Improving Stability and Accessibility of Quercetin in Olive Oil-in-Soy Protein Isolate/Pectin Stabilized O/W Emulsion

Plant and animal protein mixed systems as wall material for microencapsulation of Mānuka essential Oil: Characterization and in vitro release kinetics

Combination of plant and animal protein diet is becoming a valuable source of nutrition in the modern diet due to the synergistic functional properties inherent in these protein complexes. Moreover, the synergy between animal and plant proteins can contribute to the high stability and improved solubility of the encapsulated bioactive ingredients (e.g., essential oils). Therefore, the study was designed to evaluate the plant (pea protein (PP) and lupine protein (LP)) and animal protein (whey protein, WP) mixed systems as a wall material for microencapsulation of mānuka essential oil, as an example of bioactive compound. Moreover, physicochemical properties and in vitro release profile of encapsulated mānuka essential oil were studied. Mānuka essential oil microcapsules exhibited low moisture content (5.3-7.1 %) and low water activity (0.33-0.37) with a solubility of 53.7-68.1 %. Change in wall material ratio significantly affected the color of microcapsules, while microcapsules prepared with 1:1 protein/oil ratio demonstrated a high encapsulation efficiency (90.4 % and 89.4 %) for protein mixed systems (PP + WP and LP + WP), respectively. Microcapsules further showed low values for lipid oxidation with a high oxidative stability and antioxidant activity (62.1-87.0 %). The zero order and Korsmeyer-Peppas models clearly explained the release mechanism of encapsulated oil, which was dependent on the type and concentration of the protein mixed used. The findings demonstrated that the protein mixed systems successfully encapsulated the mānuka essential oil with controlled release and high oxidative stability, indicating the suitability of the protein mixed systems as a carrier in encapsulation and application potential in development of encapsulated functional foods.

General approaches to biopolymer-based Pickering emulsions

Pickering emulsion is a type of emulsion that uses solid particles or colloidal particles as emulsifiers rather than surfactants to adhere at oil-water interface. Pickering emulsions have gathered significant research attention recently due to their excellent stability and wide range of potential uses compared to traditional emulsions. Major advancements have been made in development of innovative Pickering emulsions using different colloidal particles by various techniques including homogenization, emulsification and ultrasonication. Use of biopolymer particles gives Pickering emulsions a more escalating possibilities. In this review paper, we seek to present a critical overview of development in food-grade particles that have been utilized to create Pickering emulsions with a focus on techniques and application of Pickering emulsions. Particularly, we have evaluated protein, lipid, polysaccharide-based particles and microalgal proteins that have emerged in recent years with respect to their potential to stabilize and add novel functionalities to Pickering emulsions. Some preparation methods of Pickering emulsions in brief, applications of Pickering emulsions are also highlighted. Encapsulation and delivery of bioactive compounds, fat substitutes, film formation and catalysis are potential applications of Pickering emulsions. Pickering double emulsions, nutraceutical and bioactive co-delivery, and preparation of porous materials are among research trends of food-grade Pickering emulsions.

Fabrication and characterization of anthocyanin-loaded double Pickering emulsions stabilized by β-cyclodextrin

Anthocyanins, one of the important water-soluble pigments, are sensitive to environmental factors, which limits the application of anthocyanins in food field. In order to overcome this limitation, double Pickering emulsions stabilized by β-cyclodextrin were developed. The optimum preparation conditions of the emulsions were determined firstly and the performance and structure of emulsions were investigated. Results showed that the optimum preparation conditions of emulsions were the ratio of (W1/O): W2 = 6:4 and 4 % β-cyclodextrin concentration. Optical microscope and confocal laser scanning microscope results confirmed that β-cyclodextrin adsorbed onto the surface of droplets forming stable double Pickering emulsions structure. In vitro gastrointestinal digestion experiments proved that double Pickering emulsions played a controlled-release effect in the small intestine. Rheological analysis proved that the emulsions exhibited elastic properties and demonstrated shear thinning behavior. The emulsions showed excellent stability under centrifugation and thermal conditions. These findings will promote anthocyanins' application in daily diet.

