Influence of molecular weight on in vitro immunostimulatory properties of instant coffee.
Instant coffee was prepared and fractionated into higher (>100kDa), medium (5-10, 10-30, 30-100kDa) and lower (1-5, <1kDa) molecular weight fractions. Sugars and linkage composition characteristics of arabinogalactans and galactomannans were recovered in all fractions. Also, amino acid analysis performed after hydrolysis showed similar compositions in all fractions. On the contrary, free chlorogenic acids and caffeine were only detected in the lowest molecular weight fraction (<1kDa). A direct relationship between the melanoidins browning index and the molecular weight was observed. The fractions obtained were incubated in vitro with murine spleen lymphocytes in order to evaluate their possible immunostimulatory abilities. The surface expression of CD69 (early activation marker) on different lymphocyte sub-populations showed that the fraction with 1-5kDa was able to induce activation of B-lymphocytes. This was the only fraction to induce B-lymphocyte activation, since all the other fractions failed, even when higher concentrations were used.
QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: cpassos@ua.pt.
Cláudia P
CP
Passos
QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Márcio R
MR
Cepeda
QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Sónia S
SS
Ferreira
UTAD, Department of Chemistry, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal.
Fernando M
FM
Nunes
CICECO, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Dmitry V
DV
Evtuguin
ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal.
Pedro
P
Madureira
ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal.
Manuel
M
Vilanova
QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Manuel A
MA
Coimbra
D000818:Animals; D003069:Coffee / Q000737:chemistry*; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight
D003069:Coffee
Caffeine; Chlorogenic acids; Immunostimulatory activity; Melanoidins; Polysaccharides; Ultrafiltration