Changes In Physicochemical Properties Research Articles

Differentiation of electron beam and X-ray irradiation modified starch under vacuum conditions: Multi-scale structure and properties

This study modified lentil starch stored in a vacuum and regular (Ziplock-packed) conditions using electron beam irradiation and X-rays. The effects of these irradiations and environments on starch modification were evaluated by comparing changes in physicochemical and functional properties. Both electron beam and X-ray irradiation significantly reduced the short-range order and molecular weight of the starch while increasing the content of short chains. Under a vacuum environment, all irradiations exhibited more substantial degradation effects than regular conditions. Electron beam irradiation significantly reduced the relative crystallinity and the content of long chains, whereas X-rays had a more pronounced impact on disrupting the crystal structure of lentil starch. The vacuum environment enhanced the effectiveness of irradiation in improving the antidigestive properties of starch, leading to an increase in resistant starch content from 75.75% to 79.22%. This study offers new insights into producing modified starches using irradiation in combination with specific treatment environments.

The Impact of pH on Fouling and Related Physicochemical Properties of Skim Milk Concentrate during Heat Treatment Using a Laboratory-Scale Fouling Rig.

The objective of this study was to investigate the effect of pH (6.1, 6.3, 6.5, and 6.7) on heat-induced changes in concentrated skim milk as related to fouling in heat exchangers. Skim milk (30%, w/w, total solids) was recirculated in a laboratory-scale fouling rig at an initial target temperature of 85 °C for 90 min to simulate thermal processing and preheating of evaporated liquid concentrate feeds in dairy processing. This study investigated key changes in relevant physicochemical properties, such as viscosity, particle size, and sedimentation, as major contributors to fouling at lower pHs (6.1 and 6.3). Additionally, protein aggregation and calcium phosphate precipitation were identified as significant contributors to fouling deposits. Possible strategies to mitigate fouling were determined, including optimizing pH and adjusting heat treatment parameters to minimize protein denaturation and mineral deposition. The findings indicate that carefully controlling pH and processing parameters can greatly enhance the efficiency of milk concentration by evaporation and tailor finished product quality. Moreover, this study showed that monitoring of CIP solutions for protein content and turbidity provides valuable information on the intensity of fouling and the efficiency of cleaning.

The Local Changes in the Physicochemical Properties during Cu Electrodeposition in an Ionic Liquid Composed of [CuCl2]–

The equimolar mixture of CuCl and 1-butyl-1-methylpyrrolidinium chloride (BMPCl) was found to yield an ionic liquid composed predominantly of BMP+ and [CuCl2]–. Fine deposits of metallic Cu were obtained by potentiostatic reduction of [CuCl2]– in CuCl-BMPCl (50.0-50.0 mol%). The change in the local physicochemical properties near the electrode during the electrodeposition of Cu was analyzed using electrochemical quartz crystal microbalance. The resonance resistance of a quartz crystal electrode increased with an increase in the local viscosity near the electrode, probably reflecting the change in the composition of the electrolyte.

Mechanistic understanding of changes in physicochemical properties of different rice starches under high hydrostatic pressure treatment based on molecular and supramolecular structures

The molecular and supramolecular structures of japonica and waxy rice starches under high hydrostatic pressure treatment (450 MPa) were studied and the changes in physicochemical properties were analyzed based on these structures. The molecular structures of japonica and waxy rice starch cause differences in the lamellar structure and physicochemical properties. The thickness of amorphous lamella of japonica rice starch increased at 5 min (2.95 nm) followed by a gradual collapse of lamellar structure. Whereas the thickness of crystalline lamellae of waxy rice starch increased at 15 min (5.92 nm) and the lamellae collapsed suddenly at 20 min. The pasting, rheological and textural characteristics of both starches increased significantly within 10 to 15 min. The decreasing onset temperature and enthalpy of high hydrostatic pressure-treated starches indicated easier gelatinization. High hydrostatic pressure-treatment offers potential for developing starch-based products with low swelling capacity, easy gelatinization, high viscosity and hardness.

