Inertial microfluidics for continuous particle filtration and extraction

In this paper, we describe a simple passive microfluidic device with rectangular microchannel geometry for continuous particle filtration. The design takes advantage of preferential migration of particles in rectangular microchannels based on shear-induced inertial lift forces. These dominant inertial forces cause particles to move laterally and occupy equilibrium positions along the longer vertical microchannel walls. Using this principle, we demonstrate extraction of 590 nm particles from a mixture of 1.9 μm and 590 nm particles in a straight microfluidic channel with rectangular cross-section. Based on the theoretical analysis and experimental data, we describe conditions required for predicting the onset of particle equilibration in square and rectangular microchannels. The microfluidic channel design has a simple planar structure and can be easily integrated with on-chip microfluidic components for filtration and extraction of wide range of particle sizes. The ability to continuously and differentially equilibrate particles of different size without external forces in microchannels is expected to have numerous applications in filtration, cytometry, and bioseparations.     

Physicochemical properties of cross-linked-annealed wheat starch

Starch in its native form, may not be able to provide functional properties such as high or low temperatures and shear forces bearings expected in modern industries. Therefore, it is usually modified to make it compatible for different applications. The main aim of this research was to study the effects of dual modification using cross-linking and annealing on physicochemical properties of wheat starch. Therefore, starch was first cross-linked using different levels of POCl₃ (0, 0.1, 0.2, 0.4?%, w/w, starch basis) and then annealed at 40?°C for 72?h. Scanning electron micrographs showed the presence of some spots on the granules of the dual-modified samples. The results of differential scanning calorimetry showed that the onset, peak and conclusion temperatures and enthalpy increased upon dual modification. The X-ray diffraction pattern of the modified samples remained unchanged while water solubility and swelling decreased. The results of rapid visco analyzing showed lower peak, setback, breakdown and final viscosities for the dual-modified samples. These samples produced stronger gels as determined using a texture analyzer. In total, annealing of the cross-linked starch could enhance some of its functional properties for further applications.     

Functionalized Hybrid Coatings on ABS Surfaces by PLD and Dip Coatings

It is important to give water-repellent and antibacterial properties to the acrylonitrile butadiene styrene (ABS) surfaces of the hearing aids. In this study, the sol–gel Si and sol–gel Ti solutions were prepared from the reactions of silicon ethoxide, titanium butoxide and methacrylic acid. The catalyst and Dynasylan F8815 were added to the sol–gel solutions to give hydrophobic properties onto the ABS surfaces. Additionally, silver nanoparticles were synthesized by nanosecond laser and added to the coating solutions to give extra antibacterial properties. The surfaces of the ABS targets were coated using the sol–gel dip coating and pulsed laser deposition techniques. The coatings with good adhesion between film and substrate and good water-repellent properties were achieved. The average contact angles for the coated ABS surfaces were measured in the range between 120 and 125 degrees. The obtained sol–gel materials and produced thin films onto the ABS surfaces were also analyzed in terms of the antibacterial properties. The highly antibacterial properties were observed in the sol–gel solutions and the thin films.     

Double Layer Coatings: A New Technique for Maintaining Physico-Chemical Characteristics and Antioxidant Properties of Dragon Fruit During Storage

A double layer coating was evaluated for maintenance of quality of dragon fruit during storage at 10?±?2 °C and 80?±?5 % RH for 28 days. Significant differences (p?<?0.05) were observed between control and the treated fruit. However, a double layer coating with 600 nm droplet size?+?1.0 % conventional chitosan showed promising results in all the tested parameters, while the fruit treated with 1,000 nm droplet size?+?1.0 % conventional chitosan showed some negative effects on fruit surface. Increase in weight loss was 12.0 % in fruit treated with 600 nm droplet size and 1.0 % conventional chitosan as compared to the control. Antioxidants and gaseous analysis also proved the efficacy of double layer coatings with 600 nm droplet size?+?1.0 % conventional chitosan. Thus it can be concluded from the present investigation that double layer coating could be used for maintaining quality in dragon fruit for up to 28 days without any off-flavours.     

