Insight into the effects of ultrasound-assisted intermittent tumbling on the gelation properties of myofibrillar proteins: Conformational modifications, intermolecular interactions, rheological properties and microstructure.

The aim of the present study was to evaluate the effects of ultrasound-assisted intermittent tumbling (UT) at 300 W, 20 kHz and 40 min on the conformation, intermolecular interactions and aggregation of myofibrillar proteins (MPs) and its induced gelation properties at various tumbling times (4 and 6 h). Raman results showed that all tumbling treatments led the helical structure of MPs to unfold. In comparison to the single intermittent tumbling treatment (ST), UT treatment exerted more pronounced effects on strengthening the intermolecular hydrogen bonds and facilitating the formation of an ordered ß-sheet structure. When the tumbling time was the same, UT treatment caused higher surface hydrophobicity, fluorescence intensity and disulfide bond content in the MPs, inducing the occurrence of hydrophobic interaction and disulfide cross-linking between MPs molecules, thus forming the MPs aggregates. Additionally, results from the solubility, particle size, atomic force microscopy and SDS-PAGE further indicated that, relative to the ST treatment, UT treatment was more potent in promoting the polymerization of myosin heavy chain. The MPs aggregates in the UT group were more uniform than those in the ST group. During the gelation process, the pre-formed MPs aggregates in the UT treatment increased the thermal stability of myosin, rendering it more resistant to heat-induced unfolding of the myosin rod region. Furthermore, they improved the protein tail-tail interaction, resulting in the formation of a well-structured gel network with higher gel strength and cooking yield compared to the ST treatment.

Exploring the Effects of S-Nitrosylation on Caspase-3 Modification and Myofibril Degradation of Beef In Vitro.

This study aimed to explore the effects of S-nitrosylation on caspase-3 modification and its subsequent effects on beef myofibril degradation in vitro. Recombinant caspase-3 was reacted with different concentrations of S-nitrosoglutathione (GSNO, nitric oxide donor) at 37 °C for 30 min and subsequently incubated with purified myofibrillar protein from bovine semimembranosus muscle. Results indicated that the activity of caspase-3 was significantly reduced after GSNO treatments (P < 0.05) and showed a dose-dependent inhibitory effect, which was attributed to the increased S-nitrosylation extent of caspase-3. LC-MS/MS analysis revealed that caspase-3 was S-nitrosylated at cysteine sites 116, 170, 184, 220, and 264. Moreover, the degradation of desmin and troponin-T was notably suppressed by S-nitrosylated caspase-3 (P < 0.05). To conclude, protein S-nitrosylation could modify the cysteine residues of caspase-3, which accounts for the reduced caspase-3 activity and further represses its proteolytic ability on beef myofibrillar protein.

Exploring the role of bacterial communities on the quality formation and biogenic amines accumulation during ripening and storage of dry-cured Chinese bacon (Larou).

This study aimed to reveal the impact of bacterial dynamics on the quality and biogenic amine (BA) accumulation of dry-cured Chinese bacon (Larou). Physicochemical parameters, free amino acids, BAs, amino acid decarboxylase, and microbial profiles were determined, and their relationships were explored during Larou ripening and storage. The results showed that moisture and sodium nitrite decreased significantly during the Larou ripening stage (p < 0.05), while pH, NaCl, TBARS, and total volatile basic nitrogen considerably increased (p < 0.05). BAs were mainly formed during the stages of dry-ripening and storage of Larou and may present a risk of tyramine and phenylethylamine poisoning. Firmicutes and Actinobacteriota were the predominant phyla, and the dominant genera were Staphylococcus, Corynebacterium and Lactococcus. Correlation analysis showed Corynebacterium, Brevibacterium, Lactobacillus, Tetragenococcus and Staphylococci spp. played a crucial role in determining the quality and safety of Larou. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01472-1.

Ultrasound-induced modifications of beef flavor characteristics during postmortem aging.