Physicochemical and Morphological Changes in Long-Grain Brown Rice Milling: A Study Using Image Visualization Technologies

This study evaluated the changes in physicochemical properties and appearance quality of long-grain rice during the grinding process using image technologies and aimed to provide reference for future research. The brown rice milling process was divided into three stages, and flatbed scanning, scanning electron microscopy (SEM), X-ray micro-computed tomography (micro-CT), low-field nuclear magic resonance (LF-NMR), and headspace–gas chromatography–ion mobility spectrometry (HS–GC–IMS) were employed to examine the physicochemical and volatile properties of the samples. Results revealed a continuous increase in the degree of milling, with a broken rice rate and a whiteness value increasing by 50.84% and 21.13%, respectively, compared with those during the initial stage; dietary fiber and vitamin B1 contents were reduced by 54.41% and 66.67%, respectively. The image results visualized showed that the cortex of brown rice was gradually peeled off with the increase in milling degree; the cortical thickness was gradually reduced, the endosperm was gradually exposed, and the surface was smoother and shinier. T2 populations exhibited a shift toward longer relaxation times, followed by a decrease in relaxation time during the milling process. Additionally, 31 target compounds impacting rice flavor, mainly ketones, alcohols, and esters, were identified, and the concentration of volatile substances in the B region decreased with the reduction in the bran layer; the concentration of volatile substances in the C region provided rice flavor, which increased with the milling process. This study showed changes in the physicochemical properties and appearance quality of long-grain brown rice during milling. Furthermore, the use of various image processing techniques offers significant insights for optimizing processing parameters and enhancing overall quality and taste.

The Application of Bicyclo[1.1.1]pentane as a Bioisostere of the Phenyl Ring in Pharmaceutical Chemistry

AbstractBicyclo[1.1.1]pentane (BCP) is a bridging ring skeleton with three-dimensional structure. BCP is a bioisostere of the phenyl ring, tert-butyl group, and alkynes; it has excellent physical and chemical properties compared with phenyl ring, so it has been widely considered by the pharmaceutical chemistry. This short review examines related reports of BCP as a bioisostere of the phenyl ring, and the changes in physicochemical properties and biological activity after substitution. The solubility, clogP, and metabolic toxicity of the drug are improved by BCP bioisosteres, but the biological activity of BCP is lower than the phenyl ring. The application of BCP in drug research and development will be further expanded to provide more possibilities for future drug innovation and development.1 Introduction2 Replacement of Phenyl Rings by BCP3 Conclusion

Surface Plasmon Resonance Allows to Correlate Molecular Properties With Diffusion Coefficients of Linear Chain Alcohols.

Every biological and physicochemical process occurring in a fluid phase depends on the diffusion coefficient (D) of the species in solution. In the present work, a model to describe and fit the behaviour of as a function of structure and extensive thermodynamics parameters in binary solutions of linear chain organic molecules is developed. Supporting experimental and computational evidences for this model are obtained by measuring for a series of -alcohols through a novel surface plasmon resonance method and molecular dynamics simulations. This allows to propose a kind of combined analysis to explain the dependence of on various thermodynamic and structural parameters. The results suggest that for small linear systems in the range from 0 to 200 g mol-1 and under the assumption that the diffusive activation energy is a linear function of mass, is strictly dependent on the molecular shape and on the relative strength of the solute-solvent intermolecular forces represented by a parameter named R. The newly proposed approach can be utilized to characterize and monitor progressive changes in physicochemical properties for any investigated species upon increasing the dimension of the aggregate/molecule along a certain direction.

Dicyandiamide Applications Mitigate the Destructive Effects of Graphene Oxide on Microbial Activity, Diversity, and Composition and Nitrous Oxide Emission in Agricultural Soil.

The widespread production and utilization of graphene oxide (GO) raise concerns about its environmental release and potential ecological impacts, particularly in agricultural soil. Effective nitrogen (N) management, especially through nitrification inhibitors like dicyandiamide (DCD), might mitigate the negative effects of GO exposure on soil microbes via N biostimulation. This study quantified changes in soil physicochemical properties, nitrous oxide (N2O) emissions, microbial activity, biomass, and community after treatments with GO and DCD. The GO exposure significantly reduced bacterial 16S rRNA gene abundance and the biomass of major bacterial phyla. It also stimulated pathways linked to human diseases. However, DCD application alleviated the negative effects of GO exposure on soil bacterial biomass. While DCD application significantly reduced soil N2O emission, the GO application tended to hinder the inhibiting performance of DCD. Our findings highlight the hazards of GO exposure to soil microbes and the potential mitigation strategy with soil N management.

