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Abstract Excessive intake of red meat may cause damage to colorectal tissue but not cause significant damage to the small intestine. However, the underlying mechanism is not clear. In this study, the effect of myoglobin extracted from red meat was explored on the intestinal barrier function of the mice, and its potential mechanism was elucidated through cell culture experiments. Exclusively high‐dose myoglobin (3.39%, equivalent to 450 g red meat per day for human) resulted in marked intestinal permeability with increased levels of serum endotoxin, diamine oxidase, and d‐lactate but reduced the mRNA levels of tight junction proteins and mucin 2 in the duodenal and colonic tissues. The diet also increased free iron and heme levels in the duodenal and colonic tissues, leading to higher level of oxidative stress and inflammatory response. Metabolomic analysis of colonic contents showed that exclusively high‐dose myoglobin altered the relative content of indole and its derivatives, phenolic compounds, and 5‐hydroxy‐l‐tryptophan by regulating tryptophan metabolism and kynurenine cycle and destroying intestinal homeostasis. The very high myoglobin hydrolysate induced oxidative stress and apoptosis more seriously in HT29 cells than in INT407 cells, which could be the main reason for more severe colon injury. Nevertheless, normal low‐dose intake (0.38% myoglobin, equivalent to 50 g per day for human) did not show the above‐mentioned harmful effects. The findings provided a risk assessment for the dosage of red meat intake and new insights into the relationship between red meat intake and intestinal health.

Background Idiopathic Pulmonary Fibrosis (IPF) presents a severe respiratory challenge with a poor prognosis due to the lack of reliable biomarkers. Recent evidence suggests that Endoplasmic Reticulum Stress (ERS) may be associated with IPF pathogenesis. This study focuses on uncovering ERS-associated biomarkers for IPF.Methods Sequencing data from diverse datasets were analyzed, utilizing differential gene expression analysis and Weighted Gene Co-expression Network Analysis (WGCNA). Endoplasmic Reticulum Stress (ERS)-related genes were extracted from the GeneCards database. Hub genes were identified through Protein-Protein Interaction (PPI) analysis. Diagnostic and prognostic models were developed using machine learning algorithms and validated across both training and validation sets. Additionally, techniques such as Cell-type Identification by Estimating Relative Subsets of RNA Transcripts and single-cell RNA sequencing were employed to identify potential IPF-related cells. These findings were further investigated to elucidate their underlying mechanisms through in vitro experiments.Results Differentially expressed genes, WGCNA-identified blue module genes, and ERS-related genes extracted from the GeneCards database were intersected, and the resulting genes were used to construct diagnostic and prognostic models. Validation using multiple datasets indicated that both the diagnostic and prognostic models possess strong predictive capabilities. PPI analysis highlighted SPP1 as a potential hub gene in IPF. Moreover, M2 macrophages were found in higher quantities in the lung tissue of IPF patients, with a significant increase in SPP1-expressing M2 macrophages compared to the control group. In vitro experiments demonstrated that exogenous SPP1 inhibited the proliferation and migration of M2 macrophages and promoted apoptosis within a certain concentration range.Conclusion This study identifies ERS-related biomarkers in IPF, highlighting SPP1 and M2 macrophages. The resulting diagnostic and prognostic models offer strong predictive capabilities, unveiling new therapeutic avenues.

The Chishui River Basin, a vital waterway in Southwest China, has experienced rapid urbanization, leading to significant ecological and environmental changes, among which the urban heat island (UHI) effect is particularly pronounced. The UHI effect not only affects the quality of life for residents but also influences urban energy consumption and climate change, underscoring the need for in-depth study of its spatial distribution and contributing factors. The unique karst topography of the region further complicates UHI research, necessitating an investigation that can inform urban planning and sustainable development strategies. This study leveraged Landsat 8 TIRS satellite remote sensing imagery to examine the land surface temperature (LST) and UHI effect in the Chishui River Basin during the summers of 2016 and 2021. Employing the Mono-window Algorithm (MWA), the research quantitatively inverted the LST and analyzed its spatial distribution and the spatiotemporal characteristics of the surface urban heat island (SUHI) effect. The findings indicated a notable increase in average summer temperatures between the 2 years, with a 1.67°C rise from 2016 to 2021. Despite this increase, there was an observed reduction in the extent of SUHI areas, suggesting potential mitigation efforts. Additionally, the study revealed that karst regions were more susceptible to forming “abnormal” heat islands due to their distinct geomorphological features. The implications of this research are critical for urban development planning and the pursuit of sustainable urbanization in the Chishui River Basin. By understanding the thermal dynamics and their relationship with urbanization and karst landscapes, policymakers and urban planners can devise strategies to minimize the adverse effects of SUHI while promoting ecological balance and environmental health. Future research should extend the temporal analysis, employ higher resolution data, compare findings with other regions, and provide a detailed examination of mitigation efforts to enhance the robustness and applicability of the conclusions, provide stronger scientific evidence for the ecological sustainability of the Chishui River Basin.

Plant-based meat analogs have become an important topic in recent years. To scientifically understand the research situation of plant-based meat analogs, we analyzed 2,595 publications from January 2000 to October 2023 by bibliometric method based on the PubMed database. The results showed a gradual rise in the number of annual publications, with the fastest growth rate of 58.5% in 2021. The country with the most publications was the United States (685, 24.87%), followed by China (242, 8.79%) and the United Kingdom (196, 7.12%). The University of Helsinki, Texas A&M University and the University of California were core research institutions. Popular and important journals were mainly Foods, Nutrients, Meat Science, Food Research International, and Critical Reviews in Food Science and Nutrition. Current research topics focused on alternative proteins and their functional and nutritional characteristics, as well as sustainable development. The research interests have gradually expanded from quality characteristics to nutritional characteristics. Further improving the quality, controlling natural toxin contamination, as well as systematically investigating the effects on health were future research trends. The effects of plant-based meat analogs on metabolic pathways and diseases were important clues in the study of nutritional health. This bibliometric analysis comprehensively and quantitatively presents the research landscape and hotspots, and further suggests future research directions. These findings can benefit researchers in selecting appropriate journals and finding potential collaborators to achieve in-depth research in this field.

