scholarly journals ANALISIS KANDUNGAN KAFEIN PADA KOPI DI DESA SESAOT NARMADA MENGGUNAKAN SPEKTROFOTOMETRI UV-VIS

Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Aryanu Fahmi Arwangga ◽  
Ida Ayu Raka Astiti Asih ◽  
I Wayan Sudiarta
Keyword(s):  
Water Content ◽  
Correlation Coefficient ◽  
Calibration Curve ◽  
Coffee Bean ◽  
Caffeine Content ◽  
Coffee Powder ◽  
Food And Drink ◽  
Curve Equation ◽  
Maximum Limit ◽  
Standard Solutions

Coffee is one of the agriculture commodities that are cultivated by farmers. One of the compounds in the coffee is caffeine. Caffeine is one of alkaloids which contains in coffee bean. The purpose of this study was to determine the contents of caffeine in unripe coffee, pure coffee powder, and mix coffee powder by using UV-Vis spectrophotometer. Standard solutions of caffeine used were 1 ppm; 3 ppm; 6 ppm; 9 ppm; 12 ppm; and 15 ppm. Caffeine calibration curve equation was y = 0.0494x ??+ 0.01862 with a correlation coefficient (r) of 0.99714. Caffeine content in unripe coffee was 1,28±0,82 % with water content 3%, pure coffee powder 1,63±0,13 % with water content 1%, and mix coffee powder 0,87±0,01 % with water content 1%. According to SNI 01-7152-2006 maximum limit of caffeine in food and drink was 150 mg/day and 50 mg/dish.

scholarly journals Pengaruh Lama Penyangraian Yang Berbeda Terhadap Karakteristik Dan Mutu Organoleptik Seduhan Bubuk Kopi Liberika Tungkal Komposit”.

2020 ◽  
Vol 5 (1) ◽  
pp. 15
Author(s):  
Ridawati Marpaung ◽  
Lutvia Lutvia
Keyword(s):  
Water Content ◽  
Environmental Design ◽  
Coffee Bean ◽  
Evaluation Result ◽  
Organoleptic Quality ◽  
Randomized Design ◽  
Coffee Powder ◽  
Completely Randomized Design ◽  
Roasting Time

Penelitian ini bertujuan untuk mengetahui untuk mengetahui pengaruh lama penyangraian yang berbeda terhadap karateristik dan mutu organoleptik seduhan bubuk kopi liberika tungkal komposit.Penelitian dilaksanakan di Jambi, dimana proses fermentasi, pulping, pengeringan dan hulling dilakukan di Desa Mekar Jaya, Betara Tanjung Jabung Barat. Sedangkan penyangraian biji kopi serta analisis organoleptik seduhan kopi dilaksanakan di Laboratorium Dasar Universitas Batanghari Jambi. Rancangan lingkungan yang digunakan pada penelitian ini adalah rancangan acak lengkap (RAL). Rancangan perlakuan yaitu lama peyangraian dengan 5 taraf perlakuan sebagai berikut: L1: 5 Menit ; L2: 10 Menit ;  L3: 15 Menit dan   L4: 20 Menit. Setiap perlakuan dilakukan dengan 3 (tiga) ulangan.Dari hasil penelitian diperoleh bahwa lama penyangraian biji kopi liberika berpengaruh nyata terhadap kadar air pH (bubuk kopi), aroma, cita rasa, kepahitan dan kesukaan (seduhan bubuk kopi). Dari hasil penelitian dan analisis statistika panelis memberi penilaian kesukaan tertinggi pada seduhan bubuk kopi dengan lama penyangraian 15 menit.Kata kunci : Lama penyangraian,  Mutu organoleptik, Kopi Liberika. SUMMARYRidawati Marpaung (1968012619994032004), and Lutvia (....). influence of difference roasting time for characteristic and quality organoleptic of steepings of coffee powder Liberika Tungkal Komposit.The aim of this research was to know the influence of difference roasting time for characteristic and  quality organoleptic of steepings of coffee powder Liberika Tungkal Komposit.The research has done in Jambi, were fermentation procces, pulping, drying and hulling do in Mekar Jaya Village, Batara Kabupaten Tanjung Jabung Barat.The environmental design was Completely Randomized Design, and treatmen design was differend time roasting : L1 = 5 minutes ; L2 = 10 minutes ; L3 = 15 minutes and L4 = 20 minutes. The treatment do with 3 (three) repeat.This result research   showed that the different time roasting was significantly effected to the water content, pH, color, smeel, taste, bitterness and preference of coffe powder liquid. The panelist evaluation result showed that the  time roasting coffee bean was20 minutes  had given  the higher of smell, taste, bitterness, and its preference.keyword:  time of roasting, organoleptic quality, coffee Liberika.