Comparing the effects of pristine and UV–VIS aged microplastics: Behavioural response of model terrestrial and freshwater crustaceans

Physico-chemical properties of microplastics (MPs) change during weathering in the environment. There is a lack of knowledge about the effects of such environmentally relevant MPs on organisms. We investigated: 1) the physico-chemical changes of MPs due to UV–VIS weathering, and 2) compared the effect of pristine and aged MPs on the behaviour of the water flea Daphnia magna and terrestrial crustacean Porcellio scaber. Dry powders of MPs were produced from widely used polymer types: disposable three-layer polypropylene (PP) medical masks (inner, middle and outer), polyester textile fibres, car tires and low-density polyethylene (LDPE) bags and were subjected to accelerated ultraviolet–visible (UV–VIS) ageing. Our results show that the extent of transformation depends on the type of polymer, with PP showing the most changes, followed by LDPE, textile fibres and tire particles. Obvious fragmentation was observed in PP and textile fibres. In the case of PP, but not polyester textile fibres, changes in FTIR spectra and surface properties were observed. Tire particles and LDPE did not change in size, but clear changes were observed in their FTIR spectra. Most MPs, aged and pristine, did not affect the swimming of daphnids. The only effect observed was a significant increase in path length and swimming speed for the pristine tire particles when the recording was done with particles remaining in the wells. After transfer to a clean medium, this effect was no longer present, suggesting a physical rather than chemical effect. Similarly, woodlice showed no significant avoidance response to the MPs tested, although there was a noticeable trend to avoid soils contaminated with pristine polyester textile fibers and preference towards the soils contaminated with aged MP of the middle mask layer. Overall, the apparent changes in physico-chemical properties of MPs after accelerated ageing were not reflected in their effects on woodlice and daphnids.

Adsorption of methylene blue onto clay/carbon composite: kinetics and isotherms study

ABSTRACT Waste treatment for pollution control is a hot topic being studied and has received growing attention. In this study, spent bleaching earth (SBE), a waste material from the oil refineries, was pyrolyzed in a N2 atmosphere to produce an environmentally sustainable clay/carbon composite (SBE@C (500 °C)). SBE@C (500 °C) was tested for its ability to remove methylene blue (MB) from water. The Langmuir model best explained the adsorption isotherms, with maximum adsorption capacity of 29.54 mg/g (MB solution (10–60 mg/L)). The pseudo-second-order kinetic model effectively described the adsorption kinetics data. Thermodynamic parameters indicated spontaneous and endothermic processes. The impact of coexisting cations on MB adsorption by SBE@C (500 °C) decreased in the following order: Fe3+ > Al3+ > Mg2+ > K+ > Na+. The ionic strength results indicated that increasing the concentration of Na+ ions led to a decrease in adsorption capacity. MB removal was greatest at pH level of 8. The adsorption mechanisms involved π–π interactions, electrostatic interactions, and changes in physicochemical properties. After 3 cycles, SBE@C (500 °C) may be recycled up to 11 times before completely losing its adsorption capacity. Overall, SBE@C (500 °C) shows promise for removing MB from wastewater, while mitigating secondary pollution from SBE.

Effects of Varied Tillage Practices on Soil Quality in the Experimental Field of Red-Soil Sloping Farmland in Southern China

Red-soil sloping farmland in southern China plays a crucial role in the local economy and food production. However, improper tillage practices have resulted in topsoil degradation and deteriorating soil quality. This study investigated changes in soil physico-chemical properties under four tillage methods—cross-slope ridge tillage (RT), down-slope ridge tillage (DT), plastic mulching (PM), and conventional tillage (CT)—on red-soil sloping farmland. The study applied the Soil Management Assessment Framework (SMAF) to assess the influence of these tillage practices on soil quality. Results indicated that PM can increase the total porosity of the soil, reduce soil bulk density, and simultaneously decrease soil surface-water evaporation, significantly improving the soil’s water-retention capacity. RT improved soil aggregate formation and stability, leading to increased macro-aggregate content, mean weight diameter, and soil water-stable aggregate stability rates. PM and RT effectively preserved soil nutrients like total nitrogen and organic matter, although PM lowered soil pH, potentially causing acidification. RT demonstrated the highest soil quality, with PM following. Crop growth positively impacted soil macro-aggregate content and stability, showing continuous improvement in soil structure and quality (p < 0.05). Priority should be given to RT in red-soil sloping farmland, followed by PM and CT, while avoiding DT if possible. This research furnishes valuable scientific substantiation for the selection of optimal tillage practices in the preservation of soil quality on red-soil slopes.

