Article

In vitro effect of phenolic antioxidants on germination, growth and aflatoxin B accumulation by peanut Aspergillus section Flavi.

Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, 5800 Córdoba, Argentina.
Journal of Applied Microbiology (Impact Factor: 2.39). 02/2005; 99(3):682-91. DOI: 10.1111/j.1365-2672.2005.02661.x
Source: PubMed

ABSTRACT The effectiveness of the food-grade antioxidants butylated hydroxytoluene (BHT), trihydroxybutyrophenone (THB), propyl paraben (PP) and butylated hydroxyanisole (BHA) at 1, 10 and 20 mmol l(-1) concentrations on germination, growth, and aflatoxin B(1) (AFB(1)) production by Aspergillus section Flavi strains was determined.
Assays on the lag phase of germination, germination percentage, germ tube elongation rate, lag phase, growth rate and AFB(1) production by three strains of Aspergillus flavus and three of Aspergillus parasiticus were carried out in vitro on peanut extract meal agar conditioned at different water activities (a(w): 0.982, 0.971, 0.955, 0.937). The antioxidants PP and BHA efficiently inhibited the germination of the two species tested at the doses 10 and 20 mmol(-1). The antioxidants PP and BHA at 1 mmol l(-1) and THB at 20 mmol l(-1) reduced the germ tube elongation rate most effectively, regardless of a(w) levels. An increase in the lag time and a reduction in the growth rate of 100% of the strains was observed, this was due to the action of BHT at the doses 10 and 20 mmol(-1) at 0.982, 0.971 and 0.955 a(w), although these treatments stimulated the AFB(1) accumulation in most of the fungi tested. The more effective antioxidants were PP and BHA, which increased the lag phase, reduced the growth rate and AFB(1) production in all of the strains at the four a(w) assayed. At concentrations 10 and 20 mmol l(-1), these antioxidants totally inhibited fungal development.
The study shows that the antioxidants BHA and PP are effective fungal inhibitors to peanut Aspergillus section Flavi in wide range of water activity.
The results suggest that phenolic antioxidants, BHA and PP, can be effective fungitoxicants on aflatoxigenic strains in peanut at industrial level.

0 Bookmarks
 · 
88 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effect of six glyphosate concentrations on growth rate and aflatoxin B1 (AFB1) production by Aspergillus section Flavi strains under different water activity (aW) on maize-based medium was investigated. In general, the lag phase decreased as glyphosate concentration increased and all the strains showed the same behavior at the different conditions tested. The glyphosate increased significantly the growth of all Aspergillus section Flavi strains in different percentages with respect to control depending on pesticide concentration. At 5.0 and 10 mM this fact was more evident; however significant differences between both concentrations were not observed in most strains. Aflatoxin B1 production did not show noticeable differences among different pesticide concentrations assayed at all aW in both strains. This study has shown that these Aspergillus flavus and A. parasiticus strains are able to grow effectively and produce aflatoxins in high nutrient status media over a range of glyphosate concentrations under different water activity conditions.
    Journal of Environmental Science and Health Part B Pesticides Food Contaminants and Agricultural Wastes 12/2013; 48(12):1070-9. · 1.10 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The antifungal potential of five plant-derived essential oils (EOs) (boldo [Pëumus boldus Mol.], poleo [Lippia turbinata var. integrifolia (Griseb.)], clove [Syzygium aromaticum L.], anise [Pimpinella anisum], and thyme [Thymus vulgaris]) was evaluated against aflatoxigenic Aspergillus strains on peanut-based medium conditioned at different water activity (aW) levels (0.98, 0.95, 0.93). Effects of EOs added to the peanut meal extract agar on the lag phase, growth rate, and aflatoxin B1 (AFB1) accumulation by Aspergillus flavus and A. parasiticus were evaluated. The five EOs analyzed have been shown to influence lag phase, growth rate, and AFB1 accumulation. Although the low dose (500 ppm) of boldo, poleo, and clove showed no significant effects on lag phase (range of increase = 0–75%) and growth rate (range of reduction = 0–65%), the application of high concentrations of these EOs (2500 μl l−1 for boldo and poleo and 1500 μl l−1 for clove) completely inhibited growth of Aspergillus species, regardless of aqueous medium availability. The anti-aflatoxigenic property of boldo and poleo EOs (500 μl l−1) was more marked with the medium aW reduction; inhibition percentages were estimated at 75, 83, and 100% at 0.98, 0.95, and 0.93 aW, respectively.These findings support the application of boldo, poleo, and clove EOs for surface treatment and leave open the possibility of using them as vapor exposure to prevent mold contamination in stored peanut.
    International Biodeterioration & Biodegradation 05/2012; 70:82–88. · 2.24 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The present investigation reports the antifungal and antiaflatoxigenic properties of essential oils (EOs) from boldo (Pëumus boldus Mol.), poleo (Lippia turbinata var. integrifolia Griseb., clove (Syzygium aromaticum L.) and from boldo and poleo mixtures present in the headspace of peanut extract medium at three water activity levels (aW) (0.98, 0.95 and 0.93). Moreover, the ability of boldo and poleo oils to maintain their antifungal activity was evaluated after subjecting them to environmental variations. Boldo EO at doses ≥1500 μL/L showed a highly significant effect on Aspergillus section Flavi lag phase (>300 h), growth rate (93–100% of inhibition) and aflatoxin B1 (AFB1) accumulation (100% of inhibition) at all aW levels assayed. The antifungal and antiaflatoxigenic effects of poleo and clove EOs were highly dependent on aW. In general boldo–poleo oil mixtures showed less inhibitory activity on Aspergillus strains than the boldo pure oil. The antifungal ability of volatile components released by boldo and poleo EOs was stable against temperature changes; while it was reduced when poleo was stored during six months and when boldo was exposed to sunlight and UV.Boldo and poleo EO volatile fractions can be used as effective non-toxic biopreservatives in stored peanut industry against AF contamination.
    Lebensmittel-Wissenschaft und-Technologie 10/2013; 53(2):434–444. · 2.47 Impact Factor

Full-text (2 Sources)

Download
8 Downloads
Available from
Oct 13, 2014