This article presented a visualization method for detecting salmon-derived components in Oncorhynchus mykiss and Salmo salar, based on fluorescence-labeled loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA). The widely recognized COI gene was targeted to design and screen optimal primer sequences for isothermal amplification. The specificity and sensitivity of the isothermal amplification methods were analyzed, and the applicability of LAMP using rapid DNA extraction and magnetic bead-based DNA extraction techniques was compared. The results demonstrated that the constructed LAMP and RPA methods exhibited high specificity. The sensitivity of LAMP detection using magnetic bead-extracted DNA reached 2.99×10⁻¹ ng/μL and 5.16×10⁻³ ng/μL, respectively, whereas using rapid DNA extraction, sensitivity reached 9.42×10⁰ ng/μL and 1.13×10¹ ng/μL, respectively. Simulated mixed samples were prepared, and results showed that the sensitivity of RPA amplification for detecting Oncorhynchus mykiss and Salmo salar components reached 0.1% (w/w), while the sensitivity of visual LAMP amplification consistently reached 0.5% (w/w). Both LAMP and RPA methods met rapid detection requirements, characterized by low technical complexity, minimal equipment cost, and short detection time. Moreover, rapid DNA extraction using lysis solutions allowed the detection process to be completed within 30~40 min, making this approach an excellent choice for on-site authenticity testing of fish species in production, processing, and market circulation stages.

To explore an efficient and low-cost temporary rearing method from the perspective of the quality assurance of raw materials, we investigated the effects of the temporary rearing of Micropterus salmoides on gallic acid on its oxidative stress level, muscle quality, and storage quality at 4 ℃. The results showed that after the temporary rearing of this fish species with 5 mg/L gallic acid for 7 days, the serum superoxide dismutase (SOD), muscle SOD, and catalase activities were reduced and the protein content of the muscle was increased along with its color, hardness, and water-holding capacity. When stored at 4 ℃, deterioration of the muscle texture slowed down. The water-holding capacity increased. The pH, whiteness, and malondialdehyde content decreased, and the activity of cathepsin B+L was inhibited. Therefore, short-term temporary rearing on 5 mg/L gallic acid for 7 days reduced oxidative stress in Micropterus salmoides and prolonged its freshness at 4 ℃ by inhibiting protein degradation and lipid oxidation.

To explore the variation patterns of starch quality in chestnuts during short-term storage, three cultivars—Dabanhong, Laoshuli, and Yanshan Zaofeng—were selected for investigation. The physicochemical and structural properties of starch were analyzed after storage at −2 ± 0.5 ℃ and 90%~95% relative humidity. After 63 days, total starch content decreased by 6.13%~15.44%, while rapidly digestible starch declined by 34.82%~43.44%. In contrast, amylose content increased by 5.37%~19.54%, and resistant starch rose by 1.04 to 3.23 times, indicating enhanced starch resistance and reduced digestibility. In terms of thermal properties, the gelatinization peak temperatures of Dabanhong and Laoshuli starches increased by 2.38% and 2.45%, respectively, while Yanshan Zaofeng starch exhibited a higher gelatinization temperature and a 23.72% increase in enthalpy, suggesting superior thermal stability. Structurally, the starch granule morphology remained unchanged, whereas both short-range molecular order and relative crystallinity increased, indicating structural reorganization induced by storage. From a processing perspective, chestnuts stored for approximately 14 days showed higher sweetness, making them suitable for chestnut paste and ready-to-eat products, those stored for 63 days, enriched in resistant starch, were ideal for developing low-glycemic index functional foods. This study elucidates the regulatory role of storage in modulating chestnut starch structure and digestibility, providing theoretical support and practical guidance for optimizing postharvest processing timing and functional product development.

