To investigate the bacterial diversity in Pandanus amaryllifolius powder and analyze the contamination status and antimicrobial resistance of Cronobacter sakazakii.

The 6 samples of Pandanus amaryllifolius powder from different brands were collected from an e-commerce platform. High-throughput 16S rDNA sequencing technology was used to analyze the bacterial diversity. Cronobacter sakazakii was detected in accordance with GB 4789.40—2024 National food safety standard-Food microbiological examination-Cronobacter spp., and its antimicrobial susceptibility was analyzed.

The dominant bacterial phyla in Pandanus amaryllifolius powder were Firmicutes, Proteobacteria and Cyanobacteria. The dominant bacterial genera were Enterobacter, Weissella and Clostridium. The 3 strains of Cronobacter sakazakii were isolated from 2 samples. The antimicrobial susceptibility results showed that these three strains were not sensitive to β-lactam antibiotics (except ertapenem) and nitrofuran antibiotics.

The bacterial flora in Pandanus amaryllifolius powder is relatively abundant with a high content of Enterobacter. The foodborne pathogenic bacterium Cronobacter sakazakii is isolated from the powder and the 3 strains exhibit multidrug resistance. Therefore, vulnerable populations should consume it with caution.

To optimize the enzymatic hydrolysis process technology of yeast milk, improve the content of amino nitrogen and total nitrogen in the product.

The effects of enzyme dosage, pH, time and temperature of papain, flavor protease and complex protease on enzymatic hydrolysis were investigated using single‑factor experiments. Subsequently, response surface methodology was employed to optimize the enzyme process parameters, and the optimal addition time of the 3 kinds of enzymes was determined by complex enzyme experiments, and the synergistic enhancement effect of nonionic surfactants was explored.

The optimal parameters from single‑factor experiments were as follows: papain dosage 1.5%, pH 6.0 and temperature 50  °C, time 15 h; flavor protease was added at 0.7%, pH 7.0, temperature 54  °C and time 13 h; the complex protease dosage 1.8%, pH 7.5, temperature 60  °C and time 12 h. After response surface optimization, the measured amino nitrogen content for papain, flavor protease and complex protease were 3.83%±0.04%, 3.93%±0.06% and 4.12%±0.06%, respectively, and the measured total nitrogen content were 9.65%±0.04%, 9.78%±0.05% and 9.87%±0.04%, respectively. The measured values were close to the model’s predicted values, confirming the reliability of the model. The compound enzyme combination test determined that the optimal addition times for papain, flavor protease and complex protease were 2, 4 and 5  h, and the amino nitrogen content was 4.24%±0.03% and total nitrogen content was 9.97%±0.04%. Furthermore, the addition of 0.030% nonionic surfactant further enhanced the enzymatic hydrolysis, increasing the amino nitrogen content to 4.57%±0.05% and total nitrogen content to 10.22%±0.04%.

The combination of complex enzyme technology with the addition of nonionic surfactant significantly improves the enzymolysis effect, providing an efficient and feasible technical approach and an important theoretical basis for the high‑value utilization of yeast milk, a by‑product of the fermentation industry.

To evaluate the improvement effect of Lactobacillus gasseri GMLCA-Lac 1 on dextran sulfate sodium (DSS)-induced ulcerative colitis in mice and its potential mechanism of action.

The strain characteristics were analyzed through whole-genome sequencing, and the changes in disease phenotype, intestinal barrier function and immune indicators were evaluated in combination with animal experiments.

The genome of Lactobacillus gasseri GMLCA-Lac 1 comprised a circular chromosome and 2 plasmids, encoding 1980 predicted open reading frames. Strain-specific genes were significantly enriched in glycolysis/gluconeogenesis, pyruvate metabolism and antioxidation pathways, which conferred robust capacities for lactic acid production, short-chain fatty acid synthesis and intestinal stress tolerance. In animal experiments, Lactobacillus gasseri GMLCA-Lac 1 exerted a dose-dependent attenuation of DSS-induced body weight loss, diarrhea and hematochezia, reducing the disease activity index, restoring colon length and ameliorating colonic pathological damage. It also promoted intestinal mucus barrier repair by increasing goblet cell density. At the same time, Lactobacillus gasseri GMLCA-Lac 1 significantly reduced the levels of pro-inflammatory cytokines in serum, included interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), lowered the spleen index and helped restore the balance of immune function.

Lactobacillus gasseri GMLCA-Lac 1 alleviates colitis in mice through the synergistic effects of repairing the intestinal mucosal barrier and modulating inflammation and immunity, providing experimental evidence for its potential as a candidate strain for microecological therapy of inflammatory bowel disease.

To establish a scientific and systematic methodology for evaluating the characteristic quality attributes of frozen fried dough sticks.

