Classification of Coffee Beans by GC-C-IRMS, GC-MS, and ¹H-NMR

Table 1

Scientific articles on determination of origin of coffee.

Analytical technical	Presentation of coffee	Number of samples	Countries	Chemometric tool	Metabolites	Reference
ICP-AES	Roasted	160	Costa Rica (20), Colombia (20), Kenya, Guatemala, Panama, Sulawesi, Ethiopia, Sumatra	PCA, CDA, DFA, ANN	Multielements (19)	[18]
EA-P-IRMS	Green	45	Ethiopia, Malawi, Yemen, Zambia, Kenya, Tanzania, Brazil (5), Colombia (3), Guatemala, Mexico, Costa Rica, India, Sumatra, Jamaica, Hawaii	LDA, CART	Stable isotope ratios of C, H, O	[19]
IRMS	Green	46	Guatemala, Panama, Costa Rica, Brazil, Mexico, Venezuela, Nicaragua, Salvador, Honduras, India, Timor, Papua NG, Sri Lanka, Cameroon, Ethiopia, Uganda, Rwanda, Kenya, Zimbabwe	PCA	Stable isotope ratios of C, N, B	[1]
NIRS	Green	120		PCA	Moisture, fat, protein, sucrose, caffeine, trigonelline, organic acids, chlorogenic acids	[20]
GC-TOF-MS	Roasted	47	Production area: Brazil (11) and Colombia (8). Markets of coffee: Brazil (2), Colombia (12), Costa Rica, Guatemala	PCA	Volatile and semivolatile compounds	[14]
IRMS/EA	Green	68	4 R (Angola), 62 A (Papua NG, Ethiopia, Tanzania, Kenya, Hawaii, Costa Rica, Jamaica, Malawi, Guatemala, Brazil (8), East Timor, Peru (2), Ecuador, Mexico, Salvador, Nicaragua, Zambia, Rwanda, Indonesia)	PCA	Stable isotope ratios of C, N, O and percentage composition of C and N	[3]
HPLC	Green	107	57 A (Guatemala, Cameroon, Congo, Uganda, India, Indonesia, Java, Vietnam), 50 A (Brazil (6), Colombia (1), Costa Rica, Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Venezuela, Cameroon, Congo, Ethiopia, Kenya, Rwanda, Uganda, Zimbabwe, India, Indonesia, Java, Papua NG, Timor, Vietnam)	PCA, LDA, PLS-DA, CART	Chlorogenic acids, amides cinnamoyl, cinnamoyl glycoside, phenolic acids	[21]
LC-MS/; GC-FID	Roasted	21	Asia (4), South America (11), Africa (6)	PCA	Total protein, total carbohydrates, monosaccharides, amines	[15]
IRMS/MC-ICP-SFMS	Green	47	5 different Hawaii coffee-producing regions	CDA	Stable isotope ratios of C, N, S, O, Sr and multielements (30)	[22]
MC-ICP-MS/ IRMS	Green	60	Rwanda, Ethiopia, Tanzania, Kenya, Malawi, Zambia, Zimbabwe, Hawaii, Mexico, Costa Rica, Guatemala, Peru, Salvador, Nicaragua, Brazil, Ecuador, Jamaica, Indonesia, East Timor, Papua NG	PCA	Stable isotope ratios of Sr and O	[23]
ICP-MS/ IRMS	Green	64	Mexico, Guatemala, Honduras, Costa Rica, Salvador, Dom. Rep., Colombia (4), Brazil (6), Uruguay, Ivory Coast, Cameroon, Congo, Ethiopia, India, Indonesia	CDA	Stable isotope ratios of H, C, N, O and multielements (54)	[2]
^1H-NMR	Roasted	40	Cape Verde, Ethiopia, Kenya, Malawi, Saint Helena, Tanzania, Brazil (5), Colombia (2), Costa Rica, Salvador, Galapagos, Hawaii, Peru (2), Guatemala, Honduras, Jamaica, Nicaragua, India, Sumatra, Nepal, Yemen	OPLS-DA	Chlorogenic acids, trigonelline, lactate, caffeine, fatty acids	[12]
^13C-NMR	Green	60	Brazil (10), Colombia (10), Guatemala, Tanzania, Indonesia, Vietnam	PCA, OPLS-DA	Sucrose, caffeine, chlorogenic acids, choline, amino acids, organic acids, trigonelline	[13]
ICP-MS/ICP-AES	Green and roasted	42	Kenya, Ethiopia, Uganda, Indonesia, India, East Timor, Australia, Papua NG, Cuba, Dom. Rep., Costa Rica, Peru (1), Guatemala, Colombia (3), Brazil (2)	LDA, PCA	Multielements (59)	[24]
FT-IR	Green	18	4 different Brazil coffee-producing regions	ANN, SIMCA, MLP		[25]
MC-ICP-MS	Green	21	Taiwan, Ethiopia, Kenya, Tanzania, Malawi, Rwanda, Uganda, Brazil, Colombia, Peru, Salvador, Guatemala, Costa Rica, Puerto Rico, Jamaica, East Timor, Indonesia, Papua NG	PCA	Stable isotope ratios of B and Sr and multielements (7)	[26]
^1H-NMR	Green and roasted	340	Brazil (19), Colombia (70), Ecuador, Peru (16), Hawaii, Costa Rica, Dom. Rep., Mexico, Guatemala, Honduras, Nicaragua, Uganda, Togo, Tanzania, Ivory Coast, Cameroon, China, India, Indonesia, Vietnam	PCA, PLS-DA	Fatty acids, caffeine, acetate, organic acids, trigonelline, chlorogenic acids	[17]
HR-CS-AAS	Roasted	9	Brazil, Ethiopia, Colombia, India, Cuba, Mexico, Honduras, Guatemala, Kenya, Papua NG, Timor, Mussulo, China	ANOVA, CDA	Ca, Mg, Na, K, Fe, Mn	[27]
PTR-TOF-MS	Roasted	6	Brazil, Ethiopia, Guatemala, Costa Rica, Colombia, India	PCA, RF, PDA, dPLS, SVM, ANOVA	H3O^+, NO^+,	[28]
NIRS	Green	90	4 different Brazil coffee-producing regions	PLS-DA	Sucrose, lipids, amino acids, caffeine, trigonelline, chlorogenic acids	[29]
UPLC-MS	Green	100	4 different Ethiopia coffee-producing regions	PCA, LDA, ANOVA	Chlorogenic acids	[30]

