In order to investigate the effects of different processing methods on the rheological properties and flavor components of Laiyang pear paste, this study analyzed the fluid types and compared the volatile substances of three homemade pastes (freeze-drying concentration, vacuum concentration, and atmospheric boiling) and seven commercially sampled pastes by employing a rheometer and gas chromatography-ion mobility spectroscopy (GC-IMS). The results showed that all pear paste samples exhibited pseudoplastic fluid behaviors with shear-thinning characteristics. The relationship between shear rate and shear stress conformed to the Power Law model, demonstrating an excellent fit (R²>0.99). Among the ten samples, the paste prepared by freeze-drying concentration revealed the optimal rheological properties, showing neither excessive thinness nor thickness. Furthermore, GC-IMS identified different flavor compounds in 10 kinds of pear pastes and qualitatively detected the common flavor compounds, including 15 aldehydes, 14 esters, 13 ketones, 9 alcohols, 5 terpenes, 1 carboxylic acid, and 4 other compounds qualitatively. According to orthogonal partial least squares-discriminant analysis (OPLS-DA) and relative odor activity value (ROAV) screening, the key odor markers were identified as 2-methylbutanal, 2-methylpropanal, ethyl hexanoate, and ethyl butyrate. The flavor compounds of aldehydes and esters were typically associated with fruity aromas. Meanwhile, compared to pastes produced by atmospheric boiling and vacuum concentration, the paste prepared by freeze-drying concentration contained the highest level of ethyl butyrate, which contributed to a distinct fruity aroma. It indicated that the use of this method to produce Laiyang pear paste could maximize the preservation of the fruity aroma. In conclusion, findings of this study provide valuable insights for the processing and multi-dimensional quality evaluation of pear paste products.

To investigate the effects of salt concentrations and drying times on the quality and microbial community of lightly-salted golden pomfret, changes in quality indices (e.g., biogenic amines and volatile flavor compounds) and bacterial communities in samples subjected to salting with 3%, 4%, and 5% salt concentrations followed by cold air drying for 0, 18, and 36 h, respectively, were analyzed, and the correlation between quality indices and bacterial composition was explored. The results showed that the thiobarbituric acid reactive substance (TBARS) content increased with increasing salt concentration and prolonged drying time, and the total viable count (TVC), total volatile basic nitrogen (TVB-N), TBARS, putrescine, histamine, cadaverine, and total biogenic amines significantly increased (P<0.05). Notably, the histamine content in the 36 h-dried group exceeded the maximum recommended limit (>50 mg/kg), posing a safety risk. Volatile flavor compound analysis revealed that aldehydes, alcohols, and ketones were the primary volatile organic compounds (VOCs) in lightly-salted golden pomfret, and 14 differential flavor compounds screened via partial least squares discriminant analysis (PLS-DA) could be used to effectively distinguish samples with different drying times. High-throughput sequencing indicated that Lactococcus, Pseudomonas, and Acinetobacter were the dominant genera present during processing. Pearson correlation analysis demonstrated that Morganella was significantly positively correlated with tryptamine, putrescine, and cadaverine (P<0.05). Pseudomonas was significantly positively correlated with nitrite (P<0.05), and Acinetobacter was significantly positively correlated with 3-methyl-3-buten-1-ol and 3-pentanone (P<0.01). In conclusion, the safety and quality of lightly-salted golden pomfret could be effectively improved by shortening the cold-air drying time, thereby providing a theoretical basis and technical support for product development and quality control.