Quercetin compounds have antioxidant, anti-inflammatory and anticancer pharmacological functions. Long-term exposure to acrylamide (AA) can cause liver injury and endanger human health. However, whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear. Here, we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro. In vivo studies found that quercetin-like compounds protect against AA-induced liver injury by reducing oxidative stress levels, activating the Akt/mTOR signaling pathway to attenuate autophagy, and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis. In vitro studies found that quercetin compounds protected HepG2 cells from AA by attenuating the activation of AA-induced autophagy, lowering reactive oxygen species (ROS) levels by exerting antioxidant effects and thus attenuating oxidative stress, increasing mitochondrial membrane potential (MMP), and improving apoptosis-related proteins, thus attenuating AA-induced apoptosis. Furthermore, the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity, with quercetin showing the best protective capacity due to its strongest antioxidant activity. In conclusion, quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress, autophagy and apoptosis, and their protective capacity correlates with antioxidant activity.

With the global energy crisis and the decline of fossil fuel resources, biofuels are gaining attention as alternative energy sources. China, as a major developing country, has long depended on coal and is now looking to biofuels to diversify its energy structure and ensure sustainable development. However, due to its large population and limited arable land, it cannot widely use corn or sugarcane as raw materials for bioenergy. Instead, the Chinese government encourages the planting of non-food crops on marginal lands to safeguard food security and support the biofuel sector. The Southern China Karst Region, with its typical karst landscape and fragile ecological environment, offers a wealth of potential marginal land resources that are suitable for planting non-food energy crops. This area is also one of the most impoverished rural regions in China, confronting a variety of challenges, such as harsh natural conditions, scarcity of land, and ecological deterioration. Idesia polycarpa, as a fast-growing tree species that is drought-tolerant and can thrive in poor soil, is well adapted to the karst region and has important value for ecological restoration and biodiesel production. By integrating 19 bioclimatic variables and karst landform data, our analysis reveals that the Maximum Entropy (MaxEnt) model surpasses the Random Forest (RF) model in predictive accuracy for Idesia polycarpa’s distribution. The karst areas of Sichuan, Chongqing, Hubei, Hunan, and Guizhou provinces are identified as highly suitable for the species, aligning with regions of ecological vulnerability and poverty. This research provides critical insights into the strategic cultivation of Idesia polycarpa, contributing to ecological restoration, local economic development, and the advancement of China’s biofuel industry.

Abstract Epidemiological studies have shown that excessive consumption of meat may cause memory loss and cognitive decline, but the underlying mechanism is unknown. Here, a high‐chicken‐protein diet but not a high‐pork diet was found to have a markedly negative impact on the enteric nervous system and hippocampal function. Higher serine, glutamate, and proline levels in the high‐chicken‐protein diet inhibited the absorption capacity of amino acids, reduced the levels of neurotransmitters, and further increased hippocampal β‐secretase levels. Alzheimer's disease mouse model and cell studies confirmed that high‐chicken diet‐induced changes in the intestinal function further resulted in metabolic disorders with a reduction in L‐serine and niacinamide in serum, accumulation of hippocampal β‐amyloid, and eventually aggravated memory and cognitive decline. Our findings highlight the importance of serine, glutamate, and proline as systemic mediators of diet–gut–brain axis homeostasis against memory and cognitive dysfunctions associated with excessive intake of chicken.

ABSTRACTSalmonella Enteritidis is a foodborne enteric pathogen that infects humans and animals, utilizing complex survival strategies. Bacterial small RNA (sRNA) plays an important role in these strategies. However, the virulence regulatory network of S. Enteritidis remains largely incomplete and knowledge of gut virulence mechanisms of sRNAs is limited. Here, we characterized the function of a previously identified Salmonella adhesive-associated sRNA (SaaS) in the intestinal pathogenesis of S. Enteritidis. We found that SaaS promoted bacterial colonization in both cecum and colon of a BALB/c mouse model; it was preferentially expressed in colon. Moreover, our results showed that SaaS enhanced damage to mucosal barrier by affecting expressions of antimicrobial products, decreasing the number of goblet cells, suppressing mucin gene expression, and eventually reducing thickness of mucus layer; it further breached below physical barrier by strengthening invasion into epithelial cells in Caco-2 cell model as well as decreasing tight junction expressions. High throughput 16S rRNA gene sequencing revealed that SaaS also altered gut homeostasis by depleting beneficial gut microbiota while increasing harmful ones. Furthermore, by employing ELISA and western blot analysis, we demonstrated that SaaS regulated intestinal inflammation through sequential activation P38-JNK-ERK MAPK signaling pathway, which enabled immune escape at primary infection stage but strengthened pathogenesis at later stage, respectively. These findings suggest that SaaS plays an essential role in the virulence of S. Enteritidis and reveals its biological role in intestinal pathogenesis.

The efficient synthesis of myofibrillar protein(MRN)-gallic acid (GAD) complex in ultrasound (UID)-assisted processing is a challenging problem in food manufacturing. In this investigation, the effect of viscosity characteristics on the efficiency of UID processing in MRN-based beverages was analyzed. Both viscosity and surface tension can increase sono-physico-chemical effects on the degradation of terephthalic acid and crystal violet, with surface tension having a more significant effect (negative correlation, R2 = 0.99) than viscosity (positive correlation, R2 = 0.79). The structural indicators and microstructure demonstrated that the reaggregation and refolding of the MRN structure during the modification procedure occurred with relatively small three-dimensional dimensions. Compared to the MRN/GAD4 group, the water contact angle of the MRN/GAD7 system enhanced by 129.44%, leading to greater system stability. The ABTS-scavenging capacity of the system increased by approximately 19.45% due to the increase in viscosity of these two categories.

