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.

Cichorium intybus L. is a plant with high medicinal value and wide range of uses. The roots, stems, leaves and seeds of Cichorium intybus L. are highly nutritious and have a wide range of health benefits, such as regulating blood sugar, weight loss, combating malaria and preventing cardiovascular disease. Cichorium intybus L. root is rich in inulin, a polysaccharide composed mainly of fructose units, but also contains a small amount of monosaccharides, as well as chlorogenic acid and sesquiterpene lactones and other biologically active compounds, which have the function of regulating and improving gastrointestinal function, balancing blood glucose metabolism, improving lipid metabolism, lowering blood pressure, strengthening the immune system, antioxidant, anti-fatigue effects and other functions. Cichorium intybus L. can be processed into a variety of products, such as root tea, bread, functional foods, sugar substitutes and so on. This paper summarized the nutritional composition, functional characteristics, and research progress of Cichorium intybus L. in the food industry, and proposed solutions based on the problems existing in the application of Cichorium intybus L. in the food industry, which can provide reference for the development of the Cichorium intybus L. industry.

Objective To use summer Baojing Huangjincha 1 straight black tea, jasmine flowers, and fresh Finger citron peel as raw materials, and the flower and fruit black tea with sweetness, fruitiness and tea flavor is made through processing. Methods In this study, the sensory evaluation of flower tea, high performance liquid chromatography and visible spectrophotometer were used to study the effects of kilning, drying, jacquard and other processes on the formation of the main taste substances and quality of black tea made from flowers and fruits. Results The taste intensity of floral-fruit-scented black tea showed significant differences (P<0.05) across various processing stages. During the scenting→drying→flower removal sequence, the taste characteristics exhibited dynamic evolution: Sourness and bitterness significantly intensified during scenting (P<0.05), while sweetness began transforming during drying and peaked at the flower removal stage. Key findings included: Tea polyphenols showed a “V”-shaped change pattern during processing, while free amino acids and soluble sugars accumulated continuously, enhancing umami and sweetness. Water extracts and flavonoids initially decreased before rebounding. Non-esterified catechins, gallic acid and caffeine decreased significantly in the final product, synergistically reducing astringency and bitterness. Total esterified catechin content decreased by 16.89% during scenting but partially recovered after drying and flower removal. Notably, gallocatechin gallate content increased remarkably by 55%, while epicatechin gallate showed an initial decrease followed by recovery. Sweetness-contributing amino acids (serine, threonine, alanine, proline and glycine) collectively increased by 9.40%, significantly enhancing tea sweetness. Total theaflavin content decreased significantly, with theaflavin-3-gallate, theaflavin-3’-gallate and theaflavin-3,3’-digallate decreasing by 25.69%, 27.28% and 6.02% respectively. Taste activity value analysis revealed decreasing trends for bitterness/astringency-related compounds including caffeine, gallic acid, ECG and catechins Conclusion In this study, the mixture of jasmine flowers and fresh fruit peel of Finger citron and the processing of Baojing Huangjincha 1 straight strip black tea in summer show that the taste of black tea made from flowers and fruits mainly showed the quality characteristics of “sweet and fruity”, and effectively improved the bitterness, astringency and sourness of summer black tea, which provided a theoretical basis for the brewing process of flower and fruit tea.

Objective To explore the effects of glnA gene on the production of curdlan by Agrobacterium. Methods A glnA gene knockout strain ΔglnA was constructed in this paper. The growth and metabolism of ΔglnA strain and the changes in yield, gel properties and infrared structure of the obtained gum were analyzed, and the expression of genes related to the synthesis of curdlan was explored by quantitative real-time polymerase chain reaction. Results The amino nitrogen consumption of the ΔglnA strain during fermentation was consistent with that of CGMCC11546. In terms of sucrose consumption, there was no significant difference before 12 h, but there was a significant difference between the ΔglnA strain and CGMCC11546 after 15 h, and sucrose consumption was significantly reduced compared to CGMCC11546. The ΔglnA strain could produce approximately 4 g/L of natural gum, which was 60% lower than CGMCC11546. Conclusion The glnA gene does not affect bacterial growth or the structure of collagen, but it can reduce the synthesis of collagen. This study provides insights into the role of glnA in curdlan production and lays a molecular biological foundation for further efforts to enhance curdlan yield.