scholarly journals FERMENTASI BIJI KOPI ARABIKA (Coffea arabica L.) DENGAN PENAMBAHAN BAKTERI ASAM LAKTAT (Lactobacillus sp)

2020 ◽  
Vol 10 (2) ◽  
pp. 87
Author(s):  
Zakia Arachmah Siregar ◽  
Devy Susanty ◽  
RTM Suthamihardja
Keyword(s):  
Water Content ◽  
Coffea Arabica ◽  
Ash Content ◽  
Coffee Bean ◽  
Arabica Coffee ◽  
Caffeine Content ◽  
Extract Content ◽  
Content Identification ◽  
Coffea Arabica L ◽  
Ground Coffee

FERMENTATION OF ARABIC COFFEE SEEDS (Coffea arabica L.) WITH THE ADDITION OF LACTO ACID BACTERIA (Lactobacillus sp)Coffee bean fermentation is one of a series of processes for making ground coffee that can affect coffee quality. In this study the fermentation of Arabica coffee beans was carried out using lactic acid bacteria (Lactobaciilus sp) in the form of a starter. The analysis was carried out on five samples, namely brand a coffee samples (sample A), coffee samples processed without bacteria (sample B), coffee samples processed with the addition of bacteria and substrate as many as 10:90 (sample C), 20:80 (sample D ), 30:70 (sample E). The five coffee samples were analyzed for water content, pH, extract content, ash content, and caffeine content. Identification of caffeine was carried out by the UV-Vis spectrophotometric method at a wavelength of 275.0397 nm. The highest caffeine content was in sample C at 0.95% and the lowest caffeine content was in sample E 0.71%. The highest extract content was found in sample E at 27.72% and the lowest content in C at 24.60%. The highest water content results were found in sample C of 4.56% and the lowest in sample E of 4.26%. The highest ash content was found in coffee C samples at 4.98% and the lowest ash content in E at 4.43%. The highest value of the degree of acidity (pH) was found in sample B (6.19) and the lowest in sample A (5.41). The results showed that the Arabica ground coffee met the SNI 01-3542-2004 requirements on parameters of moisture content, extract content, ash content and caffeine content. Keywords: Arabica coffee, fermentation, Lactobacillus sp, CaffeineABSTRAKFermentasi biji kopi merupakan salah satu rangkaian proses pengolahan pembuatan kopi bubuk yang dapat mempengaruhi kualitas kopi. Pada penelitian ini fermentasi biji kopi Arabica dilakukan menggunakan bakteri  asam laktat (Lactobaciilus sp) dalam bentuk starter. Analisis dilakukan terhadap lima sampel  yaitu sampel kopi merk a (sampel A), sampel kopi yang diproses tanpa bakteri (sampel B) , sampel kopi yang diproses dengan penambahan bakteri dan substrat sebanyak  10:90 (sampel C), 20:80 (sampel D), 30:70 (sampel E). Kelima sampel kopi tersebut dianalisis kadar air, pH, kadar sari, kadar abu, dan kadar kafein. Identifikasi kafein dilakukan dengan metode spektrofotometri UV-Vis pada panjang gelombang 275,0397 nm. Kadar kafein tertinggi terdapat pada sampel C sebesar 0,95 % dan  kadar kafein terendah pada sampel E 0,71%. Kadar sari tertinggi terdapat pada sampel E sebesar 27,72%  dan kadar sari terendah pada C sebesar 24,60%. Hasil kadar air tertinggi terdapat pada sampel C sebesar 4,56% dan kadar terendah pada sampel E sebesar  4,26%. Kadar abu tertinggi terdapat pada sampel kopi C sebesar 4,98% dan kadar abu terendah pada E sebesar 4,43%. Nilai derajat keasaman (pH) tertinggi didapatkan pada sampel B yaitu sebesar 6,19 dan terendah pada sampel A yaitu 5,41. Hasil uji menunjukkan bahwa kopi bubuk arabika dengan proses fermentasi enggunakan bakteri asam laktat memenuhi syarat SNI 01-3542-2004  pada parameter kadar air, kadar sari, kadar abu dan kadar kafein.Kata kunci: Kopi arabika, fermentasi, Lactobacillus sp, Kafein

scholarly journals ANALISIS KADAR KAFEIN, ANTIOKSIDAN DAN MUTU BUBUK KOPI BEBERAPA INDUSTRI KECIL MENENGAH (IKM) DI KABUPATEN TANAH DATAR [Analysis of Cafein, Antixidant and Quality Levels Coffee Powder of Some Medium Small Industries (IKM) In the Tanah Datar Regency]

