To clarify the effects of deastringency and 1-methylcyclopropene (1-MCP) treatments on the electrical properties of Diospyros kaki L. Huoshi during storage.

High-concentration short-term CO₂ treatment was applied to Diospyros kaki L. Huoshi for deastringency, and 500 nL/L 1-MCP was used for preservation, respectively, with untreated fruits as the control (CK). Inductance-capacitance-resistance (LCR) impedance analyzer was employed to determine the dynamic changes of impedance, inductance, capacitance and conductance of the treated fruits at 5 frequencies (0.1, 1.0, 10.0, 100.0 and 1000.0 kHz) during room-temperature storage.

The impedance and inductance of Diospyros kaki L. Huoshi showed a power function decrease with increasing frequency, while conductance increased in a power function pattern, and capacitance exhibited a slow decrease followed by fast increase manner. During storage, the impedance and inductance of fruits in all treatments decreased in a linear relationship, and capacitance and conductance increased in an exponential relationship. The frequency of 1.0 kHz was the sensitive frequency for changes in fruit impedance, inductance and capacitance. The 1-MCP treatment significantly inhibited the decrease rate of impedance and inductance, as well as the increase rate of capacitance and conductance. At 1.0 kHz, after 24 d of storage, the impedance and inductance of 1-MCP treated fruits were 60.8% and 59.7% higher than those of the CK, respectively; while the capacitance and conductance were 60.6% and 44.6% of those in CK, respectively. Deastringency accelerated the changing process of electrical parameters: On the 6th day, the impedance and inductance decreased by 88.9% and 88.8% compared with 0 d, respectively; the capacitance and conductance were 9.2 and 15.4 times those on 0 d, respectively.

Deastringency and 1-MCP treatments only alter the time and amplitude of electrical parameter variations in Diospyros kaki L. Huoshi persimmon, but not the pattern;the electrical parameters are sensitive to above 2 kinds of treatments. This study provides a reference for the non-destructive detection of deastringency efficiency and storability and 1-MCP preservation effect of persimmon fruits.

To investigate the intervention effect of different fermentation groups on the model of alcoholic fatty liver disease (AFLD) by optimising the proportion of turpentine Pinus massoniana pollen compound and fermentation strains (morel mushroom and yeast), and to screen the optimal liver protection formula.

The mouse AFLD model was constructed by alcohol liquid feed, and a blank control group, model group, Pinus massoniana pollen+peach kernel unfermented group, Pinus massoniana pollen+peach kernel morel fermented group, Pinus massoniana pollen+peach kernel morel fermented group, Pinus massoniana pollen+peach kernel morel fermented group, Pinus massoniana pollen+peach kernel morel fermented group, Pinus massoniana pollen+peach kernel morel fermented group, Pinus massoniana pollen+peach kernel morel fermented group, yeast fermented group of kudzu root were set up. At the end of the intervention, serum samples were collected to test the levels of triglyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C); liver tissues were collected to determine the levels of hepatic TG, TC, malondialdehyde (MDA) and glutathione (GSH) levels, and liver pathology was analyzed by hematoxylin staining.

After the intervention of different fermentation groups, all of them showed a certain degree of hepatoprotective effect, and the effect was better than that of the unfermented group. Among them, the Pinus massoniana pollen+peach kernel+kudzu root Saccharomyces fermentation group had the most significant effect, followed by the Pinus massoniana pollen+peach kernel morel mushroom fermentation group. The serum TG, TC, ALT, AST and LDL-C levels in the yeast-fermented Pinus massoniana pollen+peach kernel+Pueraria lobata group were (0.62±0.04) mmol/L, (3.13±0.28) mmol/L, (0.68±0.15) U/mL, (2.66±0.31) U/mL and 0.75±0.08 mmol/L, respectively, which were reduced compared with those in the model group, respectively by 32.61%, 31.51%, 71.43%, 20.60% and 54.27%, respectively; and the serum HDL-C content was (2.17±0.32) mmol/L, which was increased by 33.13% compared with the model group. Its liver TG, TC and MDA contents were (0.09±0.02), (0.020±0.002) and(0.34±0.03) mmol/gprot, respectively, which were 55.00%, 45.95% and 37.04% lower compared with that of the model group; its liver GSH content was (9.52±3.25) μmol/gprot, which was 2.15 times higher than that of the model group.

