EGCG-based nanoparticles: synthesis, properties, and applications.

(-)-Epigallocatechin-3-gallate (EGCG) is a natural phenolic substance found in foods and beverages (especially tea) that exhibits a broad spectrum of biological activities, including antioxidant, antimicrobial, anti-obesity, anti-inflammatory, and anti-cancer properties. Its potential in cardiovascular and brain health has garnered significant attention. However, its clinical application remains limited due to its poor physicochemical stability and low oral bioavailability. Nanotechnology can be used to improve the stability, efficacy, and pharmacokinetic profile of EGCG by encapsulating it within nanoparticles. This article reviews the interactions of EGCG with various compounds, the synthesis of EGCG-based nanoparticles, the functional attributes of these nanoparticles, and their prospective applications in drug delivery, diagnosis, and therapy. The potential application of nanoencapsulated EGCG in functional foods and beverages is also emphasized. Top-down and bottom-up approaches can be used to construct EGCG-based nanoparticles. EGCG-based nanoparticles exhibit enhanced stability and bioavailability compared to free EGCG, making them promising candidates for biomedical and food applications. Notably, the non-covalent and covalent interactions of EGCG with other substances significantly contribute to the improved properties of these nanoparticles. EGCG-based nanoparticles appear to have a wide range of applications in different industries, but further research is required to enhance their efficacy and ensure their safety.

The enhancement of energy supply in syngas-fermenting microorganisms.

After the second industrial revolution, social productivity developed rapidly, and the use of fossil fuels such as coal, oil, and natural gas increased greatly in industrial production. The burning of these fossil fuels releases large amounts of greenhouse gases such as CO2, which has caused greenhouse effects and global warming. This has endangered the planet's ecological balance and brought many species, including animals and plants, to the brink of extinction. Thus, it is crucial to address this problem urgently. One potential solution is the use of syngas fermentation with microbial cell factories. This process can produce chemicals beneficial to humans, such as ethanol as a fuel while consuming large quantities of harmful gases, CO and CO2. However, syngas-fermenting microorganisms often face a metabolic energy deficit, resulting in slow cell growth, metabolic disorders, and low product yields. This problem limits the large-scale industrial application of engineered microorganisms. Therefore, it is imperative to address the energy barriers of these microorganisms. This paper provides an overview of the current research progress in addressing energy barriers in bacteria, including the efficient capture of external energy and the regulation of internal energy metabolic flow. Capturing external energy involves summarizing studies on overexpressing natural photosystems and constructing semiartificial photosynthesis systems using photocatalysts. The regulation of internal energy metabolic flows involves two parts: regulating enzymes and metabolic pathways. Finally, the article discusses current challenges and future perspectives, with a focus on achieving both sustainability and profitability in an economical and energy-efficient manner. These advancements can provide a necessary force for the large-scale industrial application of syngas fermentation microbial cell factories.

Gain of C-Ala enables AlaRS to target the L-shaped tRNAAla.

Unlike many other aminoacyl-tRNA synthetases, alanyl-tRNA synthetase (AlaRS) retains a conserved prototype structure throughout biology. While Caenorhabditis elegans cytoplasmic AlaRS (CeAlaRSc) retains the prototype structure, its mitochondrial counterpart (CeAlaRSm) contains only a residual C-terminal domain (C-Ala). We demonstrated herein that the C-Ala domain from CeAlaRSc robustly binds both tRNA and DNA. It bound different tRNAs but preferred tRNAAla. Deletion of this domain from CeAlaRSc sharply reduced its aminoacylation activity, while fusion of this domain to CeAlaRSm selectively and distinctly enhanced its aminoacylation activity toward the elbow-containing (or L-shaped) tRNAAla. Phylogenetic analysis showed that CeAlaRSm once possessed the C-Ala domain but later lost most of it during evolution, perhaps in response to the deletion of the T-arm (part of the elbow) from its cognate tRNA. This study underscores the evolutionary gain of C-Ala for docking AlaRS to the L-shaped tRNAAla.

