Anhydrogalacturonic acid, content

Summarised in Table 1 is the neutral sugar compositions and anhydrogalacturonic acid content of XRPP released by pectinase reaction and acid hydrolysis, respectively. In both cases, XRPP were found to be rich in xylose and galactose content, but low in mannose content. The total neutral sugar content in XRPP released by acid hydrolysis was 28.4%,... 

The yields of crude pectins, as well as their anhydrogalacturonic acid content are given in Table I. This Table shows that about one third of the alcohol-insoluble residue can be solubilised as crude pectins, but the anhydrogalacturonlde content of these pectins is very low. Most of the pectins are extracted with acid and subsequently with alkali. Even after these extractions not all of the pectin is solubilised from the alcohol-insoluble residue its anhydrogalacturonic acid content is still some 5%. 

Table 1. The composition of neutral sugars and content of anhydrogalacturonic acid (%) in XRPP extracted with pH 1.6 HCl solution at 85° C for 4 h (1 g wheat straw/100 mL extractant) from defatted, protein-free wheat straw.

After Michaelic constant (KJ determination pectin concentration with known esterification degree was expressed in mol/M according to the content of anhydrogalacturonic acid. 

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