Electronic Theses and Dissertation

Penelitian ini bertujuan untuk mengetahui pengaruh lima metode pengolahan kopi (fullwash, semiwash, natural, honey, dan wine) terhadap komposisi kimia, kandungan asam organik biji kopi, dan senyawa volatil pada kopi sangrai. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) non faktorial satu faktor dengan tiga kali ulangan. Parameter yang dianalisis meliputi kadar air, abu, lemak, protein, dan karbohidrat pada biji kopi dan bubuk kopi. Analisis statistik dilakukan dengan menggunakan ANOVA dan dilanjutkan dengan uji DMRT. Senyawa volatil dalam kopi sangrai diidentifikasi menggunakan GC-MS, sedangkan asam organik dalam biji kopi dianalisis menggunakan LC-MS/MS QTOF. Kadar air biji kopi berkisar antara 7,83%-11,3%, kadar abu 3,91%-5,71%, kadar lemak 13,59%-17,57%, kadar protein 3,5%-14,2%, dan karbohidrat 57,30%-67,31%. Kadar air bubuk kopi berkisar antara 2,67%-3,34%, kadar abu 3,66%-4,78%, kadar lemak 11,27%-15,77%, kadar protein 3,18%-14,24%, dan karbohidrat 68,20%-78,03%, hasil penelitian ini telah memenuhi Standar Nasional Indonesia (SNI). Analisis GC-MS mengidentifikasi tujuh kelas senyawa volatil, dengan ester asam lemak sebagai komponen dominan dalam semua metode pengolahan. LC-MS/MS QTOF mengungkapkan adanya chlorogenic acid pada metode honey dan wine, phenylpropionic acid pada metode fullwash, dan indoleacrylic acid pada metode semiwash, madu, dan wine.
Kata kunci: Kopi Arabika Gayo, pengolahan pasca panen, komposisi kimia, green bean, GC-MS, LC-MS/MS QTOF

Abstract. This study aimed to find out the effect of five coffee processing methods (fullwash, semiwash, natural, honey, and wine) on the chemical composition, organic acid content of green beans, and volatile compounds in roasted coffee. This study used a one-factor non factorial Randomized Group Design (RCD) and three replications. Parameters analyzed included moisture, ash, fat, protein, and carbohydrate content in green bean and coffee powder. Statistical analysis was conducted using ANOVA and followed by DMRT test. Volatile compounds in roasted coffee were identified using GC-MS, while organic acids in green bean were analyzed using LC-MS/MS QTOF. Green bean moisture content ranged from 7.83%-11.3%, ash content 3.91%-5.71%, fat content 13.59%-17.57%, protein content 3.5%-14.2%, and carbohydrates 57.30%-67.31%. The moisture content of coffee powder ranged from 2.67%-3.34%, ash content 3.66%-4.78%, fat content 11.27%-15.77%, protein content 3.18%-14.24%, and carbohydrates 68.20%-78.03%, the results met the Indonesian National Standard (SNI). GC-MS analysis identified seven classes of volatile compound, with fatty acid ester as the dominant component in all processing methods. LC-MS/MS QTOF revealed the presence of chlorogenic acid in honey and wine method, phenylpropionic acid in fullwash, and indoleacrylic acid in semiwash, honey, and wine. Keywords: Gayo Arabica coffee, postharvest processing, chemical composition, green bean, GC-MS, LC-MS/MS QTOF