Jiu Liang Xu,a Tae Jin Kim,b Jae-Kwang Kim,b Yongsoo Choia,c,*
a Systems Biotechnology Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea
b Division of Life Science, College of Life Science and Bioengineering, Incheon National University, Incheon 22012, Republic of Korea
c Department of Biological Chemistry, University of Science and Technology, Youseng-gu, Daejeon 305-350, Republic of Korea
* Corresponding author : Yongsoo Choi, Ph.D.Systems Biotechnology Research Center, Korea Institute of Science and Technology (KIST), Daejeon-dong, Gangneung 210-340, Korea
Green coffee extracted by pressurized liquid extraction (PLE) was found to undergo a roasting process similar to traditional roasting. Liquid chromatography-tandem mass spectrometry was used to investigate the chlorogenic acid (CGA) composition and profiling changes by PLE under different extraction conditions and showed almost identical generation and degradation of CGAs occurring during traditional coffee roasting. Compared with the traditional extraction of roasted coffee, optimized PLE coffee showed three- and two-fold higher antioxidant activity and total CGA contents, respectively.
Composition diversity and the content of volatile compounds in PLE coffee were found to increase as the PLE temperature increased but were lower than those of traditionally roasted coffee. The sensory attributes of PLE coffee were also evaluated to have be associated with a profile change in the volatile compounds and non-volatile CGA compounds.
Keywords : hlorogenic acids, pressurized liquid extraction, coffee roasting, volatile compounds, antioxidant activity