Pretreatment Time Research Articles

Synergistic enhancement of nitrogenous compounds in bio-oils: Hydrogen peroxide pretreatment and nitrogen-rich pyrolysis

A novel pretreatment method, combining H2O2 and nitrogen-rich pyrolysis for biomass was proposed to address the issue of low nitrogen compounds or levoglucosan content in pyrolysis bio-oil. Bio-oil enriched with high content of levoglucosan and nitrogenous compounds was obtained. In this study, the effects of pretreatment conditions (H2O2 solution concentration, pretreatment time, solution pH) and nitrogen-rich ratio on the pyrolysis characteristics of corn stover were investigated. The difficulty of converting different components into nitrogenous compounds was evaluated for the first time. The results reveal that H2O2 pretreatment effectively removed most lignin and ash, leading to a substantial enrichment of cellulose. Notably, carbohydrate content in bio-oil increased by more than 970 %. However, excessive pyrolysis temperature and pH of H2O2 solution can aggravate the decomposition of carbohydrates. The co-pyrolysis of the pretreated corn stover with urea increased the bio-oil yield (up to 56.32 wt%) and the content of nitrogenous compounds (43.16 wt%). The order of ease in converting certain components into nitrogenous compounds is Ketones > Aldehyde > Furans > Phenols > Esters > Alcohols. This study not only clarified the correlation coupling mechanisms between raw material pretreatment conditions and nitrogen-rich ratio with pyrolysis product characteristics. It can also provide guidance for biorefining. Based on the excellent lignin removal effect of the method proposed in this study, it has broad application prospects in the field of biorefinery of lignocellulosic biomass.

A Novel Terahertz Metamaterial Microfluidic Sensing Chip for Ultra-Sensitive Detection.

A terahertz metamaterial microfluidic sensing chip for ultrasensitive detection is proposed to investigate the response of substances to terahertz radiation in liquid environments and enhance the molecular fingerprinting of trace substances. The structure consists of a cover layer, a metal microstructure, a microfluidic channel, a metal reflective layer, and a buffer layer from top to bottom, respectively. The simulation results show that there are three obvious resonance absorption peaks in the range of 1.5-3.0 THz and the absorption intensities are all above 90%. Among them, the absorption intensity at M1 = 1.971 THz is 99.99%, which is close to the perfect absorption, and its refractive index sensitivity and Q-factor are 859 GHz/RIU and 23, respectively, showing excellent sensing characteristics. In addition, impedance matching and equivalent circuit theory are introduced in this paper to further analyze the physical mechanism of the sensor. Finally, we perform numerical simulations using refractive index data of normal and cancer cells, and the results show that the sensor can distinguish different types of cells well. The chip can reduce the sample pretreatment time as well as enhance the interaction between terahertz waves and matter, which can be used for early disease screening and food quality and safety detection in the future.

Effect of Ultrasound and Freeze‐Drying to Enhance the Extraction of Phenolic Compounds in Dragon Fruit Peels and Apply Them in Edible Starch‐Based Films

ABSTRACTIn this study, dragon fruit peels were subjected to different times (5, 10, 15, 20 and 25 min) of ultrasound pretreatment (4.870 W m−2/25°C) and then freeze‐drying (FD) (−56°C/48 h) to obtain powder particles, which underwent physical–chemical, functional and structural characterisation. Additionally, the extraction of total phenolic compound (TPC) was evaluated through ultrasound‐assisted kinetics and mechanical agitation. Finally, films based on black rice starch were developed with the addition (0.5, 1.5 and 2.5%) of dragon fruit peel powder particles, and their physical, barrier, antioxidant, structural and mechanical properties were evaluated. The results obtained showed that all particles had low water content (4.21%–6.58%) and high solubility (84.62%–88.73%) with a reduction in particle size (23.21–39.32 μm). In the extraction of TPC, the synergistic effect of the tested conditions increased efficiency, reaching 686.66 mg GAE/100 g for pretreated dragon fruit peel powder particles (25 min) in 180 min of extraction. Furthermore, the type ‘A’ crystallinity structure did not change significantly with pretreatment, but there was a reduction in peak area, reflecting on relative crystallinity, with a maximum decrease of 29.04%. The starch‐based films produced with 2.5% dragon fruit peel powder particles showed low solubility (28.72%) and low water vapour permeability (5.03 × 10−8 g mm s−1 m2 Pa), however, they contained higher levels of TPC (31.78 mg GAE/100 g film) and antioxidant activity (8.17 μmol TE/g film) that were easily migrated in aqueous medium. Furthermore, they also presented low values of tensile strength at break (3.41 MPa) and Young's modulus (4.18 MPa), as well as a high value of elongation at break (45.82%). Finally, our results highlight the potential of ultrasound as a pretreatment for FD of dragon fruit peels, paving the way for the development of rice starch‐based food packaging.

