Sukrisno Widyotomo
Research staff of Indonesia Cofee and Cocoa Reseach Institut (ICCRI)
Articles
14
Documents
KARAKTERISASI ISOTERM SORPSI AIR BIJI KOPI DENGAN MODEL BET DAN GAB Water soption isotherms characterization of green coffee beans by BET and GAB models

Jurnal Agritech Fakultas Teknologi Pertanian UGM Vol 31, No 03 (2011)
Publisher : Fakultas Teknologi Pertanian, Universitas Gadjah Mada

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Abstract

Many problems of coffee bean stability during storage and sea transportation are related to moisture content and the water activity of the beans. The moisture content of the beans is affected by temperature and relative humidity of the ambient air. Equilibrium of Moisture Content (EMC) defined as moisture content in substances was equal with moisture content in the surrounding air. EMC is a measuring rod of multiply microorganisme ability to cause destruction or degrading material during storage. The objectives of this research work were to determine water soption isotherms characterization of green coffee beans by BET and GAB models. Temperature used is 25-39 oC that usually found in storage of this commodity in tropical regions. Green beans used in this research are South Sulawesi arabika and robusta dried beans that dry process produce. The result showed that to be base on sorpsion area, water sorption isotherm regression equation by BET model showed that Robusta equilibrium moisture content on 70 % relative humidity which32 oC and 25 oC temperature storage were 11.93 % and 11.22 % by BET model, and 12.81 % and 11.87 % by GAB model. For Arabica, 11.07 % and 11.09 % by BET model, and 11.65 % and 11.78 % by GAB model.   Keywords : Coffee, water sorption isotherm, water activity, BET, GAB ABSTRAK   Permasalahan dalam mempertahankan mutu selama penyimpanan dan pengiriman berkaitan dengan kadar air dan aktivitas air di dalam bahan. Equilibrium of Moisture Content (EMC) didefinisikan sebagai kandungan air pada bahan yang seimbang dengan kandungan air udara sekitarnya. EMC merupakan tolok ukur kemampuan berkembangnya mikro organisme yang menyebabkan terjadinya kerusakan atau pembusukan bahan pada saat penyimpanan. Tujuan penelitian ini adalah untuk menentukan karakteristik isotermi sorpsi air biji kopi dengan menggunakan model BET dan GAB. Kondisi suhu yang digunakan adalah 25-39 oC sesuai dengan kondisi penyimpanan di daerah tropis. Biji kopi yang digunakan adalah kopi Arabika dan Robusta hasil pengolahan kering dari Sulawesi Selatan. Hasil penelitian menunjukkan bahwa berdasarkan pembagian daerah sorpsi, hasil analisis persamaan garis isotermi sorpsi model BET menunjukkan bahwa kadar air kopi Robusta yang berkeseimbangan dengan menggunakan model BET dan GAB pada kelembaban relatif 70 % pada suhu 32 oC masing-masing 11,93 % dan 11,22 %, sedangkan pada suhu 25 oC adalah 12,81 % dan 11,87 %. Untuk kopi Arabika pada suhu 32 oC masing-masing adalah 11,07 % dan 11,09 %, sedangkan pada suhu 25 oC adalah 11,65 % dan 11,78 %.   Kata kunci : Kopi, isotermi sorpsi air, aktivitas air, BET, GAB

ANALISIS KEBERLANJUTAN KAWASAN USAHA PERKEBUNAN KOPI (KUPK) RAKYAT DI DESA SIDOMULYO KABUPATEN JEMBER

Jurnal Agritech Fakultas Teknologi Pertanian UGM Vol 32, No 02 (2012)
Publisher : Fakultas Teknologi Pertanian, Universitas Gadjah Mada

