Preparation, characterization, and bioactivity of Zingiber officinale Roscoe powder-based Pickering emulsions.

BACKGROUND: Biocompatible Pickering emulsions (PE) stabilized by tailor-made antioxidant-loaded particles have been known for some time now, but antioxidant-rich natural plant particle-based emulsions are much less well known. This study aimed to investigate the physico-chemical properties of commercial Zingiber officinale powders obtained from biological and conventional agricultural practice and ginger powder-based PE. RESULTS: The physico-chemical and biological properties of Zingiber officinale powders (GDPs) obtained from conventional (GDPC1 and GDPC2) and biological agricultural (GDPBIO) practices, and the properties of derived PE (PE_GDPs) were examined. All GDPs showed weak aggregation in aqueous media and a sufficiently hydrophobic surface to stabilize oil-in-water (O/W) PE against coalescence for at least 1 month. Zingiber officinale powders (2% w/w) derived from biological agricultural practices (GDPBIO) demonstrated the best emulsifying properties. The Zingiber officinale powders and PE_GDPs were also characterized by their phytochemical profiles. All the investigated samples exhibited ferric reducing ability power greater than the positive control, butylated hydroxytoluene (BHT), with values ranging from 91.21 to 102.63 µmol L-1 Fe (II) g-1 for GDPC2 and 05PE_GDPC1 (O/W=1:1), respectively. In ß-carotene bleaching test the following trend GDPC1 > GDPBIO > GDPC2 was observed. A 05PE_GDPBIO sample with the oil volume fraction equal to 50% was stable to oxidation and exhibited a promising α-amylase inhibitory activity. CONCLUSION: The results suggest that ginger powder should be used as a starting point to design biocompatible PEs for different applications in the functional food, nutraceutical, and pharmaceutical industries. In fact, powder and based PE are characterized by a promising antioxidant activity, carbohydrate hydrolyzing enzyme and lipase inhibitory properties. Further in vivo studies are necessary to confirm these findings. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Influence of Three Extraction Methods on the Physicochemical Properties of Kefirans Isolated from Three Types of Animal Milk.

Kefiran is a heteropolysaccharide biopolymer usually extracted from kefir grains cultured in cow milk. Due to the lack of information on exopolysaccharides from other types of animal milk, in the present study, cow, buffalo and goat milks were used as raw materials for fermentation. The kefiran extractions from kefir grains were carried out with cold water (method I), hot water (method II) and mild heated water-ultrasound (method III), and then the recovery yield and the physicochemical properties of the kefirans were evaluated to establish the influence of both the extraction conditions and the type of milk. The highest yield was recorded for the cow kefiran using method III (4.79%). The recoveries of goat and buffalo kefirans with methods II and III were similar (2.75-2.81%). Method I had the lowest yields (0.15-0.48%). The physicochemical characteristics were studied with Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Differential Scanning Calorimetry (DSC). Fourier-transform infrared spectroscopy showed the same qualitative profile for all the samples, regardless of the method and the type of milk, confirming that the extraction methods did not affect the chemical structure of the kefirans. Otherwise, the thermal and morphological features of the samples showed differences according to both the type of the milk and the extraction method. The kefiran samples were very thermally stable, having a temperature of degradation (Td) in the range from 264 to 354 °C. The resulting morphological and thermal differences could lead to different practical applications of kefirans in the fields of nutrition and pharmacology.

Chemical Vapor Deposition of Photocatalyst Nanoparticles on PVDF Membranes for Advanced Oxidation Processes.

The chemical binding of photocatalytic materials, such as TiO2 and ZnO nanoparticles, onto porous polymer membranes requires a series of chemical reactions and long purification processes, which often result in small amounts of trapped nanoparticles with reduced photocatalytic activity. In this work, a chemical vapor deposition technique was investigated in order to allow the nucleation and growth of ZnO and TiO2 nanoparticles onto polyvinylidene difluoride (PVDF) porous membranes for application in advanced oxidation processes. The thickness of obtained surface coatings by sputtered nanoparticles was found to depend on process conditions. The photocatalytic efficiency of sputtered membranes was tested against both a model drug and a model organic pollutant in a small continuous flow reactor.

Electro-Conductive Membranes for Permeation Enhancement and Fouling Mitigation: A Short Review.