Oral delivery of probiotics using single-cell encapsulation.

Adequate intake of live probiotics is beneficial to human health and wellbeing because they can help treat or prevent a variety of health conditions. However, the viability of probiotics is reduced by the harsh environments they experience during passage through the human gastrointestinal tract (GIT). Consequently, the oral delivery of viable probiotics is a significant challenge. Probiotic encapsulation provides a potential solution to this problem. However, the production methods used to create conventional encapsulation technologies often damage probiotics. Moreover, the delivery systems produced often do not have the required physicochemical attributes or robustness for food applications. Single-cell encapsulation is based on forming a protective coating around a single probiotic cell. These coatings may be biofilms or biopolymer layers designed to protect the probiotic from the harsh gastrointestinal environment, enhance their colonization, and introduce additional beneficial functions. This article reviews the factors affecting the oral delivery of probiotics, analyses the shortcomings of existing encapsulation technologies, and highlights the potential advantages of single-cell encapsulation. It also reviews the various approaches available for single-cell encapsulation of probiotics, including their implementation and the characteristics of the delivery systems they produce. In addition, the mechanisms by which single-cell encapsulation can improve the oral bioavailability and health benefits of probiotics are described. Moreover, the benefits, limitations, and safety issues of probiotic single-cell encapsulation technology for applications in food and beverages are analyzed. Finally, future directions and potential challenges to the widespread adoption of single-cell encapsulation of probiotics are highlighted.

Co-infections of Klebsiella pneumoniae and Elizabethkingia miricola in black-spotted frogs (Pelophylax nigromaculatus).

Pelophylax nigromaculatus is a common commercial specie of frogs that generally cultured throughout China. With the application of high-density culture, P. nigromaculatus can be co-infected by two or more pathogens, which thereby induce synergistic influence on the virulence of the infection. In this study, two bacterial strains were simultaneously isolated from diseased frogs by incubating on Luria-Bertani (LB) agar. Isolates were identified as Klebsiella pneumoniae and Elizabethkingia miricola by morphological, physiological and biochemical features, as well as 16S rRNA sequencing and phylogenetic analysis. The whole genome of K. pneumoniae and E. miricola isolates consist single circular chromosome of 5,419,557 bp and 4,215,349 bp, respectively. The genomic sequence analysis further indicated that K. pneumoniae isolate conserved 172 virulent and 349 antibiotic-resistance genes, whereas E. miricola contained 24 virulent and 168 antibiotic resistance genes. In LB broth, both isolates could grow well at 0%-1% NaCl concentration and pH 5-7. Antibiotic susceptibility testing revealed that both K. pneumoniae and E. miricola were resistant to kanamycin, neomycin, ampicillin, piperacillin, carbenicillin, enrofloxacin, norfloxacin and sulfisoxazole. Histopathological studies showed that co-infection caused considerable lesions in the tissues of brain, eye, muscle, spleen, kidney and liver, including cell degeneration, necrosis, hemorrhage and inflammatory cell infiltration. The LD50 of K. pneumoniae and E. miricola isolates were 6.31 × 105 CFU/g and 3.98 × 105 CFU/g frog weight, respectively. Moreover, experimentally infected frogs exhibited quick and higher mortality under coinfection with K. pneumoniae and E. miricola than those single challenge of each bacterium. To date, no natural co-infection by these two bacteria has been reported from frogs and even amphibians. The results will not only shed light on the feature and pathogenesis of K. pneumoniae and E. miricola, but also highlight that co-infection of these two pathogen is a potential threat to black-spotted frog farming.

Future foods: Alternative proteins, food architecture, sustainable packaging, and precision nutrition.

