Application of high-pressure treatment on ovine brined cheese: Effect on composition and microflora throughout ripening

Ovine brined cheese was high-pressure (HP) treated at 200 or 500 MPa for 15 min at 20 °C on the 15th day of ripening. Compared to control cheese, HP treatment did not affect significantly (P > 0.05) the pH values, moisture, fat in dry matter, protein in dry matter and salt in moisture contents of cheeses at 90 days. The counts of total aerobic mesophilic bacteria, thermophilic lactococci, thermophilic lactobacilli and non starter lactic acid bacteria (NSLAB) were not affected by HP treatment of cheese at 200 MPa throughout ripening. After 90 days of ripening, the same microbial groups in cheese treated at 500 MPa were about 1.2, 3.6, 2.1 and 4 log units lower than in control cheese respectively. Coliforms were reduced faster at non detectable levels in HP treated cheeses than in control cheese. Regarding the bacterial enzymatic activities in cheese, aminopeptidase activity (Apep) was marginally favoured by both HP treatments. However, its activity was decreased at 90 days due probably to loss in brine. In contrast, lactate dehydrogenase (LDH) activity, following the bacteria cell lysis, was negatively affected by HP treatment at 500 MPa throughout ripening.Industrial relevanceThe data obtained from this work suggest that application of HP treatment under optimized conditions on ovine cheese in brine can be used to reduce effectively the undesirable microbial load in it and to cause moderate enhancement of aminopeptidase activity, without modifying its composition.     

Electrochemical and thermal characterization of doped ceria electrolyte with lanthanum and zirconium

Nanocomposites electrolytes consisting of La³⁺ and Zr⁴⁺ doped with ceria labelled as La_0.2 Ce_0.8 O_2-δ (LDC), Zr_0.2Ce_0.8O_2-δ (ZDC) and Zr_0.2La_0.2Ce_0.6O_2-δ (ZLDC) have been synthesized via a co-precipitation route. DC conductivity was studied with a four-probe method in the range of temperature 450–650 °C and maximum conductivity was found to be 0.81 × 10^?2 S.cm^?1 (LDC) > 0.32 × 10^?2 S.cm^?1 (ZLDC) > 0.15 × 10^?2 S.cm^?1 (ZDC) at a temperature of 650 °C, respectively. Further, electric behavior of doped and co-doped ceria electrolytes was investigated by A.C electrochemical impedance spectroscopy (frequency range ~ 0.1 Hz?4 MHz). The phase/structural identification of the material prepared was studied using X-ray diffraction and found ceria to possess a cubic fluorite structure. Scanning electron microscopy (SEM) was carried out to study its morphology and particle size (~ 90–120 nm). Thermal behavior on its change in weight and length with the temperature were studied by thermogravimetric analysis (TGA) and dilatometry respectively. Furthermore, thermal expansion coefficients (TECs) of prepared electrolytes are calculated and found as follows: 13.4 × 10^?6 °C^?1, 13.6 × 10^?6 °C^?1and 15.3 × 10^?6 °C^?1 for LDC, ZDC and ZLDC, respectively, in the temperature range 150–1150 °C.     

Adsorption of methylene blue onto powdered activated carbon immobilized in a carboxymethyl sago pulp hydrogel

The potential of crosslinked carboxymethyl sago pulp (CMSP) beads immobilized with powdered activated carbon (PAC) as an adsorbent for methylene blue (MB) adsorption was investigated. The finely powdered PAC had an excellent adsorption capacity for MB but was disadvantageous for the separation process from treated effluents. To ease the separation process, the CMSP medium could be advantageous for the process by acting an immobilizing medium for PAC. The MB adsorption reached equilibrium at the 14th hour, and further adsorption was studied to determine the effects of the CMSP concentration, PAC dosage, and pH. Different CMSP concentrations in the preparation of CMSP–PAC beads showed no significant differences; this proved that CMSP–PAC adsorbed more MB than CMSP did. The MB adsorption increased with increasing PAC concentration, whereas the CMSP–PAC beads disintegrated at pH 11.5. In the equilibrium study, the Langmuir isotherm fit well into the experimental data with a linear correlation coefficient (R ²) of 0.9837 and a maximum adsorption capacity of 250 mg/g. The kinetic study showed that pseudo‐second‐order kinetics accommodated the experimental data well with an R ² value of 0.9512 and a pseudo‐second‐order rate constant value of 3.61 × 10^?3 min^?1. The crosslinked CMSP–PAC beads have the potential to remove MB dye, and this could be exploited as an alternative to treating colored dye effluents produced by industries such as the textile, printing, and cosmetics industries. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44271.     

Raman Study on Lipid Droplets in Hepatic Cells Co-Cultured with Fatty Acids

The purpose of the present study was to investigate molecular compositions of lipid droplets changing in live hepatic cells stimulated with major fatty acids in the human body, i.e., palmitic, stearic, oleic, and linoleic acids. HepG2 cells were used as the model hepatic cells. Morphological changes of lipid droplets were observed by optical microscopy and transmission electron microscopy (TEM) during co-cultivation with fatty acids up to 5 days. The compositional changes in the fatty chains included in the lipid droplets were analyzed via Raman spectroscopy and chemometrics. The growth curves of the cells indicated that palmitic, stearic, and linoleic acids induced cell death in HepG2 cells, but oleic acid did not. Microscopic observations suggested that the rates of fat accumulation were high for oleic and linoleic acids, but low for palmitic and stearic acids. Raman analysis indicated that linoleic fatty chains taken into the cells are modified into oleic fatty chains. These results suggest that the signaling pathway of cell death is independent of fat stimulations. Moreover, these results suggest that hepatic cells have a high affinity for linoleic acid, but linoleic acid induces cell death in these cells. This may be one of the causes of inflammation in nonalcoholic fatty liver disease (NAFLD).     

