TOXICOLOGY AND ANTIOXIDANT ACTIVITIES OF NON-ENZYMATIC BROWNING REACTION PRODUCTS: REVIEW

This article summarizes toxicity and antioxidative activity of non-enzymatic browning reaction products. The subject focuses on the formation and toxicity testing of mutagenic Maillard reaction products (MPRs) formed in food model systems and in actual foods. The MRPs have also been investigated for nutritional, physiological, and biological activities. The antioxidant properties of MRPs are also reviewed in terms of protection potential against oxidative damage associated with a wide variety of diseases such as diabetes and cancer, and pathological conditions such as aging.     

Indoor air quality,air exchange rates,and radioactivity in new built temporary houses following the Great East Japan Earthquake in Minamisoma,Fukushima

This study measured air exchange rates, indoor concentrations of aldehydes and volatile organic compounds (VOCs), and radioactivity levels at 19 temporary houses in different temporary housing estate constructed in Minamisoma City following the Great East Japan Earthquake. The 19 surveyed houses represented all of the companies assigned to construct temporary houses in that Minamisoma City. Data were collected shortly after construction and before occupation, from August 2011 to January 2012. Mean air exchange rates in the temporary houses were 0.28/h, with no variation according to housing types and construction date. Mean indoor concentrations of formaldehyde, acetaldehyde, toluene, ethylbenzene, m/p‐xylene, o‐xylene, styrene, p‐dichlorobenzene, tetradecane, and total VOCs (TVOCs) were 29.2, 72.7, 14.6, 6.35, 3.05, 1.81, 7.29, 14.3, 8.32, and 901 μg/m³, respectively. The levels of acetaldehyde and TVOCs exceeded the indoor guideline (48 μg/m³) and interim target (400 μg/m³) in more than half of the 31 rooms tested. In addition to guideline chemicals, terpenes (α‐pinene and d‐limonene) and acetic esters (butyl acetate and ethyl acetate) were often detected in these houses. The indoor radiation levels measured by a Geiger–Müller tube (Mean: 0.22 μSv/h) were lower than those recorded outdoors (Mean: 0.42 μSv/h), although the shielding effect of the houses was less than for other types of buildings.     

Ultrasound cutting of polymer materials

Recommendations are given for the structural and technological design of dissimilar welded joints in the form of the optimum selection of the angle of inclination of the joint in relation to the ratio of the shear modulus and the Poisson coefficient ensuring the absence of stress concentration in the critical corner points. The brittle strength of dissimilar welded joints with a high stress concentration in the corner points of the joint is evaluated on the basis of the fracture mechanics criteria.     

Assessment of Nutritional and Antioxidant Potential of Selected Vitality Strengthening Himalayan Medicinal Plants

Three Himalayan medicinal plants (Habenaria intermedia, H. edgeworthii, and Roscoea procera), widely used in vitality strengthening Ayurvedic formulations in India, were assessed for nutritional phytochemical constituents, and antioxidant activity. These target species emerged as a good source of minerals and possessed important micro elements. Individually, H. intermedia contained a high content of total phenols, thiamins, tannins, and calcium; R. procera was rich in potassium and iron content; and H. edgeworthii emerged as a good source of sodium. While various antioxidant assays provided evidences on the antioxidant potential of target species, greater antioxidant potential of H. intermedia as compared to the other two species was revealing. This study, therefore, highlighted the possibilities of harnessing nutritional and antioxidant potential of these species.     

Photocatalytic hydrogen evolution from aqueous solutions of organophosphorous compounds

Photocatalytic hydrogen production from water solutions of dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), and radiation protective amine WR 2721, that imitate nerve chemical warfare agents was studied for the first time. Platinized titianium dioxide Degussa P25 was used as catalyst. No significant hydrogen evolution was detected without organic electron donors – sacrificial agents.     

Luminescence properties of Ca1−xSrxSe:Ce phosphors and their potential application for GaN-based LEDs

A series of solid solution phosphors Ca_1−xSr_xSe:0.02Ce³⁺ were prepared using high-temperature solid-state reaction technique. Their diffuse reflectance and luminescent spectra at room temperature were investigated and discussed. The optical band gap E_g energies of CaSe and SrSe were derived. Because of its broad band absorption in the range of 400-500 nm, Ca_1−xSr_xSe:Ce³⁺ can suit the application requirements for GaN-based light-emitting diodes (LEDs). The emission wavelength and the coordinates systematic shift from yellowish green to bluish green with an increase in x of Ca_1−xSr_xSe:Ce³⁺. Using Dorenbos's empirical equation, the values of energies of the lowest f-d transition absorption E, redshift D and Stokes shift ΔS for Eu²⁺ in the same host were predicted. The results were in good agreement with the experimental data.     

Mathematical modeling and mass transfer considerations in supercritical fluid extraction of Posidonia oceanica residues

Posidonia oceanica residues were extracted with supercritical CO₂ in order to isolate phenolic compounds. The process was optimized by developing a mathematical model based on mass transfer mechanism consisting of adsorption of supercritical fluid on the solid particles, desorption of solute and convective transfer of solute phase along the column. Henry relation between solute concentrations on the surface of the solid (Cs) and in the solid (q) was approximated in order to describe the adsorption/desorption equilibrium. The model parameters such as solid-liquid film mass transfer coefficient (kf), molecular diffusivity coefficient (D_AB) and axial dispersion (D_ax) were estimated using empirical methods. The linear driving force model was applied to improve the yield of total phenolic acid recovery. The optimum parameters were elicited as 25 MPa, 323.15 K and a co-solvent mass ratio of 20% yielding 34.97 μg per gram of dry feed and the model satisfactorily described the extraction yield which can be used for scale-up purposes.     

Controlled synthesis of crystalline calcium carbonate aggregates with unusual morphologies involving the phase transformation from amorphous calcium carbonate

Peanut-shaped CaCO₃ aggregates, featured of two dandelion-like heads built up from rod-like subunits, have been synthesized via a facile precipitation reaction between Na₂CO₃ and CaCl₂ at ambient temperature in the presence of magnesium ions and ethanol solvent. The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results show that a high magnesium concentration and ethanol solvent are necessary for the formation of the unusual peanut-like aggregates. In addition, a multistep phase transformation process from amorphous calcium carbonate (ACC) to a mixture of ACC and calcite and ultimately to calcite and aragonite was observed in the formation process of the unusual structures. A possible mechanism for the formation of the unusual peanut-shape aggregates has been proposed and discussed.     

Papaya Fruit Quality Management during the Postharvest Supply Chain

Papayas are popular in tropical and subtropical regions and are being exported in large volumes to Europe, the United States, and Japan. The fruit has a sweet, exotic flavor and is rich in vitamins A and C and antioxidants. However, due to its highly perishable nature, it has not emerged as a major traded fruit. Papayas are highly susceptible to qualitative and quantitative postharvest losses. Maintenance of papaya fruit quality during the supply chain depends on orchard management, harvesting practices, packing operations, postharvest treatments, temperature management, and transportation and storage conditions. Postharvest losses are attributed to mechanical damage, rapid flesh softening, decay, physiological disorders, pest infestation, and improper temperature management. The aim of postharvest technology and management in the supply chain is to provide favorable conditions to extend storage life and retain quality and nutritional attributes. This review focuses on the available research findings to retain overall papaya fruit quality and to reduce postharvest losses during the supply chain via adopting appropriate or novel postharvest technologies.