ICP-AES, Inductively Coupled Plasma Atomic Emission Spectroscopy; EA-P-IRMS, Elemental Analysis-Pyrolysis-Isotope Ratio Mass Spectrometry; NIRS, Near-Infrared Spectroscopy; GC-TOF-MS, Gases Chromatography-Time-of-Flight-Mass Spectrometry; HPLC, High Performance Liquid Chromatography; LC-MS, Liquid Chromatography-Mass Spectrometry; GC-FID, Gas Chromatography-Flame Ionization Detector; MC/ICP/SFMS, Multiple Detector/Collector-Inductively Coupled Plasma-Sector Field Mass Spectrometry; NMR, Nuclear Magnetic Resonance; FT-IR, Fourier Transform Infrared Spectroscopy; PCA, Principal Component Analysis; CDA, Canonical Discriminant Analysis; DFA, Discriminant Function Analysis; ANN, Artificial Neural Network; LDA, Linear Discriminant Analysis; CART, Classification and Regression Tree; PLS-DA, Partial Least Squares-Discriminant Analysis; OPLS-DA, Orthogonal Partial Least Squares-Discriminant Analysis; SIMCA, Soft Independent Modelling of Class Analogy; MLP, Multilayer Perceptron; RF, Random Forest; PDA, Penalized Discriminant Analysis; dPLS, Discriminant Partial Least Squares; SVM, Support Vector Machines.