Fat-free fermented concentrated milk products as milk protein-based microgel dispersions: Particle characteristics as key drivers of textural properties

The popularity of fat-free fermented concentrated milk products, such as fresh cheeses and high-protein yogurt, has increased over the recent years, attributed to greater availability and improvements in taste and texture. These improvements have been achieved through modifications and new developments in processing technologies, for example, higher heat treatment intensities and incorporating different membrane filtration technologies. Though numerous processing parameters are discussed in the literature, as well as reasons behind the developments, detailed examinations of how process modifications affect the final textural attributes of these products are lacking. To draw links between processing parameters and texture, we review the literature on fat-free fermented concentrated milk products from the perspective of fermented milk protein-based microgel particles as the basic structural unit. At each main processing step, relationships between process parameters, micro- and macrostructural and sensory (textural) properties are discussed.An overview of particle characteristics that drive structural changes at each processing step is developed in relation to textural characteristics. Using this approach of assessing relationships between structural characteristics of concentrated dispersions of fat-free fermented milk protein-based microgel particles and processing parameters provides a basic context for the selection of optimal parameters to achieve a desired texture.     

Self‐Healing Latex Containing Polyelectrolyte Multilayers

Self‐healing paints would have the potential benefit of protecting the underlying substrate and extending the coating's service life. As a step toward those types of coatings, this work examines layer‐by‐layer films of branched poly(ethylene imine)/poly(acrylic acid) with the inclusion of various types of latex particles with different T_g and different compositions. Due to high mobility of the polyelectrolyte chains when plasticized with water, water enabled self‐healing of these films is demonstrated, as well as steam enabled self‐healing. The films with various latex particles show different swelling ratios, surface hydrophilicity, as well as varying ability to self‐heal scratches. This self‐healing property is studied as a function of temperature. Also, the mechanical properties such as hardness and modulus of the films are measured.     

Consumer Acceptability of Muffins with Flaxseed (Linum usitatissimum)

Flaxseed has recently gained attention as a functional food. The effect of adding flaxseed (7.3%, 11.6%, and 15.5%) to muffins on consumer acceptability was evaluated by a focus group, hedonic scoring, and food action rating scale (FACT). The majority of consumers (82.6%, P < 0.001) rated the control muffin (0 % flaxseed) higher than the flax muffin for appearance, color, flavor, texture, overall acceptability, and food acceptance. Flaxseed muffin (11.6%) was “neither liked nor disliked” to “liked slightly” in overall acceptability. This may have been accounted for by the observation that many persons aged 18 to 25 y did not think they needed to consume “health foods”. This “indifferent” and in some cases “negative” attitude toward the flax muffins, which they considered a “health food”, may have influenced the ratings the flax muffins received. Texture and flavor were strongly and positively correlated (P < 0.01) to overall acceptability. A flaxseed muffin provided at least 16% fiber of the daily recommended value.     

Optimisation of preparation conditions for Ti nanowires and suitability as an antibacterial material

Ultrafine titanium dioxide (TiO₂) nanowires were synthesised using a hydrothermal method with different volumes of ethylene glycol (EG) and annealing temperatures. It shows that sodium titanate nanowires synthesised using 5 and 10 ml EG, which annealed at 400°C produced TiO₂ nanowires that correspond to a photochemically active phase, which is anatase. The influences of annealing temperatures (400–600°C) on the morphological arrangement of TiO₂ nanowires were evident in the field emission scanning electron microscopy. The annealing temperature of 500°C led to agglomeration, which formed a mixture of TiO₂ nanoparticles and nanowires. High thermal stability of TiO₂ nanowires revealed by thermogravimetric analysis and Fourier transform infrared spectroscopy spectrum showed the presence of the Ti–O–Ti vibrations as evidenced due to TiO₂ lattices. An antibacterial study using TiO₂ nanowires toward Escherichia coli and Klebsiella pneumoniae showed large zones of inhibition that indicated susceptibility of the microbe toward TiO₂. Growth kinetic analysis shows that addition of TiO₂ has reduced optical density (OD) suggesting an inhibition of the growth of bacteria. These results indicate TiO₂ nanowires can be effectively used as an antimicrobial agent against gram‐bacteria. The TiO₂ nanowires could be exploited in the medical, packaging and detergent formulation industries and wastewater treatment.Inspec keywords: nanowires, titanium compounds, antibacterial activity, nanomedicine, semiconductor materials, semiconductor growth, nanofabrication, annealing, liquid phase deposition, field emission scanning electron microscopy, nanoparticles, thermal stability, thermal analysis, Fourier transform infrared spectra, microorganismsOther keywords: optimisation, preparation conditions, antibacterial material, ultrafine titanium dioxide nanowires, hydrothermal method, ethylene glycol, annealing temperatures, sodium titanate nanowires, photochemically active phase, anatase, morphological arrangement, field emission scanning electron microscopy, agglomeration, nanoparticles, thermal stability, thermogravimetric analysis, Fourier transform infrared spectroscopy, vibrations, Escherichia coli, Klebsiella pneumoniae, microbe, growth kinetic analysis, optical density, incubation time, bacterial survivability, colony‐forming units, antimicrobial agent, Gram negative bacteria, Gram positive bacteria, temperature 400 degC to 600 degC, TiO₂