Peluang Ekspor Biji Kopi Kabupaten Bandung Terbuka Lebar

REPUBLIKA.CO.ID, SOREANG -- Pasar ekspor biji kopi Kabupaten Bandung masih terbuka lebar. Selain kualitas kopi yang bagus dan diperhitungkan, banyak kecamatan di Kabupaten Bandung yang cocok untuk ditanami kopi. Upaya pemerintah untuk mendorong pengembangan kopi dinilai belum maksimal. Sehingga, peluang yang ada belum ditangkap secara maksimal.

Anggota Koperasi Sunda Hejo Rancamanyar, Kabupaten Bandung, Egi Maya Kurnia, mengatakan, peluang ekspor kopi ke Amerika serikat dan Eropa, hingga saat ini masih terbuka luas. Bahkan, peluang ekspor kopi mencapai 500 hingga 1000 ton per bulannya. "Kebutuhan kopi di luar negeri masih sangat besar, seharusnya peluang seperti ini tidak boleh disia-siakan," ujarnya saat dihubungi, Jumat (12/4).

Egi mencontohkan, saat ini Koperasi Sunda Hejo mampu mengekspor 100 hingga 200 ton biji kopi kualitas terbaik. Koperasi Sunda Hejo mengekspor ke Kota San Francisco, Amerika Serikat. Pihaknya sudah berkosentrasi mengembangkan tanaman kopi selama dua tahun.
"Kami baru mampu di jumlah 100 sampai 200 ton. Sebenarnya, kalau ada pengembangan lahan dan dibantu pemerintah, bisa lebih tambah lagi," katanya.

Egi mengatakan, selain pasar ekspor ke Amerika Serikat, peluang ekspor kopi dari Kabupaten Bandung ini masih terbuka luas ke negara-negara lainnya. Terutama negara-negara Eropa. Apalagi, kata dia, kualitas kopi dari Kabupaten Bandung ini, jauh di atas produk kopi dari Nigeria, ataupun kopi dari Gayo, Aceh.
"Selain pasar Amerika Serikat sebagai tujuan ekspor. Pasar ekspor ke Eropa juga terbuka luas. Ini tinggal kesiapan dan kemauan kita untuk mengisinya," ujarnya.

Selama ini, kata Egi, pertanian kopi di Kabupaten Bandung, lebih banyak mengembangkan jenis Linies (Arabika). Jenis kopi ini memiliki kualitas baik dan sesuai dengan iklim serta geografis wilayah Kabupaten Bandung. Sehingga, sangat cocok untuk terus dikembangkan.

"Perkebunan kopi rakyat di Kabupaten Bandung tersebar di beberapa kecamatan. Seperti di Kecamatan Kertasari, Pacet, Pangalengan, Pasirjambu, Ciwidey dan Rancabali. Luasan perkebunan lebih dari 400 hektare. Potensi perluasan kebunnya pun masih memungkinkan," katanya.

Meski potensi pertanian kopi di Kabupaten Bandung ini cukup luas, kata Egi, dorongan dan dukungan dari pemerintah sangat kurang. Padahal, pemerintah bisa mengambil peran lebih. Seperti melakukan sertifikasi terhadap bibit kopi unggulan dari Kabupaten Bandung.

Dengan sertifikasi, memberikan jaminan terhadap kualitas produk saat dipasarkan. "Contohnya di Jawa Tengah ada sertifikasi yang

dikeluarkan pemerintahnya untuk pohon jati, dengan nama Jati Unggul Nusantara, kita juga bisa melakukannya untuk kopi," ujarnya.

Selain itu, kata Egi, pemerintah juga bisa melakukan sosialisasi mengenai keuntungan menanam kopi kepada masyarakat. Pemerintah juga bisa berperan memberikan bantuan bibit. Pemanfaatan lahan kritis dan tidak terpakai, bisa dilakukan untuk mengembangkan luas kebun kopi.
"Kan banyak juga tanah cari desa atau lahan tidur lainnya yang bisa dipakai. Selain itu, pola kemitraan juga dapat meningkatkan derajat para buruh tani menjadi petani. Dengan begitu, otomatis dapat meningkatkan kesejahteraan masyarakat," katanya.

