Monoolein Cubic Phase Including Hydrophobized Modified Gelatin and Poly(ethyleneimine) and Its Effect on the Stability of Retinyl Palmitate.

Retinyl palmitate (RP) was added in monoolein (MO) cubic phase including decanoyl poly(ethyleneimine) (DePEI) and decanoyl gelatin (DeGel) in its water channel. RP, DePEI, and DeGel was incorporated In the cubic phase without structural disintegration, as confirmed by transmission electron microscopy. Differential scanning calorimetric and polarized optical microscopic analysis showed that adding the additives reduces phase transition temperature of cubic phase by 2 °C to 3 °C. The time-dependent chemical stability of RP added in the cubic phase was analyzed for 4 weeks at 5 °C, 20 °C, 30 °C, and 40 °C, using RP loaded in o/w emulsion as a control. The chemical stability of RP added in cubic phase containing DePEI and DeGel was somewhat higher as compared to the RP added in the cubic phase without DeGel/DePEI, possibly because DeGel/DePEI complex might shield RP from its environment by blocking the water channels inside the cubic phase. Moreover, the chemical stability of RP added in the cubic phase was comparatively higher than RP added in o/w emulsion.

Supercooling as a potentially improved storage option for commercial kimchi.

The supercooling degree (SD), which refers to the difference between the ice nucleation temperature and freezing point of kimchi, varies depending on the type of kimchi, manufacturer, recipe, and manufacturing season. The aim of this study is to investigate the major influencing factors for the supercooled storage of kimchi and to analyze the possibility of supercooled storage for commercial kimchi. Pearson correlation analysis determined that, in commercial kimchi manufactured between March and July 2018, the SD of kimchi correlated to the number of aerobic bacteria (P < 0.01), however, was not associated with lactic acid bacteria. Moreover, the ice nucleation temperature of saline solution inoculated with aerobic bacteria was reduced from -3.03 ± 0.04 to -6.18 ± 0.11 °C by 10 kGy gamma ray sterilization. Meanwhile, the ice nucleation temperatures of 1.8 kg of commercial red cabbage kimchi and 500 g of white cabbage kimchi manufactured in February 2020 were -3.93 ± 0.06 °C and -3.57 ± 0.06 °C, respectively, and they could be stored at -2.5 °C for 12 weeks without freezing. Additionally, supercooled storage of kimchi at -2.5 °C caused a fermentation delay effect compared to control storage at 1 °C, considering the acidity and amount of lactic acid bacteria. Therefore, if the number of aerobic bacteria is controlled during the manufacturing process of kimchi, supercooled storage at temperatures below -2.5 °C may extend the shelf life of kimchi. PRACTICAL APPLICATION: We have shown that aerobic bacteria are the key influencing factor for ice nucleation of kimchi during supercooled storage. Aside from the initial sterilization process, fermentation of kimchi can also be delayed by lowering the storage temperature below -2.5 °C. Moreover, the method of direct cool refrigeration may have an industrial-level application.

Gelatin-loaded cubosomes stabilized with hydrophobically modified quaternized cellulose nanofiber and their pH-dependent release property.

Monoolein cubic phase immobilizing hydrophobically modified gelatin (HmGel) in its water channel was prepared by a melt-hydration method. The cubic phase was micronized into cubosomes by using hydrophobically modified quaternized cellulose nanofiber (HmQCNF) as a stabilizer. The phase transition temperature of the cubic phase was about 68-70 °C. Small angle X-ray diffraction revealed that HmGel-loaded cubosome stabilized with HmCNF was a diamond type of cubic phase. HmGel-loaded cubosomes stailized with HmQCNF were dependent on the pH value in terms of the release of their payload (i.e, methylene blue) much more strongly than HmGel-loaded cubosomes stabilized with Pluronic F127.

Oxidation-Responsive Emulsions Stabilized with Poly(Vinyl Pyrrolidone-co-allyl Phenyl Sulfide).

