It was also possible to verify that
at both VRF 4 and 6 all the phenolic compounds quantified
were in significantly greater amounts than in the optimized
extract (unfiltered) (p < 0.05) (Table 4). Nghiem and Hawkes
(2007) and Wang et al. (2010) indicate that an increase of some
compounds in the concentrate during concentration through
membranes can be explained by some factors, such as reduction
of pore size of the membrane, adsorption of solutes,
concentration polarization and fouling. Schäfer et al. (2010)
suggested that the organic matter of some matrices can show
interactions among the compounds, especially between cellulose
and phenolic hydroxyl, thus resulting in a higher content
of aglycone.