2020 ◽  
Vol 25 (1) ◽  
pp. 1
Author(s):  
Ruri Wijayanti ◽  
Malse Anggia
Keyword(s):  
Water Content ◽  
Sampling Method ◽  
Quality Standards ◽  
Ash Content ◽  
The Public ◽  
Caffeine Content ◽  
Powder Samples ◽  
Coffee Powder ◽  
Small Industries

The caffeine, antioxidant levels, and the quality of coffee powder produced by some small and medium industries in Tanah Datar District were determined in this study. The results of this study are expected to be a reference for the public regarding the caffeine and antioxidants content, as well as the quality of the coffee powder. Samples were obtained from 3 sub-districts in Tanah Datar District, including Salimpauang District, Sungai Tarab District, and Limo Kaum District. The purposive sampling method was used in this study by considering the most famous coffee powder products and well-liked by the public. Analysis of the characteristics of the coffee powder included the caffeine and antioxidant levels, water content, and ash content, as well as organoleptic tests. The results showed that the caffeine content of the coffee powder of most SMI (4 from 6 SMI sample) in the Tanah Datar Regency met the quality standards of SNI.  The content of antioxidant was ranged from 32,79 to 39,53%. Likewise, the water (7%)  and ash (5%) content have fulfilled the SNI 01-3542-2004 quality standards. 

scholarly journals TINGKAT KEMATANGAN BIJI KOPI ARABICA (Coffea arabica L.) DALAM MENGHASILKAN KADAR KAFEIN

2019 ◽  
Vol 9 (1) ◽  
pp. 22
Author(s):  
Srikandi Srikandi ◽  
Aprilia Widia Kristanti ◽  
RTM Sutamihardja
Keyword(s):  
Water Content ◽  
Coffea Arabica ◽  
Maturity Level ◽  
Arabica Coffee ◽  
Caffeine Content ◽  
Coffee Arabica ◽  
Coffee Powder ◽  
Coffea Arabica L ◽  
Caffeine Level ◽  
Ground Coffee

Levels of Arabica (Coffea Arabica L.) Coffee Materials in Producing Caffein Coffee is a plantation crop that has long been cultivated in Indonesia. One type of coffee grown in Indonesia, namely arabica coffee. Arabica coffee is coffee that has superior quality compared to other types of coffee. Testing of caffeine content in Sukamakmur village arabica coffee is differentiated into three types of coffee berries based on the maturity level of the coffee fruit. The level of maturity of coffee fruit is marked by the color of coffee fruit skin. The collection of young coffee fruit is characterized by green fruit rind, half-aged coffee, orange rind and old coffee, dark red rind. Arabica coffee fruit is processed from drying, drying, and roasting and grinding into arabica ground coffee. Powder coffee samples are used for water content testing, phytochemical identification, and caffeine level testing. Caffeine content testing using UV-Vis spectrophotometry. The results of water content testing showed that the highest water content was found in coffee with a maturity level of half old, the lowest moisture content found in old coffee. Phytochemical identification testing performed showed powdered coffee samples containing active compounds of saponins, flavonoids, and alkaloids, as well as tannins. The highest caffeine content is found in ground coffee with the maturity level of coffee half old at 1.56% and the lowest caffeine level in ground coffee with a young coffee level of 0.93%.Keywords : Coffea arabica L., Level of maturity, Level of caffeine. ABSTRAKKopi adalah tanaman perkebunan yang sudah lama dibudidayakan di Indonesia. Salah satu jenis kopi yang ditanam di Indonesia, yaitu kopi arabika. Kopi arabika merupakan kopi yang memiliki kualitas superior dibanding jenis kopi lainnya. Pengujian kadar kafein pada kopi arabika desa Sukamakmur dibedakan menjadi tiga jenis pengambilan buah kopi berdasarkan tingkat kematangan buah kopi. Tingkat kematangan buah kopi ditandai dengan warna kulit buah kopi. Pengambilan buah kopi muda ditandai dengan kulit buah berwarna hijau, kopi setengah tua, kulit buah berwarna jingga dan kopi tua, kulit buah berwarna merah tua. Buah kopi arabika diolah dari penjemuran, pengeringan, dan penyangraian serta penggilingan menjadi kopi bubuk arabika. Sampel kopi bubuk digunakan untuk bahan pengujian kadar air, identifikasi fitokimia dan pengujian kadar kafein. Pengujian kadar kafein menggunakan metode spektrofometri UV-Vis. Hasil pegujian kadar air menunjukkan bahwa kadar air tertinggi terdapat pada kopi dengan tingkat kematangan setengah tua, kadar air terendah terdapat pada kopi tua. Pengujian identifikasi fitokimia yang dilakukan menunjukan sampel kopi bubuk mengandung senyawa aktif saponin, flavonoid, dan alkaloid, serta tanin. Kadar kafein tertinggi terdapat pada kopi bubuk dengan tingkat kematangan kopi setengah tua sebesar 1,56% dan kadar kafein terendah pada kopi bubuk dengan tingkat kopi muda sebesar 0,93%.Kata kunci: Coffea arabica L., Tingkat kematangan, Kadar kafein.

