Myofibrillar Proteins Research Articles

Inhibitive effect of trehalose and sodium pyrophosphate on oxidation and structural changes of myofibrillar proteins in silver carp surimi during frozen storage

This work investigated the cryoprotective effect of trehalose (TH) and sodium pyrophosphate (SPP) alone and in combination on myofibrillar protein (MP) oxidation and structural changes in silver carp surimi during 90 days of frozen storage (-20 °C). TH combined with SPP was significantly more effective than single TH or SPP in preventing MP oxidation (P < 0.05), showing a higher SH content (6.05 nmol/mg protein), and a lower carbonyl (4.24 nmol/mg protein) and dityrosine content (1280 A.U.). SDS-PAGE results indicated that TH combined with SPP did not differ significantly from TH and SPP in inhibiting protein degradation but was more effective in inhibiting protein crosslinking. Moreover, all cryoprotectants could stabilise the secondary and tertiary structures and inhibit unfolded and aggregation of MP, with the combination of TH and SPP being the best. It's worth noting that TH combined with SPP had a synergistic effect on inhibiting the decrease in α-helix content and gel-forming ability, and the increase in surface hydrophobicity. Overall, TH combined with SPP could significantly inhibited MP oxidation and structural changes in surimi during frozen storage and improve the gel-forming ability, which was significantly better than single TH or SPP.

Conformational changes induced by selected flavor compounds from spices regulate the binding ability of myofibrillar proteins to aldehyde compounds

Interactions among flavor compounds from spices (FCS) and myofibrillar proteins (MP) were investigated. Fluorescence and Fourier transform infrared spectroscopy showed that hydrogen bonding and hydrophobic interactions were the main binding forces between FCS and MP. The FCS increased the particle size and SH content of MP and caused a reduction of zeta potential from −5.23 to −6.50 mV. Furthermore, FCS could modify the binding ability of MP and aldehydes. Eugenol reduced the ability of MP to bond with aldehydes by 22.70–47.87 %. Molecular dynamics simulations demonstrated that eugenol may combat nonanal to attain binding site of amino acid residue (PHE165) and induce protein conformational changes. Electrostatic interactions and van der Waals forces within myosin-nonanal may be disrupted by these alterations, which could reduce stability of complex and cause release of nonanal. This study could provide new insights into regulating the ability of proteins to release and hold flavors.

Uncovering quality changes of surimi-sol based products subjected to freeze–thaw process: The potential role of oxidative modification on salt-dissolved myofibrillar protein aggregation and gelling properties

Frozen surimi quality generally correlates with oxidation, but impacts of protein oxidation on salt-dissolved myofibrillar protein (MP) sol in surimi remain unclear. Hence, physicochemical and gelling properties of MP sol with different oxidation degrees were investigated subjected to freeze–thaw cycles. Results showed that mild oxidation (≤1 mmol/L) improved unfrozen MP gel quality with lowest cooking loss (3.29 %) and highest hardness (829.76 N). Whereas, oxidized sol suffering freeze-thawing degenerated severely, showing reduction of 23.85 % of salt soluble protein contents with H2O2 concentrations of 10 mmol/L. Shearing before heating influenced gelling properties of freeze-thawed sol, depending on oxidation levels. Oxidized gel with shearing displayed disorganized network structures, whereas gel without shearing displayed relatively complete appearances without holes under high oxidation condition (10 mmol/L). Overall, freeze–thaw process aggravated denaturation extents of MP sol subjected to oxidation, further causing high water loss and yellow color of heat-induced gel, especially to gel with shearing.

Proteomics reveals the mechanism of protein degradation and its relationship to sensorial and texture characteristics in dry-cured squid during processing

Proteolysis in dry-cured squid contributes to the development of sensory and textural attributes. In this study, label-free quantitative proteomics was conducted to study the mechanism of proteolysis and its correlation with quality changes. The results showed that the protein profile of dry-cured squid changed markedly during processing, which was confirmed by the quantification of myofibrillar protein, amino nitrogen and total free acids, and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Thirty-two key differentially abundant proteins were found to be correlated with sensory and texture characteristics, including myofibrillar protein, tubulin beta chain, collagens, heat shock proteins and cytochrome c. The correlation analysis indicated that myosin regulatory light chain and tubulin beta chain played the most important role in the development of texture and sensory attributes in squid samples during the dry-curing process. The results offered novel insights into proteolysis in dry-cured squid and its relationship to quality changes.