Objective To investigate the endogeneity and distribution characteristics of vanillin in different growth stages of Oryza sativa. Methods Longjing 46, Yanfeng, and Liaoxing were selected as the experimental materials. Samples were taken at different parts of Oryza sativa during its whole growth period. The vanillin content was determined by high performance liquid chromatography-tandem mass spectrometry method. Results Vanillin was present in Oryza sativa plants as early as the seedling stage. Its content in roots and leaves was 1100-1450 μg/kg and 596-972 μg/kg, respectively. During the growth process of Oryza sativa, the vanillin content in roots reached its peak at heading stage, with a content of 6560-8900 μg/kg. Subsequently, from full-heading stage to maturity stage, the vanillin content in roots gradually decreased, and at maturity stage, the content dropped to 2900-3230 μg/kg. The vanillin content in the leaves reached its peak at maturity stage. The vanillin in Oryza sativa grains started to accumulate continuously from the dough stage and reached its peak at maturity stage. In addition, at the late stage of reproductive growth, the vanillin content in the upper part of the plant (flag leaves and the upper part of the stem) was significantly higher than that in the lower part of the plant (lower leaves and the lower part of the stem), and the vanillin content in Oryza sativa husk was extremely significantly higher than that in the brown Oryza sativa. Conclusion This study confirms that vanillin has a natural background throughout the whole growth period of Oryza sativa, and vanillin is endogenously produced for the first time. Its content shows stage-specific and differential changes at different parts and growth stages. It is speculated that it may be a natural growth regulator of Oryza sativa.

Objective To analyze the status of foodborne pathogenic bacteria contamination in meat and meat products in Yantai City, Shandong Province from 2020 to 2023, and understand the safety of related food in the city. Methods According to national food safety standard Food microbiological examination GB 4789 series standards and the requirements of Shandong food pollutants and harmful factors risk monitoring manual, 6 kinds of foodborne pathogens were detected from meat and meat products, including Salmonella, Listeria monocytogenes, Yersinia enterocolitica, Campylobacter, Diarrheagenic Escherichia coli and Staphylococcus aureus. Results The 5 kinds of foodborne pathogens and 46 positive strains were detected in 363 samples, with the total detection rate of 12.67%. The highest detection rate was Salmonella (10.48%), followed by Campylobacter (1.97%) and Staphylococcus aureus (1.33%), and no Diarrheagenic Escherichia coli was detected. Among the 4 types of samples, the highest detection rate was in raw poultry meat (26.67%) and the lowest was in cooked meat products (2.35%). The detection rate of Salmonella in prepared meat products reached 20.00%. The detection rates of pathogenic bacteria in the samples collected by farmers’ markets and online stores were relatively high (19.53%, 22.22%). Salmonella had the highest probability of causing illness in the third quarter. Conclusion Meat and meat products in Yantai City are contaminated by foodborne pathogens to various degrees, so it is necessary to focus on raw poultry meat and bulk prepared meat products, especially those originating from farmers’ markets and online stores, and it is important to strengthen the relevant circulation supervision, enhance food safety awareness and take measures to reduce the risk of cross-contamination during the sale of bulk meat products, so as to ensure food safety for consumers.

Objective To understand the overall situation of biogenic amine content in various types of seafoods in Hainan Province, and conduct dietary risk assessment on the detected histamine. Methods A total of 387 batches of seafoods from supermarkets and farmers’ markets in 19 cities and counties of Hainan Province in 2022 were detected for 14 kinds of biogenic amines by ultra performance liquid chromatography-tandem mass spectrometry. Based on the detection results, the dietary exposure risk of the detected histamine was assessed by the hazard quotient (HQ). Results The average content of biogenic amine detected in 387 batches of seafoods were 0.101-55.248 mg/kg, and the maximum value were 2.248-10819.835 mg/kg. The higher levels of several biogenic amines were spermine, spermidine, histamine, putrescine, cadaverine and so on. And two samples detected histamine levels over 200 mg/kg. The dietary risk assessment showed that the estimated daily of histamine in different populations in Hainan Province were 0.00000-0.06690 mg·kg^-1·bw^-1·d^-1, with HQ of 0.00000-0.00134 (HQ<1). Conclusion Biogenic amines are detected in all kinds of seafoods in Hainan Province to varying degrees, but the risk of histamine exposure is low, posing a small threat to human health.

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 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.