Abstract The objective of this study was to investigate the mechanism of fracture properties modulated by microstructure in the myofibrillar protein (MP) and polysaccharides gel systems. Compare to the modified starch, the dietary fiber significantly improved the fracture stress and reduced the fracture strain at same concentration. The treatment with 2% dietary fiber had the highest value of fracture stress and the lowest value of fracture strain, which were 259 g and 1.12 respectively. From the skeleton structure, the Raman spectroscopy result showed that dietary fiber addition significantly reduced the intensity at 2945 cm−1, which suggested that the aggregation of hydrophobic groups was improved. The SEM showed that the treatment with 2% dietary fiber had the highest fractal dimension value of 1.7772 and the lowest lacunary value of 0.258. From the filling structure, the paraffin section showed that the polysaccharides were just simply trapped in MP gel networks and formed numerous large volumes and no-elastic of cavities. The principal component analysis suggested that the compactness of three-dimensional gel networks determined fracture stress of composite gel. The no- no-elastic of cavities formed by modified starch and dietary fiber resulted in the reduction of fracture strain. These results would promote the development of innovative nutritional meat product formulation with satisfied textural property. Graphical Abstract

To investigate the spoilage characteristics of Jinhua ham, sensory scores, volatile compounds, biogenic amine, physicochemical parameters and microbial counts were evaluated between normal and spoiled hams. The results showed that off-odors of spoiled hams were dominated by rancid, sour, sulfide and ammonia odors derived from these compounds including butanoic acid, methanethiol and dimethyl disulfide. Total content of biogenic amine in spoiled hams was significantly higher (more than 10-fold) compared with normal hams, and putrescine, cadaverine and histamine were the key components of biogenic amine of spoiled hams. Lower salt content, and higher moisture, TVB-N and thiobarbituric acid reactive substances (TBARS) values were observed in spoiled hams compared with normal hams. The populations of Enterobacteriaceae and Enterococcus of spoiled hams were obviously higher than that of normal hams. High moisture and low salt content caused the abnormal growth of Enterobacteriaceae and Enterococcus in spoiled hams, which contributed to the spoilage of Jinhua ham.

This study aimed to examine the sono-physico-chemical effects of ultrasound (UND) and its impact on the conjugate rates of morin (MOI) following the addition of polysaccharides in various conditions. In comparison to the control group, the incorporation of quaternary ammonium chitosan decreased the rate of MOI conjugation by 17.38%, but the addition of locust bean gum enhanced the grafting rate by 29.89%. Notably, the highest degree of myofibrillar protein (MRN) unfolding (fluorescence intensity: 114435.50), the most stable state (−44.98 mV), and the greatest specific surface area (393.06 cm2/cm3) were observed in the UMP/LBG group. The outcomes of atomic force microscopy and scanning electron microscopy revealed that the inclusion of locust bean gum led to a different microscopic morphology than the other two polysaccharides, which may be the primary cause of the strongest sono-physico-chemical effects of the system. This work demonstrated that acoustic settings can be tuned based on the characteristics of polysaccharides to maximize the advantages of sono-physico-chemical impacts in UND-assisted MOI processing.

Abstract Relationships between meat consumption and gut diseases have been debated for decades, and the gut microbiota plays an important role in this interplay. It was speculated that the gut microbiota and relevant indicators of hosts with different body weight indexes (BMIs) might respond differentially to meat-based diet alterations, since lean and obese hosts have different gut microbiota composition. Forty-five young Chinese volunteers were recruited and assigned to high-, middle- and low-BMI groups. All of the volunteers were given a beef-based diet for 2 weeks and subsequently with a chicken-based diet for another 2 weeks. Body weight and blood indexes were measured, and fecal samples were obtained for 16S rRNA sequencing, metabolome and proteome analyses. The fecal metabolites of the low-BMI volunteers showed greater sensitivity to meat-based diet alterations. In contrast, the fecal proteome profiles and blood indexes of the high- and middle-BMI volunteers indicated greater sensitivity to meat-based diet alterations. Replacing the beef-based diet with the chicken-based diet largely changed operational taxonomic units of Bacteroides genus, and thus probably induced downregulation of immunoglobulins in feces. Compared with the beef-based diet, the chicken-based diet decreased inflammation-related blood indexes, especially in high- and middle-BMI volunteers. This work highlighted the role of BMI as an important factor predicting changes in gut homeostasis in response to meat consumption. Compared with the chicken-based diet, the beef-based diet may induce more allergic and inflammation-related responses in high- and middle- BMI Chinese at the current level.

Optimizing ultrasound (ULD)-assisted flavonoid modification is an important component of enhancing its application potential. In this work, diverse flavonoids, such as quercetin (Que), apigenin (Api), and morin (Mor), were used to modify protein in myofibrillar protein (MP)/cellulose nanocrystal (CN) complexes using ULD-assisted method. Compared with the MP/CNs group, the triiodide contents of MP-Que/CNs, MP-Api/CNs, and MP-Mor/CNs increased by 1175.84%, 479.05%, and 2281.50% respectively. The findings revealed that the actual intensity of ULD was drastically reduced by the molecular weight decrease of these flavonoids. For olive oil emulsions prepared with mixed emulsifiers, the low interfacial diffusion rates (0.03 mN·m·s−1/2) and weak emulsifying activity (8.33 m2/g) of the MP/CN complexes were significantly improved by the flavonoids after ULD-assisted treatment. Notably, the emulsions prepared using MP-Api/CNs contained smaller oil droplets and exhibited better emulsifying properties, compared to emulsions prepared with MP-Mor/CNs or MP-Que/CNs. This study is essential for ULD-assisted treatment since the processing impact may be increased by choosing the most suitable flavonoid.

As the main cutting tool of Tunnel Boring Machine (TBM) for rock-breaking, the rock-breaking efficiency of TBM disc cutters directly affects the TBM’s boring speed, which in turn affects the overall progress of the tunnelling project. Therefore, a simple and accurate evaluation method of the rock-breaking efficiency of TBM disc cutters is an essential prerequisite to improve the rock-breaking performance of TBM. In this paper, the classical force prediction equations of disc cutters were summarized and the applicability of each equation for the constant cross-section disc cutters was analyzed. The calculation equation of the specific energy per ring of TBM rock-breaking was derived based on the Rostami prediction equations and the specific energy theory for disc cutter rock-breaking. The specific energy per ring equation was verified through a practical engineering case. The results show that the maximum relative error of the effective thrust force and the effective torque of the cutter head based on the Rostami force prediction equations is 9.8%. The relative error of the specific energy per ring is 8.0%, which indicates that the prediction of the specific energy per ring equation can accurately reflect the rock-breaking efficiency of disc cutters. The derived equation of the specific energy per ring can not only simplify the rock-breaking efficiency evaluation of TBM disc cutters, but also serve as a valuable reference for practical engineering projects.

