As one of the famous teas in China, Pu’er tea has a high reputation at home and abroad. As one of the main active components in tea, tea polyphenols have the effects of lipid-lowering, anti-inflammatory, regulating intestinal microflora, anti-oxidation, anti-cancer, inhibiting viral infection, and anti-bacteria. It has broad application prospects in many fields such as food and medical treatment. With the in-depth development of research and the continuous discovery of new functions of tea polyphenols, it has firmly occupied an important position in contemporary human life in the 21 st century and has attracted the attention of many researchers. In this paper, systematically reviewed the content determination method of tea polyphenols in Pu’er tea and the related research on biological activity in disease prevention and improvement by consulting the relevant literatures published at home and abroad in recent years. The purpose of this review is to provide a scientific basis for the targeted research of tea polyphenols in Pu’er tea, which is conducive to the better use of tea polyphenols in Pu’er tea, so as to provide a positive reference for the innovation and development of Pu’er tea related industries in China.

Objective To establish a rapid analysis method based on solid phase extraction-high performance liquid chromatography-evaporative light scattering detection (SPE-HPLC-ELSD) for determining the γ-aminobutyric acid (GABA) content in edible enzymes from medicinal and edible homologous sources. Methods Fermented panacis quinquefolii radix liquid was selected as a representative sample. After centrifugation (8000 r/min, 10 min) and ultrasonic extraction (10 min, 25 ℃), 3 kinds of different sample pretreatment methods—non-purification, dispersive solid phase extraction purification, and hydrophilic-lipophilic balance (HLB)-based solid phase extraction purification were compared and optimized. An optimized HPLC-ELSD instrumental method was developed to achieve accurate content determination. The method was then applied to determine the GABA content in other medicinal and edible homologous enzyme products. Results GABA was determined by optimized SPE-HPLC-ELSD. GABA showed a good linear relationship (r=0.999) in the mass concentration range of 50-2000 μg/mL. The recovery rate ranged from 85.93% to 96.30%, with a repeatability relative standard deviation of 0.87% (n=6). Conclusion This method is efficient and accurate, suitable for the quantitative analysis of GABA in various medicinal and edible homologous enzymes. It also provides a new approach and reference for GABA determination in complex matrices and for detecting small molecules with strong polarity and low ultraviolet absorption.

Objective To gain a more intuitive understanding of the academic context and evolutionary trends of the ion mobility spectrometry applied in the field of food science. Methods This study took the literature from the Web of Science core database over the past 15 years as the research object, and used bibliometric analysis methods to reveal the current status, hotspots and development trends of research in this field. Results Our study had shown that the number of publications on the application of ion mobility spectrometry in food science research is constantly increasing, which involves the interdisciplinary fields such as chemistry, nutrition, biochemistry, agriculture, spectroscopy, environment and pharmacy beyond food science and technology. The number of the China’s publication was far ahead, and its institutions had great international discourse power, but the personal academic influence of Chinese authors still needs to be improved. At present, the main hotspots included the studies on different food qualities and flavors, metabolomics, volatile (organic) compounds and enrichment, optimization of instrument parameters and conditions, statistical methods, sample identification and classification, and multiple instrument combination analysis based on the application of ion mobility spectrometry. The co-occurrence, clustering and emergence analysis of the keywords further reveal the evolution process and mutation situation of research hotspots. Conclusion This study can provide theoretical basis for experts and scholars in the fields of food science and analytical chemistry to grasp the international application status and future development trends of ion mobility spectrometry.

Objective To establish an ultra performance liquid chromatography-photodiode array detector method to analysis 3 kinds of furanocoumarins in dried citrus slices. Methods The samples were ultrasonically extracted with 40 mL ethyl acetate for 40 min twice. Vortex-assisted extraction were then repeated twice using 20 mL of ethyl acetate for 10 min. The ethyl acetate extracts were combined, concentrated to dryness in a rotary evaporator at 30 °C. The determination was carried out using an Acquity UPLC HSS C₁₈ SB column (2.1mm×150 mm, 1.8 μm) with a flow rate of 0.3 mL/min, column temperature of 30 ℃, and detector wavelength of 310 nm. A gradient elution was performed with mobile phase A water and acetonitrile as mobile phase B. Results The 6’,7’-dihydroxybergamottin, epoxybergamottin and bergamottin showed good linearity within 3.00~300.00 μg/mL, 4.32-432.00 μg/mL and 4.12-412.00 μg/mL with correlation coefficients greater than 0.999. The limits of detection were 0.09-0.17 μg/g. The limits of quantitation were 0.31-0.57 μg/g. The average recoveries with 3 concentration levels were 94.4%-99.1%. The relative standard deviations were between 2.7% and 4.7% (n=6). This method could separate 3 kinds of furanocoumarins in dried citrus slices well in 25 minutes. The developed method was successfully applied to determine 3 kinds of furanocoumarins in 18 kinds of dried citrus slices and powders. The content of 6’,7’-dihydroxybergamottin was between 1.52 and 159.04 μg/g. The content of epoxybergamottin was between 49.57 and 60.09 μg/g. The content of bergamottin was between 1.49 and 248.71 μg/g. Conclusion The established method has good repeatability and high accuracy, and can be used for the 3 kinds of furanocoumarins determination in dried citrus slices.