Gastrointestinal digestion behavior and bioavailability of greenly prepared highly loaded myofibrillar-luteolin vehicle

In this study, the highly loaded myofibrillar protein (MP)-luteolin (Lut) complexes were noncovalently constructed by using green high-pressure homogenization technology (HPH) and high-pressure micro-fluidization technology (HPM), aiming to optimize the encapsulation efficiency of flavonoids in the protein-based vehicle without relying on the organic solvent (i.e. DMSO, ethanol, etc.). The loading efficiency of Lut into MPs could reach 100 % with a concentration of 120 μmol/g protein by using HPH (103 MPa, 2 passes) without ethanol adoption. The in vitro gastrointestinal digestion behavior and antioxidant activity of the complexes were then compared with those of ethanol-assisted groups. During gastrointestinal digestion, the MP digestibility of complexes, reaching more than 70.56 % after thermal treatment, was higher than that of sole protein. The release profile of Lut encapsulated in ethanol-containing and ethanol-free samples both well fitted with the Hixson-Crowell release kinetic model (R2 = 0.92 and 0.94, respectively), and the total phenol content decreased by ≥ 40.02 % and ≥ 62.62 %, respectively. The in vitro antioxidant activity (DPPH, ABTS, and Fe2+) of the digestive products was significantly improved by 23.89 %, 159.69 %, 351.12 % (ethanol groups) and 13.43 %, 125.48 %, 213.95 % (non-ethanol groups). The 3 mg/mL freeze-dried digesta significantly alleviated lipid accumulation and oxidative stress in HepG2 cells. The triglycerides and malondialdehyde contents decreased by at least 57.62 % and 67.74 % after digesta treatment. This study provides an easily approached and environment-friendly strategy to construct a highly loaded protein–flavonoid conjugate, which showed great potential in the formulation of healthier meat products.

Integrated Multi-Spectroscopy and Molecular Dynamics Simulations to Explore the Interaction Mechanism of Phenolic Compounds and Sea Bass Myofibrillar Protein

Integrated Multi-Spectroscopy and Molecular Dynamics Simulations to Explore the Interaction Mechanism of Phenolic Compounds and Sea Bass Myofibrillar Protein

Effect of interaction between resveratrol and myofibrillar protein on the production of bound heterocyclic amines

To elucidate the pathways and mechanisms by which polyphenols inhibit protein-bound heterocyclic amines (HAs), the influence of resveratrol on bound/free HAs and the structure changes of myofibrillar proteins (MP) in the system of creatinine/MP/glucose model was studied. The results demonstrate that resveratrol significantly reduced bound and free HAs in the reaction systems (P < 0.05), and facilitates the transition from bound to free HAs. In addition, resveratrol altered the secondary structure of MP and had a static quenching effect on MP fluorescence. The strong interactions between resveratrol and MP are mainly hydrogen bonding and hydrophobic interactions. Furthermore, the results of molecular docking demonstrated that resveratrol exposed more hydrophobic amino acids (Ala, Lys and Pro) at the 556–578 amino acid sites of myosin. These results indicate that resveratrol controls the formation of bound HAs by reducing exposure to amino acids involved in the HAs reaction and promoting exposure to non-precursor amino acids.

