Microbiological quality of ready-to-eat fresh vegetables and their link to food safety environment and handling practices in restaurants

Accepted, unedited manuscript- Published on-line 22-July-2016 Pending copyediting, typesetting, and reviewing of proof, and publishing in its final form.he increased consumption of ready-to-eat salads outside homes as a result of a fast paced lifestyle, awareness on their nutritional attributes and enhanced processing technology is well documented. This study aimed to determine the microbiological quality of fresh-cut salads vegetables in small and medium sized foodservice establishments (SMEs) and to identify risk factors and handling practices through observational assessment in order to investigate if an association between microbiological quality and visual assessment (inspection) scores can be established. A total of 118 samples fresh-cut vegetable salads were collected from 50 inspected locations and analysed microbiologically, in addition to 49 swabs of knives and cutting boards. There was no statistically significant correlation between visual assessment scores and bacteriological counts on vegetables or cutting boards. Nonetheless, the consistent relationship between inspection ratings on cross-contamination and cleaning components and Listeria spp. levels was statistically significant. This study demonstrated that overall visual assessment scores would not directly reflect the safety of salad vegetables and that the significance of microbiological assessment should be considered in relation to individual inspection components. It is necessary to place effective control measures on cleaning standards and risk of cross-contamination to improve the microbiological safety of fresh salad vegetables in SME

Prevalence of antimicrobial-resistant Escherichia coli from raw vegetables in Lebanon

Introduction: Fresh produce has been implicated in a number of documented outbreaks of foodborne illness caused by bacteria, viruses, and parasites. Shiga toxin-producing Escherichia coli (STEC) have been detected on vegetables, raising concerns about the prevalence of E. coli contamination in produce, which can take place at various points from farm to fork. This study aimed to detect the presence of STEC and multidrug-resistant (MDR) E. coli on fresh vegetables and water from different sources along the fresh produce supply chain in Lebanon. Methodology: E. coli isolates (n = 60) were group serotyped using trivalent antisera (trivalent 1 [O111+O55+O26], trivalent 2 [O86+O119+O127], trivalent 3 [O125; O126; O128], and trivalent 4 [O114+O124+O142]) and tested for stx1 and stx2 genes by polymerase chain reaction (PCR) assay. Resistance to antimicrobial agents was determined using the disk diffusion method. Results: The virulence genes stx1 and stx2 were not detected in any of the isolates. However, 60% of the isolates were MDR and predominantly observed in trivalent 2 (32%). It is postulated that the inadequate post-harvest washing contributed to transmission of antimicrobial-resistant E. coli at wholesale and retail levels. Fresh vegetables harbor MDR E. coli and their consumption poses risks of increasing the reservoir of antimicrobial resistance in the intestines of the Lebanese population. Conclusions: Greater emphasis should be placed on vigilant sanitation measures at the consumption level, and effective national risk mitigation strategies are crucial to minimize fecal contamination in the early stages of production, particularly in the post-harvest washing processes

Understanding the routes of contamination of ready-to-eat vegetables in the Middle East

publisher: Elsevier articletitle: Understanding the routes of contamination of ready-to-eat vegetables in the Middle East journaltitle: Food Control articlelink: http://dx.doi.org/10.1016/j.foodcont.2015.10.024 content_type: article copyright: Copyright © 2015 Elsevier Ltd. All rights reserved

Effects of Process Variables and Size Scale on Solidification Microstructure in Laser-Based Solid Freeform Fabrication of Ti-6Al-4V

Mechanical Engineerin

Gain in Three-Dimensional Metamaterials utilizing Semiconductor Quantum Structures

We demonstrate gain in a three-dimensional metal/semiconductor metamaterial by the integration of optically active semiconductor quantum structures. The rolling-up of a metallic structure on top of strained semiconductor layers containing a quantum well allows us to achieve a three-dimensional superlattice consisting of alternating layers of lossy metallic and amplifying gain material. We show that the transmission through the superlattice can be enhanced by exciting the quantum well optically under both pulsed or continuous wave excitation. This points out that our structures can be used as a starting point for arbitrary three-dimensional metamaterials including gain

Status Of The FAIR Synchrotron Projects SIS18 And SIS100

A large fraction of the program to upgrade the existingheavy ion synchrotron SIS18 as injector for the FAIR synchrotron SIS100 has been successfully completed. With the achieved technical status, a major increase of theaccelerated number of heavy ions could be reached. Thenow available performance especially demonstrates thefeasibility of high intensity beams of medium charge stateheavy ions with a sufficient control of the dynamicvacuum and connected charge exchange loss. Two furtherupgrade measures, the installation of additional magneticalloy (MA) acceleration cavities and the exchange of themain dipole power converter, are presently beingimplemented. For the FAIR synchrotron SIS100, theprocurement of all major components with longproduction times has been started. With the delivery andtesting of several pre-series components, the phase ofoutstanding technical reserach and developments could becompleted and the readiness for series productionachieved

Stability of longitudinal bunch length feedback for heavy-ion synchrotrons

In heavy-ion synchrotrons such as the SIS18 at Helmholtzzentrum für Schwerionenforschung, Helmholtz Centre for Heavy Ion Research (GSI), coherent oscillations of the particle bunches are damped by rf feedback systems to increase the stability and to improve the beam quality. In the longitudinal direction, important modes are the coherent longitudinal dipole and quadrupole oscillation. In this paper we present a new and rigorous approach to analyze the longitudinal feedback to damp these modes. The results are applied to the rf feedback loop at GSI that damps the quadrupole mode. The stability analysis is compared with simulations and is in good agreement with results of a beam experiment. Finally, we summarize practical implications for the operation of the feedback system regarding performance and stability