Research Publications (Food Safety)

Publication date: June 2016
, Volume 64

Author(s): Jangho Hong, Ayato Kawashima, Minami Okamoto, Kana Kanetsuki, Takanori Makino, Noriaki Hamada

Abstract

Abstract

Summary

Enterohemorrhagic Escherichia coli (EHEC) are foodborne pathogens responsible for the development of bloody diarrhea and renal failure in humans. Many environmental factors have been shown to regulate the production of Shiga toxin 2 (Stx2), the main virulence factor of EHEC. Among them, soluble factors produced by human gut microbiota and in particular, by the predominant species Bacteroides thetaiotaomicron (B. thetaiotaomicron), inhibit Stx2 gene expression.

The periplasmic chaperone SurA is critical for the biogenesis of outer membrane proteins (OMPs) and thus the maintenance of membrane integrity in Escherichia coli. The activity of this modular chaperone has been attributed to a core chaperone module, with only minor importance assigned to the two SurA peptidyl-prolyl isomerase (PPIase) domains.

Abstract

Aims

(i) To investigate the enzymatic characterization of α-L-arabinofuranosidase from Thermotoga thermarum DSM5069. (ii) To perform its excellent properties on converting ginsenoside Rc to ginsenoside Rd.

Potent Botulinum neurotoxins (BoNTs) represent a threat to public health and safety. Botulism is a disease caused by BoNT intoxication that results in muscle paralysis that can be fatal. Sensitive assays capable of detecting BoNTs from different substrates and settings are essential to limit foodborne contamination and morbidity. In this report, we describe a rapid 96-well microfluidic double sandwich immunoassay for the sensitive detection of BoNT-A from animal sera.

Aflatoxins, which are produced by Aspergillus flavus, are toxic to humans, livestock, and pets. The value of maize (Zea mays) grain is markedly reduced when contaminated with aflatoxin. Plant resistance and biological control using non-toxin producing strains are considered effective strategies for reducing aflatoxin accumulation in maize grain.

Effect of phytol on the dehydrogenase activity of Staphylococcus aureus Bacillus cereus, Pseudomonas aeruginosa and Enterococcus faecalis isolated from grilled meat was examined via dehydrogenase assay using 2,3,5 – tripheny tetrazolium chloride (TTC) as the electron acceptor. The bacteria isolates were exposed to various concentrations of phytol (0-2000 μg) in a nutrient broth.

Publication date: May 2016
Source:LWT - Food Science and Technology, Volume 68

Author(s): María Constanza Luciardi, María Amparo Blázquez, Elena Cartagena, Alicia Bardón, Mario Eduardo Arena

Publication date: May 2016
Source:LWT - Food Science and Technology, Volume 68

Author(s): Jawhar Hafsa, Med ali Smach, Med Raâfet Ben Khedher, Bassem Charfeddine, Khalifa Limem, Hatem Majdoub, Sonia Rouatbi

Twenty plant-derived oils were evaluated for their acaricidal and insecticidal activities against Sitotroga cerealella, Sitophilus oryzae, Sitophilus zeamais, and Tyrophagus putrescentiae adults, by using the fumigant and filter paper diffusion methods. Responses varied with bioassay systems, insect or mite species, plant oils, and exposure time. Based on the 50% lethal dose (LD50) values against S. oryzae and S.

Soy wara is a common ready-to-eat food whose production and sale are currently unregulated. Microbiological sampling indicated that 21% of the samples had standard plate counts exceeding 100,000 CFU/g, and 14% had Staphylococcus aureus counts higher than 100,000 CFU/g. The occurrence of S. aureus at these levels can result in food poisoning. Listeria monocytogenes was isolated in 14.4% of the samples, although the counts were generally low, typically <1,000 CFU/g. Although counts of L.

Edible offal meats have recently received significant attention worldwide. However, studies evaluating the microbial quality of diverse edible offal and specifically investigating contamination by pathogens that cause foodborne illnesses are rare.

This study was conducted to evaluate the microbial contamination in rice cake materials and products during processing and in the operation environment in nonhazard analysis [and] critical control point factories. Furthermore, the environmental health of the processing facilities and the bacterial and fungal contamination on the workers' hands were investigated.

Increased popularity of natural and organic processed meats can be attributed to the growing consumer demand for preservative-free foods, including processed meats. To meet this consumer demand, meat processors have begun using celery juice concentrate in place of sodium nitrite to create products labeled as no-nitrate or no-nitrite-added meat products while maintaining the characteristics unique to conventionally cured processed meats.

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Pickles in the Indian market contain ascorbic acid from the raw material used and benzoate as an added preservative that are involved in the formation of benzene in soft drinks. In this work, 24 market pickle samples were surveyed for benzene content, as well as its precursors and other constituents that influence its formation.

Monitoring for chloramphenicol (CAP) in aquaculture products is primarily performed by liquid chromatography–tandem mass spectrometry (LC-MS/MS), which requires expensive equipment and specialized training. Many laboratories prefer to screen samples with facile and high-throughput enzyme-linked immunosorbent assay (ELISA) kits for CAP residues before submitting samples for LC-MS/MS quantification and confirmation.

Dry-processing environments are particularly challenging to clean and sanitize because introduced water can favor growth and establishment of pathogenic microorganisms such as Salmonella. Our objective was to determine the efficacy of an isopropyl alcohol quaternary ammonium (IPAQuat) formula for eliminating potential Salmonella contamination on food contact surfaces.

Fifty-six foods and food ingredients were analyzed for populations of naturally occurring yeasts and molds using Petrifilm rapid yeast and mold (RYM) count plates, Petrifilm yeast and mold (YM) count plates, dichloran rose bengal chloramphenicol (DRBC) agar plates, acidified potato dextrose agar (APDA) plates, and dichloran 18% glycerol (DG18) agar plates. Colonies were counted after incubating plates for 48, 72, and 120 h at 25°C.