Effects of Film Mulching on Soil Quality, Garlic Yield, and Garlic Quality

To determine the optimal film management technique for garlic planting, this study aimed to investigate the effects of various film cover methods on soil quality and garlic yield in garlic cropping systems. To achieve these goals, trials with different film cover methods were conducted at the Jiangsu Academy of Agricultural Sciences in Nanjing. To investigate the impact of changes in soil quality and garlic yield, we set up four treatments： no film treatment （CK）, black polyethylene film treatment （HPE）, black poly（butylene- adipate-co-terephthalate） （PBAT） with straw composite film treatment （HSJ）, and white PBAT film treatment （BJ） in a garlic cropping system. Our results indicated that specific mulch coverings had a positive effect on both soil quality and garlic yield. The film cover treatments resulted in significant changes in soil physicochemical properties and bacterial and fungal biomasses and indirectly improved soil quality. Compared to that under the no film treatment, the BJ treatment boosted soil quality by 70%, with the most significant impact, followed by that under the HPE and HSJ treatments, with improvements of 52% and 36%. Random forest modeling indicated that soil organic matter and total nitrogen were the most important factors influencing soil quality. The different film covers significantly increased the diameter of garlic bulbs and single quality. The HSJ treatment exhibited the most significant increase in garlic yield, with 46%, 19%, and 6% improvement compared to that in the CK, HPE, and BJ treatments, respectively. Correlation analysis showed that soil quality under film cover was significantly correlated with the starch content of garlic bulbs, garlic diameter, and single quality. This study highlights that selecting the appropriate mulch film aids in the production of garlic and helps to develop farmland that produces both high-quality and high-yield crops.

The dynamic changes and correlations between biochemical properties, flavor and microbial community during fermentation of asparagus by-products

Asparagus by-products are the promising resource that urgently need to be re-valorized. This study investigated the dynamic changes in physicochemical properties, organic acids, free amino acids, volatile flavor compounds, microbial succession, and their correlations during 7-day spontaneous fermentation of asparagus by-products. Dominant organic acids (lactic acid and acetic acid) and free amino acids (Ser, Glu, and Ala) increased with fermentation time, with lactic acid reaching 7.73 ± 0.05 mg/mL and Ser increasing 56-fold after 7 days. A total of 58 volatile flavor compounds were identified using headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPEM/GC–MS), with esters, alcohols and acids as the main volatile flavor compounds. Fourteen volatile flavor compounds had odor activity value >1. High-throughput sequencing showed Firmicutes and Proteobacteria as the main bacterial phyla, dominated by lactic acid bacteria (Levilactobacillus, Lactiplantibacillus, Weissella). Correlation analysis revealed that five bacterial genera (Levilactobacillus, Lactiplantibacillus, Enterobacter, Pediococcus and Acetobacter) were highly correlated with organic acids, free amino acids, and volatile flavor compounds, indicating their pivotal role in forming the characteristic flavor of fermented asparagus by-products (FAPS). This study provides new insights into the flavor and microbial profile of FAPS, offering a strategy for value-added processing and industrial production.

Influence of thinning on carbon storage mediated by soil physicochemical properties and microbial community composition in large Chinese fir timber plantation

