查看更多>>摘要：? 2022Sweet cherry is prone to senesce and decay due to high postharvest respiration rate and fungal infection。 The effects of natamycin-chitosan coating on physicochemical and microbial properties of sweet cherries stored at 4 °C were investigated。 Scanning electron microscopy results revealed that natamycin was more uniformly distributed on sweet cherry pericarps with the help of chitosan coating。 Respiration rate of sweet cherries was suppressed by chitosan coating during the storage and as a result， total soluble solids (13。53 %–13。80 %) and titratable acidity (0。91 %–0。93 %) were remained higher values and weight loss (2。54 %–2。85 %) was decreased in chitosan and natamycin-chitosan groups。 Although both natamycin and chitosan were effective in inhibiting yeast and mold， sweet cherries treated with the combination of natamycin and chitosan showed significantly lower yeast and mold count (3。31 log CFU/g) and decay rate (1。67 %) compared with control。 Natamycin combined chitosan inhibited the pathogenic fungi of sweet cherries， such as Alternaria， Cladosporium and Penicillium。 These results indicated that postharvest natamycin-chitosan coating has great advantages in maintaining fruit quality， inhibiting fungi， and reducing decay rate of sweet cherry。
Lima A.M.Azevedo M.I.G.Sousa L.M.Freitas C.D.T....
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查看更多>>摘要：? 2022 Elsevier B。V。Antimicrobial peptides， also known as AMPs， are cationic and amphipathic molecules found in all living organisms， composing part of the defense mechanisms against various pathogens， including fungi， viruses， bacteria， and nematodes。 AMPs derived from plants are the focus of this review because they have gained attention as alternative molecules to overcome pathogen resistance as well as new drugs to combat cancer。 Plant AMPs are generally classified based on their sequences and structures， as thionins， defensins， hevein-like peptides， knottins， stable-like peptides， lipid transfer proteins， snakins， and cyclotides。 Although there are studies reporting the toxicity of plant AMPs to nontarget cells or limitations of oral administration， synthetic AMPs with reduced toxicity or allergenicity， or greater resistance to peptidases can be designed by using different bioinformatics tools。 Thus， this review provides information about the classification of plant AMPs， their characteristics， mechanisms of action， hemolytic and cytotoxic potential， possible applications in the medical field， and finally， the use of bioinformatics to help design synthetic AMPs with improved features。
查看更多>>摘要：? 2022High pollution and low productivity of the traditional method for synthesis of vitamin group K require an efficient， low-cost， and environmentally sustainable biocatalyst as a greener process。 These have encouraged us to design and fabricate a series of novel Co NPs impregnated pectin-gelatin (Co@PTNC， Co@GTNC & Co@PT0。7GT0。3NC) and grafted pectin-gelatin modified magnetic beads (Co@MPT0。7GT0。3NC) by the in situ reduction–precipitation procedure and chemical application in the selective synthesis of vitamin K3 without any promoters or ligands。 The chemical structure and morphological properties were fully characterized。 Additionally， the influence of structural parameters (i。e。， kind of stabilizer with different ratio (nPT/nGT)， amount of Co loading， durability， size， distribution， and Leaching test) and operating parameters (i。e。， reaction time， reaction temperature， nature of the solvent， and concentration of oxidant) on the efficacy of the biocatalysts was evaluated in detail。 The green synthesis involves several advantages， like the heterogeneous nature of catalysts， environmentally-friendly and mild conditions， high recovery efficiency due to superparamagnetism， high activity， and the sustainable performance of the biocatalyst。