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Abstract

Sustainability Analysis of Smallholder Coffee Plantation at Sidomulyo Village, Jember DistrictABSTRAKDesa Sidomulyo, Kecamatan Silo merupakan salah satu sentra produksi kopi rakyat utama di Kabupaten Jember. Perkembangan produksi dan harga kopi dunia yang tidak pasti dapat berimplikasi terhadap keberlanjutan usaha pertanian kopi rakyat. Tujuan penelitian ini adalah untuk mengevaluasi keberlanjutan usaha kopi rakyat di Desa Sidomulyo, Kabupaten Jember. Berdasarkan purposive and random sampling survey, penelitian ini menggunakan kuesioner dan diskusi dengan pihak terkait dalam pengambilan data. Dimensi ekologi, sosial kelembagaan, ekonomi dan teknologi dianalisis dengan menggunakan program Rap-Coffee hasil modifi kasi dari program Rapfi sh. Berdasarkan simulasi program Rap-Coffee untuk keempat dimensi keberlanjutan, maka Indeks Keberlanjutan KUPK Desa Sidomulyo adalah 59,5 % yang berarti berlanjut. Indeks keberlanjutan ini dapat ditingkatkan melalui perbaikan terhadap faktor pengungkit (indikator sensitif). Oleh karena itu di dalam perencanaan kebijakan untuk pengembangan KUPK Desa Sidomulyo sebaiknya memprioritaskan pada peningkatan indikator yang memiliki sensitivitas tinggi di masing-masing dimensi.Kata kunci: Kopi, analisis keberlanjutan, perkebunan rakyat ABSTRACTSidomulyo village, Silo region is one of main small holder coffee producer at Jember district. Unpredictable world production and price can cause unsustainability of small holder coffee production. The research objective was to evaluate sustainability of small holder coffee plantation in Sidomulyo, Jember district. Based on purposive and random sampling survey, questionnaire and discussion with key persons were implemented in this research in collecting data. Dimension of ecology, social institutional, economic and technology were analyzed using Rap-Coffee program modified from Rapfi sh software. The result reveals that from four dimensions implemented in this research, the sustainability index was 59,5 % means that activity of small holder coffee plantation at Sidomulyo still have sustainability as a coffee production unit. This index could be increased through factors improvement of each dimension. The improvement of high sensitivity attributes in each dimension is strongly needed to develop better regulation to support the continuity of small holder plantation of coffee production unit at Sidomulyo.Keywords: Coffee, sustainability, small holder plantation

Performance Evaluation of Rotating Cylinder Type Coffee Bean Roaster

Jurnal Keteknikan Pertanian Vol 24, No 1 (2010): Jurnal Keteknikan Pertanian
Publisher : PERTETA

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Abstract

Abstract One strategy attempts to reduce dependence on primary commodity markets are overseas market expansion and development of secondary products. In the secondary product processing coffee beans is required of supporting equipment to facilitate these efforts. Research Center for Indonesian Coffee and Cocoa has developed coffee bean roaster. However, there are still many people who do not know about the technical aspects of roaster machine type of rotating cylinder so that more people use traditional ways to roast coffee beans. In order for the benefits of this machine is better known society it is necessary to study on the technical aspects. The purpose of this research is to evaluate the technical performance of the coffee beans roaster machine type of rotating cylinder. These include the technical aspects of work capacity of the machine, roasting technical efficiency, fuel requirements, and power requirements of using roaster machine. Research methods are including data collection, calculation and analysis. The results showed that the roaster machine type of a rotating cylinder has capacity of 12.3 kg/hour. Roasting efficiency is 80%. Fuel consumption is 0.6 kg. The calculated amount of the used power of current measurement is the average of 0.616 kW. Keywords: coffee beans, roasting, performance Diterima: 21 Oktober 2009; Disetujui: 8 Januari 2010

Performance of Rotary Cutter Type Breaking Machine for Breakingand Deshelling Cocoa Roasted Beans

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 21, No 3 (2005)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

Conversion of cocoa beans to chocolate product is, therefore, one of the promising alternatives to increase the value added of dried cocoa beans. On the other hand, the development of chocolate industry requires an appropriate technology that is not available yet for small or medium scale of business. Breaking and deshelling cocoa roasted beans is one important steps in cocoa processing to ascertain good chocolate quality. The aim of this research is to study performance of rotary cutter type breaking machine for breaking and deshelling cocoa roasted beans. Indonesian Coffee and Cocoa Research Institute has designed and tested a rotary cutter type breaking machine for breaking and deshelling cocoa roasted beans. Breaker unit has rotated by ½ HP power, single phase, 110/220 V and 1440 rpm. Transmission system that use for rotating breaker unit is pulley and single V belt. Centrifugal blower as separator unit between cotyledon and shell has specification 0.5 m 3 /min air flow, 780 Pa, 370 W, and 220 V. Field tests showed that the optimum capacity of the machine was 268 kg/h with 500 rpm speed of rotary cutter, 2,8 m/s separator air flow, and power require was 833 W. Percentage product in outlet 1 and 2 were 94.5% and 5.5%. Particle distribution from outlet 1 was 92% as cotyledon, 8% as shell in cotyledon and on outlet 2 was 97% as shell, 3% as cotyledon in shell. Key words:cocoa, breaking, rotary cutter, quality.

