Dietary Exposure and Risk Assessment of Mycotoxins in Thyme and Thyme-Based Products Marketed in Lebanon.

This study aimed at evaluating the incidence of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in thyme and thyme-based products, related dietary exposure, and cancer risk for regular and high consumption. A total of 160 samples were collected, and 32 composite samples were analyzed. AFB1 and OTA were respectively found in 84% (27/32) and 38% (12/32) of the samples. AFB1 exceeded the limits in 41% (13/32) and 25% (8/32) of the samples according to the Lebanese and European standards, respectively. OTA was unacceptable in only 6% (2/32) and 3% (1/32) of the samples according to the Lebanese and European standards, respectively. AFB1 and OTA daily exposure was shown to be 4.270 and 1.345 ng/kg bw/day, respectively. AFB1 was shown to be associated with 0.41 and 0.35 additional cancer cases per 100,000 persons per year for regular consumption, respectively; while for high consumption, an increase of 0.911 and 0.639 cancer cases per 100,000 person per year was noted, respectively. The margin of exposure (MOE) for OTA was >10,000 for the non-neoplastic effect and >200 for the neoplastic effect, representing no toxicological concerns for consumers.

Secondary metabolism in Penicillium expansum: Emphasis on recent advances in patulin research.

The plant pathogenic fungus Penicillium expansum is a major concern of the global food industry due to its wide occurrence and ability to produce various mycotoxins, of which the most significant is patulin. Relatively less highlighted in the literature, in comparison with the other food-borne mycotoxins, patulin is one of the main factors in economic losses of vegetables and fruits. Otherwise, patulin is a health hazard which results in both short-term and long-term risks. This review includes knowledge on the biosynthetic mechanisms used for secondary metabolite production in P. expansum, with special emphasis on patulin biosynthesis. The abiotic factors triggering the production of patulin and the strategies developed to reduce or prevent the contamination by this mycotoxin are comprehensively discussed. The database presented in this review would be useful for the prioritization and development of future research.

Quantification of Fusarium graminearum and Fusarium culmorum by real-time PCR system and zearalenone assessment in maize.

Zearalenone (ZEA) is a mycotoxin produced by some species of Fusarium, especially by Fusarium graminearum and F. culmorum. ZEA induces hyperoestrogenic responses in mammals and can result in reproductive disorders in farm animals. In the present study, a real-time PCR (qPCR) assay has been successfully developed for the detection and quantification of Fusarium graminearum based on primers targeting the gene PKS13 involved in ZEA biosynthesis. A standard curve was developed by plotting the logarithm of known concentrations of F. graminearum DNA against the cycle threshold (Ct) value. The developed real time PCR system was also used to analyze the occurrence of zearalenone producing F. graminearum strains on maize. In this context, DNA extractions were performed from thirty-two maize samples, and subjected to real time PCR. Maize samples also were analyzed for zearalenone content by HPLC. F. graminearum DNA content (pg DNA/ mg of maize) was then plotted against ZEA content (ppb) in maize samples. The regression curve showed a positive and good correlation (R²=0.760) allowing for the estimation of the potential risk from ZEA contamination. Consequently, this work offers a quick alternative to conventional methods of ZEA quantification and mycological detection and quantification of F. graminearum in maize.

Targeting a polyketide synthase gene for Aspergillus carbonarius quantification and ochratoxin A assessment in grapes using real-time PCR.

Aspergillus carbonarius is an ochratoxin producing fungus that has been considered to be responsible of the ochratoxin A (OTA) contamination in grapes and wine. In order to monitor and quantify A. carbonarius, a specific primer pair Ac12RL_OTAF/Ac12RL_OTAR has been designed from the acyltransferase (AT) domain of the polyketide synthase sequence Ac12RL3 to amplify 141 bp PCR product. Among the mycotoxigenic fungi tested, only A. carbonarius gave a positive result. This specific primer pair was also successfully employed in real-time PCR conjugated with SYBR Green I dye for the direct quantification of this fungus in grape samples. A positive correlation (R(2)=0.81) was found between A. carbonarius DNA content and OTA concentration in 72 grape samples, allowing for the estimation of the potential risk from OTA contamination. Consequently, this work offers a quick alternative to conventional methods of OTA quantification and mycological detection and quantification of A. carbonarius in grapes.