BACKGROUND: There has recently been increased interest in biodegradable and sustainable packaging within the food industry. Biopolymer materials based on renewable biomass can be used as alternatives to conventional plastic packaging. A corn protein, zein, possesses excellent film-forming properties because of its hydrophobic nature. It can be used for making edible films and for producing nanofibrous layers. Combination with polysaccharides like chitosan offers promising prospects for the production of delivery systems for the controlled release of active substances. The current trend is to minimize the content of chemical additives; thus essential oils are suitable alternatives to synthetic antimicrobials. RESULTS: This study aimed to develop various zein/chitosan-based film-forming solutions, films, and coatings with antimicrobial substances to prepare active food packaging. Thymol and three essential oils (thyme, cinnamon, oregano) were applied as bioactive ingredients against bacteria, yeasts, and fungi. The incorporation of these natural active compounds led to a decrease in particle size in most film-forming solutions and a reduction of zeta potential compared to controls. Release of the bioactive compound into an aqueous environment was proved by antimicrobial test. A zein/chitosan-based coating with thymol was applied on fresh strawberries. Microbiological analysis over 10 days confirmed the efficient control of bacterial and fungal growth. CONCLUSION: Zein/chitosan (7:1) systems are suitable as bioactive compound carriers to make barriers and to prevent moisture loss, ensuring microbial food quality and prolonging the shelf life of fruits. These systems can serve as sustainable active food packaging. © 2022 Society of Chemical Industry.

• Klíčová slova
• antimicrobial activity, chitosan, essential oil, food packaging, zein,
• MeSH
• antiinfekční látky * chemie   MeSH
• chitosan * chemie   MeSH
• obaly potravin MeSH
• oleje prchavé * chemie   MeSH
• thymol MeSH
• zein * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antiinfekční látky * MeSH
• chitosan * MeSH
• oleje prchavé * MeSH
• thymol MeSH
• zein * MeSH

Zein is renewable plant protein with valuable film-forming properties that can be used as a packaging material. It is known that the addition of natural cross-linkers can enhance a film's tensile properties. In this study, we aimed to prepare antimicrobial zein-based films enriched with monolaurin, eugenol, oregano, and thyme essential oil. Films were prepared using the solvent casting technique from ethanol solution. Their physicochemical properties were investigated using structural, morphological, and thermal techniques. Polar and dispersive components were analyzed using two models to evaluate the effects on the surface free energy values. The antimicrobial activity was proven using a disk diffusion method and the suppression of bacterial growth was confirmed via a growth kinetics study with the Gompertz function. The films' morphological characteristics led to systems with uniform distribution of essential oils or eugenol droplets combined with a flat-plated structure of monolaurin. A unique combination of polyphenolic eugenol and amphiphilic monoglyceride provided highly stretchable films with enhanced barrier properties and efficiency against Gram-positive and Gram-negative bacteria, yeasts, and molds. The prepared zein-based films with tunable surface properties represent an alternative to non-renewable resources with a potential application as active packaging materials.

• Klíčová slova
• antibacterial activity, essential oils, eugenol, film, mechanical properties, monoglyceride, wettability, zein,
• MeSH
• antibakteriální látky farmakologie   MeSH
• antifungální látky farmakologie   MeSH
• biomechanika účinky léků   MeSH
• diferenciální skenovací kalorimetrie MeSH
• Escherichia coli účinky léků   MeSH
• eugenol farmakologie   MeSH
• laurany farmakologie   MeSH
• mikroskopie atomárních sil MeSH
• monoglyceridy farmakologie   MeSH
• obaly potravin * MeSH
• oleje prchavé farmakologie   MeSH
• pára MeSH
• permeabilita MeSH
• povrchové vlastnosti MeSH
• smáčivost MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• Staphylococcus aureus účinky léků   MeSH
• zein farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• antifungální látky MeSH
• eugenol MeSH
• laurany MeSH
• monoglyceridy MeSH
• monolaurin MeSH Prohlížeč
• oleje prchavé MeSH
• pára MeSH
• zein MeSH

Pickering emulsions have been known to be promising candidates for encapsulating and delivering a wide range of bioactive compounds with antioxidant potentials. In this work, we formulated and characterized zein (ZN)/chitosan (CS) stabilized Pickering emulsion. The prepared emulsions were firstly characterized by droplet size after preparation and after storage for one month at room temperature as well as after the addition of prebiotic gum Arabic (GA). Rheological measurements were further carried out to see the behavior and stability of these emulsions after storage. Thereafter, vit-D3 was encapsulated, and the antioxidant activity of the emulsions system were evaluated. The results showed that no significant change in the mean droplet diameter of the emulsions was observed after storage for a month. This claim was further confirmed by their rheological measurements particularly, the emulsions prepared with ZN/CS ratio of 1:2 having 50% oil contents exhibited significant stability. GA addition caused a gradual increase in the droplet size up to some level, after which it led to complete destabilization of the emulsion. Finally, to protect and deliver, vit-D3 was successfully loaded in these emulsions. No significant difference in the DPPH radical scavenging activity of the vit-D3 encapsulated emulsions was observed, showing their capability as delivery vehicles irrespective of their composition.