A double-layer cellulose/pectin-soy protein isolate-pomegranate peel extract micro/nanofiber dressing for acceleration of wound healing

Multi-layered wound dressings can closely mimic the hierarchical structure of the skin. Herein, a double-layer dressing material is fabricated through electrospinning, comprised of a nanofibrous structure as a healing-support layer or the bottom layer (BL) containing pectin (Pec), soy protein isolate (SPI), pomegranate peel extract (P), and a cellulose (Cel) microfiber layer as a protective/monitoring layer or top layer (TL). The formation of a fine bilayer structure was confirmed using scanning electron microscopy. Cel/Pec-SPI-P dressing showed a 60.05 % weight loss during 7 days of immersion in phosphate buffered solution. The ultimate tensile strength, elastic modulus, and elongation at break for different dressings were within the range of 3.14-3.57 MPa, 32.26-36.58 MPa, and 59.04-63.19 %, respectively. The release of SPI and phenolic compounds from dressings were measured and their antibacterial activity was evaluated. The fabricated dressing was non-cytotoxic following exposure to human keratinocyte cells. The Cel/Pec-SPI-P dressing exhibited excellent cell adhesion and migration as well as angiogenesis. More importantly, in vivo experiments on Cel/Pec-SPI-P dressings showed faster epidermal layer formation, blood vessel generation, collagen deposition, and a faster wound healing rate. Overall, it is anticipated that the Cel/Pec-SPI-P bilayer dressing facilitates wound treatment and can be a promising approach for clinical use.

Particleboards with Recycled Material from Hemp-Based Panels

This research addresses the current need for sustainable solutions in the construction and furniture industries, with a focus on environmentally friendly particleboard. Particleboards were made from a mixture of virgin wood chips and hemp shives, which were then mechanically recycled and used to make new lightweight particleboards. Phenol-formaldehyde resin with 25% w/w phenol replacement by soybean flour (PFS) was used as the binder for the lignocellulosic materials. Laboratory analyses determined the resin properties, and FTIR confirmed the structure of the experimental PFS resin. The thermal properties of all the resins were evaluated using thermogravimetric analysis (TGA). The panels were manufactured using industrial simulation and tested for mechanical and physical properties in accordance with European standards. The FTIR study confirmed good adhesion, and the TGA showed improved thermal stability for the recycled biomass panels compared to virgin biomass panels. The study concludes that lightweight particleboards can be successfully produced from recycled hemp shive-based panels, providing a sustainable alternative to traditional materials in the construction industry.

Formulation of a dual drug-loaded nanoparticulate co-delivery hydrogel system and its validation in rheumatoid arthritis animal model

Rheumatoid arthritis (RA), a systemic autoimmune disease that dramatically affects patients' quality of life. Given the intricacy of RA's pathophysiology, no single treatment can completely halt the disease progression. Here, we attempted to treat RA holistically and synergistically by co-delivering methotrexate (MTX), a standard slow-acting anti-rheumatic drug, and phenethyl isothiocyanate (PEITC), a bioactive phytochemical, using a sodium alginate (SA)-pluronic F127 (PF-127) in situ hydrogel formulation. Therefore, in the current study, the co-delivery of MTX and PEITC in the nanoparticulate form could help enhance stability and solubility and facilitate greater penetration in the target arthritic tissues. The fabricated MTX NP and PEITC NE were found to have a minimum particle size, PDI, and good zeta potential. Results from in vitro release studies showed that MTX and PEITC were simultaneously released from the DD NP HG matrix over 6-7 days through diffusion and erosion mechanisms. An intra-articular (IA) injection of DD NP HG dramatically reduced chronic inflammation in adjuvant-induced arthritis (AIA) rats, delayed the onset of bone erosion, significantly reduced synovitis, and down-regulated the inflammatory cytokine expression. Most notably, the co-delivery strategy almost entirely restored the morphological features of the ankle joints of RA rats. The hepatic and renal function tests indicated good biological safety for DD NP HG in RA conditions. Taken together, these findings indicated that DD NP HG could achieve good anti-inflammatory activity and reverse cartilage disruption through a synergistic effect between two nanoparticulate forms of MTX and PEITC, which can effectively improve the drawbacks of their free forms.