Dune migration is one of the main processes in arid lands’ geomorphology and is important for the design of windbreaks and sand fixation projects and for the monitoring of desertification dynamics. We conducted long-term continuous positioning monitoring of barchan dunes using RTK equipment and wind regime monitoring in the Sanlongsha dune field, which is located in the northern part of China’s Kumtagh Desert. We analyzed the wind energy environment of the study area, the migration characteristics of different positions in the barchan dune, and dune shape changes during different periods. We found that (1) comparing the differences in migration distance and direction measured at six positions in the barchan, there existed variations in barchan migration across these positions. (2) The shape changes at the left horn, right horn, and windward slope of barchans were larger than at the center of the leeward toe and brink, so the estimates based on measurements at these four positions had a weaker fit with the resultant drift potential (RDP) and a greater difference from the resultant drift direction (RDD). (3) The shape of the leeward slope on the barchan did not change much during dune migration, so the center of the leeward toe and brink measurements were closer to the actual dune migration distance and direction. Thus, we recommend using the center of the leeward toe or brink as the optimal measurement points to monitor barchan dune migration. This study will provide a reference for the more accurate measurement of barchan dune migration.

As an emerging cellular agriculture technology, cultured meat aims to produce meat from in vitro cell culture instead of conventional livestock slaughtering. Various tissue engineering technologies have been applied for cultured meat. In this perspective, we will overview the cutting-edge tissue engineering strategies for cultured meat from the classifications of textured scaffolds, 3D bioprinting, molding, patterning, and cell sheet engineering, and also introduce the applied materials. The future prospects and challenges will also be discussed.

ABSTRACT: The objective of this research was to investigate the effects of Mahuang and Tuer chickens, 2 representatives of the native chicken breed, and the slaughter age on meat quality and flavor compounds of soft-boiled chickens (SCs) in comparison to a commercial cross boiler. A total of 432 chicks were randomly allocated into the following groups: 817 groups raised for 55 d, and Mahuang and Tuer chickens raised for 60, 65, 70, and 75 days (d). After the completion of rearing period, the chickens were slaughtered, and 5 carcasses per group were randomly selected for SC manufacturing. Meat quality was determined based on product yield, pH, color, meat tenderness, and textural and sensorial attributes. The volatile compounds of chicken breast were identified by gas chromatography-ion mobility spectrometry (GC-IMS). The results showed that the yellow-feathered chicken breed, especially Mahuang chicken, had a higher product yield, and lower shear force and sensorial scores than the cross broiler. The pH, L* and b* values in SC breast meat were not significantly influenced by breed (P > 0.05), while greater a* was observed in SC of yellow-feathered chickens compared to cross broilers. The slaughter age had a significant effect on the pH, color, shear force, and textural properties of SC (P < 0.05). The meat tenderness of SC was significantly decreased as the age of chicken increased from 65 d to 75 d (P < 0.05). The relatively young age of yellow-feathered chickens (60 d and 65 d) was rated to have a higher overall sensory score of SC (P < 0.05). A total of 65 organic volatile compounds were identified in SC, including 18 aldehydes, 16 alcohols, 10 ketones, 9 esters, 2 acids, 3 furans, 5 pyrazines, and 2 sulfur-containing compounds. Three chicken breeds were separately clustered in the plot of principal component analysis, indicating breed-specific flavor characteristics. Collectively, the present study provides valuable information for SC processing in terms of carcass selection of yellow-feathered chicken breeds and slaughter age.

Cultured meat is a promising alternative protein technology that aims to produce healthier, safer, and more sustainable meat. It is muscle and fat tissue generated in vitro by the culturing and biomanufacturing of animal cells for human consumption. However, producing cultured meat at large scale and low-cost is still a difficult task. Technology, regulation and consumer acceptance are all challenges for cultured meat production. In this perspective, we divided the industrial production of cultured meat into three goals according to the cell types and complexity. We discuss the technologies used to achieve low-cost cultured meat industrial production. We also discuss the regulation and consumer acceptance and how both can accelerate commercialization.

In this study, we constructed a calculation model to determine the internal temperature field distribution in a medium-sized refrigeration truck with the dimensions of 4.1 m × 2.2 m × 2.2 m. Wind speed, air temperature, and carcass temperature were designated as the initial conditions. The k-ε model of computational fluid dynamics was used to simulate different wind speeds and ventilation duct settings on the carriage. Additionally, under specific boundary conditions, the speed of the air outlet, the types of ventilation ducts, and the carcass loads were all varied to determine the uniformity of the temperature field. The results showed that, when the air outlet speed was 5 m/s, the temperature field in the refrigerated truck was relatively more uniform. The simulated results were in good agreement with the measured results. The average absolute error was 0.35 °C, and the average relative error was 9.23%.

Endogenous proteases are significant for Jinhua ham quality. Protein degradation affects the chemical traits, texture and the formation of flavor substances. Protease activities are affected by different process parameters, such as processing temperature, maturation time, salt content and the drying rate. They affect ham quality, which can be controlled by process parameters. The influences of key factors on Jinhua ham quality are briefly summarized, which can provide a theoretical basis for the selection of specific parameters in dry-cured ham processing. Furthermore, some suggestions are proposed for correcting and improving the flavor and textural defects of ham, yet the effectiveness depends on the operating conditions. The determination of enzyme activity is not real-time and unsupervised at the moment. Future research will focus on the determination of the actual endogenous protease activity and the quantitative relationship between the enzyme activity and main processing parameters.

Fungi may have evolved up to 2.4 billion years ago, but it is unclear when they first colonized land. Here Gan and colleagues report filamentous Ediacaran microfossils from South China that may represent early terrestrial fungi.