Effect of three unsaturated fatty acids on the protein oxidation and structure of myofibrillar proteins from rainbow trout (Oncorhynchus mykiss)

In this study, the impact of three unsaturated fatty acids (Oleic acid: OA, Eicosapentaenoic acid: EPA, Docosahexaenoic acid: DHA) on the oxidation and structure of rainbow trout myofibrillar protein (MP) was explored. The findings revealed a notable increase in carbonyl content (P < 0.05) and a significant decrease in total sulfhydryl content (P < 0.05) of MP with the concentration increase of the three unsaturated fatty acids. Endogenous fluorescence spectroscopy and surface hydrophobicity analyses showed that unsaturated fatty acids can cause unfolding and exposure of hydrophobic groups in MP. In addition, SDS-PAGE showed that disulfide bonds were associated with MP cross-linking and aggregate size induced by unsaturated fatty acids. Overall, three unsaturated fatty acid treatments facilitated the oxidation of myofibrillar proteins, and the extent of protein oxidation was closely associated with the concentration of unsaturated fatty acids.

Effect of starch and peanut oil on physicochemical and gel properties of myofibrillar protein: Amylose content and addition form

Starch and peanut oil (PO) were widely used to improve the gel properties of surimi, however, the impact mechanism of addition forms on the denaturation and aggregation behavior of myofibrillar protein (MP) is not clear. Therefore, the effect of starch, PO, starch/PO mixture, and starch-based emulsion on the physicochemical and gel properties of MP was investigated. The results showed that amylose could accelerate the aggregation of MP, while amylopectin was conducive to the improvement of gel properties. The addition of PO, starch/PO mixture, or starch-based emulsion increased the turbidity, solubility, sulfhydryl content of MP, and improved the gel strength, whiteness, and texture of MP gel. However, compared with starch/PO mixture group, the gel strength of MP with waxy, normal and high amylose corn starch-based emulsion increased by 22.68 %, 10.27 %, and 32.89 %, respectively. The MP containing emulsion had higher storage modulus than MP with starch/PO mixture under the same amylose content. CLSM results indicated that the oil droplets aggregated in PO or starch/PO mixture group, while emulsified oil droplets filled the protein gel network more homogeneously. Therefore, the addition of starch and PO in the form of emulsion could effectively play the filling role to improve the gel properties of MP.

The impact of pressure-shift freezing on the three-dimensional network structure and properties of myofibrillar proteins in surimi gel derived from freshwater fish

Freezing treatment can prolong the shelf life of surimi products, but it will lead to deterioration of surimi gel quality. This study compared the effects of three different processing methods — non-freezing processing (control), conventional air freezing (CAF), and pressure-shift freezing (PSF) — on the three-dimensional (3D) network structure of grass carp surimi gel. After PSF treatment, the pores in the 3D gel network structure were denser compared to the control group which facilitates interaction of water and network structure. Furthermore, the ultraviolet and fluorescence spectral analysis indicated that PSF treatment mitigates the decline in stability of the tertiary structure of myofibrillar protein (MP) during freezing. The microstructure of MP showed that PSF treatment promotes the cross-linking of MP to form protein aggregates and then promotes the gelation of MP. Industrial relevancePSF can increase the commodity value of low-value freshwater fish products and has potential in the development of new products of surimi gels. This study reported a novel idea and theoretical basis for the application of PSF technology in the frozen food and aquatic product processing industry.

The interaction mechanism of different ionic polysaccharides with myofibrillar protein and its contribution to the heat‐induced gels

AbstractPolysaccharides are widely used as quality improvers for meat products. However, the mechanisms of how different ionic polysaccharides regulate the gelling properties of myofibrillar protein (MP) are still unclear. This study aimed to elucidate the contribution of different ionic polysaccharides to MP gelation and its mechanism. The enhancement of hydrogen bond, hydrophobic interaction, and disulfide bond between carboxymethyl cellulose sodium (CMC‐Na, anionic polysaccharide) and MP made them bind tightly, which contributes to the improvement of gel strength, water‐holding capacity, and viscoelasticity. Konjac glucomannan (neutral polysaccharide) mainly relied on physical filling to support the gel network and improve the gel characteristics. The electrostatic attraction between cationic polysaccharides and MP enhanced the binding between them. However, due to the large structure of chitosan (cationic polysaccharide) sugar chain, it can only attach to the surface of protein, which limits the interaction between them. These findings will provide guidance for the application of polysaccharides as food quality improvers or fat substitutes and the design of new low‐fat restructured meat products.