There are numerous challenges facing the modern food and agriculture industry that urgently need to be addressed, including feeding a growing global population, mitigating and adapting to climate change, decreasing pollution, waste, and biodiversity loss, and ensuring that people remain healthy. At the same time, foods should be safe, affordable, convenient, and delicious. The latest developments in science and technology are being deployed to address these issues. Some of the most important elements within this modern food design approach are encapsulated by the MATCHING model: Meat-reduced; Automation; Technology-driven; Consumer-centric; Healthy; Intelligent; Novel; and Globalization. In this review article, we focus on four key aspects that will be important for the creation of a new generation of healthier and more sustainable foods: emerging raw materials; structural design principles for creating innovative products; developments in eco-friendly packaging; and precision nutrition and customized production of foods. We also highlight some of the most important new developments in science and technology that are being used to create future foods, including food architecture, synthetic biology, nanoscience, and sensory perception.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2033683.

Novel insights into the cytokine network of rainbow trout Oncorhynchus mykiss using cell lines and primary leukocyte populations.

Cytokines are small proteins that regulate innate and adaptive immune responses and are released by both immune and non-immune cell types. In the current study, the constitutive and induced gene expression profiles of a suite of proinflammatory and regulatory cytokines was examined comparatively in eight rainbow trout (Oncorhynchus mykiss) cell lines, in order to establish the cytokine repertoires of these different cell types, especially the understudied non-immune cells. They included three epithelial cell lines (RTgut, RTgill, and RTL), one endothelial cell line (RTH), one fibroblast cell line (RTG-2), two stromal cell lines (TSS and TPS-2) and one monocyte/macrophage-like cell line (RTS-11). Three types of primary leukocytes (derived from blood, spleen and head kidney) of trout were also included in the analysis, to allow comparison to the repertoires expressed in T cells, as a major source of cytokines in immune responses. The major findings are: 1) IL-2A, IL-2B, IL-4/13B1, IL-4/13B2, IL-10b, P40B1, P28B, IL-17A/F1b, TNF-α3, TNF-α4, IFNγ1, CCL20L2b and CCL20L3a are expressed mainly in leukocytes but IL-17 N, IL-17D, IL-20 and CCL20L1b2 are not expressed in these cells. Hence future studies in these cell lines will help establish their function in fish; 2) Some of the cytokines were differentially expressed in the cell lines, revealing the potential role of these cell types in aspects of trout mucosal and inflammatory immune responses, 3) Similar cell types grouped together in the cell cluster analysis, including the leukocyte cluster, stromal cell cluster, and epithelial and endothelial cell cluster. Taken together, this investigation of these trout cell lines forms a good database for studying the function of cytokines not expressed in isolated leukocytes or that are preferentially expressed in the cell lines. Furthermore, the cytokine expression analysis undertaken confirmed the phenotypic relationship of these cell types at the molecular level.

A review of advances in aptamer-based cell detection technology.

Since cells are the basic structural and functional units of organisms, the detection or quantitation of cells is one of the most common basic problems in life science research. The established cell detection techniques mainly include fluorescent dye labeling, colorimetric assay, and lateral flow assay, all of which employ antibodies as cell recognition elements. However, the widespread application of the established methods generally dependent on antibodies is limited, because the preparation of antibodies is complicated and time-consuming, and unrecoverable denaturation is prone to occur with antibodies. By contrast, aptamers that are generally selected through the systematic evolution of ligands by exponential enrichment can avoid the disadvantages of antibodies due to their controllable synthesis, thermostability, and long shelf life, etc. Accordingly, aptamers may serve as novel molecular recognition elements like antibodies in combination with various techniques for cell detection. This paper reviews the developed aptamer-based cell detection methods, mainly including aptamer-fluorescent labeling, aptamer-isothermal amplification assay, electrochemical aptamer sensor, aptamer-based lateral flow analysis, and aptamer-colorimetric assay. The principles, advantages, progress of application in cell detection and future development trend of these methods were specially discussed. Overall, different assays are suitable for different detection purposes, and the development of more accurate, economical, efficient, and rapid aptamer-based cell detection methods is always on the road in the future. This review is expected to provide a reference for achieving efficient and accurate detection of cells as well as improving the usefulness of aptamers in the field of analytical applications.