Study on Improving Physical–Mechanical Properties and Frost Resistance of Straw–Mortar Composite Wall Materials by Pretreatment

In recent years, China has increased the material utilization of crop straw, and the strength of straw–mortar composite wall materials is low, which limits their large-scale utilization. Pretreatment can improve the physico-mechanical and frost resistance properties of straw–mortar composite wall materials. In this study, the Box–Behnken design in the Design-Expert software was used to design and carry out a three-factor and three-level interactive experiment and freeze–thaw cycle experiment with the straw content, pretreatment time, and reagent concentration as influencing factors, and the compressive strength, water absorption rate, and dry density as response values. The results showed that the impact of each factor on the response value, from high to low, was the straw content, pre-preparation time, and reagent concentration. When the straw content was 10%, the preparation time was 5 min, and the reagent concentration was 5%, the physical and mechanical properties of the straw–mortar composite wall material were the best. At the same time, the compressive strength was 6.52 MPa, the water absorption rate was 17.7%, and the dry density was 1396.33 kg·m−3, which was 67% higher, 31% lower, and 37% higher than that of the untreated straw–mortar composite wall materials. After the freeze–thaw cycle, the mass loss rate of the composite materials was less than 5%, which met the requirements of the frost resistance specifications; the strength loss rate of the composite materials varied between 19.7% and 27.8%, although some test blocks did not meet the requirements of less than 25% in the specification. The compressive strength was greatly improved compared with the untreated composite materials in the related research, and the water absorption rate was about 25% lower than that of the untreated straw–mortar composite wall materials. Pretreatment significantly improved the physico-mechanical and frost resistance properties of the straw–mortar composite wall materials.

Pre-treatment of Cucurbita maxima ‘Hokkaido orange’ by Viscum album aqueous extracts in search of allelopathic potential

Viscum album L. (VA) is a unique plant with regard to its biological content. It is rich in many different metabolites with high potential in various spheres of human activity. We conducted a pilot study with 5 VA aqueous extracts of different host-tree species for pre-sowing treatment of Cucurbita maxima ‘Hokkaido orange’ seeds. We set the following objectives consisting of hypotheses (1) H01 is based on different effects of tested VA extracts depending on host trees and time of pre-treatment; (2) H02 focuses on the allopathic properties of the tested extracts affecting the plant growth and development by dose–response relationship; (3) A01 considers highly biologically active compounds of VA extracts also containing allelochemicals that can be used to regulate plant growth processes and create eco-friendly and resilient cities. The analysis of the stimulatory allelopathy index for 7 parameters demonstrates the direct effect of VA extracts in 62.3% of cases. The variability of the broad spectrum of effects of VA extracts of different host trees on the ontogenesis of C. maxima plants shows the presence of potential allelochemicals, resulting from the vital products of the host-parasite relationship. These effects are not fully explained by total polyphenol content and antioxidant activity as in previous studies of other mistletoe species. The authors consider this work a pilot study that expands the areas of application of VA extracts and knowledge about potential sources of allelochemicals.

Preparation of zwitterionically charged chitin nanofibers through one step chemical modification and their application for antireflective coatings

Chitin nanofibers are widely used in many fields because of their biocompatibility, renewability and excellent mechanical properties. Herein, zwitterionically charged chitin nanofibers (ZC-ChNFs) were prepared from chitin via one step chemical modification (oxalic acid pretreatment) and subsequent ultrasound treatment. Effects of pretreatment time on size of the ZC-ChNFs and pH of ZC-ChNF suspensions on the thickness, porosity, refractive index and antireflective capacity of ZC-ChNF coatings were investigated. It was found that, by adjusting pH of the ZC-ChNF suspension, porosity and refractive index of the ZC-ChNF coatings could be controlled. The ZC-ChNF coatings fabricated with smaller ZC-ChNFs had higher antireflective performance and the transmittance gain of a glass with a ZC-ChNF coating was about 3.5 % at a wavelength of 550 nm compared to the bare glass. The results of this work provide a promising pathway to fabricate antireflective coating with ZC-ChNFs just by controlling the pH of ZC-ChNF suspensions.