BackgroundThinning practices are useful measures in forest management and play an essential role in maintaining ecological stability. However, the effects of thinning on the soil properties and microbial community in large Chinese fir timber plantations remain unknown. The purpose of this study was to investigate the changes in soil physicochemical properties and microbial community composition in topsoil (0–20 cm) under six different intensities (i.e., 300 (R300), 450 (R450), 600 (R600), 750 (R750) and 900 (R900) trees per hectare and 1650 (R1650) as a control) in a large Chinese fir timber plantation.ResultsCompared with the CK treatment, thinning significantly altered the contents of soil organic carbon (SOC) and its fractions but not in a linear fashion; these indicators were highest in R900. In addition, thinning did not significantly affect the soil microbial community diversity indices but significantly affected the relative abundance of the core microbial community. Proteobacteria, Acidobacteria, and Actinobacteria were the dominant bacterial phyla; the relative abundances of Proteobacteria and Acidobacteria were highest in R900, and that of Actinobacteria was lowest in R900. The dominant fungal phyla were Ascomycota, Basidiomycota and Mucoromycota; the relative abundance of Ascomycota was lowest in R900, and that of Mucoromycota was highest in R900. The fungal microbial community composition was more sensitive than the bacterial community composition. The activity of the carbon-cycling genes was not linearly correlated with thinning, and the abundance of C-cycle genes was highest in R900.ConclusionsThese findings are important because they show that SOC and its fractions and the abundance of the soil microorganism community in large Chinese fir timber plantations can be significantly altered by thinning, thus affecting the capacity for carbon storage. These results may advance our understanding of how the density of large timber plantations could be modified to promote soil carbon storage.

Distinct microbial community structures formed on the biofilms of PLA and PP, influenced by physicochemical factors of sediment and polymer types in a 60-day indoor study

Microplastics (MPs) are colonized by biofilm-forming microbes. Biodegradable plastics, popular replacements for traditional plastics, still have unknown biofilm formation characteristics. We conducted a 60-day indoor experiment, where sediment was exposed to traditional MPs (polypropylene, PP), biodegradable MPs (polylactic acid, PLA), and glass beads (GLASS). The microbial communities in the MPs-biofilm were analyzed using high-throughput sequencing. Results indicated that Proteobacteria was the dominant phylum on all substrates, followed by Actinobacteria, and Firmicutes. At the genus level, the majority of microorganisms colonizing PP possessed nitrification and denitrification capabilities, while the dominant bacteria on PLA were capable of degrading lignin, cellulose and carbon metabolism. The genus Sphingomonas, a promising bacteria capable of degrading biodegradable microplastics, was particularly discovered on the PLA biofilm, meanwhile, bacterial colonization of PLA indirectly increased the potential for human transmission of pathogens. Redundancy analysis revealed that the pH and moisture significantly affected the bacterial communities. Pearson correlation heatmap indicated that the abundance of the majority of dominant bacterial genera of two MPs biofilms is negatively correlated with the physicochemical parameters of sediment (pH, moisture, TN, TP), except for salinity. The microbial communities associated with PP and PLA exhibited distinct differences caused by the combined effects of changes in physicochemical properties of sediment and different material substrates. This study provides further evidence of the significant selective features exhibited by microbial colonization on these two MPs when exposed to the same source community, offering insights into the exploration of promising bacteria for MPs degradation.

Innovative In/H-SSZ-39 Catalysts: An Exploration in NOx Reduction via CH4-SCR

Nitrogen oxides (NOx), pivotal atmospheric pollutants, significantly threaten the environment and human health. The CH4-SCR process, leveraging the abundance and accessibility have methane, emerges as a promising avenue for NOx abatement. Previous studies have demonstrated that zeolite support with twelve-membered ring (12-MR) and five-membered ring (5-MR) structures are susceptible to framework collapse in the presence of H2O, leading to catalyst deactivation. Consequently, there is a necessity to explore novel zeolites with enhanced hydrothermal stability for application in CH4-SCR processes. This research introduced for the first time an investigation into a novel In/H-SSZ-39 catalyst, which was synthesized via ion exchange and meticulously optimized for preparation conditions, including calcination temperature and In ions concentration, and reaction conditions, including CH4/NO ratio, O2 concentration, H2O content, and Gas Hourly Space Velocity (GHSV). Furthermore, long-term operation tests and stability tests were conducted on the In/H-SSZ-39 catalyst. In addition, a series of characterizations were conducted to delve into the reasons behind how preparation conditions influence catalytic activity, as well as to investigate the changes in physicochemical properties during the reaction process.

Research on electron beam irradiation in the multiscale structure of starch and its related applications: A review.

