To investigate the contamination levels and dietary risks of per- and polyfluoroalkyl substances (PFASs) in seafood products from Binzhou City.

A total of 109 seafood samples were collected. A ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for quantitative detection of 23 kinds of PFASs. Population health risks from seafood-derived PFASs intake were assessed using hazard ratio (HR) models.

The 9 kinds of PFASs were detected in seafood, with perfluorooctanoic acid (PFOA) exhibiting a detection rate of 100% and accounting for 82.2% of total mass concentration—significantly higher than other PFASs. Further analysis revealed significant compositional differences and species-specific distribution patterns in PFASs contamination levels: PFOA was the predominant contaminant in bivalve mollusks and portunus trituberculatus; perfluorotridecanoic acid (PFTrDA) accounted for the highest proportion of total PFASs in Litopenaeus vannamei shrimp; and perfluorooctane sulfonic acid (PFOS) exhibited the highest content in mantis shrimp. PFOA distribution varied significantly across different tissues of the portunus trituberculatus, with apparently higher accumulation in crab roe than in other tissues. Dietary exposure risk assessment further revealed that both PFOA and PFOS’ HR was below 1.

PFOA is the primary PFASs contaminant in seafood from Binzhou City. PFASs accumulation exhibits species specificity across seafood, with portunus trituberculatus displaying the highest total PFASs content, primarily concentrated in crab cream. No evidence of human health risks from PFOA and PFOS intake via seafood consumption has been identified.

To comprehensively evaluate the nutritional value of Juglans regia L. in different regions of Xinjiang.

Using a fully automatic amino acid analyzer, the ninhydrin post-column derivatization ion-exchange chromatography method was employed at wavelengths of 570 nm and 440 nm. By comparing with the amino acid pattern spectra of the United Nations Food and Agriculture Organization/World Health Organization(FAO/WHO) and the ideal protein standards, the ratios of essential amino acids (RAA) and the ratio coefficients of essential amino acids (RC) were calculated. The nutritional value of amino acid content in Juglans regia L. kernels was evaluated.

The 44 Juglans regia L. samples from different locations in 3 regions of Xinjiang all contained 17 kinds of amino acids, among which glutamic acid, lysine and arginine had relatively high content, and the proportion of essential amino acids was 0.32. The amino acid composition of Juglans regia L. from different regions varied greatly, and the amino acid ratio of walnuts from Kashgar region was better than that of other regions.Through the comparison and analysis of the FAO/WHO amino acid pattern spectrum, lysine and threonine were the main limiting amino acids. The score of ratio coefficient (SRC) value of the Zha 343 variety Juglans regia L. was the highest, and the defect degree of the first limiting amino acid was the lightest. Its RC value (chemical score) of lysine was 0.761. The amino acid supply and demand balance was the best, and there was no extremely excessive amino acid in this variety. The total RC value of phenylalanine and tyrosine was 1.406.

Based on the comprehensive amino acid evaluation indicators, the comprehensive nutritional quality of Zha 343 Juglans regia L. in Kashgar, Xinjiang is superior. This study provides a scientific basis for the analysis of nutritional components and processing utilization of Juglans regia L., and offers theoretical support for enhancing the market value of Xinjiang Juglans regia L.and promoting their application.

To prepare quality control samples of Listeria monocytogenes.

Listeria monocytogenes in the stationary phase was selected based on the growth curve. Then single-factor experiments and response surface methodology were used to optimize the lyoprotectant formulation. The prepared quality control samples were evaluated by homogeneity and stability.

Listeria monocytogenes cultured for 12 hours(stationary phase) was selected for freeze-drying. The optimized lyoprotectant formulation consisted of 13% skim milk powder, 8% trehalose and 3% sodium glutamate, achieving a bacterial survival rate of 82.27%. In the homogeneity test, the F-value was 2.747, which was lower than the critical F-value [F_0.05(9,10)=3.02]. In simulated stability tests, the quality control samples remained stable under transportation conditions which was 25 ℃ and 37 ℃for 7 days and storage conditions which was 4 ℃ and –20 ℃ for 28 days. The stability of the quality control samples was good.

The prepared Listeria monocytogenes control strain can be used as a quality control sample in laboratories.

To investigate the effects of 4 kinds of primary processing methods—freeze-drying, washing, sun-drying and honey processing—on the composition and content of free amino acids in Ruili arabica coffee beans.

The composition and content of free amino acids in coffee bean samples were determined using a fully automatic amino acid analyzer. Characteristic taste-related amino acids in coffee beans were screened and analyzed through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA).

The 17 kinds of free amino acids were detected in all 4 groups of coffee bean samples with different initial processing treatments, but their content, compositional distributions and proportions varied. The honey-processed coffee beans exhibited the highest total free amino acid content at 10.236 mg/g, followed by the freeze-dried group with 10.144 mg/g, while the washed group showed the lowest content of 9.823 mg/g. Among them, the honey-processed group exhibited the highest total content of sweet and bitter amino acids, while the freeze-dried group showed the highest total content of umami amino acids. The washed group had the lowest total content of both sweet and bitter amino acids, and the sun-dried group demonstrated a relatively low total content of umami amino acids. The screening analysis through PCA and OPLS-DA revealed that in coffee bean samples subjected to 4 kinds of different processing methods (freeze-drying, washing, sun-drying and honey processing), glutamic acid, tyrosine, threonine and arginine were identified as the key characteristic flavor amino acids respectively.

Different primary processing methods have a significant impact on the free amino acid content of Ruili arabica coffee. The research results provide a scientific basis for the coffee industry to optimize the primary processing technology and improve coffee quality.