Prediction of pathological complete response and prognosis in locally advanced rectal cancer.

Colorectal cancer is currently the third most common malignant tumor and the second leading cause of cancer-related death worldwide. Neoadjuvant chemoradiotherapy (nCRT) is standard for locally advanced rectal cancer (LARC). Except for pathological examination after resection, it is not known exactly whether LARC patients have achieved pathological complete response (pCR) before surgery. To date, there are no clear clinical indicators that can predict the efficacy of nCRT and patient outcomes. To investigate the indicators that can predict pCR and long-term outcomes following nCRT in patients with LARC. Clinical data of 128 LARC patients admitted to our hospital between September 2013 and November 2022 were retrospectively analyzed. Patients were categorized into pCR and non-pCR groups. Univariate analysis (using the χ 2 test or Fisher's exact test) and logistic multivariate regression analysis were used to study clinical predictors affecting pCR. The 5-year disease-free survival (DFS) and overall survival (OS) rates were calculated using Kaplan-Meier analysis, and differences in survival curves were assessed with the log-rank test. Univariate analysis showed that pretreatment carcinoembryonic antigen (CEA) level, lymphocyte-monocyte ratio (LMR), time interval between neoadjuvant therapy completion and total mesorectal excision, and tumor size were correlated with pCR. Multivariate results showed that CEA ≤ 5 ng/mL (P = 0.039), LMR > 2.73 (P = 0.023), and time interval > 10 wk (P = 0.039) were independent predictors for pCR. Survival analysis demonstrated that patients in the pCR group had significantly higher 5-year DFS rates (94.7% vs 59.7%, P = 0.002) and 5-year OS rates (95.8% vs 80.1%, P = 0.019) compared to the non-pCR group. Tumor deposits (TDs) were significantly correlated with shorter DFS (P = 0.002) and OS (P < 0.001). Pretreatment CEA, LMR, and time interval contribute to predicting nCRT efficacy in LARC patients. Achieving pCR demonstrates longer DFS and OS. TDs correlate with poor prognosis.

Optimizing dilute acid pretreatment for enhanced recovery and co-fermentation of hexose and pentose sugars for ethanol and butanol production

A systematic study of dilute acid pretreatment of sugarcane bagasse was performed to optimize the recovery of hexose-rich solid and pentose-rich liquid while minimizing fermentation inhibitors. Pretreatment experiments evaluated the effects of pretreatment time (10–90 min) and acid concentration (0.5–3.0 % w/w). The optimized pretreatment (1.4 % w/w sulfuric acid, 56.4 min at 121 °C) led to a solid fraction with 60.4 % cellulose and a liquid stream rich in pentose, in which 92.7 % of sugars was recovered as xylose (17.8 g/L). Besides that, low concentrations of by-products (3 g/L – the sum of acetic and formic acid, furfural, and HMF) were identified in the liquid fraction. Both fractions were integrated into enzymatic processes for further co-fermentation of C5- and C6- sugars. Two fermentative routes were evaluated: simultaneous isomerization of xylose and co-fermentation of glucose and xylulose (SIcF) for 2G ethanol production and acetone-butanol-ethanol (ABE) fermentation of glucose and xylose for biobutanol, utilizing Saccharomyces cerevisiae and Clostridium acetobutylicum, respectively. SIcF yielded 0.48 gethanol/gsugars (24 g/L ethanol) with complete glucose consumption and 58.2 % xylose conversion. ABE fermentation produced 0.36 gABE/gsugars (15.7 g/L ABE and 9.5 g/L butanol), with 96 % glucose consumption and 29.6 % xylose conversion. The proof-of-concept demonstrated that the hydrolysates were satisfactorily fermentable by microorganisms, thus validating the pretreatment optimization for fermentation applications.

