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Inactivation of aflatoxigenic aspergilli by treatment with ozone
L R Beuchat1, R Chmielewski, J Keswani
1Center for Food Safety and Quality Enhancement, Department of Food Science and Technology, University of Georgia, Griffin 30223-1797, USA.
Abstract:
The D-values of conidia of aflatoxigenic Aspergillus flavus and Aspergillus parasiticus exposed to 1.74 ppm. ozone in 1 mM potassium phosphate buffer (pH 7.0 and 5.5) at 25 degrees C were determined. D-values of A. flavus conidia were 1.72 and 1.54 min at pH 5.5 and 7.0, respectively; D-values of A. parasiticus were 2.08 and 1.71 min, respectively. None of these D-values was significantly (P < or = 0.05) different from each other.
Insights
Ozone effectively inactivates Aspergillus flavus and Aspergillus parasiticus conidia. The study determined D-values, indicating resistance, but found no significant differences between fungal species or pH levels.
Area of Science:
- Microbiology
- Food Science
- Mycology
Background:
- Aflatoxigenic Aspergillus species are significant food contaminants.
- Ozone is a potent antimicrobial agent used in food preservation.
- Understanding fungal resistance to ozone is crucial for effective decontamination strategies.
Purpose of the Study:
- To determine the D-values of aflatoxigenic Aspergillus flavus and Aspergillus parasiticus conidia.
- To evaluate the influence of pH on ozone inactivation efficacy.
- To compare the ozone resistance of the two fungal species.
Main Methods:
- Exposure of fungal conidia to 1.74 ppm ozone in potassium phosphate buffer.
- Determination of D-values (decimal reduction time) at pH 7.0 and 5.5.
- Statistical analysis to compare D-values between species and pH conditions.
Main Results:
- D-values for Aspergillus flavus conidia were 1.72 min (pH 5.5) and 1.54 min (pH 7.0).
- D-values for Aspergillus parasiticus conidia were 2.08 min (pH 5.5) and 1.71 min (pH 7.0).
- No statistically significant differences (P < 0.05) were observed in D-values among the tested conditions.
Conclusions:
- Both Aspergillus flavus and Aspergillus parasiticus conidia exhibit resistance to ozone inactivation.
- pH had no significant impact on the ozone D-values of these fungi under the tested conditions.
- Further research may be needed to optimize ozone treatment parameters for effective control of these aflatoxigenic molds.