To optimize the extraction process of Polygonatum kingianum, and determine the optimal process parameters under the premise of ensuring high antioxidant activity.

This study utilized the entropy weight method to ascertain the weight coefficients of various metrics, including extract yield, total polysaccharide content and antioxidant activity, facilitating the calculation of a comprehensive score. The effects of ethanol volume fraction, solid-liquid ratio, extraction duration and extraction temperature on the extraction process were examined through single-factor experiments. Based on the above, the extraction process of Polygonatum kingianum was optimized using response surface methodology, with the comprehensive score serving as the response value.

The optimal extraction conditions were an ethanol volume fraction of 60%, an extraction temperature of 90 ℃, an extraction duration of 2 h and a solid-liquid ratio of 1:40 (g:mL). By using the determined optimal process parameters, the 3 parallel batches of samples yielded comprehensive scores of 98.92, 99.09 and 98.81, with a relative standard deviation of 0.14%.

This research optimize an extraction process of Polygonatum kingianum,confirming its feasibility and providing a basis for the development and utilization of Polygonatum kingianum.

To analyze the characteristic components and antibacterial effects of Eucalyptus honey.

This study employed high performance liquid chromatography-tandem mass spectrometry for both qualitative and quantitative analysis of the characteristic components in Eucalyptus honey. Additionally, the antibacterial activity of Eucalyptus honey against Escherichia coli and Staphylococcus aureus were explored.

The 7 compounds were identified in Eucalyptus honey, including dehydrovomifoliol, 3-oxo-α-lonol, 3’-methoxyquercetin,3’,4’,5’,5,7-pentahydroxyflavone, 3’,5’,2,5,7-pentahydroxyflavone, luteolin and N1-p-coumaroylglucoside-N10-p-methoxycinnamoyl spermidine, among them, N1-p-coumaroylglucoside-N10-p-methoxycinnamoyl spermidine was reported for the first time in honey. The quantitative analysis results indicated that dehydrovomifoliol and 3-oxo-α-lonol were the main components. Through the antibacterial experiment and minimum inhibitory concentration determination,Eucalyptus honey exhibited antibacterial activity against Staphylococcus aureus at a concentration of 5.0 mg/mL and inhibitory effects against Escherichia coli at a concentration of 7.5 mg/mL.

This study conductes a systematic qualitative and quantitative analysis of the phytochemical compounds in Eucalyptus honey and demonstrates its favorable antimicrobial efficacy. Eucalyptus honey exhibites notable inhibitory activity against Staphylococcus aureus and Escherichia coli. The research provides a theoretical foundation for the authenticity assessment, quality control and functional product development of Eucalyptus honey.

To explore the consumer preferences for different types of pure milk products and their relationship with emotional responses they trigger.

The 9-point hedonic scale and the previously established pure dairy product emotion scale (PDPES) were used in this study. Cluster analysis, correlation analysis,multiple factor analysis and partial least squares analysis were also used to study preferences and emotional responses to 6 kinds of pure milk products.

Consumer preferences for different types of pure milk products differed significantly, with lactose-hydrolyzed milk and organic milk being more favored by consumers (P<0.05). Gender and age had no significant influence on pure milk consumer preferences (P>0.05). The 6 kinds of pure milk products showed significant differences in most emotional responses across the 3 dimensions: Property cognition, acceptance appraisal and neutral property cognition (P<0.05). Lactose-hydrolyzed milk, organic milk and pasteurized milk elicited stronger emotional responses. Partial least squares analysis showed that consumer preference for pure milk product was most strongly associated with the factor of acceptance appraisal, and the key emotional characteristics affecting differences in consumer preference were property cognition and acceptance appraisal.

This study identifies differences in preferences for different types of pure milk and their associated typical emotional characteristic indicators, providing a theoretical basis and data support for future product sensory claims, formula upgrades and consumer insights.

To establish a method for the rapid detection of the nicarbazine residue marker 4, 4’-dinitrogendibenzuron in chicken by colloidal gold immunochromatography.

Key parameters including extraction solvent, volume and incubation time were systematically optimized to determine the optimal detection conditions: 10.0 mL of methanol as the extraction solvent, an extraction time of 2 min and an incubation time of 3 min.

Experimental validation demonstrated that the method exhibited cross-reactivity rates of less than 0.1% with 15 kinds of common anticoccidial drugs (e.g., diclazuril, salinomycin) and 5 kinds of structural analogs, indicating excellent specificity. When applied to real sample analysis, the results showed good agreement with those obtained by the reference method, with a false negative rate, false positive rate and relative accuracy of 0%, 0% and 100%, respectively.