Source :  

REPUBLIKA ONLINE - Jumat, 12 April 2013, 18:27 WIB

http://www.republika.co.id/berita/nasional/jawa-barat-nasional/13/04/12/ml53uj-peluang-ekspor-biji-kopi-kabupaten-bandung-terbuka-lebar

Perubahan Profile Waktu dan Suhu saat Meroasting Kopi

EFFECTS OF DIFFERENT TIME-TEMPERATURE PROFILES ON COFFEE PHYSICAL AND CHEMICAL PROPERTIES

Green coffee beans provide neither the characteristic aroma nor the taste of a cup of coffee. To reveal their flavour, green coffee beans need to be roasted. Roasting is one of the most important steps in coffee processing that leads to the development of the desired aroma, taste, and color of the final brewed product. In general, the use of roasting temperature of greater than 200oC is required in order to result in desirable chemical, physical, structural, and sensorial changes in the coffee beans (Schenker 2000; Schenker et al. 2002; Baggenstoss et al. 2008).

The time and temperature conditions applied during roasting have a major impact on the physical and chemical properties of roasted coffee beans. Geiger et al. reported that CO2, a by-product formed due to Strecker reactions and the degradation of organic compounds, increased greatly towards the end phase of a high-temperature-short-time process (260oC, 170 s), while the CO2 formed was much lower when a low-temperature-long-time (228oC, 720s) process was employed (Geiger et al. 2005). Schenker et al. found that roasting process that involved a ramping temperature profile (150 to 240oC in 270 s; 240oC for 55 s) resulted in the formation of a greater quantity of aroma volatiles than a low-temperature-long-time process (isothermal heating at 220oC for 600 s) (Schenker et al. 2002). Baggenstoss also reported that high-temperature-short-time roasting led to beans of lower density, higher volume, less roast loss, and lower moisture content as compared to the low-temperature-short time process (Baggenstoss et al. 2008). Lyman et al. roasted green coffee beans under various process conditions to study the effect of roasting on brewed coffee (Lyman et al. 2003). Using a medium roast process (6.5 min to the onset of the first crack and 1.0 min to the onset of the second crack), Lyman et al. observed that coffee of balanced taste and aroma with citrus flavour was produced. However, using the so-called “sweated process” (4.5 min to the first crack and 6.5 min to the second crack), coffee beans of non-uniform bean color with “sour, grassy, and underdeveloped” were resulted. In comparison, the “baked process” (11 min to the first crack and 18 min to the second crack) produced coffees that were “flat, woody with low brightness and acidity” (Lyman et al. 2003). Based on the these observations, one can conclude that the quality of roasted coffee does not solely depend on the physical parameters at the start and end point of roasting, but rather it is dependent on the time-temperature conditions applied during the roasting process. 

Source : Physicochemical Changes of Coffee Beans During Roasting

JAVA PREANGER COFFEE ADDICT

Fadillah Satria

 

FTIP TMIP UNPAD

fadilprojectkopi@gmail.com

Coffee Roasting Mass Production

Coffee Roasting

Process Description

The coffee roasting process consists essentially of cleaning, roasting, cooling, grinding, and packaging operations. Figure 9.13.2-1 shows a process flow diagram for a typical coffee roasting operation. Bags of green coffee beans are hand- or machine-opened, dumped into a hopper, and screened to remove debris. The green beans are then weighed and transferred by belt or pneumatic conveyor to storage hoppers. From the storage hoppers, the green beans are conveyed to the roaster. Roasters are typically horizontal rotating drums that tumble the green coffee beans in a current of hot combustion gases; the roasters operate in either batch or continuous modes and can be indirect- or direct-fired. Indirect-fired roasters are roasters in which the burner flame does not contact the coffee beans, although the combustion gases from the burner do contact the beans. Direct-fired roasters contact the beans with the burner flame and the combustion gases. At the end of the roasting cycle, water sprays are used to "quench" the beans. Following roasting, the beans are cooled and run through a "destoner". Destoners are air classifiers that remove stones, metal fragments, and other waste not removed during initial screening from the beans. The destoners pneumatically convey the beans to a hopper, where the beans are stabilize and dry (small amounts of water from quenching exist on the surface of the beans). This stabilization process is called equilibration. Following equilibration, the roasted beans are ground, usually by multi-stage grinders. Some roasted beans are packaged and shipped as whole beans. Finally, the ground coffee is vacuum sealed and shipped.