Optimization of an aptamer against Prorocentrum minimum - A common harmful algae by truncation and G-quadruplex-forming mutation.

Harmful algal blooms (HABs) caused by Prorocentrum minimum have seriously posed economic losses and ecological disasters. To reduce these losses, aptamers are used as a new molecular probe to establish rapid methods. Herein, to improve the affinity and application of aptamers in the detection of harmful algae, the optimization was performed on the previously reported aptamers against P. minimum. First, a total of seven candidate aptamers, including three truncated aptamers (TA1, TA2 and TA3) and four mutant aptamers (MA1, MA2, MA3 and MA4), were obtained by truncation and G-quadruplex (GQ)-forming mutation. Next, the specificity and affinity test by flow cytometry revealed that except for TA1 and TA2, all of the candidate aptamers are specific with the equilibrium dissociation constant of (40.4 ± 5.5) nM for TA3, (63.3 ± 24.0) nM for MA1, (71.7 ± 14.6) nM for MA2, (365.9 ± 74.4) nM for MA3, and (21.1 ± 0.5) nM for MA4, respectively. The circular dichroism analysis of the mutant aptamers demonstrated that the GQ structures formed by MA1/MA2, MA3 and MA4 were antiparallel, mixed parallel and parallel, respectively. The affinity of aptamers with various GQ is in the order of parallel structure > antiparallel structure > mixed parallel structure. In addition, to further improve binding ability, the binding conditions of MA4 were optimized as follows: binding time, 60 min; binding temperature, 37 °C; pH of the binding buffer, 7.5; and Na+/Mg2+ concentration in the binding buffer, 100 mM/0.5 mM. The binding examination by fluorescence microscopy showed that MA4 had a stronger binding ability to P. minimum than the original aptamer. Taken together, this study not only obtained an aptamer with higher affinity than the original aptamer, which laid a good foundation for subsequent application, but also may provide a feasible reference method for aptamer optimization.

Natural LILRB1 D1-D2 variants show frequency differences in populations and bind to HLA class I with various avidities.

Leukocyte immunoglobulin-like receptor B1 (LILRB1) is widely expressed on various immune cells and the engagement of LILRB1 to HLA class I and pathogen-derived proteins can modulate the immune response. In the current study, 108 LILRB1 alleles were identified by screening the LILRB1 locus from the 1000 Genomes Phase 3 database. Forty-six alleles that occurred in three or more individuals encode 28 LILRB1 allotypes, and the inferred LILRB1 allotypes were then grouped into 9 LILRB1 D1-D2 variants for further analysis. We found that variants 1, 2, and 3 represent the three most frequent LILRB1 D1-D2 variants and the nine variants show frequency differences in populations. The binding assay demonstrated that variant 1 bound to HLA class I with the highest avidity, and all tested LILRB1 D1-D2 variants bound to HLA-C with lower avidity than to HLA-A and -B. Locus-specific polymorphisms at positions 183, 189, and 268 in HLA class I and dimorphisms in HLA-A (positions 207 and 253) and in HLA-B (position 194) affect their binding to LILRB1. Notably, the electrostatic interaction plays a critical role in the binding of LILRB1 to HLA class I as revealed by electrostatic analysis and by comparison of different binding avidities caused by polymorphisms at positions 72 and 103 of LILRB1. In this paper, we present a comprehensive study of the population genetics and binding abilities of LILRB1. The data will help us better understand the LILRB1-related diversity of the immune system and lay a foundation for functional studies.

Fortification of edible films with bioactive agents: a review of their formation, properties, and application in food preservation.