Objective To explore the distribution of metal elements in honeycomb and the potential food safety risks. Methods In this study, flame atomic absorption spectrometry was used to determine the content of Cd, Fe, Cr, Mg, Zn, Cu, Mn and Pb in 7 parts (nest membrane, nest column, nest wall, whole nest, adult bee, nest bottom, pupae) of honeycomb samples collected from Yunnan, Guangdong and Guangxi. Results The standard curves exhibited excellent linearity with correlation coefficients (r²)≥0.993, and the method sensitivity met trace detection requirements (limits of detection: 0.002-0.010 mg/kg). Significant differences in metal content was observed among different parts of the honeycombs (P<0.05), with the average concentrations ranked as Mg (0.97 mg/kg)> Zn (0.15 mg/kg)>Mn (0.051 mg/kg)>Cu (0.0385 mg/kg)>Fe (0.02 mg/kg) >Cd (0.0060 mg/kg)>Pb (0.00027 mg/kg)> Cr (0.00003 mg/kg). The distributions of Cd, Fe, Mg, Zn, Cu and Mn showed significant variations across parts (P<0.05), whereas Cr and Pb exhibited no significant differences (P>0.05). The results suggestted that the distribution of essential elements (Mg and Zn) was closely associated with the biological functions of honeycombs, while the localized accumulation of Cd and Pb might reflect environmental contamination. Conclusion This study systematically reveals the spatial distribution characteristics of metal elements in honeycombs, providing a scientific foundation for quality control of bee products and traceability of environmental pollutants.

Objective To evaluate of the effects of drying methods on the quality of Astragalus membranaceus based on technique for order preference by similarity to an ideal solution analysis. Methods In this study, 6 kinds of drying methods including hot air drying (HAD), heat pump drying (HPD), carbon fiber far infrared combined heat pump drying (CFFCHPD), medium short wave infrared drying (MSWID), vacuum pulsating drying (VPD), and vacuum freeze-drying (FD) were conducted to drying experiments. The effect of the drying time, unit energy consumption, color, sensory quality and effective components of Astragalus membranaceus were evaluated by technique for order preference by similarity to an ideal solution (TOPSIS). Results The results showed that CFFCHPD had the shortest drying time and lowest energy consumption for Astragalus membranaceus, with (0.15±0.00) h and (3.41±0.03) (kW·h)/kg, respectively. The L^* of the dried sample was the highest, which could have a positive effect on maintaining the color of Astragalus membranaceus, while other treatments showed varying degrees of browning. The VPD had the highest sensory score, but there was not significant difference with other treatments. CFFCHPD had a better taste, making its freshness, sweetness and richness at a high level. At the same time, retaining the nutritional components such as astragalosides, polysaccharides and calycosin-7-glucoside in Astragalus membranaceus could achieve better quality. Correlation analysis showed that the L^* was negatively correlated with the content of astragalosides and positively correlated with the content of polysaccharides. The a^* was positively correlated with the content of astragalosides, and the content of astragalosides and polysaccharides could be indirectly judged by color. Conclusion The comprehensive ranking of CFFCHPD ranked first, indicating that CFFCHPD is a promising combined drying technology suitable for drying traditional Chinese medicinal materials. This research result provides certain data support for efficient and high-quality drying of Astragalus membranaceus.

Objective To screen a strain that can antagonize the growth of Aspergillus flavus and to identify the strain, study its application and analysis its genetic preliminarily. Methods The microorganisms in the soil of peanut field in Feixian County were used as the research object, and the effective strains were obtained through the screening of Aspergillus flavus standoff test; the effective strains species were determined through morphological observation and 16S rRNA gene analysis and identification; the peanut pods and peanut kernels were infested with the suspension of Aspergillus flavus spores to validate the effective bacteria’s effect of antagonizing the growth of Aspergillus flavus; and the genome characteristics of the bacterial strains and the clusters of genes of secondary metabolites synthesis were analyzed to determine the basic characteristics of the effective bacterial strains. The genomic characteristics of the strain and the secondary metabolite synthesis gene cluster were analyzed to determine the basic characteristics of the effective strain. Results Effective strain G22, which could antagonize the growth of Aspergillus flavus, was obtained by screening. The strain G22 was identified as Burkholderia latens with 99.93% homology and named Burkholderia latens G22 by morphological characterization and gene homology analysis. The fermentation broth of the effective strain had a certain antagonistic effect on the growth of Aspergillus flavus on peanut pods and peanut seed kernels. The genome of the effective strain had 3 chromosomes and 1 plasmid, and the secondary metabolite synthesis gene cluster proved that the effective strain had antagonistic properties. Conclusion Strain G22 has good antagonistic effect on the growth of Aspergillus flavus. The application effect of strain G22 in peanut has important research significance in practice, which will lay a foundation for the further development of microbial fungicides for Aspergillus flavus.

