Roasting has revealed coffee’s potentials as a good source of bioactive compounds. This study was done to investigate the quantitative presence and activity of bioactive compounds including caffeine, chlorogenic acid (CGA), amino acids, and antioxidant capacity on Coffea arabica L. (Guatemala finca San Sebastian) and C. robusta L. (India Azad Hind). Analysis was performed on Green Bean (GB) Medium-Light (ML), Medium (ME) and Medium-Dark (MD) samples of both varieties. From the results, caffeine content was highest in ME samples of both varieties. GB samples of both varieties had high CGA content which decreased after increasing roasting time and temperature. Most amino acids in GB samples was highest, however, glutamic acid, valine, tyrosine, isoleucine, leucine and phenylalanine had highest quantitative increase in ME samples for both varieties. IC50 of DPPH and ABTS radical scavenging activity was highest in ML samples of both varieties. IC50 of reducing power and total phenolic content was highest in GB sample of both varieties but decreased after increasing roasting conditions. Generally Robusta had the highest quantity of bioactive compounds and antioxidant activity. From this study, the optimal roasting condition for coffee is ME above which there is a significant reduction of bioactive compounds and antioxidant activity.

Abstract
  Introduction
  Materials and Methods
  Results and Discussion
  References

• Jae Lim Song(School of Applied Bioscience, Kyungpook National University)
• Theophilus Siaw Asare(Regional Department of Food and Agriculture)
• Mi Young Kang(Department of Food Science and Nutrition, Kyungpook National University)
• Sang Chul Lee(School of Applied Bioscience, Kyungpook National University) Corresponding author