Effects of Partially N-acetylated Chitosans to Elicit Resistance Reaction on Brassica napus L.

The effects to elicit resistance reaction on oilseed rape (Brassica napus L. cv Xinongchangjiao ) by four partially N-acetylated chitosan 7B, 8B, 9B and 10B (Degree of acetylation (D. A.) is 30% , 20% , 10%, 0%, respectively) and Glycol chitosan (GC, D.A. is 0%) were investigated and compared. Results showed that chitosan were similar to salicylic acid (SA), and could induce resistance reaction, but the reaction was influenced by the degree of acetylation of chitosan. Fully deacetylated chitosans, 10B and GC, elicited chitinase activity, but partially acetylated chitosan, 7B, 8B and 9B, inhibited chitinase activity. Phenyalanine ammonia-lyase (PAL) was also elicited. Elicitor activity increased with on increasing degree of acetylation, 7B induced highest PAL activity among all chitosans. All chitosans induced peroxidase (POD) in a similar level. After elicited by glycol chitosan, like SA treatment, the seedlings increased disease resistance to Sclerotinia sclerotiorum significantly.

LOW MOLECULAR WEIGHT O-CARBOXYMETHYLATED CHITOSANS DERIVED FROM IRRADIATED CHITOSAN AND THEIR ANTIBACTERIAL ACTIVITY

Original chitosan with M-v of 2.7 x 10(5) was degraded by irradiation with gamma-rays and a series of low molecular weight O-carboxymethylated chitosans (O-CMCh) were prepared based on the irradiated chitosan. A kinetic model of the irradiation of chitosan was put forward. Results show that the irradiation degradation of chitosan obeys the rule of random degradation and the degree of deacetylation of irradiated chitosan is slightly raised. The antibacterial activity of O-CMCh is significantly influenced by its MW, and a suppositional antibacterial peak appears when M-v is equal to 2 x 10(5).

Preparation of Carboxymethyl Sulfochitosans with Differentially Substituted Regions

Five kinds of carboxymethyl sulfochitosans with different regions such as N-carboxymethyl-O-sulfochitosan, O-carboxymethyl-N-sulfochitosan, O-carboxymethyl chitosan sulfate, N-carboxymethyl chitosan-6-sulfate, and N,O-carboxymethyl -N,O-sulfochitosan were prepared respectively by using differential carboxymethylation and sulfation methods, and their IR spectrum and 13C-NMR spectrum were measured.

Green Synthesis and Physical and Chemical Characterization of Chitosans with a High Degree of Deacetylation, Produced by a Binary Enzyme System

Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitosan depend on its physical and chemical characteristics, which result from the treatments used for its production. In this study, we report the preparation and characterization ofchitosan oligosaccharides by a green synthesis from crystalline shrimp chitin, using a sequential enzyme treatment by chitinase and chitin deacetylase. Chitinases were purified from grapes and used to rupture the crystalline shrimp chitin structure, modifying the crystallinity index from 57.6% to 15.9%. The resultant polymers were deacetylated using a recombinant chitin deacetylase from Saccharomyces cerevisiae, which was cloned and expressed in Pichia pastoris. The chitosans produced showed an estimated DA （degree of acetylation） of approximately 20%, and the molecular weights ranged from -7,600 to -3,700 after treatment in pH 3.0 and pH 6.0 for 10 min and 40 min, respectively. Physical and chemical characterization of the products indicated that enzyme fragmentation of chitin probably makes the acetamide groups more accessible to deacetylation, forming homogeneous polymers that are free of hazardous sub-products, have defined low molecular weights, and are highly deacetylated.

ALTERED ENZYMATIC ACTIVITY OF LYSOZYMES BOUND TO VARIOUSLY SULFATED CHITOSANS

The purpose of this research is to investigate the effects of the variously sulfated chitosans on lysozyme activity and structure. It was shown that the specific enzymatic activity of lysozyme remained almost similar to the native protein after being bound to 6-O-sulfated chitosan （6S-chitosan） and 3,6-O-sulfated chitosan （3,6S-chitosan）, but decreased greatly after being bound to 2-N-6-O-sulfated chitosan （2,6S-chitosan）. Meanwhile, among these sulfated chitosans, 2,6S-chitosan induced the greatest conformational change in lysozyme as indicated by the fluorescence spectra. These findings demonstrated that when sulfated chitosans of different structures bind to lysozyme, lysozyme undergoes conformational change of different magnitudes, which results in corresponding levels of lysozyme activity. Further study on the interaction of sulfated chitosans with lysozyme by surface plasmon resonance （SPR） suggested that their affinities might be determined by their molecular structures.