Structural changes and stress relaxation behavior of κ‐carrageenan cold‐processed gels: Effects of ultrasonication time and power

Ultrasound has been used for cold gelation of κ‐carrageenan hydrocolloid. In this work, the effect of ultrasound conditions such as power (50–150 W) and time (20–240 s) of sonication has been investigated. The application of ultrasound to hydrocolloid dispersion caused an increase in water solubility. The texture profile analysis test was used in order to evaluate the mechanical properties of gels. Textural parameters of κ‐carrageenan gels, enhanced with increasing sonication time and power up to a certain level (usually 2.5 min) and longer sonication times had negative effects. In addition, intrinsic viscosities of sonicated specimens were measured to investigate the molecular characteristics of all samples. An increase in the process time and power reduced the intrinsic viscosity. The microstructural observation by scanning electron microscope determined that applying power ultrasound on κ‐carrageenan dispersions influenced the formation of gel networks significantly.     

Evaluation of the Effects of Hydrothermal Treatment on Rice Flour and Its Related Starch

The main aim of this research was to compare the effects of hydrothermal treatment on rice flour and its related rice starch. The treatment was performed at 120°C for 3 and 5 h. Scanning electron microscopy results showed that the proteins of hydrothermaled rice flour were denatured and formed clusters and the granules of hydrothermaled rice starch became aggregated and had an irregular surface. The treatment reduced water solubility and water absorption and decreased peak viscosity while increased pasting temperature. It increased the final visosity of modified rice flour while reduced the final viscosity of modified rice starch. Following hydrothermal treatment, the hardness and elasticity of the gels increased. The cohesiveness of rice flour gels decreased while that of the rice starch gels remained unchanged. This study showed how the hydrothermal treatment can have different effects on rice flour and its related rice starch. The effects of hydrothermal treatment on rice flour were stronger than rice starch. Increasing the treatment time from 3 to 5 h was more effective on rice starch.     

Aflatoxin Removal from Pistachio Nuts by Natural Natrolite

ABSTRACT: Natrolite was used to explore a physical and safe method to decontaminate aflatoxin-containing pistachio lots. Pistachio nuts with low, medium, and high levels of aflatoxin were subjected to a washing process with a slurry of 5% natrolite. Using thin-layer chromatography and scanning, the aflatoxin contents of the samples were measured. Aflatoxins B₁ and B₂ were found in pistachio nuts. The majority of total aflatoxins was aflatoxin B₁ Natrolite treatment resulted in a 38% to 100% reduction in aflatoxin B₁, depending on the initial aflatoxin level. Although natrolite was demonstrated to be an effective candidate to reduce aflatoxin B₁, its efficacy against aflatoxin B₂ was limited.     

Synthesis,Characterization, and Application of Hybrid Inorganic–Organic Composites (K/Na)ZrSi(R)O<Subscript>x</Subscript>

Hybrid inorganic–organic composites, (K/Na)ZrSi(R)O_x, were synthesized from the hydrolysis of the mixture of zirconium n-propoxide (Zr(OPrⁿ)₄) and 3-glycidyloxypropyltrimethoxy silane (GPTS) in 1:1 mol ratio. The hydrolysis reaction was carried out with 0.1 molar HCl in 150 ml of butanol. Then, the synthesized Zr(OPrⁿ)₄-GPTS-hydrolyzate reacted with KOBu^t and NaOSiMe₃ in 1:1 mol ratio at 40 and 50 °C for 24 h, respectively. After these stages, composites were washed and dried under vacuum. Composites and their oxide prepared at 1250 °C by calcinations were characterized by a combination of powder X-ray diffraction, scanning electron microscope, energy dispersive X-ray, Brunauer–Emmett–Teller analysis, Barrett–Joyner–Halenda analysis, and Fourier transform infrared spectroscopies. These hybrid inorganic–organic composites except oxides were used as catalysts in order to see their activities in the polymerization of ε-caprolactone (ε-CL). This study showed that new composite materials except their oxides were effective catalyst in ε-CL polymerization.     

Extraction of protein from food waste: An overview of current status and opportunities

The chief intent of this review is to explain the different extraction techniques and efficiencies for the recovery of protein from food waste (FW) sources. Although FW is not a new concept, increasing concerns about chronic hunger, nutritional deficiency, food security, and sustainability have intensified attention on alternative and sustainable sources of protein for food and feed. Initiatives to extract and utilize protein from FW on a commercial scale have been undertaken, mainly in the developed countries, but they remain largely underutilized and generally suited for low-quality products. The current analysis reveals the extraction of protein from FW is a many-sided (complex) issue, and that identifies for a stronger and extensive integration of diverse extraction perspectives, focusing on nutritional quality, yield, and functionality of the isolated protein as a valued recycled ingredient.