Electron beam irradiation (EBI), as a typical "green" emerging technology, can effectively alter the functional properties of starch by influencing its microstructure. This alteration enables starch to meet the current demands of consumers and the market for "health food." This paper reviews studies on modifying various starches using EBI and describes the changes in microstructure, physicochemical properties, and functional properties induced by this method. Additionally, the effects of EBI on starch-containing food products are discussed, along with issues to be addressed and research gaps in the synergistic treatment of modified starch. It is noted that the source, irradiation dose, and irradiation time all influence the effectiveness of starch modification. Given the characteristics of EBI technology, integrating physical, chemical, and biological modification methods can optimize the modification process and enhance efficiency. This technology can potentially diversify modified starch varieties and expand their applications. Furthermore, there remains significant research potential in producing modified starch using EBI technology and applying it to the food industry.

Unraveling the role of black soldier fly larvae in chicken manure conversion: Facilitating maturation and enhancing humification

Black soldier fly larvae (BSFL) have garnered considerable attention for their efficacy in mitigating waste management challenges. However, their potential in treating antibiotics contaminated chicken manure remains uncertain. This study investigates the physicochemical properties changes and nutrient dynamics during the composting of contaminated-chicken manure using BSFL. The results indicate that BSFL treatment reduces electrical conductivity (by 6.01–58.09 %), organic matter, and dissolved organic carbon content in chicken manure throughout the composting process, while maintaining a more stable pH value (pH ∼ 6.0–8.0). This is attributed to the consumption of organic matter by BSFL and the subsequent promotion of organic acid formation. Additionally, BSFL treatment improves the degree of aromatization of dissolved organic matter (DOM) in chicken manure and increases the proportions of fulvic acid (up to 48.77 %) and humic acid (maximally 14.27 %) within the DOM. The germination index and pot experiments indicated improved compost maturity and plant growth in BSFL-treated composts. Furthermore, BSFL meal demonstrated high protein and essential fatty acid content, highlighting its potential as a protein supplement in animal feed. This study underscores the efficacy of BSFL in enhancing compost quality and nutrient availability, offering a sustainable solution for waste management and animal feed production.

Insight into the effect of potassium carbonate on the physicochemical and structural properties of starch isolated from hot-dry noodles

The objective of this study was to investigate the changes in physicochemical and structural properties of starch isolated from hot-dry noodles (HDNS) treated with different contents of potassium carbonate (K2CO3). The results demonstrated that the existence of K2CO3 increased the WHC and hardness of HDNS gel with an elevated storage modulus. Meanwhile, K2CO3 promoted the gelatinization of HDNS, which displayed higher viscosity and swelling power. Moreover, the relative crystallinity of HDNS were improved. K2CO3 facilitated the transformation of HDNS from an amorphous to a more ordered and crystalline structure. Simultaneously, the microscopic characteristics exhibited that K2CO3 promoted the partial fusion of starch particles to form aggregates, and the particle size became larger. In conclusion, the physicochemical and structural properties of HDNS were improved effectively with the incorporation of K2CO3, and the research results provided new insights for the processing of high-quality hot-dry noodles.

Analysis of Tamarix chinensis Forest Characteristics, Salt Ion Distribution, and Non-Structural Carbohydrate Levels in the Yellow River Delta: A Spatial Study Based on Proximity to the Shoreline.

The distribution of vegetation in coastal wetlands is significantly influenced by soil properties. However, the mechanisms of how soil characteristics impact the physiological processes of Tamarix chinensis forests remain underexplored. This study examined changes in the soil physicochemical properties and structural attributes of natural T. chinensis forests in the Yellow River Delta with increasing distance from the shoreline. T. chinensis trees were classified into healthy, intermediate, and dying categories based on growth potential, and dynamic changes in salt ions and non-structural carbohydrates (NSCs) were investigated. Results indicated that increasing distance from the shoreline corresponded to decreased soil salinity and pH, and increased soil moisture. T. chinensis mortality rate decreased, while tree height and ground diameter increased with distance. Soil salt content was positively correlated with T. chinensis mortality, but negatively correlated with tree height and ground diameter. Trees with lower growth potential had higher Na+ but lower K+ and K+/Na+ ratio. Soil salt content was positively correlated with root and stem Na+, while soil moisture was positively correlated with leaf NSCs. These findings suggest that soil salt content and moisture significantly influence T. chinensis ion absorption and NSC accumulation, with sodium toxicity being a key factor in the spatial distribution of T. chinensis forests.