Fabrication, characterization, and bioactivity of self-assembled carrier-free colloidal dispersions from Citrus × Limon 'Rosso' essential oil and tea polyphenols.

Carrier-free nanodelivery systems are fully self-assembled from active ingredients through interactions, offering the advantages of green, safe, and large-scale manufacturing. To improve the dispersion of Citrus × limon 'Rosso' peel essential oil (CEO) in water and boost the biological activity of CEO and tea polyphenols (TP), self-assembled CEO-TP colloidal dispersions (CEO-TP Colloids) were fabricated through sonication without surfactants or carriers. The optimal CEO and TP concentrations in the CEO-TP Colloids were determined to be 10.0 and 20.0 mg/mL by particle size and stability analyzer, respectively. The CEO self-assembled with TP to form spherical nanoparticles through hydrophobic and hydrogen-bonding interactions, whereas the CEO in CEO-TP Colloids weakened TP intramolecular aggregation. Meanwhile, the CEO-TP Colloids showed synergistic effects with better antibacterial, cellular antioxidant, and anti-inflammatory activities than single components. This study opens up the possibility of carrier-free co-delivery of hydrophobic and hydrophilic active components developed into food-grade formulations with multiple bioactivities.

Macronutrient digestion and polyphenol bioaccessibility in oat milk tea products: an in vitro gastrointestinal tract study.

People are increasingly preparing milk tea using plant-based milks rather than cow's milk, e.g., vegans, those with lactose intolerance, and those with flavor preferences. However, adding plant-based milks to tea may impact the digestion, release, and bioaccessibility of nutrients and nutraceuticals in both the tea and milk. In this study, oat milk tea model systems (OMTMSs) containing different fat and tea polyphenol concentrations were used to explore the impact of tea on macronutrient digestion in oat milk, as well as the impact of oat milk matrix on the polyphenol bioaccessibility in the tea. An in vitro gastrointestinal model that mimics the mouth, stomach, and small intestine was used. Tea polyphenols (>0.25%) significantly reduced the glucose and free fatty acids released from oat milk after intestinal digestion. Tea polyphenols (>0.10%) also inhibited protein digestion in oat milk during gastric digestion but not during intestinal digestion. The bioaccessibility of the polyphenols in the tea depended on the fat content of oat milk, being higher for medium-fat (3.0%) and high-fat (5.8%) oat milk than low-fat (1.5%) oat milk. Liquid chromatography-tandem mass spectrometry (UPLC-ESI-MS/MS) analysis showed that lipids improved the tea polyphenol bioaccessibility by influencing the release of flavonoids and phenolic acids from the food matrices. These results provide important information about the impact of tea on the gastrointestinal fate of oat milk, and vice versa, which may be important for enhancing the healthiness of plant-based beverages.

Enhancement of Colorimetric pH-Sensitive Film Incorporating Amomum tsao-ko Essential Oil as Antibacterial for Mantis Shrimp Spoilage Tracking and Fresh-Keeping.

Anthocyanin-based smart packaging has been widely used for food freshness monitoring, but it cannot meet the requirements of smart films with antibacterial properties. This study aimed to enhance the antibacterial properties of intelligent films by incorporating Amomum tsao-ko essential oil (AEO) for mantis shrimp spoilage tracking and keeping the product fresh. A smart film was designed by introducing AEO and purple potato anthocyanin (PPA) to a polyvinyl alcohol/cellulose nanocrystal (PVA/CNC) polymer matrix. Our findings revealed that APP and AEO imparted the smart film with a favorable oxygen barrier, UV protection, mechanical properties, and antioxidant and pH/NH3-sensitive functions. Interestingly, the PVA/CNC-AEO-PPA film achieved 45.41% and 48.25% bactericidal efficacy against S. putrefaciens and V. parahaemolyticus, respectively. Furthermore, a visual observation confirmed that the target film (PVA/CNC-AEO-PPA) changed color significantly during mantis shrimp spoilage: rose red-light red-pink-light gray-dark gray. Meanwhile, the PVA/CNC-AEO-PPA film retarded the quality deterioration of the mantis shrimp effectively. The PVA/CNC-AEO-PPA film shows great application potential in mantis shrimp preservation and freshness monitoring; it is expected to become a rapid sensor for detecting seafood quality non-destructively and a multifunctional film for better preservation of product quality.