To investigate the effect of ultrasound treatment on the flavor profile of beef during postmortem aging, a comprehensive analysis of beef flavor was conducted at 0, 7, and 12 d of aging using sensory evaluation and electronic nose. Furthermore, the key volatile flavor compounds were identified using gas chromatography-mass spectrometry (GC-MS), and the odor activity value (OAV) was further evaluated. In addition, the primary pathway involved in flavor formation during beef aging after ultrasound treatment was explored. The results indicated that ultrasound enhanced the flavor profile of beef during postmortem aging by modifying the OAV of hexanal, heptanal, octanal, nonanal, decanal, (Z)-2-nonenal, dodecanal, pentanal, 1-octen-3-ol, octanoic acid, and 2-pentylfuran. Lipid oxidation was a crucial pathway through which ultrasound promoted the generation of volatile flavor compounds in beef, confirmed by the improved oxidation level of fatty acids, particularly monounsaturated ones. The study indicates that ultrasound technology can be regarded as an effective method for enhancing the beef flavor profile during postmortem aging.

Investigating the effects of low-salt processing on the umami peptides of dry-cured ham using peptidomics techniques.

This study investigated the effect of low-salt processing on the umami peptide profile of dry-cured hams. Peptidomics data showed 633 umami peptides in the low- and full-salt groups. Among them, 36.2% and 26.5% of shared umami peptides in the low-salt group were significantly down- and up-regulated in relative abundance. Multivariate statistical analysis showed 1011 significantly different umami peptides (SDUPs) in the low- and full-salt groups. Creatine kinase M-type (CKM) and fast skeletal muscle troponin T (TnTf) were the main precursor proteins of these SDUPs. At the end of processing, the relative expression of CKM was lower in the low-salt group than in the full-salt group (P < 0.05), but there was no significant difference in TnTf. More dipeptidyl peptidase cleavage sites were observed in CKM and TnTf proteins in the low-salt group.

A Novel Dry-Cured Ham Broth-Derived Peptide JHBp2 Effectively Inhibits Salmonella typhimurium In Vitro: Integrated Metabolomic, Proteomic, and Molecular Simulation Analyses.

JHBp2 is a peptide purified from Jinhua ham broth with antibacterial activity against Salmonella typhimurium. Untargeted metabolomics and label-free quantitative proteomics were used to analyze metabolic and protein expression changes in S. typhimurium after JHBp2 treatment. Cell wall and membrane damage results indicate that JHBp2 has membrane-disruptive properties, causing leakage of intracellular nucleic acids and proteins. Metabolomics revealed 516 differentially expressed metabolites, involving cofactor biosynthesis, purine metabolism, ABC transporters, glutathione metabolism, pyrimidine metabolism, etc. Proteomics detected 735 differentially expressed proteins, involving pyruvate metabolism, amino acid biosynthesis, purine metabolism, carbon metabolism, glycolysis/gluconeogenesis, etc. RT-qPCR and proteomics results showed a positive correlation, and molecular docking demonstrated stable binding of JHBp2 to some differentially expressed proteins. In summary, JHBp2 could disrupt the S. typhimurium cell wall and membrane structure, interfere with synthesis of membrane-related proteins, trigger intracellular substance leak, and reduce levels of enzymes and metabolites involved in energy metabolism, amino acid anabolism, and nucleotide anabolism.

S-nitrosoproteomics profiling elucidates the regulatory mechanism of S-nitrosylation on beef quality.

This study aimed to quantitively profile the S-nitrosylation in beef semimembranosus (SM) with different treatments (nitric oxide donor or nitric oxide synthase inhibitor) by applying iodoTMT-based nitrosoproteomics. Results showed that 2096 S-nitrosylated cysteine sites in 368 proteins were detected in beef SM. Besides, differential SNO-modified proteins were screened, some of which were involved in crucial biochemical pathways, including calcium-releasing-related proteins, energy metabolic enzymes, myofibrils, and cytoskeletal proteins. GO analysis indicated that differential proteins were localized in a wide range of cellular compartments, such as cytoplasm, organelle, and mitochondrion, providing a prerequisite for S-nitrosylation exerting broad roles in post-mortem muscles. Furthermore, KEGG analysis validated that these proteins participated in the regulation of diverse post-mortem metabolic processes, especially glycolysis. To conclude, changes of S-nitrosylation levels in post-mortem muscles could impact the structure and function of crucial muscle proteins, which lead to different levels of muscle metabolism and ultimately affect beef quality.

