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In order to solve the problem of polytetrafluoroethylene (PTFE) dilute emulsion for containing refractory PTFE or high energy consumption for recovery of PTFE by multistage evaporation, hydrophilic poly (vinylidene fluoride) (PVDF) composite membrane was prepared by blending modification, then it was used for recovery of PTFE. The particle size and its distribution of PTFE in the dilute PTFE emulsion were characterized by laser particle size analyzer and scanning electron microscopy (SEM). It demonstrates that the mean particle size is about 200 nm and the distribution follows normal distribution. The membrane surface pore structure and surface hydrophilicity were characterized by SEM and water contact angle measurement respectively. The results demonstrate that the maximum pore size is about 50 nm, the membrane surface can be entirely wetted by water or the PTFE emulsion. The stable flux is 33 L/ (m² ⋅ h) for dilute PTFE emulsion separation at operation pressure0. 05 MPa, membrane exhibits excellent flux recover after cleaning. [ABSTRACT FROM AUTHOR]

BACKGROUND Synthetic fungicides are most commonly used for controlling postharvest disease of fruit, although they can cause the emergence of drug‐resistant strains, environmental pollution and fruit safety issues. Bacillomycin D (BD), a novel antifungal lipopeptide, and chitosan (CTS) are applied for the preservation of cherry tomato. RESULTS: The combination of BD and CTS showed an additive inhibition on the growth of Rhizopus stolonifer and Botrytis cinerea compared to that of its individual compound. In addition, BD + CTS reduced the incidence of soft rot and gray mold in cherry tomato caused by R. stolonifer and B. cinerea, respectively. Tomato treated with BD + CTS exhibited a lower weight loss and higher firmness and higher contents of total soluble solids, titratable acidity and ascorbic acid compared to those treated with sterile water (control). The kinetics models demonstrated that the shelf life of cherry tomato treated with BD + CTS could be extended by approximately 15 days longer than the control. CONCLUSION: The utilization of BD + CTS provided a novel strategy for reducing postharvest fungal rot and maintaining the storage quality of cherry tomato. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Fabrication of a highly efficient protocol to synthesize magnetic core–shell imprinted nanospheres with controlled imprinted layer thickness remains a challenge and attracts a prominent amount of attention. Here, we developed an efficient high pressure assisted precipitation polymerization strategy to prepare magnetic core–shell imprinted nanospheres. In this work, the concentrations of the core particles, monomer, and cross-linker are raised to promote the synthesis efficiency and reduce the usage of solvent. Transmission electron microscopy (TEM) images reveal that this method could precisely control the thickness of MIP layer from 40 to 150 nm. After further modifying the imprinted nanospheres with hydrophilic dual-responsive macromolecular chains, the obtained modified-MIP nanospheres showed excellent rebinding capacity and fine selectivity recognition ability for templates in aqueous solution. When the modified-MIP nanospheres were used as drug release carriers, they manifested a controlled release property of ibuprofen in the trigger of temperature and UV light. Therefore, this synthesis strategy provides a convenient way to prepare the core–shell imprinted nanospheres. [ABSTRACT FROM AUTHOR]

In this study, we investigated the structural characterization and antidiabetic effects of Lactobacillus H31 exopolysaccharide (EPS) H31-2 from pickled cabbage. The BLAST result indicated that Lactobacillus H31 was closely related to Lactobacillus plantarum S1S2L2. In the spectrum of Fourier-transform infrared spectroscopy (FT-IR), 3370 cm−1 was the characteristic band of polysaccharide. A structural analysis showed that the monosaccharides of EPS H31-2 included d -mannose (Man) and d -glucose (Glc). The molecular weight of EPS H31-2 was around 10.75 kDa. All these results suggested EPS H31-2 was a novel polysaccharide. The inhibition ratios of crude EPS H31 and the pure fraction H31-2 of pancreatic α-amylase were 89.1 ± 2.59% and 69.2 ± 8.95%, respectively. In addition, the supernatant glucose concentration of insulin-resistant HepG2 cells decreased by treatment with 10−8 M of EPS H31-2, which meant EPS H31-2 could promote the glucose uptake of insulin-resistant HepG2 cell. Furthermore, EPS H31-2 upregulated the expression of the GLUT-4 , Akt-2 , and AMPK , which play important roles in glycometabolism. These results suggested that Lactobacillus plantarum EPS H31-2 could effectively inhibit the activity of pancreas α-amylase and has potential applications in the prevention and alleviation of diabetes mellitus. [ABSTRACT FROM AUTHOR]