Biodegradable films constructed from food ingredients are being developed for food coating and packaging applications to create more sustainable and environmentally friendly alternatives to plastics and other synthetic film-forming materials. In particular, there is a focus on the creation of active packaging materials from natural ingredients, especially plant-based ones. The film matrix is typically constructed from film-forming food components, such as proteins, polysaccharides and lipids. These matrices can be fortified with active ingredients, such as antioxidants and antimicrobials, so as to enhance their functional properties. Edible active films must be carefully designed to have the required optical, mechanical, barrier, and preservative properties needed for commercial applications. This review focuses on the fabrication, properties, and functional performance of edible films constructed from natural active ingredients. It provides an overview of the type of active ingredients that can be used, how they interact with the film matrix, how they migrate through the films, and how they are released. It also discusses the potential application of these active films for food preservation. Finally, future trends are highlighted and areas where further research are required are discussed.

Neural network in food analytics.

Neural network (i.e. deep learning, NN)-based data analysis techniques have been listed as a pivotal opportunity to protect the integrity and safety of the global food supply chain and forecast $11.2 billion in agriculture markets. As a general-purpose data analytic tool, NN has been applied in several areas of food science, such as food recognition, food supply chain security and omics analysis, and so on. Therefore, given the rapid emergence of NN applications in food safety, this review aims to provide a comprehensive overview of the NN application in food analysis for the first time, focusing on domain-specific applications in food analysis by introducing fundamental methodology, reviewing recent and notable progress, and discussing challenges and potential pitfalls. NN demonstrated that it has a bright future through effective collaboration between food specialist and the broader community in the food field, for example, superiority in food recognition, sensory evaluation, pattern recognition of spectroscopy and chromatography. However, major challenges impeded NN extension including void in the food scientist-friendly interface software package, incomprehensible model behavior, multi-source heterogeneous data, and so on. The breakthrough from other fields proved NN has the potential to offer a revolution in the immediate future.

Draft genome sequence of Pseudomonas sp. A46 isolated from mercury-contaminated wastewater.

Pseudomonas sp. A46 was first isolated from mercury-contaminated groundwater in Taiwan. This study is the first to report the draft whole-genome sequence of Pseudomonas sp. A46. Its genome consists of 126 contigs, with a total length of 6,782,516 bp and a GC content of 64.7%. Phylogenetic analysis based on 16 S rRNA gene sequences revealed that Pseudomonas sp. A46 is closely related to Pseudomonas citronellolis. Assessment of the draft genome sequence revealed that Pseudomonas sp. A46 harbors sets of genes conferring resistance to heavy metals, such as mercury, zinc, lead, copper, cadmium, chromate, and arsenate. These identified genes enable this bacterium to tolerate heavy metal stress.

Long intergenic noncoding RNA 00908 promotes proliferation and inhibits apoptosis of colorectal cancer cells by regulating KLF5 expression.

Long intergenic noncoding RNAs (lincRNAs) play a vital role in the occurrence and progression of cancer. The mechanism of lincRNAs in colorectal cancer (CRC) has not been fully elucidated. In this context, an integrated comparative long noncoding RNA (lncRNA) microarray technology was used to determine the expression profile of lncRNAs in CRC. The roles of LINC00908 are unclear. We found that LINC00908 was significantly upregulated in CRC. Inhibition of LINC00908 resulted in reduced cell proliferation and G1 cell cycle arrest, which was mediated by cyclin D1, cyclin-dependent kinase 4, and phosphorylated retinoblastoma. Moreover, inhibition of LINC00908-induced apoptosis through the intrinsic apoptosis signaling pathway, as shown by the activation of caspase-9 and caspase-3. Mechanistically, miR-143-3p directly bound to LINC00908. miR-143-3p expression was negatively correlated with LINC00908 expression in CRC tissue. Functional experiments revealed opposing roles for miR-143-3p and LINC00908, suggesting that LINC00908 negatively regulates miR-143-3p. Mechanistically, miR-143-3p directly targets LINC00908. The KLF5 inhibitor ML264 affected proliferation and apoptosis, indicating that LINC00908 may act as a competing endogenous RNA to facilitate the expression of the miR-143-3p target gene KLF5. Thus, LINC00908 has an important proliferative and antiapoptotic role in CRC by regulating the cell cycle and intrinsic apoptosis. LINC00908 could be a potential biomarker and a new therapeutic target for CRC.