• Klíčová slova
• Antioxidant activity, Characterization, Pickering emulsion, Rheology, Vit-D(3) loading,
• MeSH
• antioxidancia chemie   MeSH
• arabská guma chemie   MeSH
• chitosan analogy a deriváty   MeSH
• cholekalciferol aplikace a dávkování   MeSH
• emulze chemie   MeSH
• nanokapsle chemie   MeSH
• reologie MeSH
• vitaminy aplikace a dávkování   MeSH
• zein chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia MeSH
• arabská guma MeSH
• chitosan MeSH
• cholekalciferol MeSH
• emulze MeSH
• nanokapsle MeSH
• vitaminy MeSH
• zein MeSH

BACKGROUND: Pickering emulsions (PEs) which are stabilized by solid particles instead of surfactants have recently attracted tremendous attentions due to their non-toxic and long-term stable nature. In the current study, we fabricated and characterized zein (ZN)/chitosan (CS) complex particles (ZNCSPs) stabilized PE for the encapsulation and delivery of vitamin D3 . RESULTS: The ZNCSPs were synthesized with different ratios, i.e. 1:1, 1:1.5 and 1:2 to investigate the optimum ratio. Transmission electron microscopy observations showed the spherical nature with smooth surface of the obtained particles in the case of ZNCS ratio 1:1.5 and 1:2. Furthermore, ζ-potential values for the these particles were 32.53 ± 1.3 and 52.86 ± 0.68 mV respectively, indicating particles with (1:2) being more stable than 1:1.5. Thereafter, using these particles, the PEs were successfully formulated with different oil (medium chain triglyceride) fractions (330, 500 and 660 g kg-1 ). The emulsions were evaluated for stability during storage and against different environmental factors including pH, temperature and ionic strength on the creaming indices (CIs) of these emulsions. The results demonstrated that the PEs with oil fractions 330 and 500 g kg-1 exhibited significant stability during storage, particularly the ones with 500 g kg-1 oil fractions which were stable against all the tested parameters. Finally, the prepared PEs were evaluated as efficient delivery system by encapsulating and delivering vitamin D3 . In vitro drug release profile confirmed sustained and controlled release of the encapsulated vitamin D3 . CONCLUSION: Overall, our findings suggest that ZNCSPs can be promising stabilizers for stable PEs that can be used as potential delivery systems in food, cosmetic and pharmaceutical industries. © 2021 Society of Chemical Industry.

• Klíčová slova
• CS, PEs, ZN, characterization, preparations, vitamin-D3 encapsulation,
• MeSH
• chitosan chemie   MeSH
• cholekalciferol chemie   MeSH
• emulze chemie   MeSH
• nanočástice chemie   MeSH
• nosiče léků chemie   MeSH
• příprava léků MeSH
• stabilita léku MeSH
• systémy cílené aplikace léků MeSH
• velikost částic MeSH
• zein chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chitosan MeSH
• cholekalciferol MeSH
• emulze MeSH
• nosiče léků MeSH
• zein MeSH

Enterotoxigenic Escherichia coli (ETEC) represents a major cause of morbidity and mortality in the human population. In particular, ETEC infections affect children under the age of five from low-middle income countries. However, there is no licensed vaccine against this pathogen. ETEC vaccine development is challenging since this pathotype expresses a wide variety of antigenically diverse virulence factors whose genes can be modified due to ETEC genetic plasticity. To overcome this challenge, we propose the use of outer membrane vesicles (OMVs) isolated from two ETEC clinical strains. In these OMVs, proteomic studies revealed the presence of important immunogens, such as heat-labile toxin, colonization factors, adhesins and mucinases. Furthermore, these vesicles proved to be immunogenic after subcutaneous administration in BALB/c mice. Since ETEC is an enteropathogen, it is necessary to induce both systemic and mucosal immunity. For this purpose, the vesicles, free or encapsulated in zein nanoparticles coated with a Gantrez®-mannosamine conjugate, were administered orally. Biodistribution studies showed that the encapsulation of OMVs delayed the transit through the gut. These results were confirmed by in vivo study, in which OMV encapsulation resulted in higher levels of specific antibodies IgG2a. Further studies are needed to evaluate the protection efficacy of this vaccine approach.

