Latest ArticlesObjective To establish a screening and quantitative method for illegally added anthraquinone- containing plant laxatives in weight-loss foods. Methods The anthraquinone glycosides in foods were hydrolyzed into anthraquinone aglycones by the acid hydrolysis extraction method, and 8 kinds of anthraquinone aglycones produced by hydrolysis were determined by ultra performance liquid chromatography-Q-trap-tandem mass spectrometry (UPLC-Q-trap-MS). Multiple reaction monitoring (MRM) was used as a probe for detection, and the enhanced product ion scan (EPI) mode was triggered through information dependent acquisition (IDA). External standard method was adopted for quantification. Results The limit of detection of physcion in weight-loss foods was 5.0 mg/kg, and the limit of quantification was 12.5 mg/kg, with a good linear relationship in the range of 0.25-5.00 μg/mL. The limits of detection of the other 7 kinds of anthraquinone aglycones were 1.0 mg/kg, and the limits of quantification were 2.5 mg/kg, and they had good linear relationships in the range of 0.05-1.00 μg/mL, with correlation coefficients r≥0.992. Spike recovery tests were carried out at three concentration levels of 2.5, 5.0 and 20.0 mg/kg (physcion at 12.5, 25.0 and 100.0 mg/kg), respectively. The average recovery rates of the 8 kinds of anthraquinone aglycones were 80.6%-102.0%, and the relative standard deviations (RSDs) were 2.35%-8.80% (n=6). Conclusion This method has the characteristics of simple operation, high sensitivity and high accuracy, and is suitable for the simultaneous rapid screening and accurate quantification of 8 kinds of anthraquinone aglycones.
Objective To analyze and evaluate amino acid composition and content of 10 kinds of livestock meats and products in Hunan Province. Methods Kjeltee2300 automatic nitrogen determinator kjeldahl apparatus was used to determine the proteins in 10 kinds of livestock meats and products in Hunan Province. Amino acid composition was measured using membra Pure GmbH A300 automatic amino acid analyzer. The nutritional value of livestock meats and products was evaluated by the amino acid score method. Results There were 17 kinds of amino acids in livestock meats and products except stewed meat with smallpox fungus without proline and sour soup beef without methionine. The content of protein, amino acids and essential amino acids in stir fried pork jerky with red pepper were the highest, which were 19.50, 15.98, 5.98 g/100 g, respectively. The content of lysine in essential amino acids in 10 kinds of livestock meats and products was the highest, Except for leucine, which had the highest essential amino acid content (1.25 g/100 g) in handmade pig blood meatball, all others had the highest lysine content, which were stewed meat with smallpox fungus (0.24 g/100 g), Pingshang omasum (0.38 g/100 g), sour meat (0.49 g/100 g), sour soup beef (0.80 g/100 g), steamed pork balls with pork heart (0.96 g/100 g), large chunks of beef (1.09 g/100 g), stir fried large pieces of meat with wheat sauce (1.16 g/100 g), stir-fried smoked pork (1.36 g/100 g), stir fried pork jerky with red pepper (1.38 g/100 g) respectively, except the content of leucine in essential amino acids in handmade pig blood meatball was the highest (1.25 g/100 g). The content of lysine in 10 kinds of livestock meats and products except Pingshang omasum (50.67 mg/g protein), including steamed pork balls with pork heart (73.85 mg/g protein), large chunks of beef (80.15 mg/g protein), sour meat (64.47 mg/g protein), stewed meat with smallpox fungus (114.29 mg/g protein), stir-fried smoked pork (87.74 mg/g protein), stir fried large pieces of meat with wheat sauce (70.73 mg/g protein), sour soup beef (77.67 mg/g protein), handmade pig blood meatball (63.19 mg/g protein), stir fried pork jerky with red pepper (70.77 mg/g protein), were higher than the (World Health Organization) WHO/(Food and Agriculture Organization) FAO model value (55 mg/g protein) and ovalbumin pattern value (55 mg/g protein). The limited amino acid in 10 kinds of livestock meats and products was isoleucine or valine. Conclusion Excellent lysine content and high nutritional value in livestock meats and products; it is possible to combine the consumption of foods rich in isoleucine or valine to construct a reasonable diet and enhance their nutritional value.