LINC00511-dependent inhibition of IL-24 contributes to the oncogenic role of HNF4α in colorectal cancer.

Hepatocyte nuclear factor 4 α (HNF4α) is an important transcription factor that acts as a pro-proliferative mediator during tumorigenesis, yet its function in colorectal cancer (CRC) remain unclear. Hence, this study aims to explore roles that HNF4α plays in the CRC development. RNA quantification analysis was conducted to characterize the expression pattern of long intergenic noncoding RNA 00511 (LINC00511)/HNF4α/IL-24 in CRC tissues and cell lines. Using gain- and loss-of-function approaches, effects of HNF4α/LINC00511/IL-24 axis on biological processes such as proliferative, migrating, invading, apoptotic, and tumorigenic functions of CRC cells were evaluated. We further identified the interactions among HNF4α/LINC00511/EZH2/IL-24 using RNA binding protein immunoprecipitation, RNA pull-down along with chromatin immunoprecipitation (ChIP). LINC00511 was an upregulated lncRNA in CRC tissues and cells, which played an oncogenic role by strengthening the malignant phenotypes of CRC cells. LINC00511 downregulated IL-24 expression by interacting with EZH2. HNF4α could enhance LINC00511 transcription in an epigenetic manner, which finally accelerated cancer progression and tumorigenesis through LINC00511-mediated inhibition of IL-24. Those data together demonstrated the contribution of HNF4α to the progression of CRC through mediating the LINC00511/EZH2/IL-24 axis. Hence, our study provides a promising therapeutic target for CRC.NEW & NOTEWORTHY Our findings on the roles of hepatocyte nuclear factor 4 α/long intergenic noncoding RNA 00511/IL-24 axis provide new insights into the CRC and offer potential targets for translational applications.

Screening for upper gastrointestinal cancers with magnetically controlled capsule gastroscopy: a feasibility study.

BACKGROUND: The medical consortium is an intensive and disease-specific association that integrates tertiary public hospitals and medical examination centers in China. We aimed to evaluate the feasibility of the medical consortium for screening upper gastrointestinal (GI) cancers (MCSC) by magnetically controlled capsule gastroscopy (MCCG). METHODS: 6627 asymptomatic subjects underwent MCCG as part of health check-ups in the MCSC between March and November 2018. Relevant clinical data were collected and analyzed. RESULTS: The MCSC detected 32 patients with upper GI cancer (0.48 %) confirmed by pathology. The detection rate of early gastric cancer was 16.67 % (4 /24). Gastric polyps, ulcers, and submucosal tumors were found in 15.54 %, 3.76 %, and 3.17 % of subjects, respectively. The whole GI preparation and operation process were well tolerated. CONCLUSIONS: The MCSC was a feasible model for upper GI cancer screening, especially for asymptomatic subjects. Further prospective studies with better operational quality control are warranted.

Delivery of synergistic polyphenol combinations using biopolymer-based systems: Advances in physicochemical properties, stability and bioavailability.

When consumed at sufficiently high levels, polyphenols may provide health benefits, which is linked to their antidiabetic, antiinflamatory, antimicrobial, antioxidant, antitumor, and hypolipidemic properties. Moreover, certain polyphenol combinations exhibit synergistic effects when delivered together - the combined polyphenols have a higher biological activity than the sum of the individual ones. However, the commercial application of polyphenols as nutraceuticals is currently limited because of their poor solubility characteristics; instability when exposed to light, heat, and alkaline conditions; and, low and inconsistent oral bioavailability. Colloidal delivery systems are being developed to overcome these challenges. In this article, we review the design, fabrication, and utilization of food-grade biopolymer-based delivery systems for the encapsulation of one or more polyphenols. In particular, we focus on the creation of delivery systems constructed from edible proteins and polysaccharides. The optimization of biopolymer-based delivery systems may lead to the development of innovative polyphenol-enriched functional foods that can improve human health and wellbeing.

