atau kadar kafein dalam kopi bubuk sebesar 0,60 YO. Pada uji profil aroma senyawa volatil tertinggi berupa 2-furan methanol (40,99%), dan nilai uji sensoris aroma 6,67; cita-rasa 6,67; bodi 7,50; namun seduhan kopi berasa “dirty - somewhat flat” (hambar). Berdasarkan hasil uji kesukaan perlakuan terbaik pemanasan pada suhu 70 “C dan pH 8,O dengan penurunan kadar kafein sebesar 60,7% atau kadar kafein dalam kopi bubuk sebesar 0,79%; nilai uji sensoris aroma 6,33; cita-rasa 6,33; dan bodi 6,83; dan seduhan kopi berasa “clean” (baik).

Caffeine content of Robusta coffee is almost as twice of Arabica coffee. The except caffeine cause the brain to be fresh, warm body , it is suspected to cause heart attacks, hipertency, pancreatic cancer, and that it shortens life etc. For decreasing caffeine content is used a processlit’s called Decafeination proces. This research was done by heating Robusta coffee bean at temperature 70, 80, 90, and 100 O C and pH 7.0; 8.0; and 9.0, using ratio I : 7 for the coffee bean-water. It’s tooks 15 minutes for this heating. Decafeinated coffee bean are washed and dried by sun drying for sevent days. Afterthat, it was roasted for 10 minutes at temperature 175-1 80 OC, grinded, and screened through 75 mesh screening. The decaffeinated coffee powder were analysed caffeine content, chlorogenic acid, trigonelline, aroma profile, organoleptic test, protein, fat, carbohydrate, ash, and water content. Beside that, it was calculated coffee bean has been “growing”. The result of this study indicated that the heating treatment at temperature 100 OC pH 8.0 to cause a decreasing caffeine content up to 70.3% or caffeine content in powder coffee is 0.60 %. At the profile aroma test showed 40,99 % as highest substance 2-furan methanol and sensory value test 6.67 aroma, 6.67 flavour, 7.50 body but coffee brewed is dirty-somewhat flat. Based on Hedonic scale score the best result is, the heating on 70 O C and pH 8.0 which can decrease caffeine content up to 60.7 % or caffeine content in powder coffee 0,79 %, with sensory test value 6.33 aroma, 6.33 flavour, 6.83 body. The panelist comment, coffee brewed clean.

Kata Kunci : Pengolahan Hasil Perkebunan,Kopi Robusta,Dekafeinasi