Activation of endogenous neurogenesis and angiogenesis by basic fibroblast growth factor-chitosan gel in an adult rat model of ischemic stroke

Attempts have been made to use cell transplantation and biomaterials to promote cell proliferation,differentiation,migration,and survival,as well as angiogenesis,in the context of brain injury.However,whether bioactive materials can repair the damage caused by ischemic stroke by activating endogenous neurogenesis and angiogenesis is still unknown.In this study,we applied chitosan gel loaded with basic fibroblast growth factor to the stroke cavity 7 days after ischemic stroke in rats.The gel slowly released basic fibroblast growth factor,which improved the local microenvironment,activated endogenous neural stem/progenitor cells,and recruited these cells to migrate toward the penumbra and stroke cavity and subsequently differentiate into neurons,while enhancing angiogenesis in the penumbra and stroke cavity and ultimately leading to partial functional recovery.This study revealed the mechanism by which bioactive materials repair ischemic strokes,thus providing a new strategy for the clinical application of bioactive materials in the treatment of ischemic stroke.

Chitosan-based triboelectric materials for self-powered sensing at high temperatures

Although biopolymers have been widely utilized as triboelectric materials for the construction of self-powered sensing systems,the annihilation of triboelectric charges at high temperatures restricts the output signals and sensitivity of the assembled sensors.Herein,a novel chitosan/montmorillonite/lignin(CML)composite film was designed and employed as a tribopositive layer in the assembly of a self-powered sensing system for use under hot conditions(25-70℃).The dense contact surface resulting from the strong intermolecular interaction between biopolymers and nanofillers restrained the volatilization of induced electrons.The optimized CML-TENG delivered the highest open-circuit voltage(V_(oc))of 262 V and maximum instantaneous output power of 429 mW/m^(2).Pristine CH-TENG retained only 39%of its initial Voc at 70℃,whereas the optimized CM_(5)L_(3)-TENG retained 66%of its initial Voc.Our work provides a new strategy for suppressing the annihilation of triboelectric charges at high temperatures,thus boosting the development of self-powered sensing devices for application under hot conditions.

具有可生物降解、细胞相容、抗菌及生物膜控制的壳聚糖磺基甜菜碱衍生物薄膜生物材料的研究

The purpose of this research was to develop a chitosan sulfobetaine(CS-SNCC)film via the solutioncasting method as a biodegradable antibacterial material for biomedical applications.Chitosan and monochloro-triazine sulfobetaine were used as the raw materials for CS-SNCC preparation,and Fourier-transform infrared(FTIR),ultraviolet–visible(UV-Vis),energy-dispersive X-ray(EDX),and Xray photoelectron spectroscopy(XPS)spectra were used to characterize and analyze the structure of the synthesized CS-SNCC.Furthermore,the swelling property,thermal stability,biodegradability,cytocompatibility,and antibacterial properties of the CS-SNCC film were comprehensively investigated and compared with those of the chitosan film.The results for the film’s enzymatic biodegradation behavior show that the CS-SNCC film undergoes a weight loss of 45.54%after 21 days of incubation.In addition,the CS-SNCC film effectively resists bacterial adhesion,prevents the formation of bacteria biofilms,and exhibits high antibacterial activity,with inactivation rates of 93.43%for Escherichia coli and 91.00%for Staphylococcus aureus.Moreover,the CS-SNCC film shows good cellular activity and cytocompatibility according to the cytotoxicity results.Therefore,the prepared biodegradable,cytocompatible,antibacterial,and biofilm-controlling CS-SNCC film has potential for biomedical applications.