Eu-Based Porphyrin MOF Enables High-Performance Carbon-Based Perovskite Solar Cells.

The low power conversion efficiency (PCE) of hole transport materials (HTM) - free carbon-based perovskite solar cells (C-PSCs) poses a challenge. Here, a novel 2D Eu-TCPP MOF (TCPP; [tetrakis (4-carboxyphenyl) porphyrin]) sandwiched between the perovskite layer and the carbon electrode is used to realize an effective and stable HTM-free C-PSCs. Relying on the synergistic effect of both the metal-free TCPP ligand with a unique absorption spectrum and hydrophobicity and the EuO4(OH)2 chain in the Eu-TCPP MOF, defects are remarkably suppressed and light-harvesting capability is significantly boosted. Energy band alignment is achieved after Eu-TCPP MOF treatment, promoting hole collection. Förster resonance energy transfer results in improved light utilization and protects the perovskite from decomposition. As a result, the HTM-free C-PSCs with Eu-TCPP MOF reach a champion PCE of 18.13%. In addition, the unencapsulated device demonstrates outstanding thermal stability and UV resistance and keeps 80.6% of its initial PCE after 5500 h in a high-humidity environment (65%-85% RH).

Oat Milk Tea Model System: Exploring the Stability of Milk Tea and the Bioaccessibility of Green Tea Polyphenols.

Oat milk has become preferential because of its low calorie nature and high dietary fiber content, but its ability to "curdle" when mixed with tea can affect the consumer acceptability for oat milk tea. In this study, a model system for oat milk tea was made by combining oat milk and green tea extract to evaluate the impacts of the oat milk matrix and green tea extract concentration on the stability and polyphenol bioaccessibility. The stability analysis results showed that adding green tea extract to oat milk influenced the stability of the oat milk tea model systems. In contrast, the 3.0% fat oat milk tea model system exhibited a higher stability than the 1.5% fat oat milk tea model system. In simulated gastrointestinal digestive experiments, tea polyphenols in the oat milk tea model systems were relatively stable in oral and stomach digestive stages, while they clearly degraded in the small intestine digestive stage. Furthermore, the bioaccessibility of tea polyphenols was higher for the 3.0% fat oat milk tea model system than for the 1.5% fat oat milk tea model system, especially at low concentrations of green tea extracts (0.05%~0.25%). These results may provide a theoretical reference and data for the formulation of oat milk tea and the bioaccessibility of tea polyphenols in food matrices.

Ultra-Broadband Near-Infrared Phosphors Realized by the Heterovalent Substitution Strategy.

Near-infrared (NIR) phosphor-converted light-emitting diodes with broadband emission have received considerable interest. However, there remains a challenge in the construction of ultra-broadband NIR phosphors, hindering their further application. In this work, a heterovalent substitution strategy is proposed to construct a novel ultra-broadband NIR-emitting LaTiTaO6:Cr3+ phosphor with a full width at half maximum of ∼300 nm. Crystal structure, time-resolved emission spectroscopy, and electron paramagnetic resonance analyses confirm that only one crystallographic site of Cr3+ with separated ions exists. Electron and phonon coupling (EPC) evaluated by the Huang-Rhys factor (S) reveals that the heterovalent substitution strategy contributes to strong EPC with S = 9.185, resulting in ultra-broadband emission. Interestingly, a remarkable blue shift of emission from 1050 to 922 nm with increasing temperature is observed. Moreover, the application of LaTiTaO6:Cr3+ phosphor is demonstrated in the qualitative analysis of ethanol/water mixtures. The work will enrich the toolbox for designing broadband NIR-emitting materials.

