Fortification of soy sauce using various iron sources: sensory acceptability and shelf stability

BACKGROUND: Soy sauces are available in different types and grades, which allows them to reach consumers of all socioeconomic groups. Ferric sodium ethylenediaminetetraacetic acid (NaFeEDTA) has been used for iron fortification of soy sauces in some countries, however, its high cost may make it unattractive to policymakers and industry. OBJECTIVE: We evaluated the feasibility of using more economical iron sources for iron fortification, with soy sauce of various types and grades used as a vehicle. METHODS: Seven iron sources were tested for their feasibility for fortification of four types of soy sauce: naturally fermented in the traditional style, naturally fermented according to large-scale industrial formulas 1 and 5, and chemically hydrolyzed at 5 mg per serving (15 mL, per Thailand's food labeling regulations). Either citric acid or sodium citrate was added at 0.1% as a chelator. RESULTS: Five iron sources--ferrous sulfate, NaFeEDTA, ferric ammonium citrate, ferrous lactate, and ferrous gluconate--did not significantly affect the sensory qualities of the product over a period of 3 months (p > .05). Ferrous fumarate and ferrous bisglycinate caused unacceptable precipitation. Less than 3% of 260 and 306 commonly cooked foods out of 871 and 772 preparations using soy sauces fortified with NaFeEDTA and ferrous sulfate, respectively, were found to be different from normal with regard to sensory qualities. The cost of fortification was US 0.22 cents to US 3.28 cents per bottle (700 mL). CONCLUSIONS: Both naturally fermented and chemically hydrolyzed soy sauces could be fortified with all five iron sources. Ferrous sulfate is the most appropriate source because of its low cost and acceptable sensory characteristics. Soy sauce is a promising vehicle for iron fortification, however, the bioavailability of iron in the products examined here needs to be evaluated under normal use conditions.     

Memory-based approaches for eliminating premature convergence in particle swarm optimization

Applied Intelligence - Particle Swarm Optimization (PSO) is a computational method in which a group of particles moves in search space in search of an optimal solution. During this movement, each...     

Counterflow HE analysis of Cu and SiO2 nanofluids in the developing flow region

Three concentrations of 0.2, 0.6, and 1.0 vol.% Copper/25 nm and silica/22 nm nanofluids are prepared in a base liquid glycerol–water mixture of 30:70 ratio by volume (GW70). The thermophysical properties of Cu and SiO₂ nanofluids are determined with a TPS500S hot disc thermal analyzer and Brookfield viscometer in the temperature range of 20–80°C. The maximum enhancement in Cu and SiO₂ nanofluid viscosity (63.4%, 35.7%), thermal conductivity (100.4%, 71.3%), and density (7.5%, 1.5%) while specific heat (7.8%, 2.3%) determined for 1.0% concentration at 80°C compared to base liquid GW70. Heat transfer experiments are conducted in a short-length double pipe heat exchanger. The flow rates resulted in the lamifnar entry length region. A maximum enhancement in the overall heat transfer coefficient (HTC; 25.0%, 19.7%) and convective HTC (46.2%, 34.8%), respectively for Cu and SiO₂ nanofluids is estimated at 1.0% concentration compared to base liquid at a bulk temperature of 35°C.     

Plasmonic Lipid Bilayer Membranes for Enhanced Detection Sensitivity of Biolabeling Fluorophores

Plasmonics based sensing, using the surface plasmon resonance of metal nanoparticles, has been effectively demonstrated in various applications. Extending this methodology to cell and artificial lipid bilayer membranes is extremely beneficial in enhancing the sensitivity of the detection of binding and cellular transport of molecules across such membranes. Here, the creation of an artificial plasmonic biomembrane template is demonstrated and used to show the enhanced detection sensitivity of certain widely used biomarker molecules. The efficacy of these templates is explained in terms of the ability of the hydrophobic polymer grafted gold nanoparticles used to organize, penetrate, and fluidize the membranes. The enhancement of photoluminescence of the dye molecules used occurs over a reasonably large spectral range as compared to the plasmon resonance of gold nanoparticles. The results could, possibly, be extended to cellular membranes with relevant modifications, as well as to the detection of any other biological molecule appropriately labeled with fluorescent dye molecules, and demonstrate the versatility of these plasmonic bioinspired platforms as potential biochemical sensors.     