Effects and mechanisms of ultrasound-assisted emulsification treatment on the curcumin delivery and digestive properties of myofibrillar protein-carboxymethyl cellulose complex emulsion gel.

Different emulsion gel systems are widely applied to deliver functional ingredients. The effects and mechanisms of ultrasound-assisted emulsification (UAE) treatment and carboxymethyl cellulose (CMC) modifying the curcumin delivery properties and in vitro digestibility of the myofibrillar protein (MP)-soybean oil emulsion gels were investigated. The rheological properties, droplet size, protein and CMC distribution, ultrastructure, surface hydrophobicity, sulfhydryl groups, and zeta potential of emulsion gels were also measured. Results indicate that UAE treatment and CMC addition both improved curcumin encapsulation and protection efficiency in MP emulsion gel, especially for the UAE combined with CMC (UAE-CMC) treatment which encapsulation efficiency, protection efficiency, the release rate, and bioaccessibility of curcumin increased from 86.75 % to 97.67 %, 44.85 % to 68.85 %, 18.44 % to 41.78 %, and 28.68 % to 44.93 % respectively. The protein digestibility during the gastric stage was decreased after the CMC addition and UAE treatment, and the protein digestibility during the intestinal stage was reduced after the CMC addition. The fatty acid release rate was increased after CMC addition and UAE treatment. Apparent viscosity, storage modulus, and loss modulus were decreased after CMC addition while increased after UAE and UAE-CMC treatment especially the storage modulus increased from 0.26 Pa to 41 Pa after UAE-CMC treatment. The oil size was decreased, the protein and CMC concentration around the oil was increased, and a denser and uniform emulsion gel network structure was formed after UAE treatment. The surface hydrophobicity, free SH groups, and absolute zeta potential were increased after UAE treatment. The UAE-CMC treatment could strengthen the MP emulsion gel structure and decrease the oil size to increase the curcumin delivery properties, and hydrophobic and electrostatic interaction might be essential forces to maintain the emulsion gel.

Studying Antifatigue Mechanism of Tyr-Pro-Leu-Pro in Exercise Mice Using Label-Free Proteomics.

In our previous study, yeast-derived peptide Tyr-Pro-Leu-Pro (YPLP) was found to prolong treadmill time and relieve muscle fatigue in ICR mice. The present study aimed to further investigate the antifatigue mechanism of YPLP. Three doses of YPLP (10, 25, and 50 mg/kg·d) were given to exercise mice for 4 weeks. Results showed that YPLP reduced the oxidative response via the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway and promoted energy metabolism through the AMP-activated protein kinase (AMPK) pathway. Label-free proteomics results showed that 81 differential abundance proteins (DAPs) were regulated by high-dose YPLP. These DAPs belonged to proteasome, mitochondrial, and muscle proteins. YPLP was mainly involved in proteasome, aminoacyl-tRNA biosynthesis, focal adhesion, and MAPK signal pathways to enhance muscle endurance. Furthermore, real-time quantitative PCR and Western blotting results proved that YPLP upregulated Psmd14 expression and downregulated p38 MAPK expression. Overall, this study revealed the mechanism behind YPLP to alleviate exercise fatigue.

Effects of ultrasound-assisted intermittent tumbling on the quality of cooked ham through modifying muscle structure and protein extraction.

BACKGROUND: Tumbling treatment is widely used in the production of cooked ham. However, traditional intermittent tumbling (IT) treatment is time-consuming. To enhance the tumbling efficiency, high-intensity ultrasound was used to assist IT treatment (UIT). RESULTS: UIT treatment reduced the tumbling time and significantly improved the water holding capacity, tenderness, sliceability and texture of cooked ham compared to IT treatment. Furthermore, more violent destruction of meat tissue was exhibited in the UIT treatment. This change facilitated extraction of more salt-soluble protein, which in turn welded meat pieces tightly and improved the quality of the cooked ham. CONCLUSION: UIT treatment could accelerate the tumbling process and enhance the quality of cooked ham. These results may provide guidance on effective strategies for a high-quality meat production process. © 2023 Society of Chemical Industry.

Modification-Specific Proteomic Analysis Reveals Cysteine S-Nitrosylation Mediated the Effect of Preslaughter Transport Stress on Pork Quality Development.