Fabrication and characterization of l-ascorbyl palmitate and phospholipid-based hybrid liposomes and their impacts on the stability of loaded hydrophobic polyphenols.

The aim of this study was to evaluate the influence of l-ascorbyl palmitate (LAP) as an additive to liposome formulations by self-assembling with soy lecithin to form hybrid liposomes, in order to enhance the physical stability and bioactivator-loaded retention ratio of the LAP incorporated liposomes (LAP-LP). The addition of LAP significantly increased its surface negative charge and strong hydrophobic interactions occurred between the hydrophobic tails of LAP and phospholipids resulting in more compactly ordered, rigid and hydrophobic phospholipid bilayers as indicated by surface tension, fluorescence probes and DSC. These changes enhanced the stability of hydrophobic polyphenol loaded LAP-LP during storage. Particularly, after four weeks storage at 37 °C for naringenin loaded liposomes, the retention ratio of pure liposome decreased dramatically to 12.5 %, while the LAP-LP remained above 74.5 %. This study opens up the potential for the LAP-LP to be developed as a food-grade multifunctional formulation for encapsulating and delivering bioactivators.

Preparation of dynamic covalently crosslinking keratin hydrogels based on thiol/disulfide bonds exchange strategy.

Dynamic covalently crosslinking (DCC) hydrogels can mimic extracellular matrix and have the functions such as self-healing, self-adapting, and shape memory. The DCC keratin hydrogels based on thiol group-disulfide bonds exchange strategy have no reports so far as we know. Herein, inspired by the rich content of the intramolecular disulfide bonds and free thiol groups in the keratins extracted by reducing agents, we report a simple thiol-disulfide bonds exchange strategy for preparing the DCC keratin hydrogels. While the pH value of the keratin solution extracted by reducing agents was adjusted to 9.5-10.0, the keratin hydrogels showed the characteristic with injectability, self-healing, self-adapting, biocompatibility, and redox-responsive capacity. The extracted type II neutral/alkali keratin plays a critical role in imparting the keratin hydrogels with the reversibility behaviors due to that the keratins could build dynamic covalent bonds through thiol oxidation and disulfide exchange reactions in alkali conditions. This strategy provides an inspiration for forming DCC keratin hydrogel by avoiding the extra introduction of chemical crosslinking agents.

Encapsulation of Hydrophobic and Low-Soluble Polyphenols into Nanoliposomes by pH-Driven Method: Naringenin and Naringin as Model Compounds.

Naringenin and naringin are a class of hydrophobic polyphenol compounds and both have several biological activities containing antioxidant, anti-inflammatory and anti-tumor properties. Nevertheless, they have low water solubility and bioavailability, which limits their biological activity. In this study, an easy pH-driven method was applied to load naringenin or naringin into nanoliposomes based on the gradual reduction in their water solubility after the pH changed to acidity. Thus, the naringenin or naringin can be embedded into the hydrophobic region within nanoliposomes from the aqueous phase. A series of naringenin/naringin-loaded nanoliposomes with different pH values, lecithin contents and feeding naringenin/naringin concentrations were prepared by microfluidization and a pH-driven method. The naringin-loaded nanoliposome contained some free naringin due to its higher water solubility at lower pH values and had a relatively low encapsulation efficiency. However, the naringenin-loaded nanoliposomes were predominantly nanometric (44.95-104.4 nm), negatively charged (-14.1 to -19.3 mV) and exhibited relatively high encapsulation efficiency (EE = 95.34% for 0.75 mg/mL naringenin within 1% w/v lecithin). Additionally, the naringenin-loaded nanoliposomes still maintained good stability during 31 days of storage at 4 °C. This study may help to develop novel food-grade colloidal delivery systems and apply them to introducing naringenin or other lipophilic polyphenols into foods, supplements or drugs.