The Effects of Four Different Thawing Methods on Quality Indicators of Amphioctopus neglectus.

Amphioctopus neglectus is a species of octopus that is favored by consumers due to its rich nutrient profile. To investigate the influence of different thawing methods on the quality of octopus meat, we employed four distinct thawing methods: air thawing (AT), hydrostatic thawing (HT), flowing water thawing (FWT), and microwave thawing (MT). We then explored the differences in texture, color, water retention, pH, total volatile basic nitrogen (TVB-N), total sulfhydryl content, Ca2+-ATPase activity, and myofibrillar protein, among other quality indicators in response to these methods, and used a low-field nuclear magnetic resonance analyzer to assess the water migration that occurred during the thawing process. The results revealed that AT had the longest thawing time, leading to oxidation-induced protein denaturation, myofibrillar protein damage, and a significant decrease in water retention. Additionally, when this method was utilized, the content of TVB-N was significantly higher than in the other three groups. HT, to a certain extent, isolated the oxygen in the meat and thus alleviated protein oxidation, allowing higher levels of Ca2+-ATPase activity, sulfhydryl content, and springiness to be maintained. However, HT had a longer duration: 2.95 times that of FWT, resulting in a 9.84% higher cooking loss and a 28.21% higher TVB-N content compared to FWT. MT had the shortest thawing time, yielding the lowest content of TVB-N. However, uneven heating and in some cases overcooking occurred, severely damaging the protein structure, with a concurrent increase in thawing loss, W value, hardness, and shear force. Meanwhile, FWT improved the L*, W* and b* values of octopus meat, enhancing its color and water retention. The myofibrillar protein (MP) concentration was also the highest after FWT, with clearer subunit bands in SDS-PAGE electrophoresis, indicating that less degradation occurred and allowing greater springiness, increased Ca2+-ATPase activity, and a higher sulfhydryl content to be maintained. This suggests that FWT has an inhibitory effect on oxidation, alleviating protein oxidation degradation and preserving the quality of the meat. In conclusion, FWT outperformed the other three thawing methods, effectively minimizing adverse changes during thawing and successfully maintaining the quality of octopus meat.

Towards higher-quality low salt surimi gels: Significance of the combinatorial effects of chickpea protein with transglutaminase on their micro-structures

The textural properties of low-salt hybrid gel made from silver carp (Hypophthalmichthys molitrix) and chickpea protein (CPP) with or without external transglutaminase (TGase) were investigated. A decrease in gel strength (P﹤0.01), hardness (P﹤0.01), storage modulus (G′) and loss modulus (G″) of the hybrid gel containing CPP appeared regardless of the addition of TGase. Furthermore, the addition of CPP combining with TGase significantly induced a significantly higher resilience (from 43.5% to 50.3%), cohesiveness (from 0.72 to 0.79), proportion of immobilized water (from 95.7% to 97.4%), number of pores (from 3181 to 4868) and apparent porosity (from 30.55% to 40.26%) than those of the group containing TGase alone, which indicated the combining effect of CPP and TGase on the textural properties. The SDS-PAGE profiles showed that the covalent complex between CPP and myofibrillar proteins was not observed. During the gelation of myofibrillar protein filaments, CPP wrapped the fibres shown by the microstructure morphology and increased the friction between fibres, leading to an increase in relaxation time. TGase promoted this effect and induced the formation of a denser microstructure. The present study provided a feasible approach for the preparation of high-quality low salt surimi products with more favorable texture and acceptability.