Objective To construct a quality evaluation system for the main-sold pork in Shanghai and analyze the appearance, texture, nutrition, and flavor indicators of different pig breeds. Methods A total of 95 samples of the longissimus dorsi muscles were collected from 7 boar breeds, including Pudong White pigs. Fifty-five parameters were detected. Correlation analysis and radar charts were used to determine the core indicators for quality evaluation. Results In terms of appearance quality, different pig breeds showed differences in indicators such as pH and moisture content. Shawutou pigs, Pudong White pigs and Shanghai White pigs had slightly lower water content, while Shawutou pigs had a high drip loss rate. Topigs had slightly higher intramuscular fat content. Correlation analysis showed that the water content was negatively correlated with 24-hour drip loss. Regarding texture, Fengjing pigs had high shear force, Topigs had high hardness. Correlation analysis showed that the shear force was negatively correlated with hardness and positively correlated with elasticity. In terms of nutritional quality, it showed that the protein content in Shanghai local pig breeds was higher than that in common Duroc-Landrace-Yorkshire pigs. Three-way crossbred pigs and Shanghai White pigs had slightly lower fat content. The proportion of essential amino acids was the lowest in three-way crossbred pigs. In terms of flavor quality, the total amount of umami amino acids in each pig breed was similar. Shanghai White pigs had a high content of cytidine monophosphate, three-way crossbred pigs and Fengjing pigs had a high content of uridine monophosphate, Topigs had a low content of multiple flavor-related nucleotides, and Shawutou pigs had a high content of adenosine monophosphate. Correlation analysis showed that aspartic acid was positively correlated with the total amount of umami amino acids. Conclusion A quality evaluation system for Shanghai pork can be constructed around 13 core indicators, including water content, conductivity, shear force, hardness, resilience, protein, fat, magnesium, potassium, selenium content, adenosine monophosphate, inosine monophosphate, and aspartic acid. In the future, relevant factors need to be comprehensively considered to construct a comprehensive evaluation model.

Objective To investigate the main active components of different monthly Tetrastigma hemsleyanum Diels et Gilg (TDG) from Zhoushan City and establish the map of different monthly TDG. Methods The quality of different monthly TDG was evaluated by combining fingerprint similarity evaluation cluster analysis (CA), principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). An InterSustainSwift C₁₈ chromatographic column (4.6 mm×250 mm, 5 μm) was used, with acetonitrile-0.1 formic acid aqueous solution as the mobile phase, gradient elution, flow rate of 0.8 mL/min, detection wavelength of 20 nm, column temperature of 30 ℃, and injection volume of 10 μL. Results The fingerprint similarity evaluation results of 12 batches of different monthly TDG showed that the similarity of different monthly TDG samples varied greatly; the 13 common were identified, and 3 common peaks were recognized; CA, PCA, and OPLS-DA analysis could all classify the 12 batches of different monthly TDG into 3 categories; and 2 differential quality markers, gallic acid and quercetin, were screened out by analyzing the variable importance in projection (VIP) values under OPLS-DA. Conclusion The high performance liquid chromatography (HPLC) fingerprint and multi-component content determination method established in this study is stable and reliable, and can provide a reference for quality control of Zhoushan TDG.

Objective To investigate the potential of Cornus officinalis extract (COE) to repair skin damage caused by ultraviolet-B (UVB) exposure and to elucidate the underlying mechanisms involved. Methods By detecting the expression of UVB induced matrix metalloproteinases (MMPs) and pro-inflammatory cytokines in human keratinocytes cells (HaCaT), the photoprotective effect of COE was evaluated, and its antioxidant enzyme activity and collagen content were assessed. After exposure of mouse hairless skin to UVB radiation, extracts were applied topically and epidermal thickness, skin water content and collagen mRNA expression were determined. Results Under UVB irradiation (354.128 mJ/cm²), 1 mg/mL COE significantly enhanced antioxidant enzyme activity and significantly reduced the expression of pro-inflammatory cytokines prostaglandin E2, interleukin-1 α, and interleukin-6; simultaneously reduced the expression of MMPs; the collagen content significantly increased, with the expression levels of type I collagen and type III collagen proteins increasing by 13% and 75%, respectively. In addition, COE could alleviate the thickening of mouse skin epidermis and loss of collagen caused by UVB radiation. Meanwhile, COE treatment reduced the content of malondialdehyde (MDA) by 69%, and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) by 27% and 234%, respectively. Analysis of mRNA expression in mouse epidermis showed that treatment with COE resulted in a decrease in mRNA expression levels of Mmp1a and Mmp3, while mRNA levels of Col1a1 and Col3a1 increased. Conclusion COE can improve skin damage caused by UVB radiation. This improvement was associated with increased activity of antioxidant enzymes in cells, as well as reduced expression of pro-inflammatory cytokines and MMPs. The aim of this study is to further investigate the photoprotective potential of Cornus officinalis against UVB induced skin damage through mouse and cell models, and elucidate its potential mechanisms, providing a theoretical basis for the treatment of skin diseases caused by UVB photoaging and the development of new drugs from Cornus officinalis.