Additional operations associated with processing green coffee beans include decaffeination and instant (soluble) coffee production. Decaffeination is the process of extracting caffeine from green coffee beans prior to roasting. The most common decaffeination process used in the United States is supercritical carbon dioxide (CO2) extraction. In this process, moistened green coffee beans are contacted with large quantities of supercritical CO2 (CO2 maintained at a pressure of about 4,000 pounds per square inch and temperatures between 90° and 100°C [194° and 212°F]), which removes about 97 percent of the caffeine from the beans. The caffeine is then recovered from the CO2, typically using an activated carbon adsorption system. Another commonly used method is solvent extraction, typically using oil (extracted from roasted coffee) or ethyl acetate as a solvent. In this process, solvent is added to moistened green coffee beans to extract most of the caffeine from the beans. After the beans are removed from the solvent, they are steam-stripped to remove any residual solvent. The caffeine is then recovered from the solvent, and the solvent is re-used. Water extraction is also used for decaffeination, but little information on this process is available. Decaffeinated coffee beans have a residual caffeine content of about 0.1 percent on a dry basis. Not all facilities have decaffeination operations, and decaffeinated green coffee beans are purchased by many facilities that produce decaffeinated coffee.

In the manufacture of instant coffee, extraction follows the roasting and grinding operations. The soluble solids and volatile compounds that provide aroma and flavor are extracted from the coffee beans using water. Water heated to about 175°C (347°F) under pressurized conditions (to maintain the water as liquid) is used to extract all of the necessary solubles from the coffee beans. Manufacturers use both batch and continuous extractors. Following extraction, evaporation or freeze-concentration is used to increase the solubles concentration of the extract. The concentrated extracts are then dried in either spray dryers or freeze dryers. Information on the spray drying and freeze drying processes is not available.

JAVA PREANGER COFFEE ADDICT

Fadillah Satria

 

FTIP TMIP UNPAD

fadilprojectkopi@gmail.com

Bagan Roasting Kopi - (warna dan rasa)

Roast Colour Chart

Rasa pada KOPI Roasted!

Flavour compounds in roasted coffee

Chemical compounds present in roasted coffee can be roughly grouped into volatile and non-volatile, some of the former being responsible for aroma and the latter for the basic taste sensations of sourness, bitterness and astringency (Buffo & Cardelli-Freire 2004). Russwurm reported that carbohydrates, proteins, peptides and free amino acids, polyamines and tryptamines, lipids, phenolic acids, trigonelline, and various non-volatile acids in the green coffee beans were involved in the flavour formation during roasting (Russwurm 1970). For example, chlorogenic acid contributes to body and astringency; sucrose contributes to color, aroma, bitterness, and sourness; minor protein components like free amino acids are highly reactive by interacting with reducing sugars, which make the Maillard reaction happen; triogenlline generates pyridine and may be consequently be responsible for some objectionable flavours; and caffeine can be contributed to the bitterness (Flament 2002).

Maillard reactions have been identified to be the major pathway in the formation of volatile compounds in coffee roasting (Shibamoto 1991). In the Maillard reaction, reducing sugars such as glucose or fructose react with free amino acids to form N-substituted glycosylamine adducts, which are then rearranged to aminoketones and aminoaldoses by Amadori and Heynes rearrangements. A complex reaction cascade of Amadori and Heynes rearrangement products leads to numerous volatile compounds and complex melanoidins.