To investigate the effects of frequency conversion refrigeration on the textural properties and pectin nanostructure over the shelf life, the carrots were analyzed for textural indices such as fracturability, springiness, and adhesiveness using a texture analyzer. Additionally, the content of cell wall materials and the activity of cell wall-degrading enzymes over its shelf life were evaluated using spectrophotometric methods, and the nanostructure of pectin substances was examined with an atomic force microscope (AFM). The results showed that frequency conversion refrigeration maintained the fracturability and springiness of carrots during shelf life, as well as the content of cell wall polysaccharides, including sodium carbonate soluble pectin (SSP), chelated soluble pectin (CSP), cellulose, and hemicellulose. The increase of water-soluble pectin (WSP) content was also delayed in carrots over the shelf life. Furthermore, frequency conversion refrigeration reduced the activity of carrot polygalacturonase (PG) during the middle of the pre-shelf life period, along with the activities of carrot pectinesterase (PME), cellulase (Cx), and β-galactosidase (β-Gal) throughout the entire shelf life. The increase in the number of CSP and SSP pectin aggregates was linked to the changes in Cx and β-Gal activities. Correlation analyses further indicated significant negative correlations between fracturability and PME activity, adhesiveness and PME activity, and springiness and β-Gal activity of the carrots during shelf life. It is concluded that frequency conversion refrigeration can preserve excellent textural qualities, such as fracturability, springiness, and adhesiveness, by delaying the depolymerization of pectin in carrots throughout its shelf life, thereby providing a theoretical basis and technical support for carrot cold storage aimed at preserving freshness.

Objective: To investigate the preservative effect of grape seed proanthocyanidin (GSP) on aquatic products. Methods: Salmon salar was utilized as the model subject. The regulatory effects of different GSP concentrations on quality characteristics, including physicochemical properties, freshness, texture properties, muscle microstructure, and protein oxidation, were investigated throughout refrigerated storage (4 ℃) at intervals (0, 3, 6, 9, 12 d). The mechanism by which GSP influences the structure of myofibrillar protein (MP) was analyzed using fluorescence spectroscopy and circular dichroism (CD) spectroscopy. Results: By the end of storage, compared with the control group, pH variations were reduced and water-holding capacity was significantly increased (P<0.05) in GSP-treated groups. The increase in total viable count (TVC) was significantly inhibited (P<0.05). The exceeding of the upper limit for total volatile basic nitrogen (TVB-N) was delayed by 3 days in the 0.75 mg/mL GSP treatment group. The carbonyl content of MP was reduced by 7.31%~18.27%, and the retention rate of total sulfhydryl groups was increased by 2.8%~12.1%. The structural integrity of myofiber bundles was significantly improved. Fluorescence spectral analysis revealed that GSP bound to MP via a static quenching mechanism, inhibiting the exposure of tryptophan residues. CD spectroscopy results demonstrated that the reduction rate in α-helices proportion (19%) was significantly lower in the 0.75 mg/mL GSP group than in the control group (34%), confirming its stabilizing effect on protein secondary structure. Conclusion: It is comprehensively demonstrated that the quality of salmon during storage is more effectively maintained by GSP through the modulation of protein oxidation pathways and molecular conformation. This study can provide a theoretical basis for natural antioxidant preservation technologies in aquatic products.

To develop proanthocyanidin microencapsulated yogurt tablets with antioxidant properties, providing a new avenue for the development of proanthocyanidin-based products. Methods: The optimal formulation of the proanthocyanidin microencapsulated yogurt tablets was determined through single-factor experiments and response surface optimization. The nutritional composition and shelf life of the yogurt tablets were assessed. The short-term memory of mice was evaluated using the step-down test and the dark avoidance test. A D-galactose (D-gal)-induced aging mouse model was established, with groups including the control group, model group, positive control group, high, medium, and low Maillard reaction dose groups, the non-Maillard reaction group, the proanthocyanidin group, and the non-proanthocyanidin group, each consisting of 10 mice. After 42 days of intervention, the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD), as well as the malondialdehyde (MDA) content in the serum, liver, and brain tissues of the mice were measured. Additionally, cell morphology of liver and brain tissues was observed, and the effects of proanthocyanidin microencapsulated yogurt tablets on the D-gal-induced aging mouse model were comprehensively analyzed. Results: The optimal formulation of the proanthocyanidin microencapsulated yogurt tablets was found to be as follows: 70.5% fermented milk powder, 20.0% proanthocyanidin microcapsules, 5.1% maltodextrin, 3.8% milk powder, and 0.6% silica. The high-dose Maillard reaction group (MH: 202.5 mg/10 g) of proanthocyanidin microencapsulated yogurt tablets (ME-MRPs-PC) significantly prolonged the latency period of aging mice and reduced error frequency (P<0.05, P<0.01). In terms of physiological indices, the MH group extremely significantly increased serum GSH-Px (P<0.01) and SOD activity (P<0.01), while decreasing MDA levels (P<0.05, P<0.01). In the liver tissue of MH group mice, some cells exhibited apoptosis, vacuolation, and were infiltrated by inflammatory cells, while most cells were tightly and orderly arranged. In brain tissue, some neurons showed vacuolation and nuclear pyknosis and hyperchromasia, while the majority of cells were closely and orderly arranged. Conclusion: Proanthocyanidin microencapsulated yogurt tablets have potential anti-aging effects, likely through improving oxidative stress and maintaining physiological functions to delay the aging process.