Effect of microwave and conduction heating on the adsorption ability of myofibrillar protein to pyrazine flavor compounds

In order to clarify the modulation of microwave and conduction heating on the aroma release and adsorption of meat, the effect of different myofibrillar proteins (MP) on the release ability of pyrazines (2-methylpyrazine, 2,5-dimethylpyrazine, and 2,3,5-trimethylpyrazine) was investigated. The adsorption ability, hydrophobicity of MP, and thermodynamic parameters were analyzed. Conduction heating by water bath exhibited stronger adsorption ability of MP for 2-methylpyrazine (17.17 ± 2.27%) than that of microwave, followed by 2,3,5-trimethylpyrazine (11.50 ± 0.91%) and 2,5-dimethylpyrazine (8.63 ± 5.24%), which accounted for the structures of pyrazines. Water bath heating promoted protein unfolding leading to increased exposure of hydrophobic regions thereby enhancing binding affinity with pyrazine flavor compounds. Furthermore, fluorescence quenching ability was enhanced with increasing substituents on pyrazine flavor compounds. The hydrophobic interaction between 2,5-dimethylpyrazine and MP was dominant in both heat treatments. The interactions of conduction-heated MP with 2-methylpyrazine and 2,3,5-trimethylpyrazine predominantly involved hydrophobic forces, whereas interactions with microwave-heated proteins were primarily driven by van der Waals forces and hydrogen bonding effects. The results obtained from this study provide valuable theoretical insights into understanding the differences in the flavor release of meat product resulting from microwave versus water bath heating.

Effect of Static Magnetic Field on the Quality of Pork during Super-Chilling Storage.

Fresh pork tenderloin was stored at -3 °C under different static magnetic fields (SMF) of 0, 4, and 10 mT (control, MF-4, and MF-10) to investigate their physicochemical properties changes during storage of 8 days. The initial equilibrium temperature of the samples stored with 4 mT MF was found to be -2.3 °C, which was slightly lower (0.3 °C) than that the control value. The super-chilling phenomenon on the pork was then observed, as the samples stored under the magnetic field did not freeze throughout storage period, but the control experienced a sudden change in temperature after 138 h and then froze. The preservation effect of MF-4 on meat quality was the best in all treatment groups. MF-4 achieved a higher water-retention rate, with drip and cook losses of 6.5% and 29.0% lower than the control, respectively. Meanwhile, the MF-4 effectively delayed the color change in the meat during the storage and the texture hardening after cooking, and effectively controlled the growth of the total volatile saline nitrogen content on the samples. In addition, MF-4 delayed the reduction in myofibrillar protein solubility, sulfhydryl content, and emulsification capacity, indicating that this field inhibited the denaturation of myofibrillar protein. This study can be considered as an application reference of magnetic fields during meat storage at a super-chilled temperature.

Effects of plasma-activated slightly acidic electrolyzed water on salmon myofibrillar protein: Insights from structure and molecular docking

The present study investigated the impact of plasma-activated water (PAW), slightly acidic electrolytic water (SAEW) and plasma-activated slightly acidic electrolytic water (PASW) treatment on myofibrillar protein (MP) in salmon fillets. Additionally, the interaction mechanism between myosin and reactive oxygen species was explored by molecular docking. Compared with the control group (719.26 nm), PASW treatment group exhibited the smallest particle size (408.97 nm). The PASW treatment exhibited efficacy in reducing MP aggregation and inhibiting protein oxidation. In comparison with other treatments, PASW treatment demonstrated a greater ability to mitigate damage to the secondary and tertiary structures of MP. O3 and H2O2 interact with myosin through hydrogen bonding. Specifically, O3 interacts with Lys676, Gly677, and Met678 of myosin while H2O2 binds to Thr681, Asp626, Arg680, and Met678. This study offers novel insights into the impact of PASW on MP, and provides a theoretical foundation for its application in aquatic product processing.

Adenosine monophosphate boosts the cryoprotection of ultrasound-assisted freezing to frozen surimi: Insights into protein structures and gelling behaviors

Ultrasound-assisted freezing (UAF) is a clean technique for meat cryoprotections; however, its effectiveness is still limited compared to conventional cryoprotectants, e.g., sugars, polyols, especially at high dosages. To resolve this problem, a synergistic cryoprotection strategy was developed in this study. Adenosine monophosphate (AMP), an adenosine-type food additive, was introduced into frozen surimi at a considerably reduced content (0.08%), yet substantially enhanced the efficiency of UAF to comparable levels of commercial cryoprotectant (4% sucrose with 4% sorbitol). Specifically, UAF/AMP treatment retarded denaturation of surimi myofibrillar protein (MP) during 60-day frozen storage, as evidenced by its increased solubility, Ca2+-ATPase activity, sulfhydryl content, declined surface hydrophobicity, particle size, and stabilized protein conformation. Gels of UAF/AMP-treated surimi also demonstrated more stabilized microstructures, uniform water distributions, enhanced mechanical properties and water-holding capacities. This study provided a feasible approach to boost the cryoprotective performance of UAF, thus expanding its potential applications in frozen food industry.