More than 800 volatile compounds have already been identified in roasted coffee, among which, about 40 compounds are responsible for the characteristic aroma of coffee (Belitz et al. 2009). 

(1) Proteins, peptides and amino acids: Crude protein content is relatively stable during roasting, while the free amino acids decrease by 30%, with dark roast espresso reaching up to 50% (Belitz et al. 2009). Protein content plays an important role in espresso coffee as it affects the foamability of the beverage that the foamability increased generally with increase total protein concentration until a maximum value is reached (Nunes et al. 1997). The composition of the amino acids vary dependent on their thermal stability and reactions involved. For instance, changes in glutamic acid content are less dramatic as compared to cysteine and arginine. The latter amino acids tend to deplete rapidly during roasting due to their involvement in Maillard browning reactions (Illy & Viani 2005).

(2) Carbohydrates: Only traces of free mono and disaccharides in green coffee remain after roasting. Cellulose, hemicellulose, arabinogalactan and pectins play important roles in the retention of volatiles and contribute to coffee brew viscosity. It is reported that in espresso coffee, the foam stability is related to the amount of galactomannan and arabinogalactan (Nunes et al. 1997).

(3) Non-volatile lipids and lipid-solubles: Triglycerides, terpenes, tocopherols and sterols contribute to brew viscosity. The lipid fraction tends to be stable and survive the roasting process with only minor changes. Linoleic and palmitic acids are the predominant fatty acids in coffee. Cafestol and kahweol are diterpenes that degrade by the roasting process. Another diterpene, 16-O-methylcafestol, is present in Robusta but not Arabica coffee, making it a suitable indicator for detecting Robusta content in coffee blend (Speer et al. 1991; Belitz et al. 2009).

(4) Caffeine: Caffeine is of major importance with respect to the physiological properties of coffee, and also in determining the strength, body and bitterness of brewed coffee. The caffeine content of green coffee beans varies according to the species that Robusta coffee contains about 2.2%, and Arabica about 1.2%. Environmental and agricultural factors appear to have a minimal effect on caffeine content. During roasting there is no significant loss in terms of caffeine (Ramalakshmi & Raghavan 1999). However, caffeine content per 177 mL (6 oz) of coffee range from 50 to 143 mg, depending on the mode of preparation(Rogers & Richardson 1993; Bell et al. 1996). Bell and others (Bell et al. 1996) reported that more coffee solids, larger extents of grinding, and larger volumes of coffee prepared at a constant coffee solids to water ratio led to significantly higher caffeine content. Home-grinding yielded caffeine content similar to that of store-ground coffee, and boiled coffee had caffeine contents equal to or greater than filtered coffee (Bell et al. 1996).

(5) Acids: Acids are responsible for acidity, which together with aroma and bitterness is a key contributor to the total sensory impact of a coffee beverage. Carboxylic acids, mainly citric, malic and acetic acids are responsible for acidity in brewed coffees. Arabica coffee brews are more acidic (pH 4.85-5.15) than Robusta brews (pH 5.25-5.40) (Vitzthum 1975).

(6) Melanoidins: The final products of the Maillard reaction between amino acids and monosaccharides, are the brown-coloured substances that impart to roasted coffee its characteristic color, possess antioxidant activity, and affect on the flavor volatiles (Hofmann & Schieberle 2001; Del Castillo et al. 2002; Vignoli et al. 2011).

Source : Physicochemical Changes of Coffee Beans During Roasting

JAVA PREANGER COFFEE ADDICT

Fadillah Satria

 

FTIP TMIP UNPAD

fadilprojectkopi@gmail.com

Perubahan struktur kimia saat meroasting KOPI!