The objective of this work was to investigate the effects of oxidation and Maillard reaction on free and protein-bound Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL) formation during braised chicken processing. It was found that a positive correlation was observed between carbonyl, fat oxidation, Maillard reaction, CML and CEL (P < 0.05). The sulfhydryl groups could be used as potential indicators to evaluate the compounds’ interaction levels between Maillard reaction and protein oxidation. Frying promoted the formation of lysine (Lys), glyoxal (GO) and methylglyoxal (MGO) (P < 0.05); Boiling enhanced the formation of GO and MGO (P < 0.05) while inhibited the levels of Lys (P < 0.05); Sterilizing blocked the formation of MGO and Lys (P < 0.01) but improved GO levels (P < 0.05). Finally, a perspective was concluded that the Maillard reaction combined with oxidation is one of the main reasons for the formation of free and protein-bound CML and CEL during braised chicken processing.

We evaluated the possible protective effects of six polyphenols on benzo(a)pyrene (BaP)-induced cytotoxicity in Caco-2 cells. We show that treatment with quinic acid, ferulic acid, homovanillic acid, trolox and BaP decreased cell viability, whereas naringenin and eriodictyol affected viability in a bi-phasic manner with low concentrations decreasing viability whereas higher concentrations increase viability. Co-treatment with 20 μM eriodictyol or naringenin reduced BaP-induced cytotoxicity, including cell apoptosis, cell cycle progression, and oxidative stress. Our results show that the protective effect of eriodictyol was superior to that of naringenin. The potential protective mechanisms of eriodictyol on BaP-induced toxicity were investigated by proteomics. We identified 80 differentially expressed proteins (DEPs) with proteins associated with genetic information processing pathway representing the highest proportion and number of proteins responding to eriodictyol treatment, including key proteins such as RPA2, SNRPA, RAD23B, NUP155 and AARS. Our results provide new knowledge on how polyphenols may prevent BaP-induced carcinogenesis.

In this work, two different covalent reactions, namely, alkaline reaction and free radical oxidation, were selected to compare the difference in the strengthening effects of ultrasound treatment (UDT). The grafting effects were verified by protein electrophoresis and bound gallic acid (GA) assay. Furthermore, non-covalent interactions between myofibrillar protein (MPN) aggregates were destroyed by UDT, as proved by the lower particle sizes and higher ζ-potential. Comparatively, the results from tertiary structure index and circular dichroism revealed UDT-assisted free radical oxidation could lead to better conjugates with greater structural properties. The atomic force microscope (AFME) and protein flexibility showed that MPNs appeared to display as irregular spherical particles after alkaline reaction, however, maintained fibrous structure during the free radical oxidation. Consequently, the combination of UDT and free radical oxidation were more effectively for strengthening the influence of acoustic cavitation on MPNs, of which mechanism was the changes in viscosity properties, microstructure and acoustic cavitation radicals.

Objective The aim of this work was to assess the effect of fermented blueberry (FB; 2%, 4%, and 6%) on the oxidative stability and volatile molecule profiles of emulsion-type sausage stored at 4°C for 28 days. Methods The antioxidant activity of FB was determined through radical-scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Four formulations of sausage treatments with different FB levels (0%, 2%, 4%, 6%) were prepared, then peroxide value (POVs), thiobarbituric acid-reactive substances (TBARS) values, protein carbonyls and thiol groups were measured. The aroma profiles of sausages for each treatment was also determined. Results The half maximal inhibitory concentration indicated that FB had greater scavenging ability than ascorbic acid against DPPH and hydroxyl radicals. Sausages with FB significantly retarded increases in POVs and TBARS, as well as in the content of protein carbonyls during all storage days (p

In this study, the influence of Na content in dry-cured beef by partial replacement with KCl, L-lysine, and L-histidine was investigated. Dry-cured beef aged over 57 days, compared to the control groups (100% NaCl), salt-substituted groups (SS, 39.7% of NaCl, 51.3% of KCl and a blend of 7% L-lysine and 2% L-histidine) had a significant impact on the taste thresholds, relative odor activity value (ROAV), electronic nose (E-nose), and sensory evaluation. This study revealed that the salt substitute process modified the sensory profile by intensifying the “aroma” and differentiating the control group from SS group. The results represented salt substitute analysis of dry-cured beef and may be used by food companies and other stakeholders to understand the changes in sensory characteristics of dry-cured beef due to 100% NaCl process. Salt substitute was developed successfully, presenting a good performance.

Diets have been shown to alter metabolism and gene expression. However, few data are available about changes in gene expression in liver after intake of different meat protein diets. This work aimed to explore the long-term effects of protein source on liver metabolic enzymes. Rats were fed protein diets for 90 days to study whether intake of chicken and pork protein diets promoted gene expression involved in hepatic metabolism. Liver proteome profiles were measured by iTRAQ labeling and LC–ESI–MS/MS. Chicken protein diet induced higher level of serum amino acids in rats than soy protein. Amino acid metabolizing enzymes were downregulated by pork and chicken protein diets compared with soy protein diet. Intake of meat protein diets downregulated enzymes involved in protein synthesis, disulfide bond formation, signal peptide addition, transport, localization, degradation and glycosylation modification, but upregulated enzymes involved in prolyl cis–trans isomerization for protein synthesis. Protein diets from different sources affected the amino acid supply, and further influenced ribosome assembly and protein synthesis through mTOR signaling pathway.

Associations between meat diets and human health have been widely considered. In this study, we focused on long-term effects of different sources of meat protein on liver metabolic enzymes. For 90 days, rats were fed with semisynthetic diets that differed only with protein source. Casein was used as a reference and isolated soybean, fish, chicken, pork, and beef proteins were compared. Changes in liver proteome were determined by isobaric tag for relative and absolute quantitation (iTRAQ) labeling and liquid chromatography electrospray ionization tandem mass spectrometry/mass spectrometry (LC–ESI–MS/MS). Fish and pork protein diets upregulated the gene expression involved in cholesterol synthesis and esterification, and pork protein diet also upregulated the gene expression of high-density lipoprotein receptor and low-density lipoprotein receptor. Chicken, pork, and beef protein diets upregulated the gene expression involved in cholesterol reverse transport and bile acid production, which increased the total cholesterol level in the fish protein diet group. Total cholesterol levels in liver were lower in the pork and beef protein diet groups. Triglyceride levels in liver were lower in chicken, pork, and beef protein diet groups. Peroxisomal proliferator-activated receptor-gamma coactivator-1 was upregulated by chicken, pork and beef protein diets, and promoted the degradation and metabolism of triglyceride, resulting in lower triglyceride in the three diet groups. Meat proteins at a recommended level could be more conducive to cholesterol degradation, triglyceride decomposition, and energy balance maintenance at a healthy level. The findings give a new insight into the associations between meat diet intake and human health.

