On the basis of the presented results it can be concluded that
accurate chromatographic determination of neutral sugars and
galacturonic acid in enzymatically extracted apple pectins and
apple pomace must be preceded by two separate acidic hydrolysis
(2 M TFA, 2.5 h) conducted at different temperatures. In order to
determine the NS profiles, samples should be hydrolysed in milder
conditions – 100 C, whereas a higher temperature – 120 C, is suitable
for GalA determination. Such conditions assure the minimisation
of errors resulting from different degrees of neutral sugar
degradation or incomplete depolymerisation of polygalacturonic
acid. The levels of neutral sugars and galacturonic acid in pectins
and apple pomace subjected to the hydrolysis procedure described
above amounted to 90% and 73.8%, respectively.