查看更多>>摘要：? 2022 Elsevier B。V。Apextrin belongs to ApeC-containing proteins (ACPs) and features a signal-peptide， an N-terminal membrane attack complex component/perforin (MACPF) domain， and a C-terminal ApeC domain。 Recently， apextrin-like proteins were identified as pattern recognition receptor (PRR)， which recognize the bacterial cell wall component and participate in innate immunity。 Here， an apextrin (Rpape) was identified and characterized in Ruditapes philippinarum。 Our results showed that Rpape mRNA was significantly induced under bacterial challenges。 The Rpape recombinant protein exhibited a significant inhibitory effect on gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and bound with Vibrio anguillarum， S。 aureus and B。 subtilis。 We found Rpape protein positively activated the NF-κB signaling cascade and increased the activity of Nitric oxide (NO)。 This study revealed the immunity role of apextrin in R。 philippinarum and provided a reference for further study on the role of apextrin in bivalves。
查看更多>>摘要：? 2022Reuse of biochar residues after lignin degradation will not only save costs but also reduce the pollution， protect and improve the environment。 In this study， biochar residue (BR) after peanut shell lignin selective depolymerization on ZSM-5 were recycled， and characterized by Scanning Electron Microscopy， Surface area & pore size distribution analyzers， Thermogravimetric Analysis。 Subsequently， a series of hybrid matrix membranes were prepared using ethyl cellulose as the matrix and biochar residue after depolymerization under different reaction conditions as the filler。 The separation performance of BR/EC membranes for CO2/CH4 mixed gas and CO2/N2 mixed gas was measured。 The results showed that the gas separation membranes prepared with biochar residue (3 h， 300 °C) as filler had good gas separation characteristics。 The resulting mixed-matrix membrane exhibited a permeability of 66。00 Barrer for CO2 and selectivities of 9。97 for CO2/CH4。 Meanwhile， the resulting mixed-matrix membrane exhibited a permeability of 79。53 Barrer for CO2 and selectivities of 20。01 for CO2/N2。 Both exceed the upper limit of known pure EC membranes。 Therefore， the use of biochar residue after ZSM-5 depolymerization as a filler for gas separation membranes is a feasible way。 Furthermore， the membrane is well stabilized， proving its good potential for industrial applications。
查看更多>>摘要：? 2022 Elsevier B。V。Exploiting eco-friendly， highly controlled preparation and convenient solid-liquid separation adsorbent to separate uranium from aquatic medium is of importance and in demand。 In this study， magnetic ferroferric oxide nanoparticles synthesized through a facile hydrothermal reaction was cross-linked with chitosan。 The intermediate product was subsequently chemically grafting with four amino acids such as alanine， serine， glycine or L-cysteine to produce Ala-MCS， Ser-MCS， Gly-MCS and Cys-MCS。 The resultants were verified by SEM， EDS， XRD， VSM， FT-IR and XPS。 Adsorption of uranium with amino acids-modified magnetic chitosans were carried out。 The parameters that affected the adsorption ability， selectivity toward uranium， and reusability have been illustrated。 pH 6。5 was the most beneficial for the adsorption。 The saturation adsorption capacity of Ala-MCS， Ser-MCS， Gly-MCS， Cys-MCS were found as 658。88 mg/g ± 1。0 %， 616。10 ± 0。3 % mg/g， 646。38 ± 1。8 % mg/g， 653。96 ± 3。4 % mg/g and 409。15 ± 4。6 % mg/g， respectively。 The adsorption process was analyzed using kinetics (pseudo-first-order， pseudo-second-order and intraparticle diffusion models) and isotherms models (Langmuir and Freundlich models)。 The adsorption of uranium on Ala-MCS， Ser-MCS， Gly-MCS and Cys-MCS happened on monolayer and were controlled by chemisorption。 The certified high adsorption amount and efficient solid-liquid separation proved amino acids-modified magnetic chitosan are promising adsorbents for removal of uranium from wastewater。
查看更多>>摘要：? 2022 Elsevier B。V。To maintain the freshness of fruits and to meet environmental and consumer needs， a biobased packaging film with long-lasting antimicrobial activity was developed in this article。 Liquefied ball-milled shrimp shell chitin/polyvinyl alcohol (LBSC/PVA) blend films containing varying concentrations (0， 1， 2， 3， 4， 5 wt%) of the β-cyclodextrin/cinnamaldehyde (β-CD/CA) inclusion were prepared and characterized。 The association between β-CD and CA and the sustained release behavior of CA were explored。 The physicochemical property， antimicrobial activity and food preservation performance of the films were investigated。 Results showed that CA was successfully encapsulated into the cavity of CD by host-guest interactions， which greatly improved the sustained release of CA。 