• Klíčová slova
• Enterotoxigenic Escherichia coli (ETEC), Gantrez, mannosamine, nanoparticles, oral vaccine, outer membrane vesicle (OMV),
• Publikační typ
• časopisecké články MeSH

• MeSH
• chronická nemoc MeSH
• diatrizoát * MeSH
• dospělí MeSH
• fixní kombinace léků MeSH
• konstrikce MeSH
• lidé středního věku MeSH
• lidé MeSH
• mastné kyseliny * MeSH
• pankreas metabolismus   MeSH
• pankreatektomie MeSH
• pankreatitida patofyziologie   chirurgie   terapie   MeSH
• propylenglykoly * MeSH
• proteiny aplikace a dávkování   MeSH
• vývody pankreatu chirurgie   MeSH
• zein * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alcoholic prolamine solution MeSH Prohlížeč
• diatrizoát * MeSH
• fixní kombinace léků MeSH
• mastné kyseliny * MeSH
• propylenglykoly * MeSH
• proteiny MeSH
• zein * MeSH

• MeSH
• amidy farmakologie   MeSH
• antituberkulotika farmakologie   MeSH
• mitóza účinky léků   MeSH
• rostliny MeSH
• thioamidy farmakologie   MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• amidy MeSH
• antituberkulotika MeSH
• thioamidy MeSH
• thiobenzamide MeSH Prohlížeč

The fluctuations of electric polarization in a disordered ferroelectric substance, relaxor crystal PbMg_{1/3}Nb_{2/3}O_{3} (PMN), were studied using a nonlinear inelastic light-scattering technique, hyper-Raman scattering, within a 5-100 cm^{-1} spectral interval and in a broad temperature range from 20 to 900 K. The split ferroelectric mode reveals a local anisotropy of up to about 400 K. Spectral anomalies observed at higher temperatures are explained as due to avoided crossing of the single primary polar soft mode with a temperature-independent, nonpolar spectral feature near 45 cm^{-1}, known from Raman scattering. The temperature changes of the vibrational modes involved in the measured fluctuation spectra of PMN were captured in a simple model that accounts for the temperature dependence of the dielectric permittivity as well. The observed slowing down of the relaxational dynamics directly correlates with the huge increase of the dielectric permittivity.

• Publikační typ
• časopisecké články MeSH

Date seeds are a major waste product that can be utilised as a valuable and nutritional material in the food industry. The aim of the present study was to improve cookies quality in terms of functional and textural value and assess the effect of date seed powder flour substitution on the physical and chemical characteristics of cookies. Three substitution levels (2.5, 5 and 7.5%) of flour by fine date seed powder from six varieties locally named Khalas, Khinaizi, Sukkary, Shaham, Zahidi and Fardh were prepared. Two types of flour were used (white flour and whole wheat) at two different baking temperatures: 180 and 200 °C. The incorporation of date seed had no or slight effect on moisture, ash, fat and protein content of the baked cookies. On the other hand, incorporation significantly affected the lightness and hardness of cookies; the higher level of addition, the darker and crispier the resulting cookies. The sensory analysis indicated that the produced cookies were acceptable in terms of smell, taste, texture and overall acceptability. The results indicate that the most acceptable cookies across all evaluated parameters were produced using whole wheat flour with 7.5% levels of date seed powder using Khalas and Zahidi varieties. Overall, the analysis indicated that cookies with acceptable physical characteristics and an improved nutritional profile could be produced with partial replacement of the white/whole wheat flour by date seed powder.

• Klíčová slova
• cookies, date seed powder, sensory analysis, waste utilisation,
• Publikační typ
• časopisecké články MeSH

OBJECTIVE: The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a novel coronavirus circulating in the Arabian Peninsula since September 2012. It leads to significant respiratory disease and among patients with co-morbidities is associated with high mortality. This research studied the mortality rate of MERS-CoV among intensive care unit (ICU) patients and the correlation of mortality with different co-morbidities. METHODS: This was a retrospective observational study conducted at the Intensive Care Unit of the King Fahad Hospital, Jeddah, Saudi Arabia. Data was obtained through patient chart review. RESULTS: The total sample consisted of 52 laboratory-confirmed MERS-CoV infection patients. 39 patients died, with a 75% case-fatality rate. Many patients had underlying co-morbidities, including diabetes mellitus (51.9%), hypertension (46.2%), and chronic renal disease (21.2%). CONCLUSIONS: MERS-CoV ICU mortality remains markedly high due to a combination of factors; the disease process of MERS-CoV leads to multiple organ failure, particularly respiratory and renal failure.

• Klíčová slova
• Middle East Respiratory Syndrome Coronavirus, Saudi Arabia, intensive care units, mortality,
• MeSH
• dospělí MeSH
• jednotky intenzivní péče statistika a číselné údaje   MeSH
• komorbidita MeSH
• koronavirové infekce mortalita   virologie   MeSH
• koronavirus MERS izolace a purifikace   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• Geografické názvy
• Saudská Arábie epidemiologie   MeSH