Study on high-efficiency sulfide removement using sulfate radical-based AOPs and its oxidation mechanism of refractory gold ore

Pyrite enclosure poses a significant challenge in refractory gold ore processing, inhibiting gold leaching. This study explores Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) as an effective alternative for pretreating such ores. The oxidation pretreatments were performed under heat and ultrasound activation methods, including heat and ultrasound, and the influences of pretreatment time, pH, ultrasound power, pretreatment temperature, and precursor (PDS) concentration were investigated. Both ultrasonic and heat activation effectively mitigate the negative impact of pyrite enclosure on gold leaching. Specifically, the gold leaching rate improved from 21.9 % to 46.1 % and 74.9 % with heat and ultrasound activation, respectively The and generated by PDS dominate the pyrite oxidation according to EPR and quenching tests. Meanwhile, the SR-AOPs treatment also promotes the interactions between pyrite enclosure and leaching agent, reducing the negative influences of pyrite. Kinetic studies indicated that the oxidation processes are different under heat and ultrasound activation. Heat activation is governed by an interfacial chemical reaction, with an activation energy of 25.57 kJ/mol. In contrast, ultrasound-induced cavitation and microjets remove the oxidation layer, disrupt the pyrite crystal structure, and expose encapsulated gold. These effects accelerate pyrite oxidation, shifting the kinetic control step from interfacial chemical reaction to internal diffusion, with a reduced activation energy of 35.06 kJ/mol.

Micro-flow cell washing technique combined with single-cell Raman spectroscopy for rapid and automatic antimicrobial susceptibility test of pathogen in urine

Facing the rapid spread of antimicrobial resistance, methods based on single-cell Raman spectroscopy have proven their advances in reducing the turn-around time (TAT) of antimicrobial susceptibility tests (AST). However, the Raman-based methods are still hindered by the prolonged centrifugal cell washing procedure, which may require complex labor operation and induce high mechanical stress, resulting in a pretreatment time of over 1 h as well as a high cell-loss probability. In this study, we developed a micro-flow cell washing device and corresponding Raman-compatible washing chips, which were able to automatically remove the impurities in the samples, retain the bacterial cell and perform Raman spectra acquisition in situ. Results of washing the 5- and 10-μm polymethyl methacrylate (PMMA) microspheres showed that the novel technique achieved a successful removal of 99 % impurity and an 80 % particle retention rate after 6 to 10 cycles of washing. The micro-flow cell washing technique could complete the pretreatment for urine samples in a 96-well plate within 10 min, only taking 15 % of the handling time required by centrifugation. The AST profiles of urine sample spiked with E. coli 25922, E. faecalis 29212, and S. aureus 29213 obtained by the proposed Raman-based approach were found to be 100 % consistent with the results from broth micro-dilution while reducing the TAT to 3 h from several days which is required by the latter. Our study has demonstrated the micro-flow cell washing technique is a reliable, fast and compatible approach to replace centrifuge washing for sample pretreatment of Raman-AST and could be readily applied in clinical scenarios.

Co-production and enhancement of biogas and biohydrogen by optimizing NaOH-urera pretreatment conditions for kitchen waste

Kitchen waste (KW) constitutes a major portion of municipal solid waste, posing an imminent environmental challenge. Given its high water and organic content, KW is suitable for Anaerobic Digestion (AD) prior to its disposal, as it reduces Chemical Oxygen Demand (COD) and simultaneously generates biogas. The unique contribution of this study is the investigation of NaOH-urea pretreatment as a method to enhance AD of KW and sludge, ultimately leading to more efficient and environmentally friendly waste disposal. NaOH-urea pretreatment is selected for its ability to improve hydrolysis, increase organic matter solubilization, and enhance nutrient balance, ultimately boosting biogas yield during AD. Response surface methodology (RSM) was used for optimizing pretreatment conditions. AD experiments were performed batch-wise. For optimization, pretreatment time, temperature, and NaOH-urea concentration were selected as independent variables. RSM results indicated that optimum NaOH-urea concentration, time, and temperature conditions were 30 g/L, 30 min, and −5 °C, respectively. At optimum conditions, cumulative biogas was 316 ml, whereas biohydrogen % (v/v) was 36.21 %. Furthermore, the Modified Gompertz Model (MGM) and Logistic Function Model (LFM) were used to observe the efficacy of NaOH-urea pre-treatment of KW., The reaction kinetics were also discussed. Akaike's Information Criterion was employed to determine which model best fits the obtained experimental data. It was found that MGM is better than LFM for this study. Through experimental investigations and numerical modeling, this research provides insights into optimizing biogas and biohydrogen production from KW.

