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, λ_max 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, λ_max 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.

Objective To study the change of benzoic acid content in water extract of Paeoniae Radix Alba after decocting, and the influence of different decocting time on the content of benzoic acid. Methods The raw materials were decocted separately or in combination, and concentrate to a density of 1.15-1.20, the content of benzoic acid in the water extract after decocting and concentrating was determined by high performance liquid chromatography. Results Benzoic acid content was not detected (limit of quantification was 0.01 g/kg) in Paeoniae Radix Alba, the benzoic acid content in concentrated liquid of paeony increased to 2.91-3.77 g/kg after single decocting, and the benzoic acid content after two-stage decocting ranged from 3.26 g/kg to 4.02 g/kg. The content of benzoic acid in the mixed concentrate containing Paeoniae Radix Alba was 0.542 g/kg. Benzoic acid was not detected in others. Conclusion The content of benzoic acid in water extract of Paeoniae Radix Alba increased after high temperature decocting, and it's proportional to time. Therefore, when preparing food or health products with Paeoniae Radix Alba as the main raw material, attention should be paid to the control of decocting temperature and time, and the factory inspection of this item should be increased to prevent the harm caused by high content of benzoic acid.

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 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 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..

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 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 based on real-time fluorescent polymerase chain reaction (PCR) for the identification of the genus Cipangopaludina and Bellamya, and identify the snail-derived ingredients in the meat soup package of river snail rice noodle. Methods Specific primers and probes were designed using mitochondrial genes from the genera Cipangopaludina and Bellamya, respectively. The effectiveness of the established real-time fluorescence PCR method was evaluated for its specificity, sensitivity and repeatability. Results The real-time fluorescence PCR identification method developed in our study exhibited strong specificity, detecting fluorescence signals only in the designated channel for the DNA of the Cipangopaludina and Bellamya, with typical amplification curves observed. No fluorescence signals were detected in the designated channel for the genomic DNA of various heterogeneous animals and plants, including aquatic products, poultry, livestock, and spice and seasoning raw materials, with no observable amplification curves. The method demonstrated sensitivity as low as 0.002 ng/μL for Cipangopaludina and 0.001 ng/μL for Bellamya. The method was employed to analyze DNA extracted from snail meat soup packets in 21 batches of prepackaged river snail rice noodle across various brands in supermarket distribution. In 7 batches of prepackaged river snail rice noodle from different brands, Cipangopaludina components were detected in the DNA of the snail meat soup packets, representing 33.3%. In 18 batches of prepackaged river snail rice noodle from different brands, Bellamya components were detected in the DNA of the snail meat soup packets, representing 85.7%. In 3 batches of prepackaged river snail rice noodle from different brands, neither Cipangopaludina and Bellamya components were detected in the DNA of the snail meat soup packets, accounting for 14.3%. In 7 batches of prepackaged river snail rice noodle from different brands, both Cipangopaludina and Bellamya components were detected in the DNA of the snail meat soup packets, representing 33.3%. Conclusion This method boasts strong specificity and high sensitivity, effectively identifying snail-derived components in snail meat soup packets of river snail rice noodle, thereby providing robust technical support for market regulation.

Objective To establish a detection method for simultaneously detecting 9 kinds of biogenic amines in aquatic products using the dansyl chloride precolumn derivazation-reverse phase high performance liquid chromatography. Methods The samples were extracted with a 5% trichloroacetic acid solution and derivatized with a 10 mg/mL dansyl chloride acetone solution. The derivatization reaction was terminated with ammonia, and the resulting solution containing the dansyl chloride derivatives of the 9 kinds of biogenic amines was made up to volume with acetonitrile. The sample solution was analyzed by reverse phase liquid chromatography using a C₁₈ column, with a mobile phase gradient of acetonitrile and water, and detected at 254 nm using a ultraviolet detector. Results The limits of quantitation of the 9 kinds of biogenic amines in aquatic products ranged from 1.08 to 7.59 mg/kg, with recovery rates ranging from 85.2% to 106.7% and precision ranging from 1.5% to 4.9%. The established method was used to analyze 50 batches of high-histamine fish sold in Guangzhou. The results revealed that the overall quality of the high-histamine fish in Guangzhou was good. β-phenylethylamine and cadaverine had relatively higher detection rates compared to other biogenic amines, but their content was all below 35 mg/kg. Histamine, putrescine, spermidine, agmatine, and arginine were not detected. Conclusion The method is fast, simple, and highly sensitive, making it suitable for batch sample determination of the 9 kinds of biogenic amines in aquatic products.

Objective To study the effects of deep eutectic solvent (DES) on the absorbance of tea polysaccharide by visible spectrophotometry, and establish a fast and efficient method for the determination of tea polysaccharide. Methods Choline chloride/DL-tartaric acid was used as the extraction solvent of tea polysaccharide. The influence of DES on the determination of tea polysaccharide content in anthrone sulfuric acid and phenol-sulfuric acid 2 kinds of detection methods was investigated. The linear relationship, precision, stability, repeatability and standard recovery rate of the 2 kinds of detection methods were compared. Results The best method for the determination of tea polysaccharides was phenol-sulfuric acid method, the optimal detection wavelength was 484 nm, and the absorbance had a good linear relationship with glucose concentration between 20 and 100 μg/mL. The precision relative standard deviation (RSD) of this method was 0.10%, the stability RSD was 0.00%, the repeatability RSD was 2.40%, and the recovery rate was 94.25%-111.19%, and the content of tea polysaccharide was 54.76 mg/g. Conclusion Phenol-sulfuric acid method is suitable for the determination of tea polysaccharide in tea with DES as extraction solvent.