To utilize the nutritional composition of the meat and the mineral element composition of the shells of the Sinonovacula constricta to construct a reliable model for discriminating the origin and farming mode of the species.

The 4 major production areas in Zhejiang Province, namely Linhai, Sanmen, Ninghai(pond farming) and Xiangshan (mudflat farming), were selected as the research subjects. The quality indicators of the Sinonovacula constricta, including appearance traits, nutritional composition, amino acid composition, fatty acid composition and mineral element content, were systematically analyzed. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and variable importance in the projection (VIP) were used to screen out the key characteristic parameters that affect the discrimination of the origin of the Sinonovacula constricta, and a discrimination model for different origins of the Sinonovacula constricta was constructed.

The quality analysis indicated that there were significant differences in the characteristics of the Sinonovacula constricta from different production areas and farming modes: The amino acid content (49.88 g/100 g) and the proportion of polyunsaturated fatty acids (41.46%) of the Sanmen (pond farming) Sinonovacula constricta were the highest; the content of trace elements in the Ninghai (pond farming) Sinonovacula constricta was relatively high; and the content of multiple nutritional indicators in the Xiangshan (mudflat farming) Sinonovacula constricta was relatively low.PCA, PLS-DA and VIP screened out 19 key characteristic parameters, including 5 kinds of minerals (iron, manganese, copper, calcium and zinc) in the soft tissue of the Sinonovacula constricta, 8 kinds of fatty acids(eicosapentaenoic acid, docosahexaenoic acid, etc.), and alanine; and 5 kinds of minerals (sodium, manganese, selenium, magnesium and calcium) in the shell. The constructed PLS-DA model had a good fit. The samples from pond farming and mudflat farming were clearly distinguished in the latent variable space; at the same time, the samples from the 3 adjacent pond farming production areas (Linhai, Sanmen and Ninghai) also showed independent clustering trends, indicating that the model could effectively capture the chemical fingerprint differences shaped by both the origin and the farming mode.

This study screens out 19 key characteristic parameters for the discrimination of the origin of the Sinonovacula constricta and constructed a discrimination model that can effectively distinguish the Sinonovacula constricta from different origins and farming modes (pond and mudflat)within Zhejiang Province. The model not only overcame the interference caused by the difference in farming modes but also accurately discriminate the Xiangshan (mudflat) production area, and shows good discrimination ability for the 3 adjacent pond farming production areas (Linhai, Sanmen and Ninghai). This provides a reliable technical means for the origin traceability of the Sinonovacula constricta under complex farming backgrounds.

To study the effects of nano-copper molybdate and nano-lithium molybdate on the browning of fresh-cut Malus.

The 3 groups of fresh-cut apples were immersed in deionized water,nano-copper molybdate and nano-lithium molybdate solutions for 30 minutes, respectively, and then left in the air.Samples were taken at 0, 1.5, 3.0 and 6.0 h to measure flesh browning and related physiological indicators (total phenol content, malondialdehyde content, flavonoid content, phenylalanine ammonia-lyase activity, and polyphenol oxidase activity).

After treatment with nano-copper molybdate and nano-lithium molybdate(within 0 to 6.0 hours), the flesh color of fresh-cut Malus did not change significantly compared to that at 0 hours,while the flesh of the control group Malus showed obvious browning at 1.5 hours. Compared with the control group,the degree of browning, malondialdehyde content, flavonoid content, phenylalanine ammonia-lyase and polyphenol oxidase activity of the treated group Malus were all significantly reduced.

Nano-copper molybdate and nano-lithium molybdate significantly delayed the browning rate of the Malus. This study provides a theoretical basis for the application of nano-copper molybdate and nano-lithium molybdate in the preservation of fresh-cut fruits.

To establish a duplex real-time fluorescent polymerase chain reaction (RT-PCR) method for detecting Streptococcus salivarius subspecies and Lactobacillus delbrueckii subspecies bulgaricus in non-viable fermented milk.

The optimal reaction system of duplex RT-PCR was optimized by adjusting the ratio of 2 target primers/probes, primer/probe concentrations, Mg²⁺ concentration and annealing temperature. The specificity and reproducibility of the method were validated. Finally, the target bacteria were detected in the actual samples purchased from the market.

Optimal amplification was achieved in a 20 µL reaction system containing primer-probes for both targets at a 1:1 ratio, 0.3 µL each of forward and reverse primers (10 µmol/L), 0.15 µL each of probes (10 µmol/L), 3 mmol/L Mg²⁺ and an annealing temperature of 60 ℃. Both Streptococcus salivarius subspecies and Lactobacillus delbrueckii subspecies bulgaricus were detected in all 24 batches of commercial samples.

The established method enables rapid and accurate detection of Streptococcus salivarius subspecies and Lactobacillus delbrueckii subspecies bulgaricus in non-viable fermented milk, providing effective technical support for food authenticity supervision.

To establish a fingerprint similarity evaluation method suitable for Chinese sauce-flavor Baijiu.

The 50 batches of A2 Chinese sauce-flavor Baijiu were determined by gas chromatography, and then the gas chromatography fingerprint of A2 was constructed. Similarity evaluation methods of 6 kinds of fingerprint spectra were established, and the similarity threshold was verified by different quality of Chinese sauce-flavor Baijiu.

The correlation coefficient method, vectorial angle method, information entropy method and the Euclidean distance method could not correctly distinguish different quality liquor bodies. The accuracy rate of weight non-uniformity similarity in judging different wine bodies was 100%, which was consistent with the sensory evaluation judgment results of wine bodies.

The similarity of weight non-uniformity is suitable for the data evaluation of fingerprint spectra of sauce-flavored Baijiu. This study provides a new method for the quality control of Chinese sauce-flavored Baijiu.