Quantitative Analysis of Caffeine Levels in Local Coffee (Coffea sp) Powder on Dabo Island with UV-Vis Spectrophotometry

Coffee (Coffea sp) is a type of beverage that process comes from the processing of coffee beans. Nowadays, coffee is the second-largest beverage consumed by people all over the world, after water (Gaascht et al., 2015). Coffee has many benefits for health if used within reasonable limits, such as reducing headaches, coffee aroma relieving stress, caffeine coffee prevents cavities, relieve people with asthma, enrich the body's antioxidants, protect the skin, and stimulate brain work (Temple et al., 2017). Coffee has one compound content that is caffeine. Caffeine is one of the many types of alkaloids found in coffee beans, tea leaves, and cocoa beans (Wilson, 2018). Caffeine is a white crystalline compound. The main constituent of protein derived compounds are called Purin xanthine (Arwangga et al., 2016). Based on Indonesian National Standards (SNI) 01-7152-2006 The maximum limit of caffeine in foods and beverages is 150 mg/day and 50 mg/serving (Fajara & Susanti, 2017). This caffeine compound in normal body condition does have some efficacy among others is an analytic medication that can lower the pain and reduce fever (Grgic et al., 2018). However, on the body that also has problems with the presence of uric acid metabolism hormone, the content of caffeine in the body will trigger the formation of high uric acid (Pasalic et al., 2012). Research on the determination of caffeine levels in coffee has been done by the method of UV-Vis spectrophotometry. The research from Aptika et al. (2015) on the sample of the coffee powder in the check using UV-Vis spectrophotometry method obtained by the result of caffeine content consumed by the people of Quantitative Analysis of Caffeine Levels in Local Coffee (Coffea sp) Powder on Dabo Island with UV-Vis Spectrophotometry


INTRODUCTION
Coffee (Coffea sp) is a type of beverage that process comes from the processing of coffee beans. Nowadays, coffee is the second-largest beverage consumed by people all over the world, after water (Gaascht et al., 2015). Coffee has many benefits for health if used within reasonable limits, such as reducing headaches, coffee aroma relieving stress, caffeine coffee prevents cavities, relieve people with asthma, enrich the body's antioxidants, protect the skin, and stimulate brain work (Temple et al., 2017).
Coffee has one compound content that is caffeine.
Caffeine is one of the many types of alkaloids found in coffee beans, tea leaves, and cocoa beans (Wilson, 2018).
Caffeine is a white crystalline compound. The main constituent of protein derived compounds are called Purin xanthine (Arwangga et al., 2016). Based on Indonesian National Standards (SNI) 01-7152-2006 The maximum limit of caffeine in foods and beverages is 150 mg/day and 50 mg/serving (Fajara & Susanti, 2017). This caffeine compound in normal body condition does have some efficacy among others is an analytic medication that can lower the pain and reduce fever (Grgic et al., 2018). However, on the body that also has problems with the presence of uric acid metabolism hormone, the content of caffeine in the body will trigger the formation of high uric acid (Pasalic et al., 2012).
Research on the determination of caffeine levels in coffee has been done by the method of UV-Vis spectrophotometry. The research from Aptika et al. (2015) on the sample of the coffee powder in the check using UV-Vis spectrophotometry method obtained by the result of caffeine content consumed by the people of

Preparation of standard solutions
Caffeine standards of 250 mg are weighed and then entered in 250 ml measuring flasks. The standard is then dissolved in distilled water to the limit then homogenized by shaking. A total of 2.5 ml of the solution is then taken with a measuring pipette and then transferred in a 25 ml measuring flask. The solution is then diluted with distilled water to the limit and homogenized to obtain a standard solution of 100 ppm (Maramis et al., 2013).

Determination of the maximum wavelength
Uptake of 1 ml of standard solution was measured using a UV-Vis spectrophotometer with a wavelength range of 200-400 nm and blanks in the form of aquadest. The maximum wavelength obtained is 205.4 nm.

Determination of the calibration curve
Work standards are made by making a series of six solutions, each with a concentration of 2; 3; 4; 5; and 6 ppm. Each is made by taking as much as 2; 3; 4; 5; and 6 ml of standard solution respectively, then transferred to a 100 ml volumetric flask and dissolved with distilled water to the limit and homogenized.

Sample preparation
A total of 2 g of coffee powder from all three samples

Determination of caffeine concentration
The prepared sample was dissolved in 1 ml of distilled water and then transferred in a cuvette. The sample is then measured for absorption with a UV-Vis spectrophotometer at the maximum wavelength that has been obtained previously.

Determination of the calibration curve
Determination of the maximum wavelength obtained at the determination of the level of caffeine is used to make calibration curves, resulting in accuracy at high concentrations, thereby reducing placement errors or wavelength readings and obtaining maximum absorbance accuracy (Bhawani et al., 2015;Ahmed et al., 2015). getting closer to 1 indicates that the calibration curve that is formed is more linear, indicating a better equation (Bewick et al., 2003). The calibration curve is presented in Figure 1.  Table I.

CONCLUSION
Of the three coffee samples marketed on Dabo Island that were tested, all three met the SNI requirements. The caffeine content in Sample A was recorded at 0.3383 mg/2 g of the sample; in Sample B 0.3786 mg/2 g of the sample; and in Sample C 0.5803 mg/2 g of sample.
Further testing with other methods that have higher accuracy, such as HPLC can be done to ascertain the caffeine content of each coffee powder sample.