scholarly journals Evaluation of Diclofenac by UV-Vis Spectrophotometer in Some Locally Produced Tablets

2017 ◽  
Vol 65 (2) ◽  
pp. 163-165
Author(s):  
MK Hasan ◽  
MA Hossain ◽  
A Sultana ◽  
M Shoeb ◽  
N Nahar
Keyword(s):  
Correlation Coefficient ◽  
Active Ingredient ◽  
Calibration Curve ◽  
Diclofenac Sodium ◽  
Pharmaceutical Product ◽  
Concentration Levels

Diclofenac is a common and randomly used pharmaceutical product, was evaluated for its active ingredient by UV-Vis spectrophotometer at 282 nm. Diclofenac sodium of 50 mg dose of seven different companies of Bangladesh was extracted from the tablets, cleaned up and the active ingredient was evaluated. Evaluation was carried out with respect to calibration curve of standard diclofenac sodium. Amount of diclofenac in 50 mg tablets of seven different companies were found to be in the range of 47.91 ± 0.90 to 58.52 ± 0.41 mg. Recovery experiments were done by spiking excipient of the medicine at two different concentration levels with 5-7 replicate studies. Correlation coefficient (r2) was found to be 0.9974 and the recovery was103.39 ± 3.93 to 107.96 ± 3.56 % for the drug. Dhaka Univ. J. Sci. 65(2): 163-165, 2017 (July)

Determination and Confirmation of cis-9-Tricosene in Technical Materials by Capillary Gas Chromatography and Gas Chromatography/Mass Spectrometry

1992 ◽  
Vol 75 (5) ◽  
pp. 878-882
Author(s):  
Jinren Ko ◽  
Jack Nguyen ◽  
Jim Burleson
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Correlation Coefficient ◽  
Calibration Curve ◽  
Capillary Gas Chromatography ◽  
Methylene Chloride ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Technical Material ◽  
Standard Calibration

Abstract A capillary gas chromatographic (GC) method was developed for the quantitation of cis-9-tricosene in technical material. This method is capable of resolving cis-9-tricosene from the trans-9-tricosene isomer and other impurities in technical 9-tricosene. Samples are dissolved in methylene chloride and analyzed by splitless GC using docosane as an internal standard. The integrity and purity of the peak of interest were confirmed by GC/mass spectrometry. The overall recovery of this method was 101.3 ± 0.82%. The correlation coefficient of the standard calibration curve was 0.9999. The system and method precision for cis-9-tricosene were 0.18 and 0.20%, respectively. The reproducibility of the method by different analysts was within 0.5%.