Optimizing of a Horizontal Cylinder Type Cocoa Roaster for Dried Cocoa Cotyledon Roasting

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 22, No 2 (2006)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

The secondary process of cocoa is one of the promising alternatives to increase the value added of dried cocoa beans. One the other hand, the development for secondary cocoa process requires an appropriate technology that is not available yet for small or medium scale business. Cocoa roaster is a basic equipment to produce good and competitive secondary cocoa products for chocolate industry. The Indonesian Coffee and Cocoa Research Institute has, therefore, designed and tested a horizontal cylinder type roaster for drying cocoa cotyledon. The cylinder has 405 mm diameter, 520 mm long and is rotated by a 1 HP (0.75 kW), 220 V, single phase and 1400 rpm electric motor. Assisted with a gear reducer, the final cylinder rotation is adjusted at approximately 6 rpm. The heat for roasting process is generated from kerosene burner. At the end of roasting, the roasted beans are cooled down by ambient air inside a cooling platform by natural air flow. The raw material used in this optimizing test was dried fine cocoa cotyledon. Field tests showed that the optimum performance of the roaster was 7 kg dried fine cocoa cotyledon loaded with roasting temperature 120 oC and 25.57 kg/h optimum capacity. The organoleptic test showed that score of aromatic, flavour, acidity, bitterness, astringency and burnt were 4.8, 5.2, 5.4, 5.2, 4.8 and 0.8 with 10 scale, also 4.2 with 5 scale for likely. The roasting time was 15—25 minutes to get 2.5—3% final water content depend on roasting temperature and cocoa cotyledon loaded. Key words: cocoa, roasting, horizontal cylinder, quality.

Optimation of Temperature and Duration of Cocoa Beans Roasting in a CylindricalRoaster

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 21, No 3 (2005)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

A small scale cylindrical type cocoa roaster has been designed to improve Indonesian mallholder income and commence utilization of cocoa-base products. Capacity of the roaster was at 15 kg dried cocoa beans. Operating condition of the instrument in terms of temperature and duration of roasting for cocoa powder production has been optimized by using Response Surface Methodology in the range of 110–140 C for the former and 20–60 minute for the latter. Variable of the study were temperature profile, peroxide value of cocoa butter, color and sensory properties of the resultant cocoa powder and microbial con tamination. Result of the study showed that cocoa bean’s temperature at the first 2–8 minute roasting was 30–50 C, before increased as high 10 C per minute to the adjusted temperature. Temperature and duration of roasting influenced interactively on peroxide value of cocoa butter, color and sensory properties of the resultant cocoa powder. An optimum roasting for cocoa powder preparation was obtained at temperature of 140 C and roasting time of 20 minute. Roasting treatment significantly reduced number of microbe in total plate count, however most probable number (MPN) of coliform in term of Escherichia coli was not detected. Key words : Cocoa bean, cocoa powder, cocoa butter, roasting, small scale cylindrical roaster, sensory properties, Escherichia coli.

Quality and Flavor Profiles of Arabica Coffee Processed by Some Fermentation Treatments: Temperature, Containers, and Fermentation Agents Addition

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 29, No 3 (2013)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

Coffee fermentation is a step of wet processing. In fact, some microorganisms naturally exist on the surface of coffee cherry. Using a starter culture of microorganisms may change equilibrium of microorganism population. Among some safe fermentation agents are present in “ragi tape” (yeast), “ragi tempe”, and fermented milk. A fermentor machine equipped with eating-control and stirrer had been designed, and tested before. Some treatments investigated were fermentation containers (fermentor machine and plastic sacks); fermentation agents (fresh cage-luwakcoffee, “ragi tape”, “ragi tempe”, and fermented milk); temperature of fermentation (room, 30 C, 35 C, and 40 C); and duration of fermentation (6, 12, and 18 hours). The experiment were replicated three times. Wet-coffee parchments were washed and sundried until moisture content reached 12%. The dried parchment was hulled and examined for the bean quality and flavors. The experiment indicated that 40 C fermentation in fermentor machine resulted in higher content of “full sour defect”. Fermentation agents significanly influenced bean size. Temperature treatment significanly influenced bulk density and bean size. The best flavor profile was obtained from fermentation in plastic sack at ambient temperature. Bacteria of fermented milk and “fresh luwak coffee” as fermentation agents resulted up to excellent flavor. Twelve hours fermentation produced best flavor of Arabica coffee compared to 6 and 18 hours. Key words: Arabica coffee, fermentation, flavour, fermentation agents

Performance of Disk Mill Type Mechanical Grinder for Size Reducing Process of Robusta Roasted Beans

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 23, No 3 (2007)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