Microbial fermentation can significantly enhance the hepatoprotective efficacy of Pinus massoniana pollen compound combination. Among them, yeast-fermented Pinus massoniana pollen+peach kernel+Pueraria lobata is the optimal solution, followed by yeast-fermented Pinus massoniana pollen+peach kernel, and this study provides experimental basis for the development of functional liver protection products.

To investigate the residual status of dithiocarbamate (DTCs) pesticides in market available vegetables in Hulunbuir in 2024.

In 2024, a total of 144 vegetable samples from 6 kinds of categories, including leafy, root vegetables, fresh legumes were collected from commercial retail chain in Hulunbuir City. The content of DTCs pesticide residues (calculated as CS₂) were determined using solvent absorption gas chromatography-mass spectrometry (GC-MS). Statistical analysis was performed using Excel 2016 and SPSS 20.0 software.

The overall detection rate of DTCs pesticides was 59.03% (85/144), with residue levels ranging from 0.01 to 2.50 mg/kg (calculated as CS₂). Among the vegetable categories, both cabbage vegetables and bulb vegetables exhibited detection rates exceeding 80%, while leafy vegetables showed the highest residue level (2.50 mg/kg). The detection rates in Arong Banner and the main agricultural production areas were significantly higher than in other regions (χ²=33.329, P<0.05; χ²=12.491, P<0.05). In contrast, no statistically significant differences in detection rates were observed between samples from supermarkets and farmers’ markets, or between locally produced and non-local samples.

The detection of DTCs pesticide in commercially available vegetables in Hulunbuir is relatively common. It is recommended to promote scientific pesticide application techniques tailored to regional characteristics, strengthen pesticide residue monitoring, and further refine standard revisions. This study provides a scientific basis for risk assessment.

To clarify the residue characteristics of the novel acaricides cyetpyrafen in different parts of Malus domestica.

Field trials were conducted in accordance with the Guidelines for pesticide residue trials in crops. The 30% cyetpyrafen suspension was used as the test object, and the early-maturing Malus domestica variety Honglu was used as the test material. The whole Malus domestica trees were sprayed with the recommended dose and twice the recommended dose during the occurrence period of Malus domestica mites and before fruit harvest. Samples were randomly collected after spraying. The residues of cyetpyrafen in different parts of Malus domestica at different doses were determined by QuEChERS-high performance liquid chromatography.

Within the mass concentration range of 0.05–5.00 mg/L, the mass concentration of cyetpyrafen in the Malus domestica matrix had a good linear relationship with the response value, and the correlation coefficient was greater than 0.99. In the addition recovery test, the average recovery rate of cyetpyrafen was 98.88%–100.22%(relative standard deviation was 0.34%–0.92%). The detection results showed that the residues of cyetpyrafen mainly adhered to the Malus domestica peel, and the residues conducted to the flesh through internal absorption were very few. The average residue amount showed the trend of peel>whole fruit>flesh. Under the recommended dosage, the residue level in the fruit peel was the highest, reaching 3.19 mg/kg 2 h after application, which was over 3 times the maximum residue limit (MRL) (1 mg/kg). The residue level in the fruit peel dropped to 0.6 mg/kg 5 d after application, below the MRL (1.00 mg/kg), indicating a relatively low safety risk. At twice the recommended dose, the original residue amount in the peel 2 h after spraying was 5.90 mg/kg, which was 1.85 times that of the recommended dose. At twice the recommended dose, the residue amount in the peel 7 d after spraying was 1.11 mg/kg>1.00 mg/kg(MRL), still not meeting the standard.

The Malus domestica peel is the main residue site of etofenprox.The residue amount increases significantly with the increase of the application dose. Applying at doses exceeding the recommended level will significantly increase the residue risk and directly affect the food safety of Malus domestica.It is recommended that during production, the recommended dosage should be strictly followed for application, and the frequency of application should be controlled. It is suggested that a harvest interval of more than 7 d. Consumers can effectively reduce potential risks by peeling the fruit.