Objective To establish a method for rapid determination of chromium content in aluminum food packaging based on fiber laser induced breakdown spectroscopy. Methods The sensitivity and limit of detection of laser induced breakdown spectroscopy and flame atomic absorption spectrometry optimized by laser pulse width, energy and baseline were evaluated with reference materials, and the 2 kinds of techniques were applied to the detection of aluminum food packaging samples, and the corresponding results were compared. Results For fiber laser induced breakdown spectroscopy, the time consumption was 2 min, the limit of detection was 5.2 μg/g, and the detected Cr content of coca cola packaging, aluminum foil paper and aluminum box were 45, 22, 21 μg/g, respectively. For flame atomic absorption spectrometry, the time consumption was 4 h, limit of detection was 7.2 μg/g, and the detected Cr content of these 3 samples were 136, 16, 14 μg/g, respectively. Conclusion This method is superior to the conventional flame atomic absorption spectrometry method in terms of analyzing speed, limit of detection and cost, and its detection results of commercial samples are similar to those of flame atomic absorption spectrometry, which proves the reliability of this method and its potential applicability in analysis tasks of limited time and large sample quantity.
Objective To investigate the protective effects of Matricarla chamomilla L. extract on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism by which Matricarla chamomilla L. extract alleviates ALI. Methods Forty-eight male SPF Kunming mice were randomly divided into control group, LPS group, dexamethasone (DEX) group, and low, middle and high doses of Matricarla chamomilla L. extract groups. The mice in each group were first continuously administered by gastric gavage for 7 days, and dexamethasone was administered intraperitoneally in the dexamethasone group 5 mg/kg. Matricarla chamomilla L. extract was administered 85, 170 and 340 mg/(kg·d) for gastric lavage in the low, medium and high dose groups, respectively. Mice of all groups, except those of control group, were induced into ALI mouse model by intratracheal instillation of LPS. Subsequently, the mice were subjected to the determination of their levels of the inflammatory factors tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β) in bronchoalveolar lavage fluid (BALF) and perform Giemsa staining and white blood cell count on the BALF sediment. The content and activities of malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were detected. Lung tissue was taken and the pathological morphology of the inferior lobes of the right lung was observed. The expression levels of Toll-like receptor 4 (TLR4), recombinant myeloid differentiation factor 88 (MyD88), nuclear factor-kappa B (NF-κB) in lung tissue were detected. Results Compared with the blank group, the alveolar lavage fluid of LPS model group mice TNF-α, IL-6, IL-1β, White blood cell count and serum MDA content significantly increased (P<0.05), serum SOD significantly decreased (P<0.05), HE staining showed severe interstitial inflammation infiltration in the lungs, structural damage and abnormal morphology of lung tissue, protein expression levels of TLR4, MyD88, NF-κBp65 in lung tissue of mices increased (P<0.05). Compared with the LPS model, the levels in mice of each treatment group TNF-α, white blood cell count, and serum MDA contents were significantly reduced (P<0.05), while serum SOD content was significantly increased (P<0.05). HE staining showed a decrease in inflammatory cell infiltration in mouse lung tissue, clearer alveolar spaces, more complete lung tissue morphology, and protein expression levels of TLR4, MyD88 and NF-κBp65 in lung tissue of mice decreased (P<0.05). Conclusion Matricarla chamomilla L. extract can alleviate LPS induced pulmonary inflammation and overactivation of oxidative stress, thereby alleviating ALI in mice. Among them, a dose of 170 mg/(kg·d) has a better effect, and pathway such as TLR4/MyD88/NF-κB.