To examine the suitability of different pre-freezing treatments for Tricholoma matsutake frozen storage, three pretreatment methods—refrigerator slow freezing (RSF), immersion quick freezing (ICF), and liquid nitrogen spray freezing (LNF) were applied. Tricholoma matsutake were subsequently stored at −20 ℃ for 180 days, during which the effects of different freezing methods on freezing characteristics, post-thawing sensory quality, enzymatic activities, and other critical parameters were comprehensively assessed. Based on the experimental results, significantly shorter phase transition times and higher freezing rates (P<0.05) were observed in ICF- and LNF-treated Tricholoma matsutake compared with RSF-treated samples, with LNF demonstrating the fastest freezing rate at 0.85 ℃/min. Additionally, superior retention capacity for both moisture and soluble solids content was demonstrated in Tricholoma matsutake treated with LNF during frozen storage. During frozen storage, browning and texture softening were observed in Tricholoma matsutake, with the browning index ranking in descending order as RSF>ICF>LNF. At the same time, hardness values were maintained in the sequence LNF>ICF>RSF. Regarding enzymatic activities, a progressive reduction in superoxide dismutase (SOD) and polyphenol oxidase (PPO) activity levels was observed in frozen-stored Tricholoma matsutake throughout the storage period. Among the three methods, the LNF treatment was found to exhibit the optimal retention of SOD activity and the most potent inhibition of PPO activity. With prolonged frozen storage, the total sugars, soluble protein, and total phenolic content were decreasesd in Tricholoma matsutake. The loss of soluble protein was significantly reduced by RSF treatment (P<0.05), while LNF treatment was more effective in retaining total sugars and total phenolic content. In conclusion, LNF treatment was demonstrated to be the most effective approach for maintaining the frozen storage quality of Tricholoma matsutake. It can be considered a novel pretreatment option for Tricholoma matsutake prior to frozen storage.

In order to explore the effects of different concentrations of Pythium oligandrum pretreatment on the storage quality, disease resistance and phenylpropanoid metabolism of plum fruits during storage and shelf life, Xinjiang 'France' plum was used as the test material in this experiment. The pre-harvest plum was sprayed with P.oligandrum diluent (750 times), and the water was sprayed as the control group (CK). It was stored at 4~6 ℃ and relative humidity of 80%~90%, and the samples were taken every 8 days. The results showed that the pre-harvest spraying of 750 times P. oligandrum preparation could significantly inhibit the decrease of fruit hardness, which was 32.2% higher than that of CK group (P<0.05). The weight loss rate was reduced by 37.3% compared with the CK group. Inhibit the respiration intensity of plum fruit, the treatment group accounted for 75.2% of the CK group. At the same time, pre-harvest spraying of P. oligandrum significantly increased the phenylalanine ammonia lyase (PAL) activity by 17.6% compared with the control group (P<0.05). The cinnamic acid-4-hydroxylase (C4H) was increased by 26.2% (P<0.05) compared with the control group, and the activity of 4-coumaroyl-CoA ligase (4CL) was also increased by 8.9%, while promoting the accumulation of total phenol, flavonoids and lignin content. In summary, the treatment of P. oligandrum can delay the postharvest deterioration of plum fruits: Maintain fruit quality characteristics, enhance disease resistance and prolong storage period. This experiment provides theoretical support and technical reference for the green preservation of plum fruits.

The regulatory effects of various fungicide preservatives on the postharvest storage quality and physiological metabolism of bayberry were systematically investigated. Using 'Biqi' bayberries as the experimental material, bayberry fruits were treated with different concentrations of dehydroacetic acid (0.15, 0.3, 0.6 mmol/L), prochloraz (45, 90, 180 mg/L), sodium dichloroisocyanurate (15, 30, 60 mg/L), and 1-methylcyclopropene (2, 4, 6 g). The changes in storage quality, physiological and biochemical properties, and nutritional quality during cold storage and normal temperature storage were studied. Under refrigerated conditions, prochloraz treatment was found to significantly reduce the decay rate (reduce 80%), ethylene release, and delay softening of bayberry fruits (P<0.05), while malondialdehyde (MDA) content was inhibited. At ambient temperature, prochloraz could effectively delay fruit softening, inhibit ethylene release, and suppressed the increase in polyphenol oxidase (PPO) activity (P<0.05). Sodium dichloroisocyanurate (60 mg/L) under refrigeration was observed to reduce the decay rate (by 25%) and enhance peroxidase (POD) activity (P<0.05). During room temperature storage, sodium dichloroisocyanurate (15 mg/L) could delay fruit softening, reduce ethylene content, and suppresse the increase in PPO activity (P<0.05). 1-Methylcyclopropene treatment under both refrigeration and ambient temperature storage condition was demonstrated to reduce fruit firmness and ethylene content. Moreover, under room temperature conditions, fruit decay was effectively inhibited by 1-MCP with an active ingredient concentration of 0.03% (2 g) (P<0.05). Dehydroacetic acid (0.15 mmol/L) under refrigeration could only transiently enhance the POD activity of Chinese bayberry fruits (P<0.05), amd increased the decay rate and ethylene content to varying degrees. In contrast, under ambient temperature storage, it significantly increased fruit firmness and total soluble solids (TSS) content (P<0.05), while showing no significant effects on enzyme activity or titratable acidity (TA) content (P>0.05). In conclusion, prochloraz (90 mg/L) and sodium dichloroisocyanurate (60 mg/L) at relatively high concentrations were determined to exhibit preservative effects. The 1-MCP treatment (2 g, 0.03% active ingredient) effectively maintained postharvest fruit quality and extended the preservation period, while dehydroacetic acid showed insignificant preservative efficacy. The research results provide a theoretical basis for the precise post-harvest fresh-keeping of bayberries.