Microwave-Assisted “One-Pot” Acidolysis and Extraction for the Rapid Determination of Mancozeb in Fruit and Vegetable Samples

Mancozeb is an extensively consumed fungicide, which often leaves high residue levels on agricultural products. The conventional method for detecting mancozeb involves a time-consuming process using gas chromatography (GC) after a 2-hour water-bath acidolysis, resulting in low efficiency and recovery rates. This study developed a rapid method for detecting mancozeb in fruits and vegetables using microwave-assisted acidolysis and extraction coupled with GC analysis. Mancozeb underwent “one-pot” acidolysis to generate CS2 gas and was subsequently extracted from samples using microwave treatment, requiring only 50 seconds of pretreatment time. The average recoveries of mancozeb ranged from 81% to 112%. The limit of detection and limit of quantification were 0.003 and 0.01 mg kg−1, respectively. The scanning electron microscope imaging showed that strong cell crumpling after microwave treatment improved the acidolysis rate significantly, where the acidolysis rate was 91.8% for mancozeb. In addition, this method is rapid, simple, and precise for detecting residues of mancozeb and other dithiocarbamate fungicides.

Drying Kinetics and Thermodynamic Properties of Ultrasound Pretreatment Bitter Melon Dried by Infrared

Determination of drying characteristics of ripe and unripe bitter melon in an infrared dryer at 50, 60, and 70°C with airborne ultrasonic pretreatment with a power of 20 kW for 0, 10, and 20 minutes and a frequency of 20 kHz is the purpose of this study. At the end of drying, among the five used models that fit the moisture ratio data, the Midilli and logarithmic models were selected to properly characterize the drying behavior in the infrared dryer with ultrasonic pretreatment of ripe and unripe bitter melon samples. Moisture transfer from bitter melon samples’ ripeness and early maturity was defined using Fick’s diffusion equation. Then, the Arrhenius equation was utilized to determine the effective moisture diffusivity. Also, the activation energy of unripe and ripe bitter melon slices was reduced with the enhancement in the ultrasound pretreatment time. Water activity (aw) amounts of ripe and unripe bitter melon were achieved at various drying temperatures and ultrasound pretreatment. The trends of the experiment indicate a decrease in enthalpy (ΔH) and entropy (ΔS) amounts of bitter melon with enhancing temperature and ultrasonic. The Gibbs free energy (ΔG) increases with enhancing drying temperature and ultrasonic pretreatment. Specific energy consumption decreased with enhancing drying temperature and ultrasound pretreatment duration for both ripe and unripe bitter melon samples.

Indulging Curiosity: Preliminary Evidence of an Anxiolytic-like Effect of Castor Oil and Ricinoleic Acid.

In the process of validating the elevated zero maze, a common test of anxiety-like behavior, in our laboratory, we demonstrated an anxiolytic-like effect of castor oil and its primary component, ricinoleic acid. We tested the effects of vehicle and chlordiazepoxide in male mice in the elevated zero maze following a 30-min pretreatment time. Chlordiazepoxide is a United States Food and Drug Administration-approved drug that was previously shown to exert anxiolytic-like effects in both the elevated zero maze and elevated plus maze. Chlordiazepoxide was administered at doses of 5 or 10 mg/kg. We used 5% polyoxyl 35 castor oil (Kolliphor® EL) and saline as treatment vehicles and found that the effect of chlordiazepoxide on open zone occupancy and open zone entries was blunted when 5% Kolliphor was used as the vehicle. These tests demonstrated that chlordiazepoxide increased open zone occupancy and entries in the elevated zero maze more effectively when saline was used as the treatment vehicle and that Kolliphor dampened the anxiolytic-like effect of chlordiazepoxide when it was used as the treatment vehicle. Notably, 5% Kolliphor alone slightly increased baseline open zone occupancy and entries. Given that Kolliphor is a derivative of castor oil, we next tested the effect of 5% castor oil and 5% ricinoleic acid, which is a major component of castor oil. We found that both castor oil and ricinoleic acid increased open zone occupancy but not entries compared with saline. Altogether, our findings demonstrate that Kolliphor, castor oil, and ricinoleic acid may exert anxiolytic-like effects in male mice in the elevated zero maze. This potential anxiolytic-like effect of castor oil is consistent with its well-established beneficial effects, including anti-inflammatory, antioxidant, antifungal, and pain-relieving properties.