The 3 wt% β-CD/CA/LBSC/PVA blend film showed optimized mechanical properties with a tensile strength of 41。5 MPa and an elongation at break of 810 %。 In addition， the incorporation of β-CD/CA inclusion significantly enhanced the antimicrobial activity and food preservation performance of the blend films。 Moreover， the 3 wt% β-CD/CA/LBSC/PVA blend film exhibited evidently longer lasting antimicrobial activity and cherry tomato preservation performance than the 3 wt% CA/LBSC/PVA blend film， further demonstrating the critical role of β-CD in delaying CA release。 These novel β-CD/CA/LBSC/PVA blend films may have a potential use in active food packaging。
查看更多>>摘要：? 2022 Elsevier B。V。We developed a highly conductive and flexible， anti-freezing sulfonated lignin (SL)-containing polyacrylic acid (PAA) (SL-g-PAA-Ni) hydrogel， with a high concentration of NiCl2。 Ni2+ contributes multi-functions to the preparation of the hydrogel and its final properties， such as fast polymerization reaction as a result of the presence of redox pairs of Ni3+/Ni2+ and hydroquinone/quinone， and anti-freezing properties of the hydrogel due to the salt effects of NiCl2 so that at ?20 °C the hydrogel shows similar properties to those at the room temperature。 Thanks to the effective coordinations of Ni2+ with catecholic groups and carboxylic groups， as well as the rich hydrogen bonding capacity， the resultant hydrogel possesses excellent mechanical properties。 High ionic conductivity (6。85 S·m?1) of the hydrogel is obtained due to the supply of high concentration of Ni2+。 Moreover， the ionic solvation effect of NiCl2 in the hydrogel imparts excellent water retention ability， with water retention of ~93 % after 21-day storage。 The SL-g-PAA-Ni hydrogel can accurately detect various human motions at ?20 °C。 The supercapacitor assembled from SL-g-PAA-Al hydrogel at ?20 °C manifests a high specific capacitance of 252 F·g?1， with maximum energy density of 26。97 Wh·kg?1， power density of 2667 W·kg?1， and capacitance retention of 96。7 % after 3000 consecutive charge-discharge cycles。
查看更多>>摘要：? 2022 Elsevier B。V。To improve the mechanical strength of borax-crosslinked fenugreek galactomannan hydrogels and broaden the application field of galactomannan-based hydrogels， fenugreek galactomannan (FG) was esterified via octenyl succinic anhydride (OSA)， and the parameters affecting the esterification reaction were systematically studied。 The optimum process for OSA-modified FG (OFG) was as follows: FG concentration 1。5 wt%， n (OSA): n (FG) = 2， n (4-dimethylamino-pyridine， DMAP): n (FG) = 4， and reaction time 12 h。 Under this condition， the degree of substitution (DS) was 0。31， and the product yield was 115。05 %。 Characterization of FT-IR， H1 NMR， and HPLC confirmed that the OSA group was successfully introduced into the FG skeleton。 The mechanical strength of borax crosslinked OFG hydrogel (OFGH) is 18 times higher than that of FG hydrogel。 OFGH shows excellent self-healing， injectable properties and electrical conductivity。 This will further expand the application of borax crosslinked galactomannan-based hydrogels in the fields of sensors， drug delivery， and wound dressing。
查看更多>>摘要：? 2022 Elsevier B。V。To apply starch nanoparticles (SNP) as host materials for β-carotene encapsulation， aqueous SNP dispersions (10， 25， 50， and 100 mg/10 mL) and β-carotene in acetone (10， 50， 100， 150， and 200 μg/mL) were mixed。 The acetone in the mixture was evaporated to prepare SNP and β-carotene composites， which were homogeneously dispersed in aqueous media with over 90 % solubility。 When SNP content was higher than 50 mg， over 80 % of β-carotene was encapsulated in the composite matrix。 X-ray diffraction， nuclear magnetic resonance spectroscopy， and transmission electron microscopic analyses confirmed the micellar-shaped composite particles with diameters <120 nm and an amorphous structure。 High SNP content in the composites enhanced β-carotene stability under extremely hot and acidic conditions as well as against ultraviolet rays and oxidation reactions。 The encapsulated β-carotene was not readily released in simulated gastric fluid， but was gradually released in simulated intestinal fluid via SNP digestion in the composites。
NSTL
Elsevier