Metabolomic profile of muscles from tilapia cultured in recirculating aquaculture systems and traditional aquaculture in ponds and protein stability during freeze-thaw cycles

Muscle protein stability during freeze-thaw (F-T) cycles was investigated with tilapia cultured in recirculating aquaculture systems (RAS) and traditional aquaculture in ponds (TAP). This study found that fatty acids (eg., palmitic acid) were enriched in TAP, while antioxidants (eg., glutathione) were enriched in RAS. Generally, proteins in the RAS group exhibited greater stability against denaturation during the F-T cycle, suggested by a less decrease in haem protein content (77% in RAS and 86% in TAP) and a less increase in surface hydrophobicity of sarcoplasmic protein (63% in RAS and 101% in TAP). There was no significant difference in oxidative stability of myofibrillar protein between the two groups. This study provides a theoretical guide for the quality control of tilapia cultured in RAS during frozen storage.

Cryoprotective effect of glycopeptide complex from abalone viscera on frozen surimi and its underlying mechanism

AbstractFreezing technology is important for the long‐term preservation of aquatic products such as surimi. However, mechanical damage caused by ice crystals would lead to quality deterioration. Abalone viscera glycopeptide (AVGP) complex was prepared by hydrolysis technology, which exhibited ice recrystallization ability and antioxidant activity. Moreover, effects of AVGP on Ca2+‐ATPase activity, total sulfhydryl content, secondary structure of myofibrillar protein (MP), rheological properties, and gel properties of surimi frozen were investigated. Results showed that surimi treated with AVGP could improve the gel strength and rheological properties of surimi, reduce the gel ice crystal holes, and improve the degradation of gel matrix caused by freeze–thaw. AVGP can significantly inhibit the decrease of Ca2+‐ATPase activity and total sulfhydryl group content. When the addition of AVGP exceeded 4% (w/w), its freezing protection effect on MP was better than that of commercial antifreeze agents. Moreover, the α‐helix and β‐fold contents in the 4% AVGP group were significantly higher than those in the control group, indicating that the addition of an appropriate amount of AVGP can protect the secondary structure of MP. Therefore, AVGP could serve as a new food ingredient with antifreeze and antioxidant functions for frozen surimi.

Changes in properties of myofibrillar protein and myofibrillar protein gel from freshwater fish after low-temperature and high-pressure collaborative treatment

This study investigated the effects of low-temperature and high-pressure collaborative and conventional air freezing (CAF) on myofibrillar protein (MP) characteristics from grass carp. Turbidity, solubility, and particle size analysis showed that the pressure shift freezing (PSF) treatment could inhibit the formation of large MP aggregates to a certain extent during freezing. Chemical interaction studies unveiled that PSF treatment not only mitigates damage to the inherent structure of MP during freezing but also enhances its crosslinking ability. Microstructure analysis revealed a densely woven fibrous protein network structure within the MP gel in the PSF group. MP gel with fiber shape network structure in the PSF group exhibited stronger water-holding capacity and mechanical properties compared to the CAF group having an incomplete protein network structure. This suggests that the combined application of low-temperature and high-pressure treatment holds promising potential for utilization in the surimi gel processing industry and aquatic products processing.Industrial relevance: The quality and safety of food are closely related to the commodity value of food. Combined low-temperature and high-pressure treatment can enhance the commodity value of low-value freshwater fish products and has potential in surimi gel new product development. This study provides theoretical guidance for high-pressure and low-temperature collaborative processing and industrial production of related aquatic products.