Changes in Chemical Compositions during Roasting

Roasting causes a net loss of matters in the forms of CO2, water vapor, and volatile compounds. Moreover, degradation of polysaccharides, sugars, amino acids and chlorogenic acids also occurred, resulting in the formation of caramelization and condensation products. Overall, there is an increase in organic acids and lipids, while caffeine and trigonelline (N-methyl nicotinic acid) contents remained almost unchanged (Buffo & Cardelli-Freire 2004). The main acids present in green beans are citric, malic, chlorogenic, and quinic acids. During roasting the first three acids decrease while quinic acid increases as a result of the degradation of chlorogenic acids (Ginz et al. 2000). Formic and acetic acids yields increase up to the medium roasting degree and then begin to fall as roasting is continued. According to Balzer (Balzer 2001), a rapid increase in titratable acidity during roasting was observed from green to medium roast, followed by a smaller decrease as roasting proceeded.

The reaction products formed are highly dependent on the roasting time-temperature profile used. Excessive roasting produces more bitter coffee lacking satisfactory aroma, whereas very short roasting time may be insufficient to develop full organoleptic characteristics (Yeretzian et al. 2002; Lyman et al. 2003; Buffo & Cardelli-Freire 2004). Although the majority of phenolic antioxidants naturally occurring in coffee bean are lost during roasting, the formation of other antioxidants from Maillard reactions during roasting can enhance the antioxidant activity of coffee. Compared to medium roast coffee, dark roast coffee exhibited lower radical scavenging activity than medium roasted coffee due to the degradation of polyphenol, and thus the antioxidant activity will also depend on roasting severity and type of coffee (Giampiero Sacchetti 2009).

The profile of organic compounds generated during roasting is very dynamic and complex. Using Proton transfer reaction-Mass spectrometry (PTR-MS) technique, Yeretzian et al. (Yeretzian et al. 2002) simultaneously monitored the evolution of 8 volatile compounds at isothermal conditions as a function of time. They observed a distinctive increase in acetic acid, methyl acetate, and pyrazine concentrations in the headspace, all occurred at the same time. Concomitantly, there was a rapid decrease in water vapor and methanol concentrations. Moreover, these peaks shifted in synchronous manner with the roasting condition. For instance, at 190oC, the above observed changes took place at 19 min but shifted to 30 min when the beans were roasted at 180oC (Yeretzian et al. 2002). Similar observations were observed by Hashim and Chaveron, who concluded that methylpyrazine may be used as an indicator to monitor the roasting progress of coffee beans (Hashim & Chaveron 1995). It has been suggested that the pressure buildup within intact bean cells is comparable to inside an autoclave, which can further complicated the chemical reactions occurred in coffee bean during roasting (Buffo & Cardelli-Freire 2004).

Chemical reactions happened during coffee roasting are very complex, which have not been fully understood. Based on the literature reviewed, we can conclude that the quality of roasted coffee cannot be solely described in terms of physical parameters at the start and end point of roasting, but rather it is dependent on the path taken during the roasting process. To reach a specific flavour profile, not only that precise control of roasting time and temperature is needed, the variety/quality of green beans, cooling, and degassing conditions are expected to be important as well.

Source : Physicochemical Changes of Coffee Beans During Roasting

JAVA PREANGER COFFEE ADDICT

Fadillah Satria

 

FTIP TMIP UNPAD

fadilprojectkopi@gmail.com

Meroasting Kopi!

Roasting of coffee beans

Green coffee beans provide neither the characteristic aroma nor flavour of brewed coffee until they are roasted. Moreover, the roasting process increases the value of coffee beans, by 100-300% of the raw material (Yeretzian et al. 2002). Roasting of coffee beans typically takes place at 200-240°C for different times depending on the desired characteristics of the final product. Events that take place during roasting are complex, resulting in the destruction of some compounds initially present in green beans and the formation of volatile compounds that are important contributors to the characteristic of coffee’s aroma. The chemical compositions of green, roasted, and brewed coffee are shown in Figure 1 (Barter 2004).