To optimize ultrasonic assisted enzymatic extraction of antimicrobial peptides from Carassius auratus scales.

In this study, the diameter of inhibition zone against Escherichia coli and peptide recovery rate were used as evaluation indicators. The enzymatic effects of pepsin, trypsin, papain, and neutral protease on Carassius auratus scales were compared and analyzed to screen the optimal enzyme for enzymolysis.Through single-factor experiments, the effects of substrate concentration, enzyme activity, enzymolysis time, and ultrasonic power on the extraction efficiency of antimicrobial peptides from crucian carp scales were systematically analyzed. On this basis, three key factors (enzyme activity, enzymolysis time, and ultrasonic power) were selected for orthogonal optimization experiments.

Pepsin was identified as the optimal enzyme for enzymolysis. Under the enzymatic hydrolysis process with a substrate mass concentration of 200 mg/mL, enzymatic hydrolysis time of 4 h,ultrasonic power of 120 W, and enzyme activity force of 5000 U/g, the antibacterial effect of the obtained antimicrobial peptide was the best, with a inhibition zone diameter of (2.66±0.66) cm against Escherichia coli and a short peptide recovery rate of 22.52%±1.64%.

The ultrasonic assisted enzymatic extract of antimicrobial peptides from Carassius auratus scales provides a critical theoretical foundation for subsequent separation and purification.

To establish a method for the determination of 9 kinds of stevioside compounds in aquatic products by ultra performance liquid chromatography-tandem mass spectrometry with isotope internal standard.

The sample was extracted with methanol aqueous solution (1:1, V:V), separated on a CSH C₁₈ chromatographic column, and eluted with a gradient. The sample was analyzed in multiple reaction monitoring mode using electrospray negative ionization mode and quantified by internal standard method.

The 9 kinds of stevioside compounds showed good linear relationships in the range of 0.1–100.0 ng/mL. The limits of detection were 2.0 µg/kg, and the limits of quantitation were 5.0 µg/kg. The spiked recoveries of the method at low, medium and high spiked levels showed that the recoveries were in the range of 90.16%–103.69% with the relative standard deviations of 2.24%–6.38%. The method was used to analyze aquatic products, with a detection rate of 12%.

The method is simple, efficient, and highly accurate and sensitive, making it suitable for the determination of 9 kinds of stevioside compounds in aquatic products.

To investigate the influencing factors and optimization strategies for the matrix effects in pesticide residue analysis in Myrica rubra.

Pesticide residues in Myrica rubra were detected using liquid chromatography-tandem mass spectrometry under different conditions: Various sample pretreatment methods, different pesticide and matrix concentrations (low, medium, high), the addition of analyte protectants and varying liquid chromatography flow rates. The impact of these conditions on the matrix effect was analyzed. Analysis of variance (ANOVA) was used to compare the differences in matrix effects under different detection conditions, with a significance level of α=0.05.

Optimizing the pretreatment conditions based on the national standard method—specifically by adding graphitized carbon black adsorbent, replacing the salting-out agent and using acidified acetonitrile—effectively reduced or eliminated the matrix effects. The matrix effects varied with pesticide concentration, showed a weaker effect at medium concentrations (50 μg/L, 100 μg/L) compared to low (5 μg/L, 10 μg/L) and high concentrations (150 μg/L, 200 μg/L). Different matrix dilution factors also resulted in varying matrix effects: High dilution (×100) showed no matrix effect, medium dilutions (×50, ×10, ×5, ×2) exhibited a weak matrix effects, and the undiluted sample extract showed a strong matrix effects. The addition of analyte protectants significantly eliminated the matrix effects compared to the standard method. The matrix effects also differed with liquid chromatography flow rates, with a flow rate of 0.1 mL/min demonstrating a stronger matrix effect compared to 0.3 mL/min and 0.2 mL/min.

When detecting pesticide residues in complex matrices like Myrica rubra using liquid chromatography-tandem mass spectrometry, the matrix effect can be effectively reduced or eliminated by optimizing the sample pretreatment method, selecting appropriate matrix dilution factors and pesticide concentrations, adding analyte protectants and setting compatible flow rates.