Effect of processing of apple puree on patulin content

Mycotoxin patulin represents potential health hazard especially in apple based baby food. There are already a lot of data to predict the fate of the toxin during the processing of fruits, but not enough for the apple puree and the existing data for apple puree are not usually consistent. The objective of the study was to evaluate the course of patulin degradation during the processing of apple puree under the conditions close to the real production process. The apple samples were spiked with patulin at four levels of concentration (539 μg/kg, 140 μg/kg, 23 μg/kg and <2 μg/kg). The patulin content changes during the processing were followed. The samples were taken after the homogenization, pulping, pasteurization and aseptic packaging. All operations of apple puree production contributed to patulin reduction. The principle operation was pulping, where the patulin levels were reduced from 29% to 80% of original content.     

Colloidally stable polypeptide-based nanogel: Study of enzyme-mediated nanogelation in inverse miniemulsion

The current work presents a pivotal study of the nanogelation of the linear poly(N⁵-2-hydroxypropyl-L-glutamine) polymer precursor containing tyramine (TYR) units in an inverse miniemulsion by horseradish peroxidase/H₂O₂-mediated crosslinking. The effects of various n_H2O2/n_TYR ratios on the kinetics of nanogelation in the inverse miniemulsion and on the reaction time are investigated by linear sweep voltammetry, while the formation of dityramine crosslinking is explored by fluorescence spectroscopy. The study is completed using dynamic light scattering measurements, nanoparticle tracking analysis, and cryogenic transmission electron microscopy to acquire comprehensive information about the formed nanoparticulate systems. With the optimal ratio n_H2O2/n_TYR = 2, the strategy yields in the high-quality ~ 130 nm poly(amino acid)-based nanogel, which is prepared in 2 h. The nanogel is colloidally stable under different temperature and pH conditions for over 168 h. Moreover, the demonstrated nanogel is noncytotoxic for HeLa cells and human primary fibroblasts and is quickly enzymatically hydrolyzed into small fragments during a biodegradation study in human blood plasma. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48725.     

A Fast Determination of Chlorophylls in Barley Grass Juice Powder Using HPLC Fused-Core Column Technology and HPTLC

This work presents a novel approach to qualitative and quantitative evaluation of chlorophyll content in food supplement using simple and fast separation techniques (high performance liquid chromatography (HPLC) and high performance thin layer chromatography (HPTLC)). For the first time, an Ascentis® Express C-18 HPLC column (100?×?4.6 mm; 2.7 μm), based on fused-core particles, was utilised for the analysis of chlorophyll a and chlorophyll b in green young barley grass juice powder extracts. The mobile phase was composed of methanol, water and ethyl acetate of 40:10:50 (v/v/v) at a flow rate of 1.5 mL/min. Chlorophylls were separated in time less than 6 min. The extraction procedure was optimised by using of 90 % of acetone in water, and the method was validated. The method precision was found in the range of 1.15–2.85 %, and the method recovery was established at three concentration levels. Calibration graphs were linear in the range of 0.75–25.5 mg/L, with correlation coefficients r ²?=?0.99958 for chlorophyll a and r ²?=?0.99961 for chlorophyll b. The comparative HPTLC fingerprint analysis of three samples from different continents showed only slight qualitative differences between the particular samples. The results demonstrated that the proposed methods can be used as fast and powerful techniques for the characterisation of barley juice extracts in quality control.     

Evaluating Plan Implementation: A Conformance-Based Methodology

The planning profession lacks a robust methodology to evaluate the implementation of plans. This article proposes a conformance-based plan implementation evaluation (PIE) that relies on the analysis of plans and permits to provide a rigorous, quantitative, and systematic way of assessing the degree to which land use plans are implemented. We studied the implementation of stormwater and urban amenity management in six New Zealand plans by reviewing their land development permits. We found that the implementation of land use plans was generally low and varied greatly among plans and issues. Although it was tested in the context of local plans in New Zealand, the methodology can be used by city and county planning agencies in the U.S. and elsewhere.     

