Investigation on polysaccharide, pectin and dietary fiber fractions of buckthornton berries

The alcohol-insoluble substance (AIS) was prepared from freshly picked buckthornton berries (Hippophae rhamnoides L.) (4.70% of the fresh substance). By sequential extraction with water, ammonium oxalate, 0.05 N HCl and 0.05 N NaOH, the following quantities of galacturonan/100 g AIS were obtained: 0.15 g, 0.4 g (ca.), 0.94 g, 2.29 g resp. These pectin extracts were purified as Cu2+ salts. After dialysis they were fractionated into a water-soluble and a water-insoluble part. In these fractions Glc, Gal and Xyl were the predominant neutral saccharide units. Ara, Rha and Man were present in smaller amounts. A higher GalA content (in g per 100 original AIS) was found in the soluble fractions (with the exception of the alkali extract). The pectins from buckthornton berries are middle-esterified and partially acetylated. The composition of the AIS was determined as 9.25% pectin, 34.8% protein and 38.9% total polysaccharides. In the residue after sequential pectin extraction (RE), which contained 60.0% of the AIS, 3.89% pectin, 12.9% protein and 28.0% total polysaccharides were found. By the enzymatic method the percentages of soluble and insoluble dietary fiber were estimated as 13.6% and 34.1% respectively, whereas the RE contained 5.1% soluble and 34.4% insoluble fiber. The following dietary fiber fractions were determined by the detergent method for both preparations: in case of AIS 36.2% NDF 3.0% NDF filtrate, 28.0% ADF and 9.6% lignin were found to be present, whilst in the RE, the following components were estimated: 32.8% NDE 1.4% NDF filtrate, 26.1% ADF and 10.1% lignin. The data presented relates to 100 g original AIS. The water binding capacity was observed to decrease from 7.50 g H2O (AIS) to 3.26 g H2O (RE) per 1 g original AIS. For both of these preparations, more than 40% of bound water was found in the NDF fractions and approximately 30% in the ADF fractions.