Characterization of high molecular weight coffee fractions and their fermentation by human intestinal microbiota.

To investigate the structure and fermentability of high M(r) components of coffee brews by human gut bacteria Arabica coffee samples of three different degrees of roast (light, medium, and dark) were used for drip brew preparations and fractionation by ultrafiltration with different M(r) cut-offs. Total carbohydrates of the fractions ranged from 28.6 g/100 g to 56.

Characterization and fermentability of an ethanol soluble high molecular weight coffee fraction.

Brews from differently roasted Arabica coffees were shown to contain 8-12% ethanol soluble substances with molecular masses greater than 2 kDa, possibly contributing to their dietary fiber contents. About 13% of these substances were nondigestible carbohydrates, mainly arabinogalactans. The nondigestible high molecular weight ethanol soluble fraction (HESF) of the medium roasted coffee brew was further characterized and subjected to in vitro fermentation with human fecal bacteria.

Coffee dietary fiber contents and structural characteristics as influenced by coffee type and technological and brewing procedures.

Coffee brews contain considerable amounts of soluble dietary fiber, mainly low substituted galactomannans and type II arabinogalactans. Factors possibly influencing the content and structures of dietary fiber in coffee brews, such as type of coffee, roasting and grinding degree, and brewing procedure, were studied. In addition, several commercial samples such as instant espresso, instant coffee, instant cappuccino, decaffeinated coffees, and coffee pads were analyzed.

Dietary fiber from coffee beverage: degradation by human fecal microbiota.

Arabinogalactans and galactomannans from coffee beverages are part of the dietary fiber complex. Chemical structures and fermentability of soluble dietary fiber obtained from a standard filter coffee beverage (Coffea arabica, origin Colombia, medium roasted) by human intestinal bacteria were investigated. One cup (150 mL) of filter coffee contained approximately 0.

Isolation and structural identification of diarabinosyl 8-O-4-dehydrodiferulate from maize bran insoluble fibre.

The first saccharide ester of a dehydrodiferulic acid (DFA) other than 5-5-DFA has been isolated from maize bran insoluble fibre after acidic hydrolysis and fractionation by gel chromatography and semi-preparative RP-HPLC. HPLC-MS along with 1D, 2D and 3D NMR spectra provided the requisite structural evidence that it is the di-5-O-l-arabinosyl ester of 8-O-4-DFA. Although a range of DFAs have been well authenticated as components released from the cell walls of grasses, the only structural evidence for a DFA attached to polysaccharides had been from 5-5-DFA.