12 research outputs found

    Inactivation of palladium-based oxygen scavenger system by volatile sulphur compounds present in the headspace of packaged food

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    An oxygen scavenger based on a catalytic system with palladium (CSP) was recently developed to remove oxygen in food packagings. Although the CSP worked with various types of food, with some foods, an inhibition of the CSP was observed. Because such catalytic systems are susceptible to poisoning by sulfurcontaining compounds, the aim of this study was to understand the inactivation of palladium-based catalysts in presence of foods containing volatile sulfur compounds (VSCs). To achieve this, the oxygen scavenging activity (OSA) of the CSP was evaluated in presence of selected food products. Afterwards, VSCs mainly present in these foods were exposed to the CSP, and the influence on the OSA was evaluated. Finally, headspace analysis was performed with the diluted VSCs and with the packaged food products using proton transfer reaction time-of-flight mass spectrometry. It was found that the catalytic activity of the CSP was inhibited when VSCs were present in the headspace in concentrations ranging between 10.8–36.0 ppbv (dimethyl sulfide, DMS), 1.2–7.2 ppbv (dimethyl disulfide), 0.7–0.9 ppbv (dimethyl trisulfide), 2.1–5.8 ppbv methional) and 4.6–24.5 ppbv (furfuryl thiol). It was concluded that in packaged roast beef and cheese, DMS may be the compound mainly responsible for the inactivation of the CSP. In packagings containing ham, the key compounds were hydrogen sulfide and methanethiol; in peanuts, it was methanethiol; and in par-baked buns, an accumulation of methional, DMS, butanethiol and methionol. When potato chips were packaged, it was demonstrated that when VSCs are present in low concentrations, oxygen can still be scavenged at a reduced OSA

    Increasing Incidence of Hand and Distal Upper Extremity Injuries Associated With Electric Scooter Use.

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    PURPOSE: Electric scooters (e-scooters) have seen an increase in popularity in cities across the United States as a form of recreation and transportation. The advent of ride-sharing applications allows anyone with a smartphone to easily access these devices, without any investment or experience required. In this study, the authors analyze scooter-related injuries of the hand and upper extremity. METHODS: The National Electronic Injury Surveillance System (NEISS) was queried to look for injuries related to the use of e-scooters between 2010 and 2019. Data collected included demographic information, the location of the injury, the injury diagnosis, and disposition. National estimates (emergency room visits in the United States) were calculated using the weight variable included in the NEISS database. Miscoded reports were excluded. As a corollary, Google Trends data were utilized to establish a correlation between e-scooter-related injuries and the relative number of e-scooter hits on the Google search engine. RESULTS: From 2010 to 2019, there were 730 e-scooter-related injuries reported to the NEISS database. This corresponds to an estimated 26,412 injuries nationally during this time period. The incidence of scooter-related injuries increased by over 230% (2,130 national injuries in 2010; 7,213 national injuries in 2019; relative difference 5,083). Injuries most commonly occurred in patients aged 10 to 18 years (30.3%). The most frequent site of injury was the wrist (41.9%). The most common injury diagnosis was fracture (55.3%). Additionally, there was a correlation between the number of Google Trends e-scooter hits and the number of injuries during this time period. CONCLUSIONS: The incidence of e-scooter-related upper extremity injuries increased dramatically in the United States between 2010 and 2019. CLINICAL RELEVANCE: As novel e-scooter-sharing apps become increasingly popular, it is imperative that users are educated about the risk of injury and that use of proper protective equipment is encouraged

    Awakening the natural capability of psicose production in Escherichia coli

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    Abstract Due to the rampant rise in obesity and diabetes, consumers are desperately seeking for ways to reduce their sugar intake, but to date there are no options that are both accessible and without sacrifice of palatability. One of the most promising new ingredients in the food system as a non-nutritive sugar substitute with near perfect palatability is D-psicose. D-psicose is currently produced using an in vitro enzymatic isomerization of D-fructose, resulting in low yield and purity, and therefore requiring substantial downstream processing to obtain a high purity product. This has made adoption of D-psicose into products limited and results in significantly higher per unit costs, reducing accessibility to those most in need. Here, we found that Escherichia coli natively possesses a thermodynamically favorable pathway to produce D-psicose from D-glucose through a series of phosphorylation-epimerization-dephosphorylation steps. To increase carbon flux towards D-psicose production, we introduced a series of genetic modifications to pathway enzymes, central carbon metabolism, and competing metabolic pathways. In an attempt to maximize both cellular viability and D-psicose production, we implemented methods for the dynamic regulation of key genes including clustered regularly interspaced short palindromic repeats inhibition (CRISPRi) and stationary-phase promoters. The engineered strains achieved complete consumption of D-glucose and production of D-psicose, at a titer of 15.3 g L-1, productivity of 2 g L-1 h-1, and yield of 62% under test tube conditions. These results demonstrate the viability of whole-cell catalysis as a sustainable alternative to in vitro enzymatic synthesis for the accessible production of D-psicose
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