Influence of Proteins on Bioaccessibility of α-Tocopherol Encapsulation within High Diacylglycerol-Based Emulsions

α-Tocopherol has been widely used in medicine, cosmetics, and food industry as a nutritional supplement and antioxidant. However, α-tocopherol showed low bioaccessibility, and there is a widespread α-tocopherol deficiency in society today. The preparation of oil-in-water emulsions with high safety and low-calorie property is necessary. The aim of this research was to investigate the effects of different protein emulsifiers (whey protein isolate (WPI), soy protein isolate (SPI), and sodium casein (SC)) on the properties of emulsions delivery system, and diacylglycerol (DAG) was picked as a low-accumulated lipid. The interfacial changes, microstructural alterations, and possible interactions of the protein-stabilized DAG emulsions were investigated during the in vitro digestion. The results show that different proteins affect the degree of digestibility and α-tocopherol bioaccessibility of the emulsions. Both WPI- and SPI-coated emulsions showed good digestibility and α-tocopherol bioaccessibility (77.64 ± 2.93%). This might be due to the strong hydrolysis resistance of WPI (β-lactoglobulin) and the good emulsification ability of SPI. The SC-coated emulsion showed the lowest digestibility and α-tocopherol bioaccessibility, this might be due to the emulsification property of hydrolysis products of SC and the potential interaction with calcium ions. This study provides new possibilities for the application of DAG emulsions in delivery systems.

Upcycling soy processing waste (okara) into structured emulsions for fat replacement in sweet bread

BACKGROUND

Okara is the main waste of soy processing and represents a large economic and environmental burden. Nevertheless, the fibre and protein content of okara supports the upcycling of this critical waste. This study aimed at assessing the potentialities of okara as an innovative oil-structuring ingredient.

RESULTS

Structured emulsions containing up to 520 g oil kg^-1 and having oil holding capacity higher than 75% were prepared by high-shear mixing of okara with liquid oil. Microstructural analysis showed that the oil phase was evenly distributed in the okara matrix, probably due to the emulsification ability of the okara fibre-protein network. The performance of okara structured emulsions as palm margarine replacer were tested in the preparation of sweet bread. Okara emulsions (500 g oil kg^-1 ) resulted not only in a significant reduction of saturated fatty acids (>50%), but also in an increased protein and fibre content. Compared to the use of liquid oil solely, okara emulsions allowed reducing the oil released from bread loaf. Bread containing okara emulsion also presented physical and sensory properties similar to those of palm margarine bread, the only exception being a more perceivable oiliness and rancid defect, which are, however, easily preventable by applying appropriate formulation strategies.

CONCLUSION

The use of okara as innovative ingredient for oil structuring would answer the current demand for sustainable heathy diets, based on clean-label foods with low-saturated fat content, and increased protein and fibre supply. This approach would also allow the complete upcycling of this critical waste. © 2022 Society of Chemical Industry.