The developed method is simple, rapid, sensitive and specific, making it suitable for on-site rapid screening of nicarbazin residues in chicken.

To demonstrate the feasibility of using methyl β-orcinol carboxylate as a marker for identification of “tech cong” tea，and establish its detection method.

A detection method for methyl β-orcinol carboxylate in tea was established by using QuEChERS technology for sample preparation and gas chromatography-mass spectrometry for determination. The content of methyl β-orcinol carboxylate in teas and Yunnan Ramalina fastigiata was analyzed. Common teas were scented with Ramalina fastigiate by simulating the counterfeiting technique of “tech cong” tea. Subsequently，the content analysis of methyl β-orcinol carboxylate and sensory evaluation were carried out on the scented teas.

Methyl β-orcinol carboxylate was identified as a characteristic component of lichen-based fragrances like oakmoss extracts and treemoss extracts，not a natural constituent of genuine old-bush tea leaves. It could be transferred from Yunnan Ramalina fastigiata to ordinary tea leaves through scenting，imparting an “old-bush” flavor. A total of 31 samples labeled “old-bush Shuixian” purchased online were tested，and the detection rate of methyl β-orcinol carboxylate was 58.1%.

Methyl β-orcinol carboxylate can serve as a marker for identifying “tech cong” tea. The gas chromatography-mass spectrometry method combined with QuEChERS sample preparation can detect the content of methyl β-orcinol carboxylate. This method can be applied to the authenticity identification of “old-bush Shuixian” tea，which is of great significance for strengthening the supervision of the tea market and cracking down on the illegal counterfeiting of high-grade tea.

To establish a method for determining of lactoferrin in special formula foods such as amino acid formulas and protein hydrolyzed formulas by a complexation extraction/heparin affinity column purification-high performance liquid chromatography.

The sample was dissolved and extracted with complex phosphate buffer solution, and purified using a heparin affinity column. Separation was achieved using a C₄ 300 Å protein analysis chromatographiccolumn, with themobile phase consisting of acetonitrile-trifluoroacetic acid solution, followed by gradient elution. Detection was performed using a high performance liquid chromatography diode array detector, and quantification was achieved using an external standard method.

The lactoferrin peak exhibited a good shape and was separated from the impurity baseline. The method demonstrated a good linear relationship within the range of 2–200 μg/mL (r²>0.999). The limit of detection and limit of quantitation of the method were 2 mg/100 g and 6 mg/100 g, respectively. At 3 spiked concentration levels of low, medium and high, the average recovery rates ranged from 92.0% to 96.2%, with relative standard deviations of 2.5% to 3.7%.

This method is accurate, reliable and exhibits good repeatability and stability. It is suitable for the detection of lactoferrin in special formula foods such as amino acid formulas and protein hydrolyzed formulas. It addresses the issue that the national standard method is not applicable for detecting lactoferrin in special formula foods like amino acid formulas and deeply hydrolyzed protein milk powder.

To investigate the differences in volatile components between Chinese and European Japonica rices.

Headspace arrow-type solid-phase microextraction (HS-SPME Arrow) combined with gas chromatography-mass spectrometry (GC-MS) was used for determination, and principal component analysis (PCA),hierarchical cluster analysis (HCA), orthogonal partial least squares analysis (OPLS-DA) and odor activity value(OAV) were applied to analyze the volatile components of Chinese and European Japonica rice.

The 130 kinds of and 129 kinds of volatile components were identified based on HS-SPME Arrow combined with GC-MS for Chinese and European Japonica rices, respectively. Differences between the volatile components of Chinese and European Japonica rices were revealed by PCA and HCA; variable importance in projection (VIP) values in OPLS-DA were applied to determine the differential volatile components between Chinese and European Japonica rices, and 4 kinds of key differential volatile components were further screened by the OAV, which were 2-n-pentylfuran (26.98 in China, 6.48 in Europe), n-hexanol (4.51 in China, 0.07 in Europe), trans-2-octenal (15.61 in China, 4.82 in Europe) and trans-2,4-decadienal (369.42 in China, 84.94 in Europe).

The study reveal significant differences in volatile components between Chinese and European Japonica rices, providing a reference basis for the construction of branding and value-added enhancement of speciality rice.