Refinar búsqueda
Resultados 1-5 de 5
Food-waste enables carboxylated gold nanoparticles to completely abat hexavalent chromium in drinking water Texto completo
2022
Maddaloni, Marina | Alessandri, Ivano | Vassalini, Irene
In this work we demonstrate that the synergistic combination of organic molecules extracted from food waste can empower different types of carboxylated gold nanoparticles (Au NPs) in removal of Cr(VI) species from both milliQ and real water solutions. In particular, chitosan extracted from shrimp’s shell and dissolved in an acidic active medium based on a 1:3 M mixture of ascorbic and citric acid allows citrate-capped Au NPs to improve their abatment efficiency from 18.4 to > 99% in milliQ and 80.6% in drinking water. When citrates are exchanged with 3-mercaptopropionic or 11-mercaptoundecanoic acids, the efficiency reaches 100% in both milliQ and drinking water. 11-mercaptoundecanoic acid is found to be the best capping agent in terms of efficiency and stability. Crossing of cyclic voltammetry and UV–Vis data enabled to define the main role of each individual component in abatment of Cr(VI). This study further advances research on the rational design of hybrid nanoparticle/polymer systems for environmental remediation, inspired by criteria of circular economy and environmental sustainability.
Mostrar más [+] Menos [-]A nano-carrier platform for the targeted delivery of nature-inspired antimicrobials using Engineered Water Nanostructures for food safety applications Texto completo
2019
Vaze, Nachiket | Pyrgiotakis, Georgios | Mena, Lucas | Baumann, Robert | Demokritou, Alexander | Ericsson, Maria | Zhang, Yipei | Bello, Dhimiter | Eleftheriadou, Mary | Demokritou, Philip
Despite the progress in the area of food safety, foodborne diseases still represent a massive challenge to the public health systems worldwide, mainly due to the substantial inefficiencies across the farm-to-fork continuum. Here, we report the development of a nano-carrier platform, for the targeted and precise delivery of antimicrobials for the inactivation of microorganisms on surfaces using Engineered Water Nanostructures (EWNS). An aqueous suspension of an active ingredient (AI) was used to synthesize iEWNS, with the ‘i’ denoting the AI used in their synthesis, using a combined electrospray and ionization process. The iEWNS possess unique, active-ingredient-dependent physicochemical properties: i) they are engineered to have a tunable size in the nanoscale; ii) they have excessive electric surface charge, and iii) they contain both the reactive oxygen species (ROS) formed due to the ionization of deionized (DI) water, and the AI used in their synthesis. Their charge can be used in combination with an electric field to target them onto a surface of interest. In this approach, a number of nature-inspired antimicrobials, such as H₂O₂, lysozyme, citric acid, and their combination, were used to synthesize a variety of iEWNS-based nano-sanitizers. It was demonstrated through foodborne-pathogen-inactivation experiments that due to the targeted and precise delivery, and synergistic effects of AI and ROS incorporated in the iEWNS structure, a pico-to nanogram-level dose of the AI delivered to the surface using this nano-carrier platform is capable of achieving 5-log reductions in minutes of exposure time. This aerosol-based, yet ‘dry’ intervention approach using iEWNS nano-carrier platform offers advantages over current ‘wet’ techniques that are prevalent commercially, which require grams of the AI to achieve similar inactivation, leading to increased chemical risks and chemical waste byproducts. Such a targeted nano-carrier approach has the potential to revolutionize the delivery of antimicrobials for sterilization in the food industry.
Mostrar más [+] Menos [-]Effect of citric acid and plasma activated water on the functional properties of sodium alginate for potential food packaging applications Texto completo
2021
Sharmin, Nusrat | Sone, Izumi | Walsh, James Leon | Sivertsvik, Morten | Noriega Fernández, Estefanía
n this study, cold plasma activated water (PAW) was used in the preparation of sodium alginate (SA) solution and the effect of reactive oxygen and nitrogen species (RONS), low pH and high oxidation-reduction potential on the functional properties of SA films was evaluated. Citric acid (CA) was added to SA, and the combined effect of PAW and CA on the functional properties of SA films was assessed. With 0.5, 1 and 2 w/v% addition of CA, tensile strength (TS) of the SA films decreased by 32, 58 and 66 %, while the elongation at break (EB) increased by 150, 275 and 475 %. The, TS and EB of SA films increased by 43 and 66 % when PAW was used to prepare SA solutions. Addition of glycerol reduced the TS and tensile modulus, while the EB was increased. The linear viscoelastic region (LVE) of SA decreased with the addition of CA and glycerol. However, addition of PAW increased the LVE region. The 1 and 2 % CA and PAW containing samples showed higher storage modulus as compared to the control samples and no intersection was observed between storage and loss modulus. The CA and/or PAW containing solutions showed shear thinning properties. The water vapour transmission rate (WVTR) of SA decreased by 34 % with the addition of 1 % CA, while only 12 % reduction was observed for 0.5 and 2 % CA containing samples. A further reduction in WVTR to 44 % was observed as PAW was added to 1 % CA containing SA samples | publishedVersion
Mostrar más [+] Menos [-]Substituição de metanol por água na extração de antocianinas totais de glumas de sorgo para uso como corante alimentício. Texto completo
2016
ALVES, M. P. | QUEIROZ, V. A. V. | OLIVEIRA, K. G. de | ROCHA, M. C. | CONCEIÇÃO, R. R. P. da | MIGUEL, R. A.
Effect of cranberry pomace extracts isolated by pressurized ethanol and water on the inhibition of food pathogenic/spoilage bacteria and the quality of pork products Texto completo
2019
Tamkutė, Laura | Gil, Beatriz Melero | Carballido, Jordi Rovira | Pukalskienė, Milda | Venskutonis, Petras Rimantas
Ethanol and water extracts were prepared from defatted cranberry pomace by pressurized liquid extraction and tested in bacterial cultures of L. monocytogenes, B. thermospacta, P. putida, lactic acid bacteria (LAB), aerobic mesophilic bacteria (AMB), and pork meat products. Anthocynanins (glucosides, galactosides and arabinosides of cyanidin and peonidins), phenolic compounds and organic acids (quinic, chlorogenic, malic and citric acids; procyanidin B3, myricetin and quercetin derivatives) were determined in the extracts. The extracts effectively inhibited the growth of tested bacteria at higher than 3.3% concentration. The effect of 2% ethanol extract additive on the inhibition of the same bacteria was also determined in non-inoculated and inoculated with bacteria pork slurry, pork burgers, and cooked ham. The results showed a significant growth inhibition of pathogenic L. monocytogenes and some other species in pork slurry, burgers and cooked ham with cranberry pomace ethanol extract as compared with the control samples. The extract also effectively inhibited the formation of oxidation indicator malondialdehyde in meat products. Slight impact of extract on some physico-chemical properties of meat products such as pH, metmyoglobin content was also observed, while it did not have significant influence on water activity. Extract addition imparted some color changes; however, it did not have negative effect on the overall sensory quality of burgers and cooked ham. High effectiveness of extract additive against pathogenic L. monocytogenes and some other tested bacteria in pork slurry, burgers and cooked ham during refrigerated storage for 16, 16 and 40 days, respectively, suggest that ethanol extract of defatted cranberry pomace may be a promising natural ingredient of meat products for increasing their microbiological safety and improving oxidative stability.
Mostrar más [+] Menos [-]