Physicochemical characterization of rice straw before and after alkali-assist photocatalytic pretreatment: a comparative analysis.

The potential of alkali-assist photocatalytic (AAP) pretreatment to overcome the recalcitrant nature of lignocellulose biomass, i.e. rice straw (RS), was investigated in the present study. Box-Behenken Design (BBD) using standard response surface methodology (RSM) approach was considered to obtain optimal conditions for maximum delignification. The model was designed with three variables: alkali concentration (NaOH, 0-3% w/v), photocatalyst (TiO2 NPs (titania nanoparticles), 0-1g/L) and pretreatment time (30-240min). The availability of cellulose was increased by 96.73%, while the concentration of lignin and hemicellulose decreased by 73.89%, and 71.79%, respectively, at a combination of 1.5% NaOH, 0.5g/L TiO2 NPsand 135 min pretreatment time. The structural and morphological alterations in the RS were assessed via Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) both before and after AAPpretreatment. The FTIR measurement indicated that the original RS included a significant quantity of lignin, which was eliminated after the pretreatment procedure. The XRD pattern demonstrates that cellulose crystallinity is significantly affected by the pretreatment. The SEM analysis revealed structural distortion and surface porosity from the pretreatment procedure.

Effect of alkaline deep eutectic solvents pretreatment on CH4 yield from anaerobic digestion of corn stover

Deep eutectic solvents (DES), comprising hydrogen bond donors (HBD) and acceptors (HBA), are gaining prominence in biomass pretreatment due to their excellent lignin depolymerization capabilities. This study explored the impact of alkaline DES pretreatment, specifically focusing on CH4 yield from corn stover anaerobic digestion. Batch experiments were conducted to assess the influence of ethylene glycol (EG) concentration, pretreatment time, and organic loading rate (OLR) on CH4 yield. Results indicated that these factors markedly affected the cumulative CH4 yield. Subsequent optimization using Box-Behnken design (BBD) significantly enhanced the CH4 yield by 1.16 times, achieving the optimal conditions at 0.4 v/v EG concentration, 33.8 min of pretreatment, and 22.2 w/v OLR. Notably, DMER64 and Methanobacterium emerged as the dominant bacterial and archaeal communities, constituting 40.2 % and 71.9 % respectively. Spearman correlation analysis underscored that enhanced substrate accessibility fostered a hydrogen-based, CH4-producing synergistic metabolic pathway. Alkaline DES pretreatment notably resulted in 20.5 % of the carbon flow being directed to CH4, demonstrating its efficacy in converting corn stover into a viable clean energy source and mitigating the environmental impact of agricultural waste.

Effect of carbon dioxide mineralization curing on mechanical properties and microstructure of Portland cement–steel slag–granulated blast furnace slag ternary paste

To investigate the synergistic effects of steel slag (SS) and granulated blast furnace slag (GBFS) on cementitious systems during carbon dioxide (CO2) mineralization curing. Ternary paste specimens containing SS, GBFS, and Portland cement (PC) were prepared to analyze the influence of drying pre-treatment time and SS–GBFS mixing ratios on mechanical properties, CO2 fixation rate, and microstructure evolution. Results emphasize the significance of appropriate drying pre-treatment in enhancing mineralization degree and compressive strength. At 60 °C drying pre-treatment temperature, extending drying pre-treatment time up to 12 h enhances both compressive strength and CO2 fixation rate. However, beyond 12 h, a decline is observed in both parameters. Moreover, under the optimal drying pre-treatment time, the compressive strength of ternary paste specimens post-mineralization increases with higher SS content, with SS exerting a more pronounced positive effect on CO2 fixation rate and compressive strength compared to GBFS. After 4 h of mineralization curing, specimens with 50% SS and 10% GBFS demonstrate a 13.16% increase in compressive strength and a 9.16% increase in CO2 fixation rate compared to specimens with 10% SS and 50% GBFS. Microscopic test results reveal that the primary crystalline product in ternary paste specimens after mineralization is calcite, with traces of aragonite. The SS–GBFS mixing ratio has minimal effect on the type of reaction products but has a predominant influence on the total content and crystallinity of calcarea carbonica.

