Natural maize phytochemicals as fungal preservatives in non-sterilized maize

NESCI, A; MARÍN, S.; ETCHEVERRY, M.; SANCHIS, V.

Estanbul, Turquía

Simposio; XII International IUPAC Symposium on Mycotoxins and Phycotoxins; 2007

This study was carried out to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) and ferulic acid (FA) on Aspergillus section Flavi, natural fungal contamination and aflatoxin B1 accumulation in vitro. Two phenolic acids alone (CA: 20, 25 mM and FA: 30 mM) and 2 mixtures (CA 20 mM/FA 30 mM and CA 25 mM/FA 30 mM) were used. A factorial experiment was designed consisting of 3 factors, aw (0.99, 0.97 and 0.94), preservatives concentrations and A. flavus (RCM89) and A. parasiticus (RCM38) inoculums (1 ml of 1 x 104 spores/ml). Spanish dent maize grain were put into sterile flasks and adjusted to the appropriate aw. Flasks were incubated at 25ºC. Colonisation of grain which each fungal genera and aflatoxin B1 were determined after 11 and 35 days of incubation. The major effect on fungal contamination was that of incubation time and antifungal treatments (P<0.0001). Overall, CA 25 mM and the mixture CA 25 mM/FA 30 mM were the treatments most effective at inhibiting total natural maize fungal populations at all aw both after 11 and 35 days of incubation. The efficacy of all phenolic acids treatments against Aspergillus section Flavi was dependent on days of incubation, with better control after 11 days. The efficacy of the phenolic acids treatments against Penicillium, Eurotium and Fusarium was dependent on aw, with better control at low aw. At all aw values, the mixture CA 25 mM/FA 30 mM completely inhibited aflatoxin B1 production by both strains at all aw assayed.