INVESTIGADORES
RAPISARDA Viviana Andrea
artículos
Título:
Synergistic antifungal activity of sodium hypochlorite, hydrogen peroxide and cupric sulfate against Penicillium digitatum
Autor/es:
CERIONI, L.; RAPISARDA, V. A.; HILAL, M.; PRADO, F. E.; RODRÍGUEZ-MONTELONGO, L.
Revista:
JOURNAL OF FOOD PROTECTION
Editorial:
International Association for Food Protection
Referencias:
Año: 2009 vol. 72 p. 1660 - 1665
ISSN:
0362-028X
Resumen:
Oxidizing compounds such as sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) are widely used in food
sanitation because of their antimicrobial effects. We applied these compounds and metals to analyze their antifungal activity
against Penicillium digitatum, the causal agent of citrus green mold. The MICs were 300 ppm for NaClO and 300 mM for
H2O2 when these compounds were individually applied for 2 min to conidia suspensions. To minimize the concentration of
these compounds, we developed and standardized a sequential treatment for conidia that resulted in loss of viability on growth
plates and loss of infectivity on lemons. The in vitro treatment consists of preincubation with 10 ppm NaClO followed by
incubation with 100 mM H2O2 and 6 mM CuSO4. The combination of NaClO and H2O2 in the presence of the cupric salt
produces a synergistic effect (fractional inhibitory concentration index of 0.36). The sequential treatment applied in situ on
lemon peel 24 h after the fruit was inoculated with conidia produced a significant delay in the fungal infection. The in vitro
treatment was effective on both imazalil-sensitive and imazalil-resistant strains of P. digitatum and Geotrichum candidum, the
causal agent of citrus sour rot. However, this treatment inhibited 90% of mycelial growth for Penicillium italicum (citrus blue
mold). These results indicate that sequential treatment may be useful for postharvest control of citrus fruit diseases.