20
The values with different letters a-x in each column show a significant differencep0.05 Figure 10 Chlorogenic acid of coffee ground residue extracts
3. Caffeine
The result of caffeine was similar to those of the phenolic compound and CGA in the CGR extracts. The amount of caffeine in the CGR extract with different time of MAE was shown
in Figure 11. Sample B 3 minutes, B 4 minutes and A 3 minutes had higher amount of caffeine
compounds 192.02 mg100 g, 173.88 mg100 g, and 165.41 mg100 g, respectively than the others. Four minutes of MAE extracts also had higher amount of caffeine 22-173 mg100 g than
the other time of MAE. The results were slightly higher than those reported by Ramalakshmi et al. 2008 120 mg100 g in hexane solvent and Soxhlet extraction. Caffeine is a polar organic
molecule dissolved in polar solvent easier than in non polar solvent such as methanol and ethanol Upadhyay, 2011. The results also showed that the amount of caffeine were five-fold lower than
those in coffee beans 1000 mg100g Ramalakshmi et al., 2008. The coffee brewing could extract some bioactive compounds such as caffeine, chlorogenic acid, and flavonoid Minanisawa
et al., 2009.
4. Anthocyanin
The amount of anthocyanin in the CGR extracts obtained with different time of MAE was shown in Figure 12. The result was different from the other bioactive compounds which were
determined in this work. Generally, the amount of anthocyanin in the extracts was remarkably lower than the other compounds. The total amount of anthocyanin in Sample A 3 minutes, B 3
minutes, and B 4 minutes were 273.23 µg100 g, 208.93 µg100 g, 208.74 µg100 g, respectively, which were higher than those in the others samples. Furthermore, 3 minutes of MAE
extracts had higher amount of anthocyanin 43.31-273.23 µg100 g than those in the other time of MAE.
Anthocyanin in coffee fruit is mainly found in the pulphusk part approximately 25 mg100 g Murthy et al., 2012 and rarely found in coffee bean Murthy, 2011. The amount of
anthocyanin was very small in the CGR extracts because of the sensitivity of anthocyanin to several conditions especially light and heat exposure Ghosh, 2007. The coffee roasting and
coffee brewing made amount of anthocyanin in the CGR almost not detected.
Generally, the results of bioactive compounds content showed that the best three CGR extracts with the highest amount of the bioactive compounds were sample B 3 minutes, B 4
minutes and A 3 minutes based on the statistical analysis Appendix 3. The best three samples would be determined the antioxidant and antimicrobial activity.
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Coffee Ground Residue Extract
3 min 4 min
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21
The values with different letters a-v in each column show a significant differencep0.05 Figure 11 Caffeine content of coffee ground residue extracts
a
The amount of anthocyanin expressed as monomeric anthocyanin The values with different letters a-x in each column show a significant difference p0.05
Figure 12 Anthocyanin content of coffee ground residue extracts
D. Antioxidant Activity of Coffee Ground Residue CGR Extracts