Briefly, as temperature increases to about 100oC, green coffee beans undergo moisture loss from 8-12% in green coffee beans to about 5% in the roasted coffee beans (Illy & Viani 1998). The smell of the beans changes from herb-like green bean aroma to bread-like, the color turns from green to yellowish, and the structure changes from strength and toughness to more crumbly and brittle. When the internal temperature of beans reaches 100oC, the color darkened slightly for about 20-60 s due to the vaporization of water. At 160-170oC, the beans become lighter in color for about 60-100 s. As roasting continues at this temperature, Maillard and pyrolytic reactions start to take place, resulting in gradually darkening of the beans (Hernandez et al. 2007). The buildup of water pressure, along with the large amount of gases generated causes the cellulose cell wall to crack, giving rise to the so called “first crack”. As heating continues at the roasting temperature (160-170oC), the coffee becomes darker and more rapid popping of coffee bean occurs (“second crack”) as the carbon dioxide (CO2) buildup exceeds the strength of the cellulosic walls of the bean. Finally, after roasting, the fresh roasted coffee beans are quickly cooled to stop roasting (Yeretzian et al. 2002).

The final quality of roasted coffee is influenced by the design of the roasters and time-temperature profiles used. Although heat transfers during roasting can involve conduction, convection, and radiation, convection by far is the most important mode of heat transfer that determines the rate and uniformity of roasting (Baggenstoss et al. 2008). Coffees roasted in fluidized-bed roaster that is almost exclusive based on convective heating can result in low density and high yield coffee (Eggers & Pietsch 2001). On the other hand, coffees roasted in drum roaster that involves mainly conductive heat transfer have less soluble solids, more degradation of chlorogenic acids, more burnt flavour, and higher loss of volatiles than the fluidized bed roasters (Nagaraju et al. 1997).

The effects of time-temperature profile on coffee aroma properties have been reported by Lyman et al. (Lyman et al. 2003). They observed that the medium roasted process (6.5 min to the onset of the first crack and 1.0 min to the onset of the second crack) resulted in good balance of taste and aroma with citrus flavour. However, the “sweated process” (4.5 min to the first crack and 6.5 min to the second crack) resulted in non-uniform bean color and the coffee was “sour, grassy, and underdeveloped”. Reducing the heating rate further by using the “baked process” (11 min to the first crack and 18 min to the second crack) produced coffee of “flat, woody with low brightness and acidity” (Lyman et al. 2003). In another study, Schenker et al. reported that LHC process (150 to 240oC in 270 s; 240oC for 55 s) resulted in the formation of the highest quantities of aroma volatiles, while the long time low temperature (LTLT) approach (isothermal heating at 220oC for 600 s) generated the lowest aroma volatiles. Moreover, the distribution of the 13 volatile compounds monitored was considerably different depending on the roasting profiles used (Schenker et al. 2002).

Depending on the extent of heat treatment, coffee can be largely categorized as light, medium or dark roasts. Light roast process tends to give non-uniform bean color with sour, grassy, and underdeveloped flavour, while medium roast process produces a balanced taste and aroma with citrus flavour. By contrast, dark roast process produces coffee of low acidity sensory profiles (Lyman et al. 2003). Physical characteristics such as temperature, color, and weight-loss are often used as indicators of roast degree. However, these parameters only allow assessment of the flavour profile for coffee roasted under narrow process conditions (Sivetz 1991; Illy & Viani 1995). Other analytical methods for quantifying the degree of roast include ratio of free amino acids (Nehring & Maier 1992), alkylpyrazines (Hashim & Chaveron 1995), and chlorogenic acids content (Illy & Viani 1995). Fobe and others (Fobe et al. 1968) studied changes in chemical composition of Arabica coffee roasted at 230°C at different process times. They reported that as the roasting time increased, the following changes occurred: (1) sugar contents first increased, and then decreased; (2) minimal change in caffeine content; (3) proteins decreased continuously; (4) free fatty acids increased; and (5) unsaponifiable compounds decreased (Fobe et al. 1968).

Source : Physicochemical Changes of Coffee Beans During Roasting

JAVA PREANGER COFFEE ADDICT

Fadillah Satria

 

FTIP TMIP UNPAD

fadilprojectkopi@gmail.com