Karlsenkure5928

Protein oxidation is considered as an important factor affecting the texture quality of surimi. In this work, the myofibrillar protein (MP) from shrimp (Penaeus vannamei) was subjected to a hydroxyl radical generating system at various concentrations of H2O2, to simulate the oxidative environment during surimi processing. After the hydroxyl radical oxidation, it was found that the carbonyl content, surface hydrophobicity, and MP aggregation increased. Meanwhile, the a-helix decreased, but β-sheet increased after oxidation. β-Aminopropionitrile The moderate oxidation led to a dense network microstructure, increased water holding capacity (WHC) and decreased water mobility, which ultimately enhanced textural (hardness and springiness increased by 0.51- and 0.06-fold, respectively) and rheological properties of MP gel (MPG). However, excessive oxidation could reduce the mechanical properties of MPG. The microstructure, WHC and water distribution played a key role in the mechanical properties of MPG. This study can provide a theoretical basis for processing of shrimp surimi products.Histamine is a biogenic amine that is formed from histidine by action of the enzyme histidine decarboxylase and can be toxic at high intakes. Thus, the quantification of these analytes in foods constitutes a significant axis of food safety. In this study we present the development, validation and application of a new method for the determination of histamine and its precursor histidine in fish products and oriental sauces. The analytes were separated rapidly through a cation exchange column using an acidic mobile phase (7 mmol L-1 nitric acid) and reacted downstream with o-phthalaldehyde in post-column mode in the absence of nucleophilic reagents. The derivatives were detected spectrofluorimetrically at λex/λem. = 360/440 nm. Following investigation of the chromatographic and post-column conditions, the method was validated as for its intended applications. The limits of detection were 0.16 and 0.17 μmol L-1 for histidine and histamine respectively (ca. 0.1 mg kg-1) and the precision was better than 5%. Various food samples were successfully analyzed without matrix interferences following minimal pretreatment. The percent recoveries ranged between 91.3 and 117.9%.Mangiferin-loaded nanobilosomes (MGF-NBSs) were developed using microfluidic-based techniques to improve aqueous solubility, digestive stability, and cellular antioxidant activity (CAA) of mangiferin. Preliminary experiments showed that optimal formation conditions were 51 aqueous (water) to solvent (ethanol) phase ratio and 85 mL/min total flow rate. Further optimization using response surface methodology provided the optimal formulation (200 mg encapsulant consisting of 90.91% phosphatidylcholine and 9.09% sodium glycocholate, and 25.89 mg mangiferin), achieving 9.25% mangiferin loading and 80.65% encapsulation efficiency. Mono-dispersed MGF-NBSs with an average size of around 48.14 nm and zeta potential of -30.1 mV were obtained. FTIR and DSC results confirmed the successful encapsulation of mangiferin into the nanobilosomes and revealed interactions among the components. MGF-NBSs showed a 7-fold increase in the aqueous solubility compared with non-encapsulated mangiferin. CAA of MGF-NBSs in Caco-2 cells was 2 times higher than that of mangiferin and the in vitro digestive stability was improved.Agricultural use of pesticides has greatly increased worldwide over the last several decades, affecting soil microorganisms. Microbial basal respiration and substrate-induced respiration rates are commonly used to assess the detrimental effects of pesticides on soil quality. The goal of the present study was (1) to compare the impact of different pesticides on soil microbial respiration under field conditions, and (2) to characterize the recovery time of soil microbial respiration after pesticide application. The following pesticides were used in the present study chlorpyrifos, phosalone, dimethoate (organophosphorus insecticides), λ-cyhalothrin (pyrethroid insecticide), and kresoxim-methyl (fungicide). The application of all the pesticides at commercial doses led to a decrease in soil microbial respiration. The inhibition of basal respiration and substrate-induced respiration rate decreased in the following order chlorpyrifos > phosalone > dimethoate > λ-cyhalothrin ≈ kresoxim-methyl. Among all the pesticides assessed, chlorpyrifos showed the highest toxicity as well as the highest persistence. Several of the observed results differed greatly from previous studies; thus, local assessments are highly advisable. Given that environmental concerns can be a key decision factor for pesticide selection, assessment of different pesticides-such as undertaken in this study-could help farmers to choose the most appropriate pesticide.Visible-light driven photocatalysts are of great importance in wastewater treatment. In this work, fluorine and nitrogen co-doped titanium dioxide/silica nanocomposite (F-N-TiO2/SiO2) was synthetized using a sol-gel approach. The as-developed nanocomposite was well characterized using different techniques. In particular, an anatase structure with high surface area (345.69 m2/g) and a band gap of 2.97 eV were observed for the as-synthesized nanocomposite, which makes it a potential candidate for photocatalytic applications under visible light. A systematic density functional theory calculation was performed to get more insight into the effect of dopant atoms on the band gap of TiO2 nanoparticles. To enhance the reusability of the photocatalyst in semi-pilot scale, the as-developed nanocomposite was immobilized onto the glass beads by coupling dip-coating and heat attachment methods. A semi-pilot scale custom-designed fixed-bed photoreactor was used to evaluate the photocatalytic performance of the as-developed nanocomposite under both visible and solar irradiations. A mixture of three azo dyes (i.e., basic red 29, basic blue 41 and basic yellow 51) was used as the model industrial wastewater. The analysis of the wastewater showed that the complete removal of the pollutants under visible light and sunlight can occurred at pH of 3 and flow rate of 280 mL/min. The durability results demonstrated the successful degradation of the pollutants for five cycles. The results of this study show how careful controlling the operational parameters as well as using a highly photocatalytic nanomaterial can lead to successful decontamination of organic water pollutants. This approach might open up new windows to the future applications of photocatalytic nanomaterials for wastewater treatment.