In vitro effect of phenolic antioxidants on germination, growth and aflatoxin B accumulation by peanut Aspergillus section Flavi.
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.
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ABSTRACT: The effect of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), trihydroxybutyrophenone (THB) and propyl paraben (PP) (at concentrations of 1, 10 and 20 mmol l(-1)) on germination, growth and aflatoxin B1 production by Aspergillus section Flavi was evaluated. Studies on the percentage of spore germination, elongation rate, growth rate and aflatoxin B1 production were carried out in vitro in relation to water activity (aw) at 0.982, 0.937, 0.809 and 0.747 values. At 0.809 and 0.747aw values none of the isolates was able to germinate. Overall, PP and BHA were the antioxidants most effective at inhibiting germination of both species. In the presence of the lowest concentration of BHA and PP (1 mmol l(-1)) the conidial germination percentage ranged from 2 to 19% after 15 h of incubation at the highest water activity tested. BHA and PP at 10-20 mmol l(-1) completely inhibited conidial germination. The antioxidants more efficient in controlling Aspergillus elongation rate were PP, BHT and BHA. All strains were much more sensitive to all antioxidants tested on the percentage of spore germination and growth rate at 0.937aw. The antioxidants PP and BHA completely inhibited aflatoxin B1 production by all strains when added at 1 mmol l(-1). Decreased aflatoxin B1 levels in comparison with the control, were observed with BHT at 1, 10 and 20 mmol(-1) with the strain T20 at 0.982aw. In contrast, stimulation was observed with the antioxidant THB at 10 and 20 mmol l(-1) at 0.937aw with the strains T20 and T23. The effect of BHA and PP at 1 mmol l(-1) on lag phase and growth rate was maintained in the pH range between 6 and 8. At all pH values the inhibitory effect of BHA was higher than PP. No aflatoxin B1 was detected at all pH values. The data show that BHA and PP could be considered as effective fungitoxicants for A. flavus and A. parasiticus. The information obtained show promise for controlling growth and aflatoxin B1 in stored maize. Futher studies should be carried out to examine the potential for antioxidants, such as BHA and PP to effectively control both growth and aflatoxin production.Journal of Applied Microbiology 02/2003; 95(2):279-87. · 2.20 Impact Factor
- Journal of the American Pharmaceutical Association 09/1953; 42(8):449-57.
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ABSTRACT: Results obtained with in situ mitochondria of Trypanosoma cruzi showed that this protozoon had only two energy coupling sites, sites II and III that correspond to higher eukaryote mitochondria. Rotenone did not inhibit the oxygen uptake of the parasite. These results suggest that the NADH-ubiquinone segment of the respiratory chain has no activity. Studies with in situ mitochondria confirmed that BHA, an antioxidant food additive, blocks the mitochondrial electron transport chain at the succinate-cytochrome b segment being the molecular basis of this trypanocidal action.FEBS Letters 06/1992; 303(1):73-6. · 3.58 Impact Factor