Bentonite as a reinforcing and compatibilizing filler for natural rubber and polystyrene blends in latex stage

Bentonite clay was used as a reinforcing and compatibilizing filler for natural rubber/polystyrene (NR/PS) blend via latex blending process. The reinforcing and compatibilizing performance of bentonite clay in the NR/PS blends were evaluated. The improvement of the mechanical properties of NR/PS blends with the weight ratios of 90/10, 80/20, and 70/30 was found with the addition of 3 and 5 parts per hundred rubber (phr) clay. The characterization by using Fourier transform infrared spectroscopy and X‐ray diffraction (XRD) gave the evidence that the silicate layer was intercalated by NR and PS molecular chains. The morphology of tensile fracture surface by scanning electron microscope showed the separated phase boundaries of PS and NR blend and gradual disappearance with the bentonite content. This could be implied that the bentonite contributes to the compatibilization between PS and NR. The compatibilization action of the bentonite clay was also reflected by the shift of glass transition temperature (T_g) of NR to higher temperatures than those of the blends. These results suggested that the tensile and tear properties of the blends were controlled by compatibility between NR and PS. The most enhanced properties of blends were found with the addition of 3 phr bentonite clay. POLYM. ENG. SCI., 54:1436–1443, 2014. © 2013 Society of Plastics Engineers     

Gate-modulated graphene quantum point contact device for DNA sensing

In this paper, we present a computational model to describe the electrical response of a constricted graphene nanoribbon (GNR) to biomolecules translocating through a nanopore. For this purpose, we use a self-consistent 3D Poisson equation solver coupled with an accurate three-orbital tight-binding model to assess the ability for a gate electrode to modulate both the carrier concentration as well as the conductance in the GNR. We also investigate the role of electrolytic screening on the sensitivity of the conductance to external charges and find that the gate electrode can either suppress or enhance the screening of biomolecular charges in the nanopore depending on the value of its potential. Translocating a double-stranded DNA molecule along the pore axis imparted a large change in the conductance at particular gate voltages, suggesting that such a device can be used to sense translocating biomolecules and can be actively tuned to maximize its sensitivity.     

Characterization and encapsulation efficiency of rhamnolipid vesicles with cholesterol addition

The effect of cholesterol on the vesicle formation of a rhamnolipid biosurfactant extracted from the liquid culture of Pseudomonas aeruginosa SP4 was investigated. The rhamnolipid vesicles were prepared in a phosphate-buffer saline (PBS) solution (pH 7.4) at a biosurfactant concentration of 2.6mM, or 6.5 times the critical micelle concentration (CMC), with various amounts of cholesterol. The biosurfactant solution was characterized using turbidity, zeta potential, and dynamic light scattering (DLS) measurements. The morphology of the rhamnolipid vesicles formed at different cholesterol concentrations was examined with the use of transmission electron microscopy (TEM). The results showed that the rhamnolipid biosurfactant formed spherical vesicles both in the absence and presence of cholesterol, but the incorporation of the cholesterol into the bilayer membrane reduced the vesicle size. Sudan III, a water-insoluble dye, was used as a model hydrophobic compound in the encapsulation experiment. The encapsulation efficiency (E%) of the rhamnolipid vesicles was affected by the cholesterol concentration and the initial Sudan III concentration. The maximum E% of nearly 90% was achieved at the cholesterol concentration of 100μM and the initial Sudan III concentration of 8.8μM.     

A dodging algorithm to reconfigure photovoltaic array to negate partial shading effect

The efficiency of photovoltaic (PV) power system is hampered to a large extent when it is shaded even by a fraction. The performance dwindle in PV array due to partial shading is not proportional to the volume of shading, rather it depends on pattern of shading, array configuration, and site where PV panels are installed. Total cross‐tied (TCT) is the proven scheme among all the prevailing interconnection schemes like series, parallel, series–parallel (SP), and bridge linked to negate partial shading impact. This work aims at proposing a new adaptive algorithm to reconfigure the PV array such that it evades the shading effect. Also, it suggests a unique PV panel arrangement for a familiar shading pattern by which the shading prospects are reduced considerably. The proposed work has a clear edge over the TCT method in managing shading, ruling out multiple peaks in output power curve. This technique is highly recommended for constant power loads as the output current is maintained constant, setting aside the varying atmospheric conditions, whereas other reconfiguring techniques do not address this application. The suggested topology is simulated in matlab /Simscape environment for a 3 × 3 PV array and realized in a hardware prototype where a digital signal controller Dspic30f4011 is used to impart the proposed control algorithm. Copyright © 2015 John Wiley & Sons, Ltd.     

Total recovery of gold,palladium, and platinum using lignophenol derivative

A tertiary amine type adsorption gel was prepared by the immobilization of dimethylamine onto crosslinked lignophenol (CLP) matrix. This novel product was studied for its adsorption behavior for Au(III), Pd(II), Pt(IV), Cu(II), Zn(II), Ni(II), and Fe(III) in 0.5–6 M hydrochloric acid medium. From our previous study, crosslinked lignophenol (CLP) is known to hold solo selectivity for Au(III). After modification to dimethylamine type adsorbent (DMA-CLP), an extended selectivity of Au(III), Pd(II), and Pt(IV) was observed. The maximum loading capacity for these three metal ions was evaluated by isotherm study. For Au(III) an impressive value of 7.2 mol/kg of DMA-CLP was observed. The feasibility of recovery of precious metals from a mixture containing several other metal ions was studied in batch mode by using both model solution and actual industrial solution obtained after aqua regia leaching of metal components in obsolate e-devices. In addition, a number of adsorption–elution cycles were produced so as to know the feasibility of multiple uses.