Objective: To investigate the effects of Astragaloside IV (AS-IV) on intestinal barrier function in mice with ulcerative colitis (UC) and to explore its underlying mechanisms. Methods: The UC mouse model was established using 3% dextran sulfate sodium (DSS). Upon successful model establishment, the animals were divided into control, DSS model, and AS-IV treatment groups (10, 20 and 40 mg/kg). All treatments were administered via oral gavage once daily for 10 days. The protein expression levels of the AhR/IL-22 pathway were analyzed by Western blotting. Fluorescence in situ hybridization (FISH) was performed to examine DAPI staining patterns in colon tissue sections. Apoptosis rates were measured by flow cytometry, and transcriptional levels of AHR, CYP1A1, and IL-22 were evaluated using qRT-PCR. Results: AS-IV ameliorated intestinal inflammation, reduced intestinal permeability, and promoted the restoration of colonic tight junction structures in colitis mice, potentially through activation of the AhR/IL-22 pathway. The therapeutic effects of AS-IV were partially attenuated by the AhR antagonist CH223191, whereas the AhR agonist FICZ exhibited comparable protective effects on colitis symptoms and intestinal barrier function. In vitro mechanistic investigations demonstrated that AS-IV treatment significantly upregulated the expression of CYP1A1 (P<0.01), a downstream target protein of AhR, in MNK-3 cells. Furthermore, AS-IV markedly enhanced IL-22 secretion (P<0.01) by facilitating AhR nuclear translocation. Notably, these regulatory effects were substantially diminished in AhR-silenced MNK-3 cells (shAhR-MNK3) (P>0.05), conclusively establishing that AS-IV modulates IL-22 production through an AhR-dependent mechanism. Conclusion: AS-IV ameliorated UC by activating the AhR/IL-22 pathway in ILC3 cells, thereby restoring intestinal barrier function. These findings highlight AS-IV as a potential therapeutic candidate for UC treatment.

Objective: To investigate the effect of Heyndrickxia coagulans BC07 on loperamide hydrochloride-induced constipation in mice. Methods: Thirty mice were randomly divided into three groups: the normal control group (NC), the model group (MC) and the BC07 group, with 10 mice in each group. The NC and MC groups were intragastrically administered normal saline, while the BC07 group was intragastrically given Heyndrickxia coagulans BC07 bacterial solution for 14 days. From the 15th to the 17th day, loperamide hydrochloride was used to establish the constipation model. The time to the first black feces and intestinal transit in mice were observed. Feces, serum, cecum, and colon samples of mice were collected. Results: The intake of Heyndrickxia coagulans BC07 could significantly increase the feces water content in constipated mice (P<0.05), shorten the time to the first black feces in mice (P<0.05), and promote the propulsion rate of the small intestine. Meanwhile, it could effectively regulate the concentrations of motilin (MTL), vasoactive intestinal peptide (VIP), substance P (SP), and somatostatin (SS) in constipated mice. It also reduced the contents of pro-inflammatory cytokines IL-6 and TNF-α in the mouse serum and increased the level of the anti-inflammatory factor IL-10. In addition, after the supplementation of Heyndrickxia coagulans BC07, the structure of the intestinal microbiota in constipated mice could be effectively regulated, increasing the relative abundance of beneficial microbiota in the mouse intestine and significantly decreasing the relative abundance of harmful microflora (P<0.05). Conclusion: Heyndrickxia coagulans BC07 has the effect of increasing fecal water content and alleviating defecation difficulties. It is speculated that it may relieve constipation by regulating gastrointestinal peptide transmitters, improving the structure of the intestinal microbiota, and promoting intestinal peristalsis.

