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To explore the responses of soil microbial communities to concentration gradients of antibiotic residues in soil, 32 soil samples were collected from a typical greenhouse vegetable production base in Northern China in 2019. The total concentrations of 26 antibiotic residues in these soil samples was 83.24–4237.93 μg·kg−1, of which metabolites of tetracyclines were 23.34–1798.80 μg·kg−1. The total concentrations in 32 samples were clustered into three levels (L: 300 μg·kg−1) to elucidate the impacts of antibiotic residues on the diversity, structure, composition, function and antibiotic resistome of soil microbial community. Results showed that higher concentration of antibiotic residues in soil was prone to decrease the diversity and shift the structure and composition of soil microbial community. Antibiotic resistome occurred in soils with antibiotic residues exceeding 300 μg·kg−1. Interactions among soil bacteria followed the order of H > L > M, consistent with the relative abundances of mobile genetic elements. Bacteroidetes and Firmicutes were the top attributors impacting the profile of antibiotics in soil. According to weighted comprehensive pollution index of risk quotient, in 28.1 % of soil samples the residual antibiotics presented high ecological risk, whereas in the rest of soil samples the ecological risk is medium. The results will enrich the database and provide references for antibiotic contamination control in soils of the region and alike.

The present study was conducted to evaluate the anti-inflammatory activity of florfenicol (FFC) against lipopolysaccharide (LPS)-induced inflammatory responses in Ctenopharyngodon idella in vivo and in vitro. Head-kidney (HK) macrophages were pre-treated with 10 μg/mL LPS and then exposed to different concentrations of FFC to determine its in vitro anti-inflammatory activity. Inhibitory effect of FFC on inflammatory mediators TNF-α, IL-6 and IL-1β, as well as LPS-induced nitric oxide (NO) and prostaglandin E 2 (PGE 2) production were assayed by ELISA. The expression level of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were investigated by RT-PCR. Expression level of TLR-related genes (TLR1, TLR2, TLR4, TLR7, TLR8) expression, tumor necrosis factor receptor-associated factor 6 (TRAF6), transforming growth factor-b-activated kinase 1 (TAK1), Myeloid differentiation factor 88 (MyD88), nucleus p65, NF-κBα (IκBα) were measured by RT-PCR after grass carp were treated with 50, 100 and 200 mg FFC/kg body weight for 3 days. Results from in vitro tests demonstrated that FFC dose-dependently inhibited LPS-induced inflammatory cytokines TNF-α, IL-6 and IL-1β, inflammatory factors NO and PGE 2 production in macrophages. In addition, iNOS and COX-2 expression levels decreased significantly as compared with LPS treated group. In vivo test demonstrated that treatment with FFC prevented the LPS-induced upregulation of TNF-α, IL-6, IL-1β, NO and PGE 2. The expression level of iNOS, and COX-2 in FFC-treated grass carp were also downregulated as compared with LPS treated fish. Besides, FFC blocked the expression of Toll-like receptor 2 (TLR2) and then suppressed the phosphorylation of nuclear transcription factor-kappa B (NF-κB) p65 and degradation inhibitor of IκBα. Furthermore, administration of FFC inhibited the up-regulation of IRAK4, TRAF6 and TAK1 induced by LPS. These results suggest that the anti-inflammatory properties of FFC might be the results from the inhibition of iNOS, COX-2, IL-6, IL-1β, and TNF-α expressions through the down-regulation of Toll/NF-κB signaling pathways.

A facile single hydrothermal method was developed to synthetize P,N codoped carbon dots (P,N/CDs), which show strong and stable fluorescence, good water solubility, low toxicity and good biocompatibility. Hence, a novel and efficient “off-on” P,N/CDs fluorescent probe was developed for the highly sensitive detection of lipoic acid (LA) for the first time. The fluorescence of the P,N/CDs was quenched by Cu2+ forming a P,N/CDs-Cu2+ complex, which acted as the “off” process, but Cu2+ could be removed by LA, due to stronger chelating between LA and Cu2+, forming a more stable complex, which recovered the fluorescence of the P,N/CDs, in order to achieve the “on” process. Under optimal conditions, the concentration of LA and the increased fluorescence intensity of the P,N/CDs-Cu2+ complex displayed a good linear relationship within the range of 0.05–28 μM, with a detection limit (S/N = 3) of 0.02 μM. The established “off-on” fluorescent probe was successfully applied to the analysis of LA in urine samples. The average recoveries were in the range of 98.3–101.5%, with a relative standard deviations of less than 3.1%. In addition, the P,N/CDs were also successfully applied to cellular dual-color imaging of live T24 cells. The results show that the P,N/CDs have great application potential in clinical diagnosis, bioassay and bioimaging.

A rapid method for the determination of residues of chloramphenicol in tilapia by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. The samples were extracted with acetonitrile, and separated on a C18 column using methanol-water solution as mobile phase, and then detected under ESI- multiple reaction monitoring mode. The method showed a good linearity for the analysts over the range of 0.1-100μg/L. The detection limits were 0.10μg/kg. The recoveries ranged from 88.6% to 108% at spiked concentrations with the relative standard deviations lower than 5%. The results shows that this method has the advantages of easy to operate, fast to perform, with high sensitivity and accuracy, and it is suitable for detection of residues of chloramphenicol in tilapia.

The aim of this work was to establish a method that the residues of fungaltoxin including citrinin, alternariol and alternariolmethylether in bergamot pears were determined by UPLC-MS/MS. Samples were extracted by acetonitrile, using NaCl and anhydrous Magnesium Sulfate to remove the water, and C18 powder was used to purify and get rid of miscellaneous, then used organic membrane to filter the samples. Results showed that the detection limits of citrinin alternariol, and alternariolmethylether were 0.3 μg/kg, 0.5 μg/kg and 0. 2 μg/kg respectively. The average recovery rates of alternariolmethylether, alternariol, citrinin were 79%∼ 101%, and the relative standard deviations were between 0.3%∼4.5%.

