Amel Mehrez

Dr. Amel Mehrez


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 March 2021 in Toxins
Verified
Journal Article
Open access
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chaima ragoubichaima ragoubi
chaima ragoubi
LQLaura Quintieri
Laura Quintieri
DGDonato Greco
Donato Greco
AMAmel Mehrez
Amel Mehrez
IMImed Maatouk
Imed Maatouk
GAGiuseppina Avantaggiato
Giuseppina Avantaggiato
The removal of mycotoxins from contaminated feed using lactic acid bacteria (LAB) has been proposed as an inexpensive, safe, and promising mycotoxin decontamination strategy. In this study, viable and heat-inactivated L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells were investigated for their ability to remove aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON) from MRS medium and PBS buffer over a 24 h period at 37 °C. LAB decontamination activity was also assessed in a ZEA-contaminated liquid feed (LF). Residual mycotoxin concentrations were determined by UHPLC-FLD/DAD analysis. In PBS, viable L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells removed up to 57% and 30% of ZEA and DON, respectively, while AFB1 and OTA reductions were lower than 15%. In MRS, 28% and 33% of ZEA and AFB1 were removed, respectively; OTA and DON reductions were small (≤15%). Regardless of the medium, heat-inactivated cells produced significantly lower mycotoxin reductions than those obtained with viable cells. An adsorption mechanism was suggested to explain the reductions in AFB1 and OTA, while biodegradation could be responsible for the removal of ZEA and DON. Both viable LAB strains reduced ZEA by 23% in contaminated LF after 48 h of incubation. These findings suggest that LAB strains of L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T may be applied in the feed industry to reduce mycotoxin contamination.

11 March 2016 in World Mycotoxin Journal
Verified
Journal Article
Closed access
AMAmel Mehrez
Amel Mehrez
IMI. Maatouk
I. Maatouk
Roberto Romero-GonzálezRoberto Romero-González
Roberto Romero-González
AAA. Ben Amara
A. Ben Amara
MKM. Kraiem
M. Kraiem
ALA. Landoulsi
A. Landoulsi
The present study evaluated the effect of gamma irradiation on the stability of ochratoxin A (OTA) under various conditions. The effects of the physical state of OTA (solid vs aqueous), initial OTA concentration, irradiation dose and dose rate as well as the presence of model substances simulating food matrix compounds on OTA radiostability were investigated. First, pure OTA with and without food model compounds including α-D-glucose (monosaccharide), Methyl α-D-glucopyranoside (starch) and the amino acid derivatives N-α-acetyl-L-lysine methyl ester and N-α-acetyl-L-cysteine methyl ester (protein models) were irradiated with doses of 2, 4 and 8 kGy applied at 15.117 and 108.24 Gy/min. Secondly, artificially OTA-contaminated wheat with different moisture content (11, 14 and 16%) was irradiated with doses of 2, 4 and 8 kGy applied at 63.39 Gy/min. Residual OTA levels were analysed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Solid OTA (50 and 3,200 ng/ml)showed great irradiation stability, even with irradiation doses up to 8 kGy. Under dry conditions, the presence of food model components did not affect OTA radiostability. However, in an aqueous solution, complete reduction was achieved at the initial OTA concentration of 50 ng/ml and irradiation dose of 2 kGy. Applying gamma irradiation to cereal-based food model systems produced a significant OTA reduction (5,000 µg/kg) of 47.2% in moistened wheat kernels (16%) with an absorbed dose of 8 kGy but failed to reduce the OTA content of low moisture content wheat (11%). These model experiments offered a useful tool to assess the main key factors affecting gamma irradiation-induced OTA reduction. Gamma irradiation is promising since the irradiation doses applied could partially reduce OTA contamination. Nevertheless, its efficacy was largely affected by initial moisture content and could be dangerous if toxic by-products are produced or nutritive quality is lost and needs further study.

8 January 2022 in Journal of Food Processing and Preservation
Verified
Journal Article
Closed access
PDF file
AAAya Ben Amara
Aya Ben Amara
AMAmel Mehrez
Amel Mehrez
CRChayma Ragoubi
Chayma Ragoubi
RRRoberto Romero‐González
Roberto Romero‐González
AFAntonia Garrido Frenich
Antonia Garrido Frenich
IMImed Maatouk
Imed Maatouk

1 August 2019 in Journal of Food Protection
Verified
Journal Article
Closed access
IMImed Maatouk
Imed Maatouk
AMAmel Mehrez
Amel Mehrez
AAAya Ben Amara
Aya Ben Amara
RCRagoubi Chayma
Ragoubi Chayma
SASalwa Abid
Salwa Abid
ALAhmed Landoulsi
Ahmed Landoulsi
Gamma irradiation is a useful technology for degrading mycotoxins. The purpose of this study was to investigate the effect of irradiation on ochratoxin A (OTA) stability under different co... HIGHLIGHTS OTA in methanolic solution was highly stable up to an irradiation dose of 4 kGy. Irradiation did not affect OTA cytotoxicity in HepG2 cells. Irradiation significantly reduced the OTA con...

2 January 2021 in Fly
Verified
Journal Article
Closed access
AMAmel Mehrez
Amel Mehrez
PLPaul Lasko
Paul Lasko
Drosophila melanogaster has proven to be a powerful genetic model to study human disease. Approximately 75% of human disease-associated genes have homologs in the fruit fly and regulatory pathways are highly conserved in Drosophila compared to humans. Drosophila is an established model organism for the study of genetics and developmental biology related to human disease and has also made a great contribution to epigenetic research. Many key factors that regulate chromatin condensation through effects on histone post-translational modifications were first discovered in genetic screens in Drosophila. Recently, the importance of chromatin regulators in cancer progression has been uncovered, leading to a rapid expansion in the knowledge on how perturbations of chromatin can result in the pathogenesis of human cancer. In this review, we provide examples of how Drosophila melanogaster has contributed to better understanding the detrimental effects of mutant forms of histones, called ‘oncohistones’, that are found in different human tumours.