TY - JOUR
T1 - NMR-Based Studies on Odorant-Melanoidin Interactions in Coffee Beverages
AU - Gigl, Michael
AU - Hofmann, Thomas
AU - Frank, Oliver
N1 - Publisher Copyright:
©
PY - 2021/12/22
Y1 - 2021/12/22
N2 - A quantitative 1H NMR-based approach was established, which allowed the direct and noninvasive analysis of molecular interactions between key coffee odorants and high-molecular-weight (HMW) melanoidin polymers. A clear distinction between covalent and noncovalent interactions was achieved by monitoring the time dependency of odorant-polymer interactions, resulting in four scenarios: covalent, π-π, covalent and π-π-, as well as no interactions. Evaluation of temperature influence on e.g. 2-furfurylthiol (FFT), revealed an altered behavior with increased π-πstacking at lower temperatures and accelerated covalent interactions at higher temperatures. Human sensory experiments with HMW material and a coffee aroma reconstitution model showed a drastic reduction of "roasty/sulfury"aroma notes, as well as an increased "sweetish/caramel-like"flavor. The lack of interactions between the "sweetish/caramel"smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone with the HMW melanoidins in combination with the high binding affinity of coffee thiols explains the sensory evaluation and is obviously the reason for the fast disappearance of the typical "roasty/sulfury"aroma impressions of a freshly prepared coffee brew.
AB - A quantitative 1H NMR-based approach was established, which allowed the direct and noninvasive analysis of molecular interactions between key coffee odorants and high-molecular-weight (HMW) melanoidin polymers. A clear distinction between covalent and noncovalent interactions was achieved by monitoring the time dependency of odorant-polymer interactions, resulting in four scenarios: covalent, π-π, covalent and π-π-, as well as no interactions. Evaluation of temperature influence on e.g. 2-furfurylthiol (FFT), revealed an altered behavior with increased π-πstacking at lower temperatures and accelerated covalent interactions at higher temperatures. Human sensory experiments with HMW material and a coffee aroma reconstitution model showed a drastic reduction of "roasty/sulfury"aroma notes, as well as an increased "sweetish/caramel-like"flavor. The lack of interactions between the "sweetish/caramel"smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone with the HMW melanoidins in combination with the high binding affinity of coffee thiols explains the sensory evaluation and is obviously the reason for the fast disappearance of the typical "roasty/sulfury"aroma impressions of a freshly prepared coffee brew.
KW - aroma binding
KW - coffee beverages
KW - covalent aroma binding
KW - melanoidins
KW - noncovalent π-πinteractions
KW - qHNMR
KW - quantitative NMR spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85121055616&partnerID=8YFLogxK
U2 - 10.1021/acs.jafc.1c06163
DO - 10.1021/acs.jafc.1c06163
M3 - Article
C2 - 34874702
AN - SCOPUS:85121055616
SN - 0021-8561
VL - 69
SP - 15334
EP - 15344
JO - Journal of agricultural and food chemistry
JF - Journal of agricultural and food chemistry
IS - 50
ER -