A method for the determination of retrorsine in orange peel by ultra performance liquid chromatography tandem mass spectrometry (LC-MS/MS) was established. The acetonitrile (containing 0.1% formic acid) was extracted, ionized by electrospray ionization with positive ion mode and determined by multi-reaction monitoring mode. The results showed a good linearity in the range of 0.2-2.0 ng/mL, and the correlation Coefficient R2 was 0.998453. The average recoveries of the three additive levels were more than 70% and the RSD was 0.19%-1.57%. The method was sensitive and rapid, and could be used for the determination of retrorsine in orange peel by ultra performance liquid chromatography tandem mass spectrometry.

In the present context, the objective of this study was to synthesize and analyze the content of AA of macadamia protein and the impact of hydrogen ion concentration (pH) on AA composition. The determination of AA mainly by cation-exchange chromatography was also investigated. Reproducible and reliable techniques for quantification and identification of AA usually require derivatization. However, techniques such as AA analyzer are composed of cation-exchange chromatography and other components can sideline the derivatization with significant accuracy. The present analysis revealed a higher concentration of essential amino acids especially acidic AA, Glu and Asp and basic AA, Arg than other AA in macadamia protein. The study constitutes first report of use of bubble chart for evaluation of AA and explaination of AAS. The results may elaborate that the degradation of AA of macadamia protein for extraction of pH 11 is caused by the impact of pH. Moreover, the nutritional values of AA present in macadamia protein could change for the better by adjusting pH of extraction.

In order to determine the optimization of test conditions for TPA texture properties of avocado flesh, the method of TPA was used to explore the effect of different compression locations and test parameters on the texture properties. The results showed that the middle part of the avocado flesh was the best part for testing the texture properties. through the correlation analysis of the measured values of texture properties by the avocado flesh, the hardness, springiness and cohesiveness were determined as the key investigation indications. The compressed speed had a significant effect on hardness and cohesiveness, and the compression distance had a significant effect on hardness and springiness. The optimization test parameters of avocado flesh were compression speed of 1mm/s and compression distance of 8 mm.

The current work aims to develop a method for the determination of acrylamide in baked and fried foods using high performance liquid chromatography-mass spectrometry (UPLC-MS/MS). In this study, the extraction of acrylamide was using water and then cleaned up on a HLB and MCX SPE cartridge, followed by separating on a [Waters ACQUITY UPLC BEH C18 (100 mm×2.1 mm, 1.7 μm)] column using acetonitrile and 0.1% formic acid as mobile phase. Thereafter, the concentration of acrylamide was determined in multiple reaction monitoring mode, usingD3-acrylamide as internal standard. It was found that the proposed calibration curve was linear in the range of 0.1 to 100 μg/L with a correlation coefficient greater than 0.99 indicating a very good linearity. The limit of detection (LOD) was 5.0 μg/kg and the quantitative limit (LOQ) was 10.0 μg/kg. The average recovery at three spiked levels (5, 20 and 100 μg/kg) of roasted coffee and deep-fried dough sticks was ranged from 88.0 % to 106 % with RSD smaller than 6%. The method was also tested by analysing acrylamide in baked and fried food samples (biscuits, roasted coffee, cake, fried potato, potato chips and deep-fried dough sticks). The acrylamide concentrations were found between 28 μg/kg and 635 μg/kg in those samples. Taken together, the developed method has superior for determination of acrylamide in baked and fried foods samples, which is of simplicity, high accuracy and good stability.

A survey of biogenic amine species and content of traditional Chinese Li Nationality Shanlan liquor was carried out. Eight major biogenic amines including histamine, cadaverine, tryptamine, putrescine, tyramine, phenylethylamine, spermidine and spermine were separated by reversed-phase HPLC-DAD on Inertsil ODS-SP column after pre-column derivatisation with dansyl chloride. The results showed the eight biogenic amines were not distributed in Shanlan liquor, and the content and type of biogenic amines in different Shanlan liquors were different. Overall, total content of biogenic amines ranging from 1.02 to 38.42 μg/g were within the safe level for human health.

In this work, a convenient, sensitive method for simultaneous monitoring of malachite green, leucomalachite green in tilapia samples was developed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The tilapia samples were extracted by acetonitrile, separated withacetonitrile-5mmol/L ammonium acetate as mobile phase, and then detected under ESI+ mode. The method showed a good linearity for all the analysts over the range of 0.1-100 μg kg-1 with r2≥0.998. And the detection limits both were 0.10 μg kg-1 for Malachite green and leucomalachite green. Tests for recovery were made by addition of standards at four different concentration levels (0.5, 2.0, 10.0, 20.0 μg kg-1) to the blank sample. The recoveries of the four spiked concentrations were ranged from 81.5% to 104%, with the relative standard deviations lower than 5%. The sensitivity, accuracy and precision of this method were able to meet the requirements for malachite green and leucomalachite green residue analysis.

The fermentation process of pineapple fruit wine was studied. The juice was inoculated with 5% (v/v) active yeast and held at 20 °C for 7 days. Total sugar and pH decreased while the alcoholic strength increased with increasing length of fermentation. The fermented fruit wine contains 2.29 g/L total acid, 10.2 % (v/v) alcohol, 5.4 °Brix soluble solids, pH 3.52. Pineapple wine detected 68 kinds of aroma components, including 34 esters, 13 alcohols. The ester material accounted for 52.25% of the main aroma components. The quality and sensory evaluation results indicated that pineapple fruit wine belongs to a kind of low alcohol wine, so it is easy to be accepted by the public.