Kinetika Reaksi Penurunan Kafein dan Asam Klorogenat Biji Kopi Robusta melalui Pengukusan Sistem Tertutup

Abstract

ABSTRAKPenelitian ini bertujuan untuk mengkaji hubungan antara suhu dan lama pengukusan terhadap penurunan kandungan kafein dan asam klorogenat serta menentukan energi aktivasi (Ea) dengan pendekatan persamaan Arrhenius. Biji kopi Robusta masing-masing seberat 750 g dikukus dalam autoklaf (sistem tertutup) pada suhu 100, 110, dan 120 °C masing-masing selama 1, 2, 3, 4, 5, 6, dan 7 jam. Penelitian dilakukan dengan 3 kali ulangan. Analisis kafein dan asam klorogenat dilakukan menggunakan HPLC. Pengukusan biji kopi pada suhu 100, 110, dan 120 °C, menghasilkan penurunan kandungan kafein dan asam klorogenat tertinggi pada pengukusan selama 7 jam. Penurunan kandungan kafein selama 7 jam pada suhu pengukusan 100, 110, dan 120 °C berturut-turut 13%, 18%, dan 25%. Kandungan asam klorogenat mengalami penurunan 37%, 50%, dan 59% berturut-turut pada suhu 100, 110, dan 120 °C. Pada semua suhu yang diuji, penurunan kafein dan asam klorogenat mengikuti reaksi orde satu. Penurunan kafein mengikuti persamaan y = -0,019x + 0,862, y = -0,023x + 0,820, dan y = -0,033x + 0,759, sedangkan untuk asam klorogenat mengikuti persamaan y = -0,071x + 1,421, y = -0,089x + 1,271, dan y = -0,120x + 1,201. Besarnya energi aktivasi penurunan kafein dan asam klorogenat berturut turut adalah 33.543,66 kJ/molK dan 31.934,91 kJ/Mok. Kata kunci: Energi aktivasi; kafein; asam klorogenat ABSTRACTThis study was aimed to examine the correlation between temperature and duration of steaming on caffeine and chlorogenic acid reduction as well as to determine energy activation (Ea) according to Arrhenius equation. About 750 g of Robusta coffee was steamed by autoclaving at 100, 110, 120 °C for 1, 2, 3, 4, 5, 6 and 7 hours. The study was conducted in 3 replications. Analyses of caffeine and chlorogenic acid were performed using HPLC. Steaming coffee beans at 100, 110 and 120 °C resulted in the highest decrease of caffeine and chlorogenic acids content for 7 hours by 13%, 18% and 25% for caffeine; and by 37%, 50% and 59% for chlorogenic acids. At all temperatures investigated, decaffeination and chlorogenic acid reduction followed first order reaction. The decaffeination equation at 100 °C, 110 °C and 120 °C followed equation of y = -0.019x + 0.862, y = -0.023x + 0.820, and y = -0.033x + 0.759, respectively. Meanwhile, the chlorogenic acid reduction at 100 °C, 110 °C, and 120 °C followed equation of y = -0.071x + 1.421, y = -0.089x + 1.271, and y = -0.120x + 1.201. Activation energies of decaffeination and chlorogenic acid reduction were 33,543.66 kJ/mol K and 31,934.91 kJ/mol K, respectively. Keywords: Activation energy; caffeine; chlorogenic acids PENDAHULUAN Kopi merupakan salah satu minuman yang paling banyak dikonsumsi di seluruh dunia (Lara, 2010), termasuk juga di Indonesia. Minuman kopi disukai konsumen bukan sebagai sumber nutrisi melainkan sebagai minuman penyegar karena memiliki cita rasa dan aroma yang khas.Cita rasa ini disebabkan

Implementation of real-time image processing on bacterial cellulose formation using soybean-boiled wastewater with the variation of carbon sources during fermentation

“…The BC medium was composed of coconut water and soybean-boiled wastewater in a ratio of 70:30 with a total volume of 2.5 L [14]. The other constituent components were carbon sources (10% glucose [30], 5% sucrose [6], or 0.83% mannitol [31]), 0.2% ammonium sulfate [30], 0.2% acetic acid [30], and 20% starter [32]. All components except the starter were heated (T = 100℃; t = 30 s) and then heated at a lower temperature (T = 60℃; t = 10 m).…”

“…The most commonly used BC formation medium is coconut water [6,7,8]. Furthermore, wastewater can also be used as a BC formation medium, such as liquid waste from sugarcane processing during the jaggery [9], juice from Japanese pear, orange, apple, grape, and pineapple waste [10], waste beer yeast [11], rice wine distillation wastewater [12], liquid waste from tofu production [13], and soybean-boiled wastewater from tempeh production [14].…”

“…The observation determines the formation amount that occurred during the fermentation. This step aims to ascertain how much the BC has expanded as a result of the fermentation [6]. Nugroho et al [7] revealed a new observation method using real-time image processing (RTIP).…”

Penyuluhan penanganan pasca panen kopi robusta pada kelompok tani kopi Desa Bocek, Kabupaten Malang

“…Cita rasa kopi robusta yaitu pahit dan tajam. Cita rasa pahit dari kopi robusta dipengaruhi oleh tingginya kadar kafein pada kopi (Hastuti, 2018;Kuncoro et al, 2015).…”

Incorporation of catechin extracts from gambier products and pasak bumi in the production of functional instant green robusta coffee

“…63% than arabica, which has 36.18%. According to [14], roasting can reduce robusta caffeine and chlorogenic acid levels by 13 -25% and 37 -59%, respectively. Several studies have been conducted to maintain the antioxidant properties of coffee such as the addition of herbal cereals in [29], optimisation of roasting temperature to reduce damage to chlorogenic acid compounds in [8] and [3], and the use of a spontaneous fermentation with Wickerhamomyces anomalous (Strain KNU18Y3) on green coffee beans in [7].…”