Oxidation-responsive emulsions were obtained by stabilizing mineral oil droplets using amphiphilic poly(vinyl pyrrolidone-co-allyl phenyl sulfide) (P(VP-APS)). 1H nuclear magnetic resonance (NMR) spectroscopy revealed that P(VP-APS) whose APS content was 0%, 3.28%, 3.43% and 4.58% were successfully prepared by free radical reaction and the sulfide of APS was oxidized by H2O2 treatment. X-ray Photoelectron Spectroscopy (XPS) also disclosed that the sulfide of APS was oxidized to sulfone by the oxidizing agent. The optical density of copolymer solutions and the interfacial activity of the copolymers markedly decreased by H2O2 treatment possibly because the sulfide of APS was oxidized and the amphiphilicity of the copolymers were weakened. The increase rate of the oil droplet diameter of the emulsions was outstandingly promoted when H2O2 solution (10%, v/v) was used as an aqueous phase. The phase separation of the emulsions was also expedited by the oxidizing agent. The oxidation of APS and the weakened interfacial activity were thought to be a main reason for the demulsification of P(VP-APS)-stabilized emulsions.

Doxorubicin-carboxymethyl xanthan gum capped gold nanoparticles: Microwave synthesis, characterization, and anti-cancer activity.

An ultrafast (e.g. 75 s) synthesis of carboxymethyl xanthan gum (CMXG) capped gold nanoparticles (AuNPs) (CMXG@AuNPs) was developed using microwave irradiation (MWI) method. The synthesis of AuNPs was optimized by varying CMXG amount, gold ion concentration, and MWI time. The CMXG@AuNPs exhibited a spherical shape, high crystallinity, and narrow size distribution (i.e. 8-10 nm). The electrostatic interaction-mediated the loading of doxorubicin (DOX) onto CMXG@AuNPs. The release of DOX, loaded on CMXG@AuNPs was extensive in an acidic condition but negligible at physiological pH value. The in vitro anticancer efficacy of DOX loaded on CMXG@AuNPs (i.e. DOX@CMXG@AuNPs) in the presence of an ionophore (i.e. nigericin) was about 4.6 folds higher than that of free DOX. Flow cytometry revealed that DOX@CMXG@AuNPs exhibited a higher cellular uptake under an acidic condition than free DOX. CMXG@AuNPs showed unique excellence in the pH-responsive DOX-releasing property and the cancer cell-killing capability.

Non-destructive monitoring of apple ripeness using an aldehyde sensitive colorimetric sensor.

We developed an on-packaging colorimetric sensor label that can detect the aldehyde emission of apples based on Methyl Red. The sensor label was constructed using printable inks on paper medium and relied on the change in basicity caused by the nucleophilic addition reaction between aldehyde and hydroxide via the Cannizzaro reaction. The sensor can be used to detect aldehyde in solution and vapor. Sensitivity and stability toward changes in humidity were achieved by altering the concentration of OH-. Under exposure to ripening apples, the label changed color from yellow to orange, and then to red. The degree of ripeness was estimated by a sensory test and texture analysis. The color change of sensor label had showed a similar tendency to the changes in the parameters of the sensory test, soluble solid content, and hardness. Therefore, the sensor label can be used for real time on-package ripeness monitoring of apples during their shelf life.

Probing and evaluating anion-π interaction in meso-dinitrophenyl functionalized calix[4]pyrrole isomers.

We investigate anion-π binding modes in a cis-isomer of 3,5-dinitrophenyl-substituted calix[4]pyrrole with various anions via X-ray crystallographic analyses and compare its binding affinities with those of the corresponding trans-isomer. Sandwich-type anion-π interactions prove to not only enhancing anion binding abilities but also altering the anion-binding selectivity of the calix[4]pyrrole framework.

Investigation and optimization of the factors influencing sorghum protein extraction.

To optimize the extraction of sorghum proteins, several variables were examined: sample-to-solvent ratio, detergent type and concentration, reducing agent type and concentration, extraction time, and buffer pH and concentration. Samples were quantified and characterized by RP-HPLC, FZCE, and nitrogen analysis. These studies revealed that pH, detergent type, reducing agent type, and sample-to-solvent ratio all had significant effects on the levels of protein extracted. Increasing SDS concentration (2%) and solvent-to-flour ratio (20:1) with multiple 5 min extracts reduced extraction time by 35-80% while still extracting the same levels of total protein relative to the control methodology. Reproducibility using the multiple extractions was found to be excellent with relative standard deviations of <2% for consecutive extractions.