Objective To establish a method for the determination of ethylenediaminetetraacetic acid ferric sodium salt (NaFeEDTA) by microemulsion liquid chromatography. Methods After simple dilution and centrifugation of the sample, it could be filtered through a 0.22 μm microporous membrane and directly loaded onto a Waters BEH C18 column (2.1 mm×150 mm, 1.7 µm) was the chromatographic column. The microemulsion mobile phase was 3.64 g/L cetyltrimethylammonium bromide-50 g/L acetonitrile-8 g/L ethyl acetate-6.8 g/L potassium dihydrogen phosphate. The flow rate was 0.30 mL/min and the detection wavelength was 254 nm. The column temperature was 30 ℃ temperature. External standard method was used for quantitative determination. Results Under the selected experimental conditions, the mass concentration of NaFeEDTA had a good linear relationship (r≥0.999) within the range of 0.50-35.00 µg/mL, the limits of detection were 50 mg/kg. The recovery rates of NaFeEDTA were investigated, with average recovery rates ranging from 92.7% to 97.7%. Conclusion This method is easy to operate and has good reproducibility. The method can be used for the detection of NaFeEDTA content in soy sauce.
Objective To investigate the effects of cured meat products on the gut microbiota of mice based on high-throughput sequencing technology. Methods Mice were randomly divided into 3 groups, with half male and half female. Each group consisted of 12 mice, including the control group, the low-dose group, and the high-dose group, and feeding for a period of time. The feces and intestinal content of mice were collected for microbial structure research, and the effects of consuming cured meat on the gut microbiota of mice was analyzed. Results There was no significant difference in total bacterial count between the control group and the experimental group (P>0.05), however the changes in the number of Gram negative bacterial colonies and Gram positive bacterial colonies were significant (P<0.05). The number of lactic acid bacteria in the high-dose group showed significant changes (P<0.05), while the low-dose group had no significant changes (P>0.05). The high-throughput sequencing analysis of 16S ribosomal RNA (16S rRNA) in the gut microbiota of mice showed that the alpha diversity of the gut microbiota in the high-dose group was significantly lower than that in the control group (P<0.05) starting from the 4th week of the experiment, and starting from 12th week, that of the low-dose group also began to decrease significantly. The types of bacteria that changed in the gut microbiota of mice in the high-dose and low-dose groups were almost the same, with an increase in the proportion of Gram positive bacteria, an increase in the relative abundance of Bacteroidetes and Spirochetes, and a decrease in the relative abundance of Lactobacillus. Starting from the 4th week of the experiment, there were differences in metabolic pathways between each group of mice in terms of glucose metabolism, amino acid metabolism, protein metabolism, etc. The differences were self-compensated at the 8th week, and significant differences were observed between the high-dose and low-dose groups and the control group at the 12th week (P<0.05). The differences between the high-dose and low-dose groups increased. Conclusion Continuous intake of cured meat products can change the structure and composition of the gut microbiota, cause imbalance in the gut microbiota structure, and alter the colonization of beneficial and harmful microbiota in the intestine of mice, which may be related to the induction of intestinal diseases.
Objective To establish a method for rapid determination of 58 kinds of pesticide residues in animal derived foods by QuEChERS-gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods After dissolving the oil and fat in n-hexane, the sample was subjected to ultrasonic extraction with a saturated acetonitrile solution (containing 1% glacial acetic acid). The extract was purified with anhydrous magnesium sulfate, octadecyl bonded silica gel (C18), and N-propylethylenediamine (PSA), and then nitrogen was blown to near dryness in a water bath. An internal standard was added and dissolved in ethyl acetate. GC-MS/MS was used for determination, and the blank matrix matching standard curve internal standard method was used for quantification. Results The linear relationship between 58 kinds of pesticides was good within the mass concentration range of 0.005-0.500 mg/L, with correlation coefficients (r2) greater than 0.9945. The limits of detection and limits of quantification were 0.001-0.005 mg/kg and 0.002-0.015 mg/kg, respectively. The average recovery rates of pork, chicken, fish, eggs and milk matrices at 3 different spiked levels ranged from 71.8% to 117.4%, with relative standard deviations of 0.7% to 8.7% (n=4). Conclusion This method has high sensitivity and good accuracy, and is suitable for simultaneous determination of 58 kinds of pesticide residues in animal derived foods.