Optimization of powder injection molding of feedstock based on aluminum oxide and multicomponent water‐soluble polymer binder

Analyses crucial to optimize powder injection molding of feedstock based on aluminum oxide powder and multicomponent polymeric binder are provided with the aim to obtain defect‐free, high density parts. As the critical step of the process is the flow of highly filled (60 vol%) compound into a mold cavity, rheological properties supplemented by thermal and pressure‐volume‐temperature characteristics are measured and described. Upon shear deformation the feedstock undergoes structural changes, which are quantified in terms of yield stresses obtained using Herschel‐Bulkley and Casson methods. Further, the rheological model is developed to describe the flow behavior of the feedstock in the whole shear rate range measured. Thermogravimetric analysis is performed to optimize debinding step of the process, and two possible ways of the binder removal are proposed: purely thermal andcombined solvent/thermal. The quality of the final sintered parts is demonstrated on scanning electron microscopic images of their surfaces. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Carbon nanotube fiber microelectrodes: design, characterization, and optimization

We report on the preparation and interesting electrochemical behavior of carbon nanotube fiber microelectrodes (CNTFM). By combining the advantages of carbon nanotubes (CNT) with those of fiber electrodes, this type of microelectrode differs from CNT modified or CNT containing composite electrodes, because it's made of only CNT without any other components like additives or binders. The active CNT surface is easily regenerated. The performance of CNTFMs has been characterized, among others, by surface modification with phosphomolybdic acid. It is shown that adsorption behavior of these catalyst molecules is highly improved with a controlled orientation of CNT. A better CNT alignment inside the fiber can be achieved by a hot stretching procedure.     

Reaction of N-Acetylcysteine with Cu2+: Appearance of Intermediates with High Free Radical Scavenging Activity: Implications for Anti-/Pro-Oxidant Properties of Thiols

We studied the kinetics of the reaction of N-acetyl-l-cysteine (NAC or RSH) with cupric ions at an equimolar ratio of the reactants in aqueous acid solution (pH 1.4–2) using UV/Vis absorption and circular dichroism (CD) spectroscopies. Cu²⁺ showed a strong catalytic effect on the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical (ABTSr) consumption and autoxidation of NAC. Difference spectra revealed the formation of intermediates with absorption maxima at 233 and 302 nm (ε₃₀₂/Cu > 8 × 10³ M⁻¹ cm⁻¹) and two positive Cotton effects centered at 284 and 302 nm. These intermediates accumulate during the first, O₂-independent, phase of the NAC autoxidation. The autocatalytic production of another chiral intermediate, characterized by two positive Cotton effects at 280 and 333 nm and an intense negative one at 305 nm, was observed in the second reaction phase. The intermediates are rapidly oxidized by added ABTSr; otherwise, they are stable for hours in the reaction solution, undergoing a slow pH- and O₂-dependent photosensitive decay. The kinetic and spectral data are consistent with proposed structures of the intermediates as disulfide-bridged dicopper(I) complexes of types cis-/trans-Cu^I₂(RS)₂(RSSR) and Cu^I₂(RSSR)₂. The electronic transitions observed in the UV/Vis and CD spectra are tentatively attributed to Cu(I) → disulfide charge transfer with an interaction of the transition dipole moments (exciton coupling). The catalytic activity of the intermediates as potential O₂ activators via Cu(II) peroxo-complexes is discussed. A mechanism for autocatalytic oxidation of Cu(I)–thiolates promoted by a growing electronically coupled –[Cu^I₂(RSSR)]_n– polymer is suggested. The obtained results are in line with other reported observations regarding copper-catalyzed autoxidation of thiols and provide new insight into these complicated, not yet fully understood systems. The proposed hypotheses point to the importance of the Cu(I)–disulfide interaction, which may have a profound impact on biological systems.     

Ash decline assessment in emerald ash borer-infested regions: A test of tree-level, hyperspectral technologies

The emerald ash borer (EAB) is an exotic insect pest currently threatening ash species in the Great Lakes region. Because of the potential impact on forests in this area, multiple government agencies are currently focusing their efforts on developing new technologies to detect, monitor and control this insect pest. Previous work has shown that hyperspectral remote sensing technologies can produce detailed maps of forest health and species abundance on a landscape scale. This study examines the capability of a commercially available sensor (SpecTIR VNIR) to map ash decline due to exotic EAB infestations in Michigan and Ohio. A 6-term linear regression equation based on known stress- and chlorophyll-sensitive indices was able to predict decline on a continuous 0- to 10 scale with an r-squared of 0.71 and an average jackknifed residual of 0.61. Treated as an integer, decline was predicted to within one class with 97% accuracy. The ability of this instrument to assess decline below class 4 (when dieback and transparency reach levels first noticeable in the field) is based upon pre-visual reductions in chlorophyll content and function that are characteristic of early stress. The identification of early stress is critical in containing newly introduced exotics such as EAB. While this decline prediction technique is not stress- or species-specific, it will enable land managers to assess and monitor detailed forest health across the landscape.