In order to reveal the complex relationship among the moisture content, the water activity and the temperature, and to provide technical data for preservation of dried 'Wuye' litchi (Litchi Chinensis Sonn. cv. Wuye), the static gravimetric method was used to determine moisture sorption isotherms of dried 'Wuye' litchi pulp at three temperatures (20, 30, and 40°C) over a range of water activities from 0.112 to 0.976 based on the adsorption theory. The experimental data of dried 'Wuye' litchi pulp were fitted by eight models (BET, Halsey, Henderson, Peleg, Smith, GAB, Modified Henderson, Oswin) available in the literature. The optimal model used to describe the sorption isotherms of dried 'Wuye' litchi pulp was determined by comparing the models' coefficient of determination (R2) and root mean square error. Thermodynamic properties such as net isosteric heat, enthalpy changes, entropy changes, and free energy that provide a deeper understanding of the properties of water and energy requirements associated with sorption process were determined from moisture adsorption isotherm data of dried 'Wuye' litchi pulp at different temperatures. The results showed that the moisture sorption isotherms of dried 'Wuye' litchi pulp exhibited type III sigmoid shape. At low and intermediate water activity, the equilibrium moisture content increased slowly with water activity (0.1-0.4), while at high water activity (>0.4) equilibrium moisture content increased rapidly with water activity. The equilibrium moisture content decreased with the increasing temperature at constant water activity. The Peleg model was found to be the best for describing the relationship between the moisture content, the water activity and temperature. The agreement between experiment and predicted values of this model was excellent (R2 ranging from 0.9950-0.9979，root mean square error ranging from 1.9431-2.7102). The thermodynamic properties of dried 'Wuye' litchi pulp showed that net isosteric heat of adsorption decreased with an increasing in moisture constant, and approached to zero at high moisture content. enthalpy changes had the same values as the net isosteric heat ranged from 0.95 to 186.98 kJ/mol. entropy changes values ranged from 1.11 to 587.24 J/(mol·K) at moisture levels ranging from 8%-50% for dried 'Wuye' litchi pulp. These values decreased as moisture content increased and did not show temperature dependence. Free energy ranged from 0.60 to 18.58 kJ/mol for dried 'Wuye' litchi pulp. Free energy became smaller as the moisture content and the temperature increased. The plot of the enthalpy versus entropy showed a linear relationship for dried 'Wuye' litchi pulp with R2 equal to 0.9999, which indicated the existence of compensation. The values of isokinetic temperature and harmonic mean temperature were 319.34 K and 302.93 K respectively. Therefore, the enthalpy-entropy compensation theory was suitable for water adsorption of dried 'Wuye' litchi pulp because isokinetic temperature was significantly different from the value of harmonic mean temperature. Since isokinetic temperature > harmonic mean temperature, the mechanism of the adsorption process of dried 'Wuye' litchi pulp was enthalpy driven. The results provide a theoretical basis for the processing and storage stability of dried 'Wuye' litchi pulp. [ABSTRACT FROM AUTHOR]

Fusarium verticillioides causes ear and kernel rot in maize and produces mycotoxins, like fumonisin B 1 (FB 1 ). Bacillomycin D-C16 is a natural antimicrobial lipopeptide produced by Bacillus subtilis. In this study, the inhibitory effects of Bacillomycin D-C16 on the growth of F. verticillioides and on the production of FB 1 in maize were investigated. Bacillomycin D-C16 displayed strong fungicidal activity against F. verticillioides, with a minimum inhibitory concentration (MIC) of 32 g/L. Scanning electron microscopy (SEM) showed that Bacillomycin D-C16 altered the morphology of F. verticillioides mycelia. Bacillomycin D-C16 reduced the ergosterol content, increased the release of nucleic acids and proteins, and increased the levels of reactive oxygen species (ROS) in fungal mycelia. Bacillomycin D-C16 also significantly inhibited the production of FB 1 by inhibiting mycelial growth and decreasing the levels of fumonisin biosynthetic genes 1 (fum1), fum6 and fum14. The application of Bacillomycin D-C16 on maize kernels prior to storage inhibited the growth of F. verticillioides and the production of FB 1 . Our results suggested that Bacillomycin D-C16 has a significant antifungal activity that could be used as a potential natural antimicrobial agent to control food contamination and to ensure food safety., (Copyright © 2021 Elsevier Inc. All rights reserved.)