Objective To elucidate the influence of pH treatment on the structural and functional properties of Solanum tuberosum L. protein. Methods Solanum tuberosum L. protein was selected as the research subject, and the effects of pH on its physical and chemical properties, structure, and conformation were analyzed by fluorescence spectroscopy, Fourier transform infrared spectroscopy, particle size and potential analysis, and scanning electron microscopy. Results Significant differences were observed in the protein subunit composition, particle size distribution, and potential values following treatments at different pH levels. Compared to pH 7, pH 10 enhanced the electrostatic repulsion of Solanum tuberosum L. proteins, significantly increasing protein solubility and viscosity to 89.2% and 19625.0 mPa·s, respectively. Additionally, λmax in the endogenous fluorescence spectra of the proteins shifted to 343 nm, exposing more hydrophobic groups. The particle size of protein molecules decreased to 123.2 nm, while the absolute value of the Zeta potential increased to 41.3 mV. Protein molecules formed intramolecular disulfide bonds, leading to an increase in the denaturation temperature to 82.22 ℃. At pH 2, the protein aggregated and formed soluble aggregates while unfolding. However, viscosity decreased to 1860.6 mPa·s, λmax in the fluorescence spectrum shifted to 341 nm, particle size increased to 369.3 nm, the absolute value of the Zeta potential decreased to 8.97 mV, and the number of disulfide bonds did not change significantly. This resulted in insufficient stability of Solanum tuberosum L. protein under acidic conditions, with a tendency for aggregation. Conclusion Different pH treatments can enhance the physicochemical properties of Solanum tuberosum L. protein, and this study aims to offer scientific guidance for its application in food processing.
Carthamu stinctorius L. serves as a viable raw material for health supplements but is not classified as a general food item. It is rich in bioactive compounds such as flavonoids, alkaloids, and organic acids. Carthamu stinctorius L. exhibits significant benefits including enhancing immunity, providing antioxidant properties, maintaining healthy blood lipid and glucose levels, improving chloasma, alleviating physical fatigue, delaying aging, aiding memory improvement, and offering auxiliary protection against chemical-induced liver injury. Consequently, it has garnered considerable attention from researchers and consumers both domestically and internationally. Currently, Carthamu stinctorius L. is extensively utilized in health supplements within our country; however, there is a lack of systematic analysis regarding its application. This paper aims to examine the current status of Carthamu stinctorius L. is application in health supplements, the regulatory framework for its compliant use, and the factors influencing the efficacy of its primary active components. Additionally, it delves into the principal health functions and mechanisms of Carthamu stinctorius L., with the objective of providing insights for compliant utilization and future research and development of Carthamu stinctorius L. in the health supplement industry within our country.
Objective To investigate the effects of different storage methods on the quality safety of high-moisture harvested Zea mays L.. Methods The Zhengdan 958 (ZD958) Zea mays L. variety was selected for the experiment, and the Zea mays L. harvested under the same moisture content was stored as ear Zea mays L. and grain Zea mays L.. Changes in fungi species, quantity, and mycotoxin content were measured. Results Predominant fungi during Zea mays L. storage were Fusarium, Aspergillus, and Penicillium. In the early stage of storage, the dominant fungal genus was Fusarium, and with the extension of storage time, the dominant fungal genera changed to Aspergillus and Penicillium; with the increase of storage days, the total number of fungi in Zea mays L. stored in ear and grain storage showed a trend of first increasing and then decreasing. The number of fungi in Zea mays L. stored in ears was significantly lower than that in Zea mays L. stored in grains (P<0.05). During the storage period of 10-100 days, the number of fungi in Zea mays L. stored in ears decreased by 90.3%-98.6% compared to Zea mays L. stored in grains; with the increase of storage days, except for gibberellin in Zea mays L. kernels stored in ear, the content of vomitoxin and gibberellin in Zea mays L. showed an increasing trend. The content of vomitoxin and gibberellin in Zea mays L. stored in ears was significantly lower than that in Zea mays L. stored in grains (P<0.05). And with the increase of storage days, the difference in the content of vomitoxin and gibberellin in Zea mays L. under the two storage methods increases. Conclusion After high-moisture harvesting, ear storage can reduce fungi quantity and mycotoxin content, ensuring the quality safety of Zea mays L..