Objective This study was conducted to investigate the effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the energy metabolism in thigh muscle of embryos and neonatal broilers. Methods A total of 960 eggs were randomly assigned to three treatments: i) non-injected control group, ii) saline group injected with 0.6 mL of physiological saline (0.75%), and iii) CrPyr group injected with 0.6 mL of physiological saline (0.75%) containing 12 mg CrPyr/egg on 17.5 d of incubation. After hatching, 120 male chicks (close to the average body weight of the pooled group) in each group were randomly assigned to eight replications. The feeding experiment lasted 7 days. Results The results showed that IOF of CrPyr increased glucose concentrations in the thigh muscle of broilers on 2 d after injection (p

In this study, the influence of Na content of dry-cured beef by partial replacement with KCl, L-lysine, and L-histidine was investigated during processing. Dry-cured beef aged over 57 days, compared to control groups (100% NaCl), salt substituted groups (SS, 39.7% of NaCl, 51.3% of KCl and a blend of 7% L-lysine and 2% L-histidine); had a significant impact on the proteolysis index and total free amino acids, lower activities, and gene levels of cathepsin B and L, as well as reduced contents of protein carbonyls and thiol group. The present study provides a successful strategy for improvement of the perceived saltiness and inhibition of the bitterness, while exhibiting no significant negative effects on color or textural properties.

In this study, the ACE-inhibitory peptide (

The objective of this study was to investigate the effect of cooking and in vitro digestion on antioxidant activity of peptides in duck meat after 7 days postmortem aging. The 1, 1-diphenyl-2- picrylhydrazyl (DPPH) free radical scavenging activity and reducing power of the obtained peptides were evaluated. Results showed that the cooked sample possessed higher antioxidant activity than the raw sample and upon cooking at different temperatures, sample aged for 7 days had significantly higher antioxidant activity than that of unaged (day 0). The samples which showed higher antioxidant activity after cooking (65°C–30 min, 100°C–20 min, 121°C–10 min) were selected for in vitro digestion, and it is found that their DPPH radical scavenging activity decreased significantly but the reducing power increased significantly after gastrointestinal digestion. These results show the potential of aged duck meat as a good source of antioxidant peptides with high bioactivity after cooking and gastrointestinal digestion.

The high sodium diet is harmful to the human body. In this study, beef was cured with some salt substitutes, namely SS, 39.7% NaCl, 51.3% KCl, 7% L-lysine and 2% L-histidine, in order to reduce the Na content for the final products, and salt substitute effects the physicochemical, lipolytic, and flavor characteristics of dry-cured beef by determining free fatty acids, lipase activity, volatile compounds, and water mobility. The results showed that the lipase activity and unsaturated fatty acids were significantly increased due to the present of L-lysine and L-histidine. In addition, the SS could also enhance the lipoxygenase activity and promoted the lipid oxidation and influenced volatile compounds. The changes of T21 and T22 showed that the water mobility in SS was higher (P < .05) than in the control group. Moreover, the cadaverine, histamine, and tyramine were detected in 57-day dry-cured beef, being below their toxic limits. The present study demonstrated that salt substitute by L-lysine and L-histidine alter the water distribution and mobility, improved the amounts and types of volatile compounds, while had no influence in the quality of product.

Double-shield TBM is more efficient than shield tunnel construction in hard rock strata. It is widely used in subway tunnel construction, such as in Qingdao and Chongqing in China. However, construction vibration problems caused by double-shield TBM critically affect human comfort in surface buildings. In order to study the vibration influence law of double-shield TBM, the on-site monitoring plan of double-shield TBM is developed, relying on a tunnel section of Qingdao Metro Line 4. Then, the vibration monitoring results are analyzed, and the time domain and frequency domain characteristics of vibration acceleration are obtained. Subsequently, taking vibration peak acceleration as the research object, the transverse and longitudinal vibration laws of double-shield TBM construction are studied. Finally, according to the standard of human comfort in buildings, the vibration influence ranges of double-shield TBM construction are obtained. The research results can provide a reference for the vibration effect of double-shield TBM passing through houses, highways and bridges. Moreover, it can also provide a basis for the disputes that double-shield TBM tunnel construction affects the lives of inhabitants.

Storage temperature is considered one of the most important factors that affect the microbial spoilage of fresh meat. Chilling and superchilling are the most popular storage techniques on the market, but during transportation, the temperature may reach 10 °C and may even reach room temperature during local retail storage. In the present study, we stored fresh pork meat at different temperatures, −2 °C, 4 °C, 10 °C, and 25 °C. The composition and functional potential of fresh or spoiled meat resident microbes were analyzed based on 16S rRNA gene amplicon sequencing. The microbial composition exhibited high similarity between pork meat stored at −2 °C and 4 °C, with Pseudomonads and Brochothrix being the dominant taxa. Acinetobacter sp., Myroides sp., and Kurthia sp. were markers for spoiled pork meat stored at 25 °C. Both psychrophilic and mesophilic bacteria were observed to grow under a storage temperature of 10 °C, but the overall composition and functional potential based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were found to be similar to that of meat stored at room temperature. Our results broaden the knowledge of possible microbial changes in pork meat during storage, transportation, or retail.

