GRAPE POMACE AS A POTENTIAL FOOD FIBER

Grape pomace, and insoluble and soluble dietary fiber (DF) fractions, obtained by enzymatic-gravimetric methods, were analyzed for neutral s ugars, uronic acids, Klason lignin and amino acids. DF constituted 80% of dry matter, IDF was the major fraction. The main neutral sugar con stituent of IDF was glucose. The major part was cellulose and the rema inder, along with xylose, was a xyloglucan, which also contained fucos e. Uronic acids accounted for 64% of SDF and a high amount of arabinos e, galactose and mannose were also included in that fraction. Proteins were not well solubilized by the assay enzymes. During the isolation of DF fractions a considerable solubilization of polyphenols was obser ved. These compounds were associated with Klason lignin in the startin g material. Composition of DF fractions enables grape pomace to be con sidered a useful fiber-rich food ingredient.