One of improtant steps in secondary coffee processing that influence on final product quality such as consistency and uniformity is milling process. Usually, Indonesian smallholder used "lumpang" for milling coffee roasted beans to coffee powder product which caused the final product not uniformed and consistent, and low productivity. Milling process of coffee roasted beans can be done by disk mill type mechanical grinder which is used by smallholder for milling several cereals. Indonesian Coffee and Cocoa Research Institute have developed disk mill type grinding machine for milling coffee roasted beans. Objective of this research is to find performance of disk mill type grinding machine for size reducing process of Robusta roasted beans from several size dried beans and roasting level treatments. Robusta dried beans which are taken from dry processing method have 13—14% moisture content (wet basis), 680—685 kg/m3 density, and classified in 3 sizes level. The result showed that the disk mill type of grinding machine could be used for milling Robusta roasted beans. Machine hascapacity 31—54 kg/h on 5,310—5,610 rpm axle rotation and depend on roasting level. Other technical parameters were 91—98% process efficientcy, 19—31 ml/ kg fuel consumption, 0.3—1% slips, 50—55% particles had diameter less than 230 mesh and 38—44% particles had diameter bigger than 100 mesh, 32—38% lightness was increased, 0.6—12.6% density was decreased, and solubility of coffee powder between 28—30%. Cost milling process per kilogram of Robusta roasted beans which light roast on capacity 30 kg/hour was Rp362.9. Key words : Coffee roasted, Robusta, disk mill, mechanical grinder, size reduction.

Optimation of a Table Conveyor Type Grading Machine to Increase the Performance of Green Coffee Manual Sortation

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 22, No 1 (2006)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

Coffee consumers request a good quality of green coffee to get a good coffee cup taste. Defective beans e.g. black bean, brown bean and broken bean are associated to low coffee quality which give negative effects to final taste. To meet the standard export requirement, coffee beans have to be graded before being traded. Until now, grading process is generally carried out manually. The method gives better product, so the grading cost is very expensive about 40% of total processing cost. Meanwhile, shortage of skill workers is a limiting factor of the process. Therefore, improving the manual sorting by providing machine for grading of green coffee is good alternative to reduce the grading cost. Indonesian Coffee and Cocoa Research Institute has designed a table conveyor type grading machine in order to improve the performance of the manual grading productivity and consistent quality and to reduce the grading cost. The conveyor belt has a dimension of 5700 mm of length, 610 mm of width and 6 mm of thickness. The rotating of belt conveyor powered by an electro motor 3 HP, 3 phase and 1420 rpm. The result showed that the optimum capacity of grading machine was 390 kg/hour reached when the speed 16 rpm and 3 kg/m 2 of green beans on belt conveyor with productivity 1870 kg/man-day compared to the productivity full manually process 743 kg/man-day. Percentage of product in outlet 1 was 4.2% as broken beans, 0.26% as brown beans, 0.68% as one hole in beans and 0.61% as more than one hole in beans. Percentage of product in outlet 2 was 39.54% as broken beans, 4.23% as brown beans 7.19% as black beans, 4.47% as one hole in beans and 4.43% as more than one hole in beans. Cost of grading process per kg of green coffee is Rp20,-. Key words : Coffee, Grading, Conveyor table, Quality

Influence of Milling Process of Roasted Cocoa Beans on Size Distribution Change of Cocoa Cotyledon

Pelita Perkebunan (Coffee and Cocoa Research Journal) Vol 23, No 1 (2007)
Publisher : Indonesian Coffee and Cocoa Research Institute

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Abstract

One of important steps in secondarycocoa process is deshelling cocoa beans roasted. The aim of deshelling is to enrich cotyledon cocoa surface area which affects to reduce energy and processing time with good quality of the chocolate product. The objective of this research is to study the influence of milling process on physical characteristic change of cocoa beans roasted such as size distribution change, geometrical diameter average, uniformity index, fineness modulus, and average dimension of cotyledoncocoa roasted. The Indonesian Coffee and Cocoa Research Institute has designed and tested deshelling of roasted cocoa beans which will be used in this research. Before deshelling process, C grade bulk cocoa beans has been roasted up to 2.5—3% water contents. The result showed that optimal milling process by rotary cutter type milling unit has good size distribution change, geometrical diameter average, uniformity index, fineness modulus, and average dimension on 500 rpm rotary speed and 2.8 m/s air flow. On optimal process condition, 74.5% of cocoa cotyledon roasted has diameter size between 2.0—4.75 mm, 2.116 mm average of geometrical diameter, 0.864 mm average dimension, 3.052 fineness modulus, and 80% as crude size particel-20% as temperate size particel on uniformity index. Therefore, more than 80% of cocoa cotyledon roasted has diameter size between 2.0—4.75 mm with 700—900 rpm rotary cutter speed. Average of geometric diameter was 1.65—2.19 mm, and the dimension average was 0.69—0.89 mm. Uniformity index was crude size particle up to 80—90%, and in temperate size particle10—20%. Fineness modulus value was 2.73—3.09. Key words: cocoa, milling, size distribution, roasted beans.