Previous studies have evaluated pork quality by omics methods. However, proteomics coupled with metabolomics to investigate pork freshness by using pork exudates has not been reported. This study determined the changes in the profiles of peptides and metabolites in exudates from pork stored at different temperatures (25, 10, 4, and −2 °C). Multivariate statistical analysis revealed similar changes in profiles in exudates collected from pork stored at −2 and 4 °C, and additional changes following storage at higher temperatures. We identified peptides from 7 proteins and 30 metabolites differing in abundance between fresh and spoiled pork. Significant correlations between pork quality and most of the peptides from these 7 proteins and 30 metabolites were found. The present study provides insight into changes in the peptide and metabolite profiles of exudates from pork during storage at different temperatures, and our analysis suggests that such changes can be used as markers of pork spoilage.

Lipid oxidation is the main cause of quality deterioration in meat and meat products. To facilitate the identification of candidate molecular biomarkers that are linked to lipid oxidation, we performed the proteomic analysis of duck muscle using isobaric tag for relative and absolute quantification (iTRAQ), followed by parallel reaction monitoring (PRM) to confirm the iTRAQ results. Pectoralis major muscles were divided into 2 groups in accordance with lipid oxidation, and iTRAQ-based analysis identified a total of 301 differentially expressed proteins, of which 15 proteins were examined by PRM assay. Proteins involved in lipid binding and metabolism, lipolysis, stress response, oxidative respiratory chain, and redox regulation were found to be differentially expressed between 2 groups and might affect lipid oxidation in muscles. The findings could contribute to the improved understanding of key proteins and processes engaged in lipid oxidation of meat.

This study aimed to compare the microbial diversity in meatballs with or without blown pack spoilage (BPS) to determine the cause of BPS and to assess the synergistic effect of static magnetic field (SMF) and modified atmosphere packaging (MAP) to reduce the phenomenon of BPS. Results showed that the BPS group with a 2.26-fold larger volume and packaging containing 71.85% CO2 had Klebsiella spp. (46.05%) and Escherichia spp. (39.96%) as the dominant bacteria, which was different from the spoilage group. The results of isolation and identification of strains from the BPS group and their inoculation test confirmed that Klebsiella pneumoniae was the major strain-inducing BPS in meatballs due to its pack-swelling ability. SMF (5 mT) treatment combined with MAP (40%CO2 + 60%N2), which did not influence the sensory quality of meatballs, had a significant synergistic effect on preventing the increase in pack volume. Compared with the control group, this synergistic treatment effectively delayed bacterial growth, drop in pH, and the increase of TBARS. The findings of this study will provide further guidance for meatball manufacturers to adopt effective strategies to reduce the BPS of meatballs.

This study applied peptidomics to investigate potential biomarkers for evaluating pork-meat freshness. The spoilage time points of pork meat stored at −2, 4, 10, and 25 °C were defined by evaluating meat freshness indicators (color, total viable count, pH, and total volatile basic nitrogen). Peptide MVHMASKE was identified as a potential peptide marker via multivariate analysis. Pearson correlation revealed a negative correlation between intensity of MVHMASKE and total viable count/total volatile basic nitrogen. In addition, the correlation between peptide content and the change in pork-meat freshness was verified using real-life samples, and the content of MVHMASKE showed a significant decline during storage under 4 and 25 °C, correspondingly reflecting the change of pork meat from fresh to spoiled. This study provides favorable evidence to evaluate pork-meat freshness by monitoring the change of peptide MVHMASKE in content based on mass spectrometry-based peptidomics.

Myoglobin, a critical protein responsible for meat color, has been shown insusceptible to digestion. The underlying mechanism is not clear. The present study aimed to evaluate whether the structural properties of myoglobin are associated with its insusceptibility to digestion using spectroscopic and computational techniques. Myoglobin was degraded by only 7.03% by pepsin and 33.00% by pancreatin. The structure of myoglobin still maintained α-helix after the two-step digestion, with the exposure of some aromatic residues. In addition, molecular dynamics modeling suggested that hydrophobic amino acid residues (Phe 111, Leu 10, Ala 115, Pro 116) in pepsin and polar amino acid residues (Tyr 146, Thr 95) in myoglobin were found in the proximity of binding sites, which could result in the low digestibility of myoglobin. Our findings provide a new insight into the underlying mechanisms on the difficulty in digestion of myoglobin.

Our previous study showed that the intake of meat proteins dynamically affected fecal microbial composition. However, the digestion of processed meat proteins in vivo and its relationship with gut microbiota and host remain unclear. In this study, we collected cecal contents and intestinal tissue from the mice fed with casein, soybean protein (SP), and four processed pork proteins for 8 months, and analyzed the amino acid (AA) files, cecum microbial composition and metabolites, and intestinal morphology. Dry-cured pork protein and stewed pork protein (SPP) groups had significantly higher total AA content in gut content than the other groups, but the content of the SPP group was relatively lower in the serum. The microbial composition of the processed meat protein groups differed from the casein or SP group, which is consistent with changes in AA composition. Emulsion sausage protein and SP diets upregulated the microbial AA metabolism, energy metabolism, signaling molecules and interaction, translation, and digestive system function but downregulated the microbial membrane transport, signal transduction and cell motility function compared to the casein diet. The SPP diets increased concentrations of acetate, propionate, butyrate, and isovalerate by specific gut microbes, but it decreased the relative abundance of Akkermansia. Moreover, the mice fed SP diet had relatively lower crypt depth, higher villus height and V/C ratio in duodenum, with the longer small intestines and the heavier cecum than other diets. These results suggested that processing methods altered bioavailability of meat proteins, which affected the intestinal morphology and the cecum microbial composition and function.