The 12 commercially available mainstream brands of frozen fried dough sticks were selected as the research subjects. The measurements of quality indicators including textural properties, chromaticity, flavor compounds and nutritional composition were conducted. The fuzzy binary comparison decision-making method was performed to identify key sensory evaluation indicators across 5 dimensions: visual, olfactory, auditory, gustatory and tactile perceptions. Key indicators were further screened and comprehensively evaluated through correlation analysis, principal component analysis and cluster analysis.

The total of 20 indicators that could be categorized into 6 principal components with a cumulative variance contribution rate of 91.217% were selected. The cluster analysis, taste, internal structure, brightness (L^*), red green ratio index (a^*), sodium chloride content, moisture content and fat content were identified as the core evaluation indicators for the quality of frozen fried dough sticks.

The quality evaluation system developed in this study enables an objective and quantitative assessment of the overall quality of frozen fried dough sticks. It not only provides guidance for consumer decision-making but also offers a precise scientific basis for optimizing formulations and advancing the industrial production of healthier, low-oil, and low-salt frozen fried dough sticks.

To investigate the protective effects and toxicological safety of the American ginseng ultrafine powder compound on alcoholic liver injury in mice.

The 50 ICR mice were randomly divided into 5 groups of 10 mice each, including the negative control group, the model control group, the American ginseng-free compound group, the American ginseng extract compound group and the American ginseng ultrafine powder compound group. The negative control group and model control group were gavaged with the same amount of purified water, and the remaining groups were gavaged with the corresponding test substances daily for 30 days. Except for the negative control group, the rest of groups were gavaged with 50% ethanol once after the last administration to establish an acute alcoholic liver injury model in mice. The body weight of mice, the content of malondialdehyde (MDA), glutathione(GSH) and triglyceride (TG) in liver tissue were determined. Additionally, the pathological analysis of liver tissue stained with Oil Red O was performed to evaluate the protective effect of test substances. After screening the optimal compound, according to the Technical standards for testing & assessment of health food (2003 edition), the tests of acute oral toxicity, genetic toxicity and 28 days oral toxicity were performed to systematically evaluate its toxicological safety.

Compared with the model control group, the content of MDA and TG in the liver tissue of the American ginseng ultrafine powder compound group were significantly decreased (P<0.05), and the content of GSH was significantly increased (P<0.05), and the degree of fatty degeneration of liver cells was significantly reduced (P<0.05).Although the indicators in the American ginseng-free compound group and American ginseng extract compound group showed improvement trends, the differences were not statistically significant (P>0.05). The results of toxicological safety showed that the maximum tolerated dose of the American ginseng ultrafine powder compound for both male and female mice was greater than 12.0 g/kg BW, indicating that it was practically non-toxic. The results of Ames test, bone marrow micronucleus test and sperm malformation test were all negative, indicating that it had no genotoxicity. No toxicological effects on body weight, feed intake, feed utilization rate, blood physiological and biochemical indicators, organ/body weight ratio and main tissues in rats were found in the 28 days oral toxicity test. The no-observed-adverse-effect level of the American ginseng ultrafine powder compound was 4.5 g/kg BW.

The American ginseng ultrafine powder compound has a significant protective effect on alcoholic liver injury in mice, and its effect is better than that of the American ginseng extract compound and the American ginseng-free compound.Moreover, the compound has high food safety within the experimental dose range.

To investigate the endogenous characteristics and consumption safety risk of semicarbazide (SEM) residues in farmed Scylla paramamosain.

A total of 239 mud crab samples were collected from aquaculture ponds along the coasts of Sanmen Bay and Yueqing Bay, covering 5 counties (cities): Ninghai, Sanmen, Wenling, Yuhuan and Yueqing. In addition, 119 water samples and 119 sediment samples were simultaneously collected.SEM residues were detected using high performance liquid chromatography-tandem mass spectrometry, yielding 478 valid data points in total.

No SEM was detected in any water or sediment samples, while the detection rate in Scylla paramamosain reached 92.1%, confirming that the detected SEM was confirmed to be mainly derived from the endogenous background. The detected values exhibited a typical positively skewed distribution, with 75.9% of samples concentrated in the dominant concentration range of 0.1–0.4 μg/kg, and only 0.45% of samples exceeded 1.0 μg/kg.Tissue distribution analysis revealed that SEM concentrations in the hepatopancreas were generally higher than those in muscle, but 51.2% of samples showed hepatopancreas/muscle ratios between 1 and 2, indicating a uniform distribution pattern characteristic of bound residues without extreme enrichment. No statistically significant differences were observed among regions (P>0.05), with both Sanmen Bay and Yueqing Bay belonging to endogenous background areas.Significant gender differences (P<0.05) were primarily regulated by the dynamic process of lipid transport to ovaries during the female reproductive cycle. Temporally, SEM concentrations exhibited regular fluctuations with reproductive rhythms, peaking in female hepatopancreas at 0.40 μg/kg in mid-September, coinciding with ovarian maturation. Food safety risk assessment indicated that the average SEM intake per Scylla paramamosain was approximately 50 ng, equivalent to only 1/300000 of the toxic reaction dose in experimental animals, indicating extremely low food safety risk.