Objective: To investigate the effects of zinc-enriched probiotic preparations on gastrointestinal hormones and gastrointestinal mucosa in rats with functional dyspepsia (FD). Methods: The FD model rats were established via intragastric administration of iodoacetamide-sucrose solution, exhaustive swimming stress, and intermittent fasting. Mosapride citrate served as the positive control. The efficacy of zinc-enriched probiotic preparations in alleviating FD was systematically evaluated through behavioral observation, biochemical analysis, pathological examination, and detection of related genes in gastrointestinal tissues. Results: Compared with the model group, zinc-enriched probiotic preparations significantly increased body weight and food intake in FD rats (P<0.05), decreased serum levels of 5-hydroxytryptamine (5-HT), gastrin (Gas), and cholecystokinin (CCK) (P<0.01), while increasing serum levels of substance P (SP) and amylase (AMS) (P<0.001). They also enhanced pepsin and trypsin activity (P<0.05). Histopathological examination revealed that the villus length and villus length-to-crypt depth ratio in the duodenum and jejunum were significantly increased (P<0.05). The expression of tight junction proteins (Cldn1, Tjp1) in the duodenum and the expression of tyrosine kinase receptor (c-Kit) and stem cell factor (SCF) in the gastric tissues were significantly upregulated (P<0.01). Conclusion: Zinc-enriched probiotic preparations can effectively alleviate FD by increasing digestive enzyme activity, regulating gastrointestinal hormone levels, enhancing gastrointestinal motility, and repairing the mucosal barrier (through upregulation of tight junction proteins and activation of the stem cell factor pathway). They have potential clinical application value and are worthy of further in-depth research.

To investigate the effects of D-allulose (D-Alu) on the lifespan and antioxidant capacity of Drosophila melanogaster, D. melanogaster were fed with different concentrations (0, 1, 5, 10 mg/mL) of D-allulose, and experiments on lifespan, climbing, reproduction, food intake, intestinal homeostasis, and antioxidant enzyme activities were carried out. The results showed that the mean and maximum lifespan of D. melanogaster in the group with 5 mg/mL of D-allulose were prolonged by 18.86% and 25.77%, which were significantly higher than those in the control group (P<0.05). The exercise capacity of aged D. melanogaster was significantly improved, and the climbing index of D. melanogaster at 30 d of age with the addition of D-allulose 5 mg/mL was increased by 21.10% compared with the control group (P<0.01). The egg production of D. melanogaster in the group supplemented with D-allulose 1 mg/mL increased by 10.9% (P<0.05) and the developmental cycle of D. melanogaster was shortened by 7.81% (P<0.01) compared with the control group. In addition, the addition of D-allulose 5 mg/mL increased the intestinal length of 30-d-old D. melanogaster by 13.06% (P<0.01) compared with the control group, and the proportion of intestinal leakage was reduced by 4.06% (P<0.01) compared with the control group, which reduced the shortening of the intestinal tract and the increase in permeability caused by aging. In the antioxidant assay, the mean survival time of D. melanogaster under oxidative stress conditions was prolonged by 12.34% (P<0.05) in the group supplemented with D-allulose 5 mg/mL, and the activities of D. melanogaster's superoxide dismutase (SOD) Cu/Zn-SOD and Mn-SOD were increased by 13.49% (P<0.01) and 16.19% (P<0.05), catalase (CAT) activity increased by 32.21% (P<0.01), and the malonaldehyde (MDA) content decreased by 20.75% (P<0.01) compared to the control. In conclusion, D-allulose can significantly improve the antioxidant capacity and prolong the healthy lifespan of D. melanogaster, showing a potential anti-aging efficacy.