This study aimed to explore the effects of preslaughter transport stress on protein S-nitrosylation levels and S-nitrosylated proteome in post-mortem pork longissimus thoracis (LT) muscle. Pigs (N= 16) were randomly divided into 3 h transport (high-stress group, HS) and 3 h transport followed by 3 h resting treatments (low-stress control group, LS). Results demonstrated that high transport stress levels induced nitric oxide (NO) overproduction by promoting NO synthase (NOS) activity and neuronal NOS (nNOS) expression, which thereby notably increased protein S-nitrosylation levels in post-mortem muscle (p < 0.05). Proteomic analysis indicated that 133 S-nitrosylation-modified cysteines belonging to 85 proteins were significantly differential, of which 101 cysteines of 63 proteins were higher in the HS group (p < 0.05). Differential proteins including cytoskeletal and calcium-handling proteins, glycolytic enzymes, and oxidoreductase were mainly involved in the regulation of muscle contraction and energy metabolism that might together mediate meat quality development. Overall, this study provided direct evidence for changes in S-nitrosylation levels and proteome in post-mortem muscle in response to preslaughter transport stress and revealed the potential impact of S-nitrosylated proteins on meat quality.

Effects of Long-Term Administration of Bovine Bone Gelatin Peptides on Myocardial Hypertrophy in Spontaneously Hypertensive Rats.

The research purpose was to investigate the effects and the underlying molecular mechanisms of bovine bone gelatin peptides (BGP) on myocardial hypertrophy in spontaneously hypertensive rats (SHR). BGP relieved myocardial hypertrophy and fibrosis in SHR rats in a dose-dependent manner by reducing the left ventricular mass index, myocardial cell diameter, myocardial fibrosis area, and levels of myocardial hypertrophy markers (atrial natriuretic and brain natriuretic peptide). Label-free quantitative proteomics analysis showed that long-term administration of BGP changed the left ventricle proteomes of SHR. The 37 differentially expressed proteins in the high-dose BGP group participated in multiple signaling pathways associated with cardiac hypertrophy and fibrosis indicating that BGP could play a cardioprotective effect on SHR rats by targeting multiple signaling pathways. Further validation experiments showed that a high dose of BGP inhibited the expression of phosphoinositide 3-kinase (Pi3k), phosphorylated protein kinase B (p-Akt), and transforming growth factor-beta 1 (TGF-ß1) in the myocardial tissue of SHR rats. Together, BGP could be an effective candidate for functional nutritional supplements to inhibit myocardial hypertrophy and fibrosis by negatively regulating the TGF-ß1 and Pi3k/Akt signaling pathways.

Study on the anti-inflammatory activity of the porcine bone collagen peptides prepared by ultrasound-assisted enzymatic hydrolysis.

In this study, the effects of ultrasound-assisted enzymatic hydrolysis on the extraction of anti-inflammatory peptides from porcine bone collagen were investigated. The results showed that ultrasound treatment increased the content of α-helix while decreased ß-chain and random coil, promoted generation of small molecular peptides. Ultrasound-assisted enzymatic hydrolysis improved the peptide content, enhanced ABTS+ radical scavenging and ferrous ion chelating ability than non-ultrasound group. At the ultrasonic power of 450 W (20 min), peptides possessed significant anti-inflammatory activity, where the releasing of interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) was all suppressed in lipopolysaccharide (LPS) induced RAW264.7 cells. After the analysis with LC-MS/MS, eight peptides with potential anti-inflammatory activities were selected by the PeptideRanker and molecular docking. In general, the ultrasound-assisted enzymatic hydrolysis was an effective strategy to extract the bioactive peptides from porcine bone, and the inflammatory regulation capacity of bone collagen sourced peptides was firstly demonstrated.

Distribution and Degradation of Pork Filamin during Postmortem Aging.