SEM residues in farmed Scylla paramamosain from Sanmen Bay and Yueqing Bay represent an endogenous background phenomenon regulated by reproductive cycles, posing no systematic safety risk, and consumers can safely consume these products.

To clarify the influence of the culture environment on the quality of Litopenaeus vannamei, and systematically compare the quality differences between seawater and freshwater (greenhouse, open-air) culture modes.

In this study, analyses were performed using sensory evaluation, conventional nutritional composition detection, amino acid and nucleotide analysis, fatty acid determination and texture profile analysis (TPA).

The total sensory score of seawater-cultured shrimp was 8.35, which was significantly higher than that of the freshwater groups (5.83 and 5.94), with an extremely weak earthy flavor and more prominent umami and sweetness. The crude protein content (22.5 g/100 g) was found to be significantly higher than that of freshwater shrimp under the two modes (21.0 g/100 g and 21.4 g/100 g), while no significant difference was observed in fat content. The total umami amino acid content (7.11 g/100 g) and inosine monophosphate content (75.52 mg/100 g) of seawater-cultured shrimp were measured as the highest, and the proportion of monounsaturated fatty acids was determined to be significantly higher, whereas the total amount of n-3 polyunsaturated fatty acids in freshwater-cultured shrimp was observed to be higher. In terms of texture, superior hardness (16.85 N), springiness (0.89) and chewiness (2.69 mJ) were recorded in seawater shrimp compared to freshwater shrimp, while higher cohesiveness was exhibited by freshwater-cultured shrimp.

Superior comprehensive performance in sensory properties, nutrition and texture is demonstrated by seawater-cultured shrimp, whereas advantages in specific fatty acids are held by freshwater shrimp. This study provides a theoretical and practical basis for the selection of shrimp culture modes, feed optimization and quality improvement in the industry.

To prepare a composite film with antibacterial function using chitosan (CS) and gelatin(GEL) as film-forming substrates and tea polyphenols (TP) as an active additive.

CS/GEL composite films with different TP additions were prepared by solution blending and casting method. The water content, water solubility, swelling degree, light transmittance, antibacterial activity and preservation effect on strawberries of the films were analyzed and determined.

The CS/GEL/TP composite films exhibited a smooth appearance. The introduction of TP optimized the properties of the composite films. When the TP addition was 1.5%, the composite film showed the best overall performance: the ultraviolet light transmittance was as low as 0.113%, and inhibition rates against Escherichia coli and Staphylococcus aureus reached 73.34% and 99.78%, respectively. In the strawberry preservation experiment, the composite film effectively inhibited the weight loss of the fruits, with a loss rate as low as 15.27% after 11 days, delayed the sensory deterioration of strawberries, and extended the shelf life by 4 days.

The water content, water solubility, swelling degree, ultraviolet light transmittance and antibacterial activity of the CS/GEL composite film with appropriate addition of TP are improved, effectively prolonging the preservation period of strawberries, and showing a certain application potential in the field of fruit preservation.

To optimize the cooking process of dry-fried Phaseolus vulgaris L. in a combi-steam oven, and compare the differences in volatile flavor compounds between samples prepared by traditional stir-frying and by the combi-steam oven.

Taking dry-fried Phaseolus vulgaris L. as the research object, the heating temperature, humidity and cooking time of the combi-steam oven were optimized through single-factor and orthogonal experiments.Gas chromatography-mass spectrometry (GC-MS) was employed to detect the volatile components of products obtained by the 2 kinds of methods, and the relative odor activity value (ROAV) was calculated to identify the key flavor compounds.

The optimal cooking conditions for the combi-steam oven were a heating temperature of 200  ℃, a humidity of 70%, and a cooking time of 8.5  min, under which the product achieved the best sensory quality. A total of 30 volatile compounds were identified by GC-MS, covering 9 chemical classes including esters, aldehydes and olefins.ROAV analysis demonstrated that 2-methylbutanal, isovaleraldehyde and heptanal were the key flavor compounds common to both cooking methods, playing a dominant role in the dry-fried flavor. The ROAV values of styrene, isovaleraldehyde, heptanal and other compounds were higher in the combi-steam oven group, making their contributions to the overall flavor more prominent.

This study establishes standardized combi-steam oven process parameters for dry-fried Phaseolus vulgaris L., reveals the key flavor compounds and the influence of processing methods on their contributions, and provides reliable process parameters and a flavor chemistry foundation for the standardized and digital processing of this dish.