In order to investigate the novel method to extend the shelf life of chilled chicken, thereby addressing the bottleneck restricting that constrains high-quality development of the industry, the antibacterial effect and storage quality at 4 ℃of plasma activated water (PAW) and organic acids (0.2% citric acid, 0.2% lactic acid solution) on chilled chicken were explored in the current investigation. The results showed that PAW synergistic organic acid treatment effectively inhibited the increase of total viable count (TVC) and coliform population of chilled chickens (P<0.05). It reduced the initial TVC by 0.77~1.21 lg CFU/g and the coliform bacteria count by 0.07~0.57 lg CFU/g. During storage, the PAW synergistic organic acid treatment inhibited the increase of the pH, K value and malondialdehyde content of chilled chickens (P<0.05). In the early stage of storage (0~8 d), PAW synergistic organic acid treatment had not an adverse effect on the color. The synergistic treatment of PAW with organic acid reduced the shear force of the sample, but not significant (P>0.05). Although PAW and organic acid treatment increased the nitrite content of chilled chickens (P<0.05), to a maximum of 21.43 mg/kg, which was still within the safe range and would not cause food safety issues. In conclusion, compared with NaClO treatment, PAW and PAW synergistic organic acids treatment effectively extended the shelf life of chilled chicken by 8 and 12 d, and maintain storage quality. This study could provide a theoretical basis for the application of PAW synergistic organic acids in the preservation of chilled chicken.

Enzymatic hydrolysates of purple sweet potato polyphenol-protein complexes (PPPCs) exhibited potential hypoglycemic activity. In this study, PPPCs were synergistically hydrolyzed using papain and alkaline protease, followed by fractionation through 3 kDa and 10 kDa ultrafiltration membranes to obtain three peptide fractions (fraction 1: <3 kDa, fraction 2: 3~10 kDa, and fraction 3: >10 kDa). The hypoglycemic effects of these fractions were evaluated in a diabetic mice model induced by a high-fat diet and streptozotocin (STZ) injection. The most active peptide fraction was further purified by gel chromatography, and its glucose uptake-enhancing activity was assessed using an insulin-resistant HepG2 cell model. Results showed that the group of high-dose fraction 1 (D+H1) in the treatment groups exhibited the most potent hypoglycemic effect. Compared with the modeling group without treatment (D+HF), mice in this group demonstrated significantly reduced fasting blood glucose levels (P<0.05), markedly improved glucose tolerance (P<0.05), and significant amelioration of diabetes-induced weight loss and damage to the liver, kidneys, and heart (P<0.05). Levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) in serum were significantly reduced (P<0.05), while high-density lipoprotein cholesterol (HDL-C) levels were significantly elevated (P<0.05). Notably, its subfraction 1 (Peak 1) significantly increased glucose consumption in insulin-resistant HepG2 cells by 16.20% at a concentration of 0.1 mg/mL (P<0.05). This study confirmed that enzymatic hydrolysates of PPPCs possessed potent hypoglycemic properties. Among them, the <3 kDa peptide fraction had the best hypoglycemic effect and exhibited a certain degree of dose dependency, and its hypoglycemic activity primarily originated from its subfraction 1. These findings provide a theoretical foundation for developing purple sweet potato-derived bioactive peptides as nutritional interventions for diabetes. Additionally, this study highlights the potential for high-value utilization of agricultural byproducts in functional food applications.

