Modulation of coffee aroma via the fermentation of green coffee beans with Rhizopus oligosporus: I. Green coffee.
Modulation of coffee aroma via the biotransformation/fermentation of different coffee matrices during post-harvest remains sparingly explored despite some studies showing their positive impacts on coffee aroma. Therefore, this is an unprecedented study aimed at modulating coffee aroma via the fermentation of green coffee beans with a food-grade fungus Rhizopus oligosporus. The objective of part I of this two-part study was to characterize the volatile and non-volatile profiles of green coffee beans after fermentation. Proteolysis during fermentation resulted in 1.5-fold increase in the concentrations of proline and aspartic acid which exhibited high Maillard reactivity. Extensive degradation of ferulic and caffeic acids led to 2-fold increase in the total concentrations of volatile phenolic derivatives. 36% of the total volatiles detected in fermented green coffee beans were generated during fermentation. Hence, the work presented demonstrated that R. oligosporus fermentation of green coffee beans could induce modification of the aroma precursors of green coffees.
Food Science and Technology Programme, Department of Chemistry, National University of Singapore, S14 Level 5, Science Drive 2, Singapore 117542, Singapore.
Liang Wei
LW
Lee
Kerry Ingredients Asia Pacific, 8 Biomedical Grove, #02-01/04 Neuros, Singapore 138665, Singapore.
Mun Wai
MW
Cheong
Firmenich Asia Pte Ltd., 10 Tuas West Road, Singapore 638377, Singapore.
Philip
P
Curran
Silesia Flavours South East Asia Pte Ltd., 41 Science Park Road, The Gemini, Science Park II, Singapore 117610, Singapore.
Bin
B
Yu
Food Science and Technology Programme, Department of Chemistry, National University of Singapore, S14 Level 5, Science Drive 2, Singapore 117542, Singapore; National University of Singapore (Suzhou) Research Institute, No. 377 Linquan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China. Electronic address: chmLsq@nus.edu.sg.
Shao Quan
SQ
Liu
D003069:Coffee / Q000737:chemistry*; D005285:Fermentation; D010636:Phenols; D012233:Rhizopus / Q000737:chemistry*; D012903:Smell
D003069:Coffee; D010636:Phenols
Aroma precursors; Extracellular enzymes; Fermentation; Green coffee beans; Rhizopus oligosporus; Volatile profile