一种双层多糖水凝胶用于增强益生菌肠道靶向口服递送

Transplantation of probiotics to the intestine can positively regulate the gut microbiota,thereby promoting the immune system and treating various diseases.However,the harsh gastrointestinal environment and short retention time in the gastrointestinal tract significantly limit the bioavailability and intestinal colonization of probiotics.Herein,we present a double-layer polysaccharide hydrogel(DPH)in the form of a double-layer structure composed of a carboxymethyl cellulose(CMCL)supramolecular inner layer and a dialdehyde alginate(DAA)cross-linked carboxymethyl chitosan(CMCS)outer layer.This doublelayer structure allows DPH to encapsulate and deliver probiotics in a targeted manner within the body.In the stomach,the cage structure of the DPH is closed,and the outer layer absorbs surrounding liquids to form a barrier to protect the probiotics from gastric fluids.In the intestine,the cage structure opens and disintegrates,releasing the probiotics.Thus,DPH endows probiotics with excellent intestine-targeted delivery,improved oral bioavailability,enhanced gastrointestinal tract tolerance,and robust mucoadhesion capacity.The encapsulated probiotics exhibit almost unchanged bioactivity in the gastrointestinal tract before release,as well as improved oral delivery.In particular,probiotics encapsulated by DPH exhibit 100.1 times higher bioavailability and 10.6 times higher mucoadhesion than free probiotics in an animal model 48 h post-treatment.In addition,with a remarkable ability to survive and be retained in the intestine,probiotics encapsulated by DPH show excellent in vitro and in vivo competition with pathogens.Notably,DAA-mediated dynamic crosslinking not only maintains the overall integrity of the hydrogels but also controls the release timing of the probiotics.Thus,it is expected that encapsulated substances(probiotics,proteins,etc.)can be delivered to specific sites of the intestinal tract by means of DPH,by controlling the dynamic covalent crosslinking.

Constructing a biofunctionalized 3D-printed gelatin/sodium alginate/chitosan tri-polymer complex scaffold with improvised biological andmechanical properties for bone-tissue engineering

Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.

Using Electrodeposition of Carboxylated Chitosan for Green Preparation of Copper Nanoclusters and Nanocomposite Films

On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient and eco-friendly process,mild conditions,and simple post-treatment.The experimental results reveal that a homogeneous deposited film(Cu NCs/CCS nanocomposite film)is generated on the Cu plate(the anode)after electrodeposition,which exhibits an obvious red florescence.The results from TEM observation suggest there are nanoparticles(with the average particle size of 2.3 nm)in the deposited film.Spectral analysis results both demonstrate the existence of Cu NCs in the deposited film.Moreover,the Cu NCs/CCS film modified electrode is directly created through electrodeposition of CCS,which enables promising application in the electrochemical sensing.By means of fluorescence properties of Cu NCs,the Cu NCs/CCS film also owns the potential in fluorescence detection.Therefore,this work builds a novel method for the green synthesis of Cu NCs,meanwhile it offers a convenient and new electrodeposition strategy to prepare polysaccharide-based Cu NCs nanocomposites for uses in functional nanocomposites and bioelectronic devices.

The ceRNA Network Indicates Its Immune Function in Peripheral Blood Leukocytes of Half-Smooth Tongue Sole(Cynoglossus semilaevis)After Stimulation with Chitosan Oligosaccharide

