However, it was lower than those described for pectins from apple pomace (82%; Min et al., 2011), Akebia trifoliata var. australis peel (80% and 71%; Jiang et al., 2012) and creeping fig seeds (78–88%; Liang et al., 2012). However, it was observed by Jiang et al.

(2012) that pectins obtained under the same conditions had different uronic acid contents depending on the extractant. These authors observed that pectin obtained with hydrochloric acid had higher uronic acid contents (80%) than had that obtained with citric acid (71%). Fig. 2A shows the HPSEC elution profiles of fractions GHW-II and GHW-IIET. The GHW-IIET fraction showed a remarkable reduction of the peak around 38 min as compared to the native fraction (GHW-II). The main peak

of the GHW-IIET fraction was observed around 48 min, and this peak could Y-27632 in vitro correspond to the pectic polysaccharide. Fraction GHW-IIET was then subjected to ultrafiltration (0.1 μm) to yield fraction GHW-IIETF. The monosaccharide composition of fraction GHW-IIETF was similar to that of GHW-IIET (Table 2). After ultrafiltration, HPSEC analysis showed a unimodal profile for fraction GHW-IIETF with a molar mass of 157,788 g/mol (Fig. 2). To allow the identification of the uronic acid units using GC-MS, fraction GHW-IIETF was subjected to the process of MEK activity carboxy-reduction with NaBD4 to obtain the neutral glycosidic units that correspond to acidic sugar. After hydrolysis and derivatization, the carboxy-reduced sample showed an increase of Gal of approximately seven times when compared

to GHW-IIETF fraction, confirming, as expected, the presence of galacturonic acid (GalA). The presence of GalA was also confirmed, based on the fragments containing 6,6-dideuteriomethylene that had two additional mass units, such as m/z 75, 219, 261, and 291. The low Rha:GalA ratio suggests that the pectin fraction isolated from guarana powder consists predominantly of a linear homogalacturonan chain. According to the monosaccharide composition, the 5-Fluoracil concentration branched regions are primarily linked to arabinan side chains. These results are similar to those obtained for pectins of sunflower (Miyamoto & Chang, 1992), lemon albedo (Ros, Schols, & Voragen, 1998), prickly pear fruit skin (Habibi, Heyraud, Mahrouz, & Vignon, 2004) and apple pomace (Min et al., 2011). However, they differ from those for pectins of quince (Forni, Penci, & Pollesello, 1994), spent hops (Oosterveld, Voragen, & Schols, 2002), butter squash fruit (O’Donoghue and Somerfield, 2008), cupuassu pulp (Vriesmann & Petkowicz, 2009) and cacao pod husks (Vriesmann et al., 2011), whose neutral side chains are mainly galactans or arabinogalactans. GHW-IIETF was examined using 13C-NMR spectroscopy (Fig. 2B). Resonances of δ 100.0 and 99.