Preparation and Characterization of a Novel Natural Quercetin Self-Stabilizing Pickering Emulsion

In contrast to their well-known physiological properties, phytochemicals, such as flavonoids, have been less frequently examined for their physiochemical properties (e.g., surface activity). A natural quercetin self-stabilizing Pickering emulsion was fabricated and characterized in the present study. The antisolvent precipitation method was used to modify quercetin (in dihydrate form), and the obtained particles were characterized by light microscope, atom force microscope, XRD, and contact angle. The antisolvent treatment was found to reduce the particle size, crystallinity, and surface hydrophobicity of quercetin. We then examined the effects of the antisolvent ratio, particle concentration, and oil fraction on the properties of the quercetin particle-stabilized emulsions. In addition, increasing the antisolvent ratio (1:1~1:10) effectively improved the emulsification performance of the quercetin particles. The emulsion showed good storage stability, and the particle size of the emulsion decreased with the rising particle concentration and increased with the rising oil phase ratio. The findings indicate that natural quercetin treated with antisolvent method has a good ability to stabilize Pickering emulsion, and this emulsion may have good prospective application potential for the development of novel and functional emulsion foods.

Preparation of microgel co-loaded with nuciferine and epigallocatechin-3-gallate for the regulation of lipid metabolism

This study aims to enhance the stability and bioavailability of nuciferine (NF) and epigallocatechin-3-gallate (EGCG) by loading NF into liposomes and then incorporating the liposomes and EGCG into porous microgels (NFEG-microgel) prepared with chitosan and proanthocyanidin. Analysis of particle size (0.5-3.0 μm), electron microscopy, rheology, stability, and simulated gastrointestinal release confirmed that the prepared microgels had high encapsulation rate and good stability and release characteristics. Intervention experiments were performed by orally administering NFEG-microgel to high-fat diet rats to evaluate its efficacy and regulatory mechanism for blood lipid metabolism. NFEG-microgel intervention significantly reduced the body weight and serum lipid level, and the mechanism was related to the expression regulation of key genes involved in lipid metabolism and miRNAs (miR-126a-5p and miR-30b-5p) in serum extracellular vesicles. In addition, NFEG-microgel improved the diversity of gut microbiota by enriching short-chain fatty acids (SCFA)-producing bacteria and reducing harmful bacteria, suggesting that it can ameliorate lipid metabolism by regulating the intestinal flora community in rats.

In Vitro Digestion and Storage Stability of β-Carotene-Loaded Nanoemulsion Stabilized by Soy Protein Isolate (SPI)-Citrus Pectin (CP) Complex/Conjugate Prepared with Ultrasound

In this study, we employed the ultrasound-prepared electrostatic complex and covalent conjugate of soy protein isolate (SPI) and citrus pectin (CP) to prepare β-carotene-loaded nanoemulsions. The in vitro digestion and storage stability of nanoemulsions stabilized by different types of emulsifiers were investigated and compared. Nanoemulsions stabilized by ultrasound-treated complex/conjugate showed the highest encapsulation efficiency; during gastric digestion, these nanoemulsions also demonstrated the smallest droplet sizes and the highest absolute values of zeta potential, indicating that both electrostatic complexation/covalent conjugation and ultrasound treatment could significantly improve the stability of the resulting nanoemulsions. In comparison, complexes were more beneficial for the controlled release of β-carotene; however, the conjugate-stabilized nanoemulsion showed an overall higher bioaccessibility. The results were also confirmed by optical micrographs. Furthermore, nanoemulsions stabilized by ultrasound-prepared complexes/conjugates exhibited the highest stability during 14-day storage at 25 °C. The results suggested that ultrasound-prepared SPI–CP complexes and conjugates had great application potential for the delivery of hydrophobic nutrients.