As an efficient immunostimulant,chitosan oligosaccharide(COS)can enhance the immunity of teleosts;however,the underlying molecular mechanisms still require elucidation.Competing endogenous RNAs(ceRNAs)are vital regulators in the immune response,but their roles in half-smooth tongue sole(Cynoglossus semilaevis)remain unclear.In this study,for the first time,we studied whole-transcriptome expression profiles and analyzed ceRNA networks in peripheral blood leukocytes of half-smooth tongue sole treated with COS.A total of 19 circRNAs(DE-circRNAs),18 miRNAs(DE-miRNAs)and 50 previously identified lncRNAs(DElncRNAs)were differentially expressed after COS stimulation.The DE-lncRNAs and DE-miRNAs targeted numerous immunity-related genes,and were enriched in important pathways,including MAPK and Toll-like receptor signaling pathways,suggesting the immunoregulatory roles of COS.Furthermore,we constructed circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA regulatory networks using DE-circRNAs,DE-miRNAs,DE-lncRNAs,and DE-mRNAs.Additionally,a ceRNA network with immunity-related DEmRNAs was constructed,showing that 3 DE-circRNAs,12 DE-lncRNAs,and 29 DEGs exhibited crosstalk through 9 DE-miRNAs.Intriguingly,a DE-miRNA in the ceRNA network,miR-144-3p,was targeted by DE-lncRNA tnrc6a,and negatively regulated the genes of inhibitor of nuclear factor kappa B kinases(IKKs)(ikbkg,ikbkb,and ikbip)and c3ar1.Ikbkg,ikbkb,and c3ar1 were significantly up-regulated in macrophages stimulated by LPS.It could be inferred that ncRNAs participated in the immune and inflammatory response by acting as ceRNAs after COS stimulation in teleosts.These findings indicate that COS could enhance the immunity of teleosts by regulating ncRNAs,and lay the foundation for further practical application of COS in aquaculture.

Chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor for neurotrophic keratopathy

Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.

Simple preparation of C(CS)/g-C_(3)N_(4)/Co carbon aerogel and its catalytic performance for ammonium perchlorate

Biomass chitosan(CS)was used as a template,graphitic phase carbon nitride(g-C_(3)N_(4))with high nitrogen content and certain catalytic activity was used as a dopant,and nano-transition metal cobalt(Co)was used as a catalytic center point.The carbon aerogel(C(CS)/g-C_(3)N_(4)/Co)with a three-dimensional network-like structure was prepared by assembling the three materials through experimental operations such as freeze-drying and high-temperature carbonization.It was demonstrated by scanning and transmission characterization that the CS in the carbon aerogel could provide more active sites for the cobalt nanoparticles,and the doping of graphite-phase carbon nitride as a template dispersed the cobalt nanoparticles and changed the conductivity of the CS.To investigate the catalytic effect of carbon aerogel on ammonium perchlorate(AP),it was investigated by differential thermal analyzer and TG thermal analysis.This carbon aerogel was very effective in catalyzing AP,and the 10 wt% content of the catalyst reduced the AP pyrolysis peak from 703.9 to 595.5 K.And to further investigate the synergistic effect of the three materials,further carbon aerogels such as C(CS)/Co,g-C_(3)N_(4)/Co were prepared and applied to catalyze AP,and the same ratio reduced the AP pyrolysis peak by 98.1℃ and 97.7℃.This result indicates a synergistic effect of the assembly of the three materials.

Synthesis of chitosan oligosaccharide selenium and its antitumor activity

Background:Polysaccharides have various biological activities;the complexation of polysaccharides with trace element ions can produce synergistic effects,improving the original biological activities of sugars and trace elements.Methods:The preparation process of chitosan oligosaccharide selenium(COSSe)was optimized by the response surface method,followed by a detailed analysis of the resultant compound’s characteristics.The anti-cancer activity of COSSe was studied using the human ovarian cancer cell line SKOV3 as a cell model.Results:The prepared COSSe response surface was well predicted,indicating successful chitosan oligosaccharide binding with selenium.Response surface method analyses identified the optimal synthesis conditions for COSSe:the reaction time of 5.08 h,the reaction temperature of 71.8°C,and mass ratio(Na2SeO3:chitosan oligosaccharide)of 1.02.Under the optimal conditions,the final product,the selenium content,reached 1.302%.The results of cell experiments showed that COSSe significantly inhibited SKOV3 proliferation in a concentration-dependent manner.RNA-seq results showed that chitosan oligosaccharide and COSSe significantly modulated the expression of genes’DNA metabolic processes and cell cycle in SKOV3 cells.Gene enrichment analysis showed the inhibition of the cell cycle,and the results of flow cytometry showed that SKOV3 cells increased in the S phase and decreased in the G2/M phase,with a noted suppression in the protein expression of cyclin-dependent kinase 2(CDK2)and cyclin A1(CCNA1).Conclusion:COSSe has a stronger effect than chitosan oligosaccharide,leading to the arrest of the cell cycle in the S phase.Thus,COSSe may be an effective candidate for the treatment of ovarian cancer.