Objective: To investigate the effect and potential mechanisms of soybean isoflavones (SIF) on the efficacy of lowering blood glucose and repairing testes in rats with subacute aging diabetes mellitus. Methods: After 6 consecutive weeks of administration of SIF by gavage on subacute aging diabetic rats, the fasting blood glucose, body weight, oral glucose tolerance and insulin levels were measured in rats. Also, enzyme-linked immunosorbent assay kits were used to detect the levels of superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and glutathione peroxidase (GSH-Px), and the morphological changes. Moreover, expression of genes and proteins related to janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway was measured in testes. Results: SIF could significantly reduce fasting blood glucose, oral glucose tolerance test-area under the curve (OGTT-AUC), insulin secretion, and increase body mass in rats (P<0.01). All doses of SIF (low, medium, and high doses) reduced oxidative stress, with high-doses SIF had the most significant effect (P<0.01). In addition, SIF significantly down-regulated P53, JAK, STAT3, and BAX at both gene and protein levels, and significantly up-regulated Bcl-2 from both gene and protein levels, in which high-doses SIF showed the most significant effect (P<0.01). Conclusion: SIF significantly ameliorated testicular damage in subacute aging diabetic rats by synergistically regulating blood glucose, attenuating oxidative stress, and inhibiting the JAK/STAT3 pathway, providing a new strategy for the development of functional foods for reproductive dysfunction.

Objective: To optimize the extraction process of total flavonoids from Pueraria lobata (TFPL), and evaluate its therapeutic potential in alleviating aluminum-induced intestinal barrier dysfunction. Methods: The extraction process was optimized via orthogonal design, with the yield of total flavonoids as the index. An in vitro intestinal barrier injury model was established using aluminum-exposed HT-29 cells. The protective effect of TFPL on the intestine was comprehensively assessed through a multi-parameter evaluation system, which encompassed in vitro antioxidant capacity assays, intestinal epithelial monolayer permeability measurements, quantitative analysis of intracellular reactive oxygen species (ROS) levels, and molecular profiling of both inflammatory cytokines and tight junction protein expression. Results: The optimized extraction parameters were established as follows: Ultrasonic power of 400 W, solid-to-liquid ratio of 1:30 g/mL, extraction duration of 60 min, and ethanol concentration of 60%. Under these optimal conditions, the maximum yield of total flavonoids reached 4.65±0.05 mg/g. The in vitro antioxidant assays indicated TFPL was capable of scavenging DPPH, ABTS⁺, and hydroxyl radicals. In aluminum-exposed HT-29 cells, TFPL was demonstrated to significantly (P<0.05) improve reduced TEER value, increased FITC-dextran permeability, elevated ROS levels, upregulated secretion of TNF-α and IL-1β, activated NF-κB pathway, and downregulated expression of Claudin-4 and Occludin. Conclusion: TFPL exhibited protective effects on the intestine against aluminum-induced damage. The underlying mechanism might be associated with oxidative stress mitigation, anti-inflammatory actions, and tight junction modulation.

To investigate the digestive characteristics of milk and soybean powders from different sources in the infant gastrointestinal tract and their effects on gut microbiota, this study compared cow milk powder (CM), goat milk powder (GM), sheep milk powder (SM), and soybean powder (SB). An in vitro continuous infant gastrointestinal digestion model combined with fecal fermentation was established to evaluate protein hydrolysis, short-chain fatty acid (SCFA) production, and gut microbial composition. Results showed GM and CM exhibited significantly higher in vitro protein hydrolysis rates than SM and SB (P<0.05). During in vitro fecal fermentation, the three animal milk powders increased butyric acid and valeric acid concentrations by 4~7 times and 1~2 times, respectively. Microbiota analysis revealed that CM and SM generated gut microbial profiles more similar to those of breastfed infants, significantly increasing the abundance of Anaerococcus (P<0.05), which was associated with butyrate production. In contrast, SB showed lower protein digestibility, significantly elevated acetic acid levels and disrupted microbial homeostasis. It was characterized by a marked reduction in the abundance of beneficial genera such as Bifidobacterium and Clostridium_sensu_stricto_1. Correlation analysis further confirmed a strong negative correlation between acetic acid concentration and Bifidobacterium abundance (P<0.01). In summary, goat-milk powder and sheep-milk powder were more suitable raw materials for infant formula, offering scientific evidence to inform the rational selection of base powders in infant formula development.