Changes on the conformational and functional properties of soybean protein isolate induced by quercetin

The conformational changes and functional properties of SPI induced by quercetin was investigated via fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy and molecular docking. A decrease in the fluorescence intensity and a blue shift in the maximum wavelength were observed due to the binding process with fluorescent residues. The analysis of Stern-Volmer equation showed that the fluorescence quenching induced by quercetin took the form of static quenching, and the binding stoichiometry between SPI and quercetin was 1:1. The values of ΔH and ΔS were both positive illustrating that hydrophobic interaction was the primary binding force between quercetin and SPI. Results of FTIR and CD indicated that the binding with quercetin changed the secondary structure of SPI, resulting in a partially unfolded and more flexible structure. SDS-PAGE confirmed there was no covalent interaction between the two constituents. Molecular docking demonstrated that there were stable configurations and high matching degrees in both 11S and 7S proteins with quercetin via hydrogen bonds and hydrophobic interactions. Meanwhile, modification by quercetin enhanced the foaming and emulsifying capacities of SPI. These findings might provide theory reference for elucidation the mechanism of polyphenols-proteins interaction and development of related food additive products in future.

Quercetin: A Molecule of Great Biochemical and Clinical Value and Its Beneficial Effect on Diabetes and Cancer

Quercetin belongs to the broader category of polyphenols. It is found, in particular, among the flavonols, and along with kaempferol, myricetin and isorhamnetin, it is recognized as a foreign substance after ingestion in contrast to vitamins. Quercetin occurs mainly linked to sugars with the most common compounds being quercetin-3-O-glucoside or as an aglycone, especially in the plant population. The aim of this review is to present a recent bibliography on the mechanisms of quercetin absorption and metabolism, bioavailability, and antioxidant and the clinical effects in diabetes and cancer. The literature reports a positive effect of quercetin on oxidative stress, cancer, and the regulation of blood sugar levels. Moreover, research-administered drug dosages of up to 2000 mg per day showed mild to no symptoms of overdose. It should be noted that quercetin is no longer considered a carcinogenic substance. The daily intake of quercetin in the diet ranges 10 mg-500 mg, depending on the type of products consumed. This review highlights that quercetin is a valuable dietary antioxidant, although a specific daily recommended intake for this substance has not yet been determined and further studies are required to decide a beneficial concentration threshold.

Flavonoids Extraction Kinetics, Antimicrobial Activity and Radical Scavenging Potential of Bulgarian Woundwort (Solidago virgaurea L.)

The medicinal plant woundwort (Solidago virgaurea L.) characterizes by diuretic, antimutagenic, anti-inflammatory activity and it has been applied for urinary tract, nephrolithiasis and prostate disorders treatment. The aim of the present study was to analyze the extraction kinetics of catechin, epigallocatechin and quercetin from Bulgarian woundwort extracts, to assess the antibacterial potential of the medicinal plant extracts against four bacterial strains (Staphylococcus aureus ATCC25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Bacillus cereus), their antioxidant capacity and radical scavenging potential. The concentrations of the flavonoids in the extracts obtained at different extraction conditions (solvent, temperature, extraction time) were determined by newly-developed by the scientific team RP-HPLC-PDA methodologies. The agar well diffusion method was applied to evaluate the antibacterial activity of the plant extracts. The 70% EtOH extracts at 20 °C displayed significantly higher antibacterial activity against the foodborne pathogenic bacteria S. aureus and P. aeruginosa as compared to the 70% and 98% EtOH extracts at 30 °C and 20 °C, respectively. The medicinal plant exhibited satisfactory antioxidant potential and radical-scavenging activity.

Food-Grade Pickering Emulsions: Preparation, Stabilization and Applications

In recent years, Pickering emulsions have emerged as a new method and have attracted much attention in the fields of food sciences. Unlike conventional emulsions, Pickering emulsions are stabilized by solid particles, which can irreversibly adsorb on the oil-water interface to form a dense film to prevent the aggregation of droplets. The research and development of food-grade solid particles are increasingly favored by scientific researchers. Compared with conventional emulsions, Pickering emulsions have many advantages, such as fewer using amounts of emulsifiers, biocompatibility and higher safety, which may offer feasibility to have broad application prospects in a wide range of fields. In this article, we review the preparation methods, stabilization mechanism, degradation of Pickering emulsions. We also summarize its applications in food sciences in recent years and discuss its future prospects and challenges in this work.