The filamin C (FLNC) was hypothesized to be colocalized with its certain binding partners in pork tissues and calpain as well as caspase was assumed responsible for the postmortem degradation of FLNC. Therefore, the specific distribution of pork FLNC and its degradation pattern during postmortem aging were investigated in this study. The longissimus thoracis muscles from 12 pigs were removed from the carcasses and then aged at 4 °C for 1, 6, 12, 24, 72, and 168 h, respectively. The FLNC signals appeared to localize in subsarcolemmal areas by cross-sectional images, while the localization was found surrounding the myofibrils at the level of the Z-discs in longitudinal sections. FLNC displayed a highly overlapped spatial colocalization with actin or integrin. Western blot results showed that the intact 290 kDa FLNC was rapidly degraded to produce an approximately 280 kDa band. An almost overlapped distribution pattern was observed between FLNC and µ-calpain or caspase-3 in porcine skeletal muscle cells. Moreover, both the µ-calpain inhibitor and the caspase-3 inhibitor could inhibit the degradation of FLNC in porcine LT muscles during postmortem aging.

Effect of Yeast-Derived Peptides on Skeletal Muscle Function and Exercise-Induced Fatigue in C2C12 Myotube Cells and ICR Mice.

In our previous study, the antioxidant peptides (XHY69AP, AP-D, YPLP, and AGPL) were obtained from potential probiotic yeast (Yamadazyma triangularis XHY69), which was selected by our lab from dry-cured ham. This work aimed to explore the effects of yeast-derived peptides on skeletal muscle function and muscle fatigue. Results showed that yeast-derived peptides up-regulated slow-twitch fiber expression and down-regulated fast-twitch fiber expression in C2C12 cells (p < 0.05). The peptides improved mitochondrial membrane potential, adenosine triphosphate generation, and expression of cytochrome-relative genes, thus promoting mitochondrial function. Among these peptides, YPLP up-regulated the relative gene expression of the AMP-activated protein kinase (AMPK) pathway and activated AMPK by phosphorylation. Moreover, YPLP could prolong treadmill time, increase muscle and liver glycogen contents, reduce lactic acid and urea nitrogen contents, and alleviate muscle tissue injury in ICR exercise mice. These results demonstrate that yeast-derived peptides could change the muscle fiber composition, improve muscle function, and relieve muscle fatigue.

Effect of Pre-Slaughter Transport Stress on Protein S-Nitrosylation Levels of Pork during Postmortem Aging.

This study aimed to investigate the effect of pre-slaughter transport stress on the protein S-nitrosylation levels of pork during 0, 3, and 6 days of aging. Pigs (N = 16) were randomly selected and divided into two treatments: 3 h transport (transport stress, TS) and 3 h transport followed by 3 h resting (control, CON). Results showed that the TS group at 0 and 3 days presented a higher nitric oxide synthase (NOS) activity and neuronal NOS (nNOS) expression than the CON group (P < 0.05). Additionally, nNOS was not only abundantly localized in the membrane but also observed in small amounts in the cytoplasm. The immunoblot of overall S-nitrosylated protein showed that protein S-nitrosylation levels in the TS group were greater than in the CON group during postmortem aging (P < 0.05). This work can deliver novel insights into the mechanism of meat quality changes in response to pre-slaughter stress.

Flavor-food ingredient interactions in fortified or reformulated novel food: Binding behaviors, manipulation strategies, sensory impacts, and future trends in delicious and healthy food design.

With consumers gaining prominent awareness of health and well-being, a diverse range of fortified or reformulated novel food is developed to achieve personalized or tailored nutrition using protein, carbohydrates, or fat as building blocks. Flavor property is a critical factor in the acceptability and marketability of fortified or reformulated food. Major food ingredients are able to interact with flavor compounds, leading to a significant change in flavor release from the food matrix and, ultimately, altering flavor perception. Although many efforts have been made to elucidate how food matrix components change flavor binding capacities, the influences on flavor perception and their implications for the innovation of fortified or reformulated novel food have not been systematically summarized up to now. Thus, this review provides detailed knowledge about the binding behaviors of flavors to major food ingredients, as well as their influences on flavor retention, release, and perception. Practical approaches for manipulating these interactions and the resulting flavor quality are also reviewed, from the scope of their intrinsic and extrinsic influencing factors with technologies available, which is helpful for future food innovation. Evaluation of food-ingredient interactions using real food matrices while considering multisensory flavor perception is also prospected, to well motivate food industries to investigate new strategies for tasteful and healthy food design in response to consumers' unwillingness to compromise on flavor for health.