Research Progress of Biomass-Based Porous Oil-Absorbing Materials

As oil is now an important resource for the survival and development of mankind,the consumption of oil continues to increase each year,and there have been a number of major oil spills in history,such as the oil spill from the Deepwater Horizon drilling rig.Therefore,oil spills during storage and transportation have become an issue of serious concern.Current methods such as incineration and chemical methods cause secondary environmental pollution and fail to enable resource recovery.The adsorption method by porous materials has attracted worldwide attention due to its simplicity,portability,and efficiency.It has become an important factor to explore how porous adsorption materials can adsorb efficiently and reduce environmental pollution.Biomass resources are abundant,cost-effective,biodegradable,and sustainable,which have been extensively explored for the production of porous materials.Herein,recent advances in cellulose-based,chitosan-based,wood-based and other biomassbased oil-absorbing porous materials are summarized,and cellulose-based porous materials,such as nanocellulose,bacterial cellulose,and regenerated cellulose and their related derivatives,are further expanded.In addition,typical environmentally friendly manufacturing methods and the oil adsorption capacities of various oil-absorbing porous materials are also discussed.Compared with the traditional petrochemical adsorption materials,the development advantages of biomass porous oil absorption materials are analyzed.The reasons hindering the popularization and use of oil-absorbing biomass materials are summarized and the future application fields are prospected.

Encapsulation of Clove Oil Nanoemlusion in Chitosan-Based Nano-Composite: In Vitro and in Vivo Antifungal Activity against Rhizoctonia solani and Sclerotium rolfsii

Rhizoctonia solani Kühn and Sclerotium rolfsii Sacc.are the primary soil-borne plant diseases responsible for sig-nificant reductions in global crop yields.The primary goal of this study was to investigate the antifungal potentials of clove essential oil(CEO),nanoemulsion form(CEONE)and chitosan/nanoemulsion nanocomposite(CS/CEONE)against R.solani and S.rolfsii through in vitro and in vivo trials.Both CEONE and CS/CEONE were prepared and investigated for their physical chemical and morphological characterization.The poisoned medium method was utilized to evaluate the inhibitory effects of CEO,CEONE and CS/CEONE on the mycelial growth and enzymatic activity of R.solani and S.rolfsii.The changes of hyphae of R.solani and S.rolfsii in response to treating with CEONE and CS/CEONE were observed with scanning electron microscope(SEM).The results revealed that CEONE have larger size 86±3 nm and a broader range of PDI 0.121±0.011 on the average.While,CS/CEONE has smaller size of 49±4 nm and narrower PDI of 0.099±0.009.Both nanoemulsions had uniform spherical nanodroplets form and exhibited acidic nature.Fourier Transform Infrared Spectroscopy(FTIR)and UV-Visible Spectroscopy(UV-Vis)verified the successful incorporation of both CS and CEO within the nanoe-mulsion system.The results demonstrated a sustained and prolonged release profile from CS/CEONE for up to 4 days.The inhibitory effect of CEONE and CS/CEONE showed dose-dependent activity against mycelial growth of both fungi.CEONE and CS/CEONE at concentration 500µL/L exhibited the strongest inhibition with a sig-nificant(p<0.05)variation among them with value ranging from 56.11%to 71.94%and 52.2%to 79.2%,respec-tively.Comparing to control,CS/CEONE revealed the highest inhibitory effect against S.rolfsii after 96 h followed by CEONE with value reached 50.6%and 44.1%,respectively.The antifungal activity of the nanoemulsion showed strain–dependent behavior,where S.rolfsii was the most affected.SEM images showed changes in the hyphal structure of S.rolfsii and R.solani resulting from the impact of CEONE and CS/CEONE.Activity of pectinase and cellulase secreted by both fungi was also negatively affected by CEO,CEONE and CS/CEONE at all tested concentrations.Greenhouse trials revealed that increasing the concentrations of CEO,CEONE,and CS/CEONE from 50 to 500μL/L gradually increased their effectiveness in reducing the DI%and DS%of black scurf,stem canker,pre-damping off,and post-damping off diseases on potato.The results suggest that incorporation of CS to CEONE enhanced its activity and can be utilized as a secure and non-toxic nanocomposite.