Preparation, characterization, and coating effect of bio-active nano-emulsion based on combined plant essential oils on quality of grass carp fillets

This study aimed to develop a satisfactory essential oil (EO) nano-emulsion through high pressure microjet technology and explore its physiochemical properties and synergistic coating effects on grass carp fillets. The optimal conditions for oregano/litsea cubeba (6:4, wt%/wt%) nano-emulsion were shown to be 80 s high pressure microjet pretreatment time, 9000 lb per square inch pretreatment pressure, 6 % oil phase, and 3:2 Km (mass ratio of surfactant to co-surfactant). The obtained nano-emulsion exhibited 100.42 ± 0.96 nm oil diameter at 4 °C after 15-day storage, coupled with high stability after centrifugation, freeze–thaw and heating treatment. Compared with untreated samples at day 6 storage, the nano-emulsion-treated grass carp fillets exhibited improved textural properties, higher water-holding capacity (74.23 % ± 0.80 %), lower total volatile basic nitrogen (TVB-N, 13.46 ± 0.30 mg/100g)/thiobaric acid (TBA,0.43 ± 0.02 mgMDA/100g), and lower total viable spoilage bacteria count (4.98 ± 0.21 lgCFU/g). This study facilitates understanding the combined EOs nano-emulsion on improving the shelf life of grass carp fillets.

Improved determination of nitrate isotopes in irrigated agricultural areas and Bayesian mixing model quantification of nitrate sources and fate

Technological advancements in isotope techniques have been widely utilized in environmental pollution research, particularly for the monitoring of nitrate pollution in water. The utilization of pretreatment with an aqueous nitric acid solution offers numerous advantages in analyzing isotopic composition; however, there is still room for improvement regarding conversion efficiency, reduced reaction time, and cost control. In light of this, this study proposes an enhanced chemical conversion method that involves mitigating the interference caused by the nitrogen azide reaction during the pretreatment process, optimizing the purge gas to remove interfering factors, and improving the inlet device for measuring nitrous oxide. The improved method was applied to determine nitrate isotopes in the Ulansuhai Basin, Inner Mongolia and its reliability was verified through analytical results obtained from bacterial denitrification methods. The mean δ15N-NO3- and δ18O-NO3- values determined using the chemical transformation method were 4.85‰ and 23.44‰, respectively. Compared with the previous method, the improved method enhanced the maneuverability of precise control, the pretreatment time was reduced from 2 to 3 hours to 1.5 hours, and the experimental cost was scaled down to half of the original one. In addition, the contribution of each source was calculated by combining nitrate isotopes with a Bayesian stable isotope mixing model. It was found that manure sewage accounted for (50.1±22.6) % while soil nitrogen sources contributed (25.1±20.4) % to nitrate levels in Ulansuhai Lake's water. The chemical conversion methods successfully improved within this study can also be applied to other watersheds or regions. These research findings provide a valuable theoretical foundation for managing nitrogen sources within watersheds.

Effect of pretreatment temperature and time on fat bonding and fat reduction in deep-fried surimi

Deep frying (DF) is a popular cooking technique resulting in desirable sensory quality. However, DF also results in negative perception related to increased fat uptake and thus poor nutritional quality. In this study, a development of a novel strategy for fat reduction in DF surimi without additives and coatings was attempted. Novel pre-baking and pre-roasting were applied to surimi prior to DF. This novel pre-treatment strategy for DF surimi has not been reported in literature. Total, free, and bonded fat contents and corresponding fat reductions in DF surimi were determined. Cook and moisture losses as well as water holding capacity, expressible moisture, in addition to color and texture were also investigated. Fat uptake during DF of surimi was reduced (P < 0.05) by ≥ 25 % with pre-baking. Pre-baking improved (P < 0.05) or did not (P > 0.05) affect cook and moisture losses, water holding capacity, expressible moisture, color, and texture. However, pre-roasting increased (P < 0.05) fat content and adversely affected most quality parameters. Pre-baking of surimi at lower-temperature (116 °C) for longer-time (12–15 min) followed by DF at lower-temperature (170 °C) for longer-time (4 min) was most optimal for fat reduction, cook and moisture losses, water holding capacity, expressible moisture, color, and texture of surimi.