Evaluation of ultrasound-assisted process as an approach for improving the overall quality of unsmoked bacon.

Our previous study has found that ultrasonic application on raw meat could improve the flavor of unsmoked bacon. For comprehensively evaluating the impacts of ultrasonic pretreatment (0, 250, 500 or 750 W, 20 kHz) on the overall quality of unsmoked bacon during processing, the following indicators were determined including salt and water content, pH, shear force, color, water distribution, texture and myofibril microstructure. Results manifest that ultrasonic pretreatment could significantly improve the salt and water content, pH and redness of unsmoked bacon. The water retention capacity was obviously enhanced by ultrasonic pretreatment proved by increased immobile water and decreased free water. Meanwhile, the shear force, the hardness and the chewiness were notably ameliorated after ultrasonic pretreatment, suggesting a better tenderness verified by the observation results of transmission electron microscope. However, no significant differences were found on the brightness, yellowness, springiness, cohesiveness and resilience of unsmoked bacon after ultrasonic pretreatment. Consequently, ultrasound could be considered as a potential tool for the overall-quality improvement of unsmoked bacon.

Crosstalk between dietary pomegranate and gut microbiota: evidence of health benefits.

Gut microbiota (GM) is an invisible organ that plays an important role in human health. Increasing evidence suggests that polyphenols in pomegranate (punicalagin, PU) could serve as prebiotics to modulate the composition and function of GM. In turn, GM transform PU into bioactive metabolites such as ellagic acid (EA) and urolithin (Uro). In this review, the interplay between pomegranate and GM is thoroughly described by unveiling a dialog in which both actors seem to affect each other's roles. In a first dialog, the influence of bioactive compounds from pomegranate on GM is described. The second act shows how the GM biotransform pomegranate phenolics into Uro. Finally, the health benefits of Uro and that related molecular mechanism are summarized and discussed. Intake of pomegranate promotes beneficial bacteria in GM (e.g. Lactobacillus spp., Bifidobacterium spp.) while reducing the growth of harmful bacteria (e.g. Bacteroides fragilis group, Clostridia). Akkermansia muciniphila, and Gordonibacter spp., among others, biotransform PU and EA into Uro. Uro contributes to strengthening intestinal barrier and reducing inflammatory processes. Yet, Uro production varies greatly among individuals and depend on GM composition. Uro-producing bacteria and precise metabolic pathways need to be further elucidated therefore contributing to personalized and precision nutrition.

Gut microbiota plays a critical role in maintaining host health.Pomegranate is rich in bioactive components.Consumption of pomegranate positively modulates gut microbiota.Gut microbiota can transform ellagitannins in pomegranate into urolithin.Urolithin has high bioavailability and multiple health benefits.

Effects of ultrasound on the oxidation and structure of myofibrillar protein in the presence or absence of soybean oil.

BACKGROUND: Ultrasound is widely used as a novel non-thermal processing technique to improve protein properties. In recent decades, applying ultrasound-assisted emulsification (UAE) to produce protein-stabilized emulsion has attracted people's attention. Instead of applying ultrasound to treat a single protein solution, UAE treatment refers to the use of sonication to a mixture of protein and oil. The purpose of this study was to compare the different effects of ultrasound treatment on the properties of myofibrillar protein (MP) in the presence or absence of soybean oil. A suitable sonication power was selected based on the change in emulsion properties. RESULTS: 300 W sonication power was selected because of its most effectively decreased emulsion droplet size and increased absolute zeta potential. Sonication more significantly increased the protein carbonyl content and disulfide bonds of the MP-soybean oil sample compared with the MP sample. Due to the presence of oil, ultrasound could unfold more protein molecules, illustrated by a lower α-helix content and intrinsic fluorescence intensity, and a higher surface hydrophobicity. Results of liquid chromatography-tandem mass spectrometry illustrated that sonication enhanced the myosin heavy chain and actin content at the soybean oil interface as well as accelerated the myosin light chain to separate from myosin in the MP-soybean oil system. CONCLUSION: Ultrasound treatment could lead to a higher level of protein oxidation and greater protein molecule exposure in the MP in the presence of oil system than in the oil-free MP system. © 2023 Society of Chemical Industry.