Articles, Conferences and Workshop Papers Collection

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Browsing Articles, Conferences and Workshop Papers Collection by Author "Fox, Glen P."

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    Curcumin-based photosensitization inactivates aspergillus flavus and reduces aflatoxin B1 in maize kernels
    (ELSEVIER, 2019) Temba, Benigni A.; Fletcher, Mary T.; Fox, Glen P.; Harvey, Jagger; Okoth, Sheila A.; Sultanbawa, Yasmina
    Different methods have been applied in controlling contamination of foods and feeds by the carcinogenic fungal toxin, aflatoxin, but nevertheless the problem remains pervasive in developing countries. Curcumin is a natural polyphenolic compound from the spice turmeric (Curcuma longa L.) that has been identified as an efficient photosensitiser for inactivation of Aspergillus flavus conidia. Curcumin mediated photoinactivation of A. flavus has revealed the potential of this technology to be an effective method for reducing population density of the aflatoxin-producing fungus in foods. This study demonstrates the influence of pH and temperature on efficiency of photoinactivation of the fungus and how treating spore-contaminated maize kernels affects aflatoxin pro duction. The results show the efficiency of curcumin mediated photoinactivation of fungal conidia and hyphae were not affected by temperatures between 15 and 35 °C or pH range of 1.5–9.0. The production of aflatoxin B1 was significantly lower (p < 0.05), with an average of 82.4 μg/kg as compared to up to 305.9 μg/kg observed in untreated maize kept under similar conditions. The results of this study indicate that curcumin mediated pho tosensitization can potentially be applied under simple environmental conditions to achieve significant reduc tion of post-harvest contamination of aflatoxin B1 in maize.
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    Inactivation of aspergillus flavus spores by curcumin-mediated photosensitization
    (ELSEVIER, 2016) Temba, Benigni A.; Fletcher, Mary T.; Fox, Glen P.; Harvey, Jagger J. W.
    Minimizing fungal infection is essential to the control of mycotoxin contamination of foods and feeds but many potential control methods are not without their own safety concerns for the consumers. Photo dynamic inactivation is a novel light-based approach which offers a promising alternative to conven tional methods for the control of mycotoxigenic fungi. This study describes the use of curcumin to inactivate spores of Aspergillus flavus, one of the major aflatoxin producing fungi in foods and feeds. Curcumin is a natural polyphenolic compound from the spice turmeric (Curcuma longa). In this study the plant has shown to be an effective photosensitiser when combined with visible light (420 nm). The experiment was conducted in in vitro and in vivo where A. flavus spores were treated with different photosensitiser concentration and light dose both in buffer solution and on maize kernels. Comparison of fungal load from treated and untreated samples was determined, and reductions of fungal spore counts of up to 3 log CFU ml 1 in suspension and 2 log CFU g 1 in maize kernels were obtained using optimal dye concentrations and light dose combinations. The results in this study indicate that curcumin mediated photosensitization is a potentially effective method to decontaminate A. flavus spores in foods and feeds.
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    Tools for defusing a major global food and feed safety risk: non biological postharvest procedures to decontaminate mycotoxins in foods and feeds
    (American Chemical Society, 2016) Temba, Benigni A.; Sultanbawa, Yasmina; Kriticos, Darren J.; Fox, Glen P.; Harvey, Jagger J. W.; Fletcher, Mary T.
    Mycotoxin contamination of foods and animal feeds is a worldwide problem for human and animal health. Controlling mycotoxin contamination has drawn the attention of scientists and other food and feed stakeholders all over the world. Despite best efforts targeting field and storage preventive measures, environmental conditions can still lead to mycotoxin contamination. This raises a need for developing decontamination methods to inactivate or remove the toxins from contaminated products. At present, decontamination methods applied include an array of both biological and nonbiological methods. The targeted use of nonbiological methods spans from the latter half of last century, when ammoniation and ozonation were first used to inactivate mycotoxins in animal feeds, to the novel techniques being developed today such as photosensitization. Effectiveness and drawbacks of different nonbiological methods have been reported in the literature, and this review examines the utility of these methods in addressing food safety. Particular consideration is given to the application of such methods in the developing world, where mycotoxin contamination is a serious food safety issue in staple crops such as maize and rice.