Phenolic concentrations of plant extracts used in the trials of
the
first year are shown in Table 1. In O. crenata, TPC increased
almost linearly with the extract concentration, whereas, in 3
S.
minor extract, TPC was only slightly above the previous dilution
(2). Phenolic concentration was not significantly influenced by
salts, except for 3
S. minor solution containing NaHCO3, in which a
strong reduction (more than 60%) compared to the corresponding
solution without NaHCO3 was found (Table 1). Such result might be
explained by the possible presence in this solution of components
particularly sensitive to alkaline pH induced by NaHCO3 (pH = 9.5).
Phenolic concentrations of plant extracts used in the trials of the
second year were not significantly different from those of the
first
year (data not shown).