Distinguishing between Decaffeinated and Regular Coffee by HS-SPME-GC×GC-TOFMS, Chemometrics, and Machine Learning

Coffee, one of the most popular beverages in the world, attracts consumers by its rich aroma and the stimulating effect of caffeine. Increasing consumers prefer decaffeinated coffee to regular coffee due to health concerns. There are some main decaffeination methods commonly used by commercial coffee producers for decades. However, a certain amount of the aroma precursors can be removed together with caffeine, which could cause a thin taste of decaffeinated coffee. To understand the difference between regular and decaffeinated coffee from the volatile composition point of view, headspace solid-phase microextraction two-dimensional gas chromatography time-of-flight mass spectrometry (HS-SPME-GC×GC-TOFMS) was employed to examine the headspace volatiles of eight pairs of regular and decaffeinated coffees in this study. Using the key aroma-related volatiles, decaffeinated coffee was significantly separated from regular coffee by principal component analysis (PCA). Using feature-selection tools (univariate analysis: t-test and multivariate analysis: partial least squares-discriminant analysis (PLS-DA)), a group of pyrazines was observed to be significantly different between regular coffee and decaffeinated coffee. Pyrazines were more enriched in the regular coffee, which was due to the reduction of sucrose during the decaffeination process. The reduction of pyrazines led to a lack of nutty, roasted, chocolate, earthy, and musty aroma in the decaffeinated coffee. For the non-targeted analysis, the random forest (RF) classification algorithm was used to select the most important features that could enable a distinct classification between the two coffee types. In total, 20 discriminatory features were identified. The results suggested that pyrazine-derived compounds were a strong marker for the regular coffee group whereas furan-derived compounds were a strong marker for the decaffeinated coffee samples.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:27

Enthalten in:

Molecules (Basel, Switzerland) - 27(2022), 6 vom: 10. März

Sprache:

Englisch

Beteiligte Personen:

Zou, Yun [VerfasserIn]
Gaida, Meriem [VerfasserIn]
Franchina, Flavio A [VerfasserIn]
Stefanuto, Pierre-Hugues [VerfasserIn]
Focant, Jean-François [VerfasserIn]

Links:

Volltext

Themen:

3G6A5W338E
Aroma profile
Caffeine
Coffee
Decaffeination
Journal Article
PCA
PLS-DA
Random forest
Solid-phase microexaction
T-test
Time-of-flight mass spectrometry
Two-dimensional gas chromatography

Anmerkungen:

Date Completed 01.04.2022

Date Revised 01.04.2022

published: Electronic

Citation Status MEDLINE

doi:

10.3390/molecules27061806

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM338654178