The research on electro-conductive membranes has expanded in recent years. These membranes have strong prospective as key components in next generation water treatment plants because they are engineered in order to enhance their performance in terms of separation, flux, fouling potential, and permselectivity. The present review summarizes recent developments in the preparation of electro-conductive membranes and the mechanisms of their response to external electric voltages in order to obtain an improvement in permeation and mitigation in the fouling growth. In particular, this paper deals with the properties of electro-conductive polymers and the preparation of electro-conductive polymer membranes with a focus on responsive membranes based on polyaniline, polypyrrole and carbon nanotubes. Then, some examples of electro-conductive membranes for permeation enhancement and fouling mitigation by electrostatic repulsion, hydrogen peroxide generation and electrochemical oxidation will be presented.

Nanotechnology for the Environment and Medicine.

Nanotechnology encompasses the production and applications of physical, chemical, and biological systems at scales ranging from individual atoms or molecules to around 100 nanometres, as well as the integration of the resulting nanostructures into larger systems. Nanomaterials differ from bulk materials for their relatively larger surface-area-to-mass ratio, consequently they become more chemically reactive and can show different optical, magnetic and electrical behaviours. In recent years, engineered nanomaterials have gained a particular attention in some fields such as environmental protection (soil, air and water remediation/treatment) and medicine (bio-sensing, imaging, and drug delivery). Nanoparticles can be used to monitor in real-time some pollutants (including heavy metal ions, organic compounds, microbiological pathogens, etc.) present even at extremely low concentrations in different environments. The use of nanomaterials for waste remediation/treatment results in a technology more cost-effective and rapid than current conventional approaches thanks to their enhanced surface area, transport properties, and sequestration characteristics. In addition, the integration of molecular biology and medicine with nanotechnology has resulted in new active nanostructures able to interact with biological systems. Nanocarriers based on carbon nanotubes, fumed silica (SiO2), titanium dioxide (TiO2), and magnetite and maghemite (Fe3O4, and γ-Fe2O3) nanoparticles have a distinct advantage over other drug carriers as they can be opportunely designed to reach the desired targets. As a consequence, such nanostructures can represent an important platform for enhanced medical imaging and controlled drug delivery. Here, some applications of nanomaterials as water purifying agents and drug delivery systems are reported.

Nanotechnology for the Environment and Medicine.

Nanotechnology encompasses the production and applications of physical, chemical, and biological systems at scales ranging from individual atoms or molecules to around 100 nanometres, as well as the integration of the resulting nanostructures into larger systems. Nanomaterials differ from bulk materials for their relatively larger surface-area-to-mass ratio, consequently they become more chemically reactive and can show different optical, magnetic and electrical behaviours. In recent years, engineered nanomaterials have gained a particular attention in some fields such as environmental protection (soil, air and water remediation/treatment) and medicine (bio-sensing, imaging, and drug delivery). Nanoparticles can be used to monitor in real-time some pollutants (including heavy metal ions, organic compounds, microbiological pathogens, etc.) present even at extremely low concentrations in different environments. The use of nanomaterials for waste remediation/treatment results in a technology more cost-effective and rapid than current conventional approaches thanks to their enhanced surface area, transport properties, and sequestration characteristics. In addition, the integration of molecular biology and medicine with nanotechnology has resulted in new active nanostructures able to interact with biological systems. Nanocarriers based on carbon nanotubes, fumed silica (SiO2), titanium dioxide (TiO2), and magnetite and maghemite (Fe3O4, and γ-Fe2O3) nanoparticles have a distinct advantage over other drug carriers as they can be opportunely designed to reach the desired targets. As a consequence, such nanostructures can represent an important platform for enhanced medical imaging and controlled drug delivery. Here, some applications of nanomaterials as water purifying agents and drug delivery systems are reported.

Light responsive polymer membranes: a review.

In recent years, stimuli responsive materials have gained significant attention in membrane separation processes due to their ability to change specific properties in response to small external stimuli, such as light, pH, temperature, ionic strength, pressure, magnetic field, antigen, chemical composition, and so on. In this review, we briefly report recent progresses in light-driven materials and membranes. Photo-switching mechanisms, valved-membrane fabrication and light-driven properties are examined. Advances and perspectives of light responsive polymer membranes in biotechnology, chemistry and biology areas are discussed.