Chitosan/Sodium Alginate Multilayer pH-Sensitive Films Based on Layer-by-Layer Self-Assembly for Intelligent Packaging

The abuse of plastic food packaging has brought about severe white pollution issues around the world.Developing green and sustainable biomass packaging is an effective way to solve this problem.Hence,a chitosan/sodium alginate-based multilayer film is fabricated via a layer-by-layer(LBL)self-assembly method.With the help of superior interaction between the layers,the multilayer film possesses excellent mechanical properties(with a tensile strength of 50 MPa).Besides,the film displays outstanding water retention property(blocking moisture of 97.56%)and ultraviolet blocking property.Anthocyanin is introduced into the film to detect the food quality since it is one natural plant polyphenol that is sensitive to the pH changes ranging from 1 to 13 in food when spoilage occurs.It is noted that the film is also bacteriostatic which is desired for food packaging.This study describes a simple technique for the development of advanced multifunctional and fully biodegradable food packaging film and it is a sustainable alternative to plastic packaging.

Smart Colorimetric Corn Starch Films Combined with Anthocyanin-Loaded Glutenin-Carboxymethyl Chitosan Nanocomplexes for Freshness Monitoring of Chilled Pork

In this study,intelligent,pH-responsive colorimetric films were prepared by encapsulating anthocyanins in nanocomplexes prepared from glutenin and carboxymethyl chitosan.These nanocomplexes were added to a corn starch matrix and used in the freshness monitoring of chilled pork.The effects of anthocyanin-loaded nanocomplexes on the physical,structural,and functional characteristics of the films were investigated.The addition of anthocyanin-loaded nanocomplexes increased the tensile strength,elongation at break,hydrophobicity,and light transmittance of the films while decreasing their water vapor permeability.This is because new hydrogen bonds are formed between the film components,resulting in a more homogeneous and dense structure.The colorimetric film has a significant color response to pH changes.These films were used in experiments on the freshness of chilled pork,in which the pH changes with changing freshness states.The results show that the colorimetric film can monitor changes in the freshness of chilled pork in real time,where orange,pink,and green represent the fresh,secondary fresh,and putrefied states of pork,respectively.Therefore,the intelligent colorimetric film developed in this study has good application potential in the food industry.

Adding chitosan nanoparticles of green tea extract in diluent and thawing temperatures ameliorate the post-thawed quality of Boer buck semen

Objective:To improve the quality of post-thawing Boer buck semen for artificial insemination by adding green tea extract chitosan nanoparticles to skimmed egg yolk diluent,and the proper thawing temperature.Methods:The ejaculate of Boer buck was added to skimmed egg yolk diluent without(the control group)and with adding 1μg of chitosan nanoparticles of green tea extract per mL of diluent(the treatment group).Then,the diluted semen was filled in French mini straws containing 60×106 live sperm per straw,frozen in a standard protocol,and stored as frozen semen at−196℃for a week.Six replicates from each group were diluted for 30 s at 37℃or 39℃sterile water to evaluate the semen quality.Results:Post-thawing(at 37℃or 39℃)of live sperm,progressive motility,and plasma membrane integrity were lower compared to those of the pre-freezing stage(P<0.05).Thawing at 37℃resulted in no significant difference in live sperm,progressive motility,and plasma membrane between the control group and the treatment group(P>0.05).The live sperm,progressive motility,and plasma membrane of the treatment group in the pre-freezing stage,and post-thawed at 39℃were higher compared to those of the control group(P<0.05).There was no significant difference in malondialdehyde(MDA)concentration,DNA fragmentation,and catalase concentration of thawing at 37℃compared to those of 39℃in the same group.The MDA concentration and DNA fragmentation in thawing at 37℃and 39℃of the treatment group were significantly lower than those of the control group(P<0.05).However,the catalase concentration in thawing at 37℃and 39℃of the treatment group was not significantly different than the control group(P>0.05).Conclusions:Higher quality post-thawing Boer buck semen is achieved by adding 1μg/mL of chitosan nanoparticles of green tea extract to the skimmed egg yolk diluent and thawing at 39℃.