These results confirmed the strong efficacy of S. minor extract
already reported by Gatto et al. (2011). Moreover, it should be
considered that these results refer to crude extracts, which could
contain substances (e.g., sugars) able to counteract the inhibitory
effect of active compounds present in the extract. It is possible that
purified extracts and/or single active principles might provide
better results. The combined use of extracts and salts did not show
any additive/synergistic effect. Indeed, the observed inhibitory
effect was not significantly different from the one obtained with
extracts or salts applied alone (Fig. 2). The presence of salts in plant
extracts could modify the phenolic compounds activity; for
example, the alkaline pH of NaHCO3 solution (pH = 9.5) might
alter compound stability, while Ca2+ ions present in CaCl2 solution
might interfere with the complex inhibition mechanism either
reducing the effectiveness of phenols or stabilizing the fungal
cytoplasmic membrane (Pitt and Ugande, 1984).