Salmonella can resist various stresses and survive during food processing, storage, and distribution, resulting in potential health risks to consumers. Therefore, evaluation of bacterial survival profiles under various environmental stresses is necessary. In this study, the resistance profiles of five Salmonella isolates [serotypes with Agona, Infantis, Typhimurium, Enteritidis, and a standard strain (ATCC 13076, Enteritidis serotype)] to acidic, hyperosmotic, and oxidative stresses were examined, and the relative expressions of non-coding small RNAs were also evaluated, including CyaR, MicC, MicA, InvR, RybB, and DsrA, induced by specific stresses. The results indicated that although all tested strains displayed a certain resistance to stresses, there was great diversity in stress resistance among the strains. According to the reduction numbers of cells exposed to stress for 3 h, S. Enteritidis showed the highest resistance to acidic and hyperosmotic stresses, whereas ATCC 13076 showed the greatest resistance to oxidative stress, with less than 0.1 Log CFU/ml of cell reduction. Greater resistance of cells to acidic, hyperosmotic, and oxidative stresses was observed within 1 h, after 2 h, and from 1 to 2 h, respectively. The relative expression of sRNAs depended on the isolate for each stress; acidic exposure for the tested isolates induced high expression levels of DsrA, MicC, InvR, RybB, MicA, and CyaR. The sRNA RybB, associated with sigma E and outer membrane protein in bacteria, showed a fold change of greater than 7 in S. Enteritidis exposed to the tested stresses. CyaR and InvR involved in general stress responses and stress adaptation were also induced to show high expression levels of Salmonella exposed to hyperosmotic stress. Overall, these findings demonstrated that the behaviors of Salmonella under specific stresses varied according to strain and were likely not related to other profiles. The finding also provided insights into the survival of Salmonella subjected to short-term stresses and for controlling Salmonella in the food industry.

Indigenous chickens possess desirable characteristics and account for considerable proportions of the total chicken production in China. The current study examined the growth performance, carcass characteristics and muscle metabolites among a crossbred broiler and two indigenous, yellow-feathered chickens (Mahuang and Tuer) with different ages (60 and 75 days). Results indicated that the crossbred broiler had better feed efficiency, higher breast and thigh muscle yield, as well as a lower abdominal fat percentage than Mahuang and Tuer chickens (p < 0.05). Gas chromatography–mass spectrometry-based metabolomics and multivariate analysis revealed sugars, amino acids and organic acids were the predominant metabolites that differed among the three chicken breeds. Growth performance and carcass traits of yellow-feathered chickens exhibited significant differences with the extension of the feeding period (p < 0.05). Moreover, differential metabolites reflected altered aminoacyl-tRNA biosynthesis, ATP-binding cassette transporters, pantothenate and CoA biosynthesis, as well as glutathione metabolism in yellow-feathered chickens affected by age. Collectively, this study contributes to a deeper understanding of the production efficiency and chemical composition of precursor flavor in Chinese indigenous, yellow-feathered chicken.

To investigate the effects of pre-oxidized myofibrillar protein (MP) on stability of heat-induced MP gelation throughout 28 days of refrigeration, a hydroxyl radical generating system (10 μM FeCl3, 0.1 mM ascorbic acid, with 10 mM H2O2) was employed. Results demonstrated that an increase of carbonyl content followed a similar trend in both pre-oxidized and non-oxidized protein gels. Unexpectedly, pre-oxidized protein gels yielded increased (P

The objective of this study was to investigate changes in flavor components in broth prepared by pork ribs that were aged for 1 d, 3 d, and 7 d. The contents of free amino acids (FAAs), nucleic acid-related compounds, organic acids, and volatile compounds in broth were measured. The overall taste and aroma profiles were evaluated by electronic tongue, electronic nose, and sensory panelists. The results showed that the FAAs and succinic acid contents increased, while the 5ʹ-guanosine monophosphate, 5ʹ-inosine monophosphate, and 5ʹ-adenosine monophosphate contents decreased as the aging time increased. These changes led to the taste characteristics of broth being more savory. However, the results of gas chromatography-mass spectrometry, electronic nose, and sensory test all showed that there were no significant differences in aroma among the samples, where the main volatile compounds of broth were aldehydes, including hexanal, nonanal, octanal, heptanal, (Z)-2-heptanal, and (E)-2-decenal. Hence, postmortem aging affected the taste rather than the aroma of pork rib broth, and extending aging time can improve the taste of broth.

This study analyzed the effect of initial inoculum proportions on Listeria monocytogenes growth when cocultured with two different Weissella viridescens strains. W. viridescens C1 had a strong antimicrobial effect on L. monocytogenes which may be due to the acid, H2O2 and proteinaceous nature of its antimicrobial compounds. W. viridescens C2 had no antimicrobial properties. In liquid coculture, W. viridescens C1 inhibited L. monocytogenes growth, while W. viridescens C2 did not. Thus, L. monocytogenes showed the same growth in the W. viridescens C2 coculture as in the monoculture. Coculturing with W. viridescens at different initial inoculum proportions in laboratory media had no effect on L. monocytogenes growth. This study may help to characterize the interactions between L. monocytogenes and W. viridescens.

Objective This study investigated the effects of different dietary energy sources on early postmortem muscle metabolism of finishing pigs. Methods Seventy-two barrow (Duroc×Landrace×Yorkshire, DLY) pigs (65.0±2.0 kg) were allotted to three iso-energetic and iso-nitrogenous diets: A (44.1% starch, 5.9% crude fat, and 12.6% neutral detergent fibre [NDF]), B (37.6% starch, 9.5% crude fat, and 15.4% NDF) or C (30.9% starch, 14.3% crude fat, and 17.8% NDF). After the duration of 28-day feeding experiment, 24 pigs (eight per treatment) were slaughtered and the M. longissimus lumborum (LL) samples at 45 min postmortem were collected. Results Compared with diet A, diet C resulted in greater adenosine triphosphate and decreased phosphocreatine (PCr) concentrations, greater activity of creatine kinase and reduced percentage bound activities of hexokinase (HK), and pyruvate kinase (PK) in LL muscles (p

Abstract The impact of dietary soybean oil, lard and fish oil on physiological responses in middle age is little studied. In this study, we investigated the changes of oxidative stress, inflammatory cytokines, telomere length, and age-related gene expression in the liver of middle-aged rats in response to the above three fat diets. Male Sprague Dawley rats (12 months old) were fed AIN-93M diets for 3 months, in which soybean oil was equivalently replaced by lard or fish oil. As compared to the lard diet, intake of fish oil diet significantly decreased body weight gain, white blood cell count, and levels of hepatic triacylglycerol, total cholesterol, fat accumulation, low-density lipoprotein, oxidative stress and inflammatory cytokines (P