Calibration curve equation in local voltammetry of heterogeneous alloys

2017 ◽  
Vol 72 (2) ◽  
pp. 203-205
Author(s):  
E. Yu. Moshchenskaya ◽  
V. V. Slepushkin ◽  
Yu. V. Rublinetskaya ◽  
B. I. Kashkarov
Keyword(s):  
Calibration Curve ◽  
Curve Equation ◽  
Heterogeneous Alloys ◽  
Local Voltammetry

Reproducibility and uncertainty of wastewater turbidity measurements

2008 ◽  
Vol 57 (10) ◽  
pp. 1667-1673 ◽  
Author(s):  
C. Joannis ◽  
G. Ruban ◽  
M.-C. Gromaire ◽  
J.-L. Bertrand-Krajewski ◽  
G. Chebbo
Keyword(s):  
Water Quality ◽  
Calibration Curve ◽  
Field Measurement ◽  
The Other ◽  
Special Focus ◽  
Sewer Systems ◽  
Other Hand ◽  
Main Components ◽  
Standard Solutions

Turbidity monitoring is a valuable tool for operating sewer systems, but it is often considered as a somewhat tricky parameter for assessing water quality, because measured values depend on the model of sensor, and even on the operator. This paper details the main components of the uncertainty in turbidity measurements with a special focus on reproducibility, and provides guidelines for improving the reproducibility of measurements in wastewater relying on proper calibration procedures. Calibration appears to be the main source of uncertainties, and proper procedures must account for uncertainties in standard solutions as well as non linearity of the calibration curve. With such procedures, uncertainty and reproducibility of field measurement can be kept lower than 5% or 25 FAU. On the other hand, reproducibility has no meaning if different measuring principles (attenuation vs. nephelometry) or very different wavelengths are used.

Determination of Sucralose by Controlled UV Photodegradation Followed by UV Spectrophotometry

2013 ◽  
Vol 96 (3) ◽  
pp. 603-606
Author(s):  
Mohd Idris ◽  
V Jayathirtha Rao ◽  
Deepak Middha ◽  
Sudhir Kumar Shukla ◽  
Tulsidas Ramachandra Rao Baggi
Keyword(s):  
Correlation Coefficient ◽  
Alkaline Medium ◽  
Spectrophotometric Method ◽  
Calibration Curve ◽  
Artificial Sweeteners ◽  
Uv Spectrophotometry ◽  
Medium Ph ◽  
Accuracy And Precision ◽  
Uv Photodegradation

Abstract A simple and time-efficient UV spectrophotometric method was developed for the determination of sucralose in artificial sweeteners. The procedure is based on the UV spectrophotometric determination of the photodegraded product at 270 nm in alkaline medium (pH 12). LOD for this method was 0.02 g/L, and the calibration curve was found to obey Beer's law in the concentration range of 0.1 to 1.2 g/L, with a correlation coefficient (R2) value of 0.9977. The proposed method was studied for accuracy and precision.

Impact of density on the hydraulic properties of peat and the time domain reflectometry (TDR) moisture calibration curve

2005 ◽  
Vol 42 (1) ◽  
pp. 279-286 ◽  
Author(s):  
Anushka Shibchurn ◽  
Paul J Van Geel ◽  
Paula L Kennedy
Keyword(s):  
Dielectric Constant ◽  
Soil Moisture ◽  
Water Content ◽  
Time Domain ◽  
Calibration Curve ◽  
Hydraulic Properties ◽  
Time Domain Reflectometry ◽  
Organic Soils ◽  
Dry Density ◽  
Water Contents

The hydraulic properties of a peat used in a commercial peat biofilter were evaluated to determine their relationship with density and to establish a time domain reflectometry (TDR) calibration curve for water content as a function of the measured dielectric constant. The peat studied was a milled Sphagnum peat with a high organic content (99%). The dry densities evaluated in this study ranged from 90 to 180 kg/m3. The saturated hydraulic conductivity (Ks) decreased with an increase in dry density (ρdry) and was found to follow a log-linear relationship (Ks = 0.2462 exp(–0.0438ρdry), correlation coefficient R2 = 0.9789). As expected, the soil moisture curve was impacted by density, with a higher density resulting in higher water contents for a given suction. The data were fit to the van Genuchten relationship. A TDR calibration curve was generated at five different densities. A comparison of the curves indicates that the water content as a function of dielectric constant was not dependent on density because of the significantly larger dielectric constant (Ka) of water compared with those of peat solids and air-filled voids. The TDR calibration curve for the peat evaluated in this study (volumetric water content Θv = 0.2667 ln(Ka) – 0.1405, R2 = 0.9564) predicted higher water contents for a given dielectric constant compared with those from similar calibration curves for peat published in the literature. The data were compared with those from six other studies and indicated that the TDR calibration varied for different organic soils. The density-dependent hydraulic parameters and TDR calibration curve are important parameters needed to study the hydraulics of peat biofilters.Key words: peat, TDR, time domain reflectometry, density, hydraulics, soil moisture.

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