Detection of coffee adulteration with soybean and corn by capillary electrophoresis-tandem mass spectrometry

Autor(es)

Daniel, Daniela ^{[1, 2]} ; Lopes, Fernando Silva ^[2] ; dos Santos, Vagner Bezerra ^[3] ; do Lago, Claudimir Lucio ^[2]

Afiliação do(s) autor(es)

^[1] Agilent Technol, Alameda Araguaia, 1142, BR-06455000 Barueri, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Ave Prof Lineu Prestes, 748, BR-05508000 Sao Paulo, SP - Brazil

^[3] Univ Fed Para, Inst Ciencias Exatas & Nat, Rua Augusto Correa, 01 Setor Basico, BR-66075110 Belem, PA - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Food Chemistry; v. 243, p. 305-310, MAR 15 2018.
• Citações Web of Science: 9

Resumo

The detection of coffee adulteration with soybean and corn by capillary electrophoresis-tandem mass spectrometry was accomplished by evaluating the monosaccharides profile obtained after acid hydrolysis of the samples. The acid hydrolysis, using H2SO4 as a catalyst, increases the ionic strength of the sample impairing the electrophoretic separation. Therefore, Ba(OH)(2) was used to both neutralize the medium and reduce the content of sulfate by precipitation of BaSO4. The best separation of nine determined monosaccharides (fucose, galactose, arabinose, glucose, rhamnose, xylose, mannose, fructose and ribose) plus inositol as internal standard was obtained in 500 mmol.L-1 triethylamine, pH 12.3. The monosaccharides are separated as anionic species at this pH. The proposed method is simple, fast (< 12.0 min), present linear calibration curves (r(2) = 0.995), and relative standard deviation for replicate injections lower than 5%. The LOQ for all monosaccharides was lower than 0.01 mmol.L-1, which is in accordance with the tolerable limits for coffee. Principal component analysis (PCA) was used to evaluate interrelationships between the monosaccharide profile and the coffee adulteration with different proportions of soybean and corn. Fucose, galactose, arabinose, glucose, sucrose, rhamnose, xylose, mannose, fructose, and ribose were quantified in packed roast-and-ground commercial coffee samples, and differences between adulterated and unadulterated coffees could be detected. (AU)

• Processo FAPESP: 13/14993-1 - Caracterização e quantificação de monoalquil carbonatos em meio aquoso empregando dispositivos microfluídicos acoplado a um espectrômetro de massas
• Beneficiário: Vagner Bezerra dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/06642-1 - Formação e propriedades de adutos de hidróxi-compostos orgânicos com carbonato em meio aquoso e condições biológicas
• Beneficiário: Claudimir Lucio Do Lago
• Modalidade de apoio: Auxílio à Pesquisa - Regular