Evolution of IFN subgroups in bony fish - 2. analysis of subgroup appearance and expansion in teleost fish with a focus on salmonids.

A relatively large repertoire of type I interferon (IFN) genes is apparent in rainbow trout/Atlantic salmon, that includes six different IFN subgroups (IFNa-IFNf) belonging to the three known type I IFN groups (1-3) in bony fish. Whether this is true for other salmonids, and how the various type I subgroups evolved in teleost fish was studied using the extensive genomic resources available for fish. This confirmed that salmonids, at least the Salmoninae, indeed have a complex (in terms of IFN subgroups present) and large (number of genes) IFN repertoire relative to other teleost fish. This is in part a consequence of the salmonid 4 R WGD that duplicated the growth hormone (GH) locus in which type I IFNs are generally located. Divergence of the IFN genes at the two GH loci was apparent but was not seen in common carp, a species that also underwent an independent 4 R WGD. However, expansion of IFN gene number can be found at the CD79b locus of some perciform fish (both freshwater and marine), with expansion of the IFNd gene repertoire. Curiously the primordial gene order of GH-IFNc-IFNb-IFNa-IFNe is largely retained in many teleost lineages and likely reflects the tandem duplications that are taking place to increase IFN gene number. With respect to the evolution of the IFN subgroups, a complex acquisition and/or loss has occurred in different teleost lineages, with complete loss of IFN genes at the GH or CD79b locus in some species, and reduction to a single IFN subgroup in others. It becomes clear that there are many variations to be discovered regarding the mechanisms by which fish elicit protective (antiviral) immune responses.

Simultaneous Ultrasound and Heat Enhance Functional Properties of Glycosylated Lactoferrin.

Protein-polysaccharide covalent complexes exhibit better physicochemical and functional properties than single protein or polysaccharide. To promote the formation of the covalent complex from lactoferrin (LF) and beet pectin (BP), we enhanced the Maillard reaction between LF and BP by using an ultrasound-assisted treatment and studied the structure and functional properties of the resulting product. The reaction conditions were optimized by an orthogonal experimental design, and the highest grafting degree of 55.36% was obtained by ultrasonic treatment at 300 W for 20 min and at LF concentration of 20 g/L and BP concentration of 9 g/L. The formation of LF-BP conjugates was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) spectroscopy. Ultrasound-assisted treatment can increase the surface hydrophobicity, browning index, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals scavenging activity of LF due to the changes in the spatial configuration and formation of Maillard reaction products. The thermal stability, antioxidant activity and emulsifying property of LF were significantly improved after combining with BP. These findings reveal the potential application of modified proteins by ultrasonic and heat treatment.

Effect of Membrane Surface Modification Using Chitosan Hydrochloride and Lactoferrin on the Properties of Astaxanthin-Loaded Liposomes.

Astaxanthin-loaded liposomes were prepared by a thin-film ultrasonic method, and the effects of the different membrane surface modifiers chitosan hydrochloride (CH) and lactoferrin (LF) on the physicochemical stability of the liposomes and bioaccessibility of astaxanthin were studied. Based on the negative charge characteristics of egg yolk lecithin, LF and CH with positive charge were assembled on the surface of liposomes by an electrostatic deposition method. The optimal concentrations of modifiers were determined by particle size, zeta potential and encapsulation efficiency. The interaction between the liposomes and the coatings was characterized by Fourier Transform infrared spectroscopy. The stability of astaxanthin in different systems (suspension and liposomes) was investigated, and its antioxidant capacity and bioaccessibility were determined. The results showed that both membrane surface modifications could interact with liposomes and protect astaxanthin from oxidation or heat degradation and enhance the antioxidant activity of the liposome, therefore membrane surface modification played an important role in stabilizing the lipid bilayer. At the same time, the encapsulated astaxanthin exhibited higher in vitro bioaccessibility than the free astaxanthin. CH and LF modified liposomes can be developed as formulations for encapsulation and delivery of functional ingredients, providing a theoretical basis for the development of new astaxanthin series products.