Meat Myofibrillar Proteins Research Articles

Optimizing gelation properties of mixed meat myofibrillar proteins: investigating the effects of different proportions of beef, pork and chicken on physicochemical, structural and gelation properties.

The gelation properties of myofibrillar protein (MP) directly affect the texture, taste and water-holding capacity (WHC) of meat products. To enhance the gelation properties of single-species meat MP, the present study investigated the influence of different proportions of beef, pork and chicken MP on the physicochemical properties, structure and gelation properties of the MP. The results revealed that, when the proportion reached 5:2:3, the particle size decreases, leading to the maximum decomposition and unfolding of MPs, which exposes a greater number of hydrophobic amino acid residues. These changes promote interactions between protein molecules, especially the unfolding of α-helices and the formation of β-sheets during the heating process, which provides favorable conditions for the formation of protein gels and improves the gel strength and WHC of MP gels. Additionally, scanning electron microscopy revealed that the mixed MP gels are more compact and have more uniform gel networks and pores compared to single-species MP gels. Based on these results, the synergistic effect is induced by the interactions between proteins from different. This research provides a method for the subsequent development of new meat products and improvement of meat product quality, and also lays a theoretical foundation for composite research of proteins from different sources. © 2024 Society of Chemical Industry.

Effect of pulsed electric field-assisted thawing on the gelling properties of pekin duck meat myofibrillar protein

Effect of pulsed electric field-assisted thawing on the gelling properties of pekin duck meat myofibrillar protein

Using nanocellulose to improve heat-induced cull cow meat myofibrillar protein gels: effects of particle morphology and content.

Enhancing protein gel properties is essential to improve the texture of meat products. In this study, the improvement effects of three types of nanocellulose, i.e. rod-like cellulose nanocrystals (CNC), long-chain cellulose nanofibers (CNF) and spherical cellulose nanospheres (CNS) with different concentrations (1, 3, 5, 10, 15 and 20 g kg-1 ), on cull cow meat myofibrillar protein (MP) gel were investigated. Compared with needle-shaped CNC and spherical CNS, the addition of 10 and 20 g kg-1 long-chain CNF had the most significant improvement effect on gel hardness and water-holding capacity, respectively (P < 0.05), increasing to 160.1 g and 97.8%, respectively. In addition, the incorporation of long-chain CNF shortened the T2 relaxation time and induced the formation of the densest network structure and promoted the phase transition of the gel. However, excessive filling of nanocellulose would destroy the structure of the gel, which was not conducive to the improvement of gel properties. Fourier transform infrared results showed that there was no chemical reaction between the three nanocellulose types and MP, but the addition of nanocellulose was conducive to gel formation. The improvement of MP gel properties by adding nanocellulose mainly depends on its morphology and concentration. Nanocellulose with higher aspect ratio is more beneficial to the improvement of gel properties. For each nanocellulose type, there is an optimal addition amount for MP gel improvement. © 2023 Society of Chemical Industry.

Insight into the Interaction of Malondialdehyde with Rabbit Meat Myofibrillar Protein: Fluorescence Quenching and Protein Oxidation.

This research explored the effects of oxidative modification caused by different malondialdehyde (MDA) concentrations on rabbit meat myofibrillar protein (MP) structural characteristics and the interactions between MDA and MP. The fluorescence intensity of MDA-MP adducts, and surface hydrophobicity increased, whereas the intrinsic fluorescence intensity and free-amine content of MPs decreased as MDA concentration and incubation time increased. The carbonyl content was 2.06 nmol/mg for native MPs, while the carbonyl contents increased to 5.17, 5.57, 7.01, 11.37, 13.78, and 23.24 nmol/mg for MP treated with 0.25 to 8 mM MDA, respectively. When the MP was treated with 0.25 mM MDA, the sulfhydryl content and the α-helix content decreased to 43.78 nmol/mg and 38.46%, while when MDA concentration increased to 8 mM, the contents for sulfhydryl and α-helix decreased to 25.70 nmol/mg and 15.32%. Furthermore, the denaturation temperature and ΔH decreased with the increase in MDA concentration, and the peaks disappeared when the MDA concentration reached 8 mM. Those results indicate MDA modification resulted in structural destruction, thermal stability reduction, and protein aggregation. Besides, the first-order kinetics and Stern-Volmer equation fitting results imply that the quenching mechanism of MP by MDA may be mainly driven by dynamic quenching.

Effect of Artemisia sphaerocephala Krasch gum on the gel properties of myofibrillar protein and its application in cooked sheep sausage

Artemisia is widely distributed in desert areas northern China. Its seeds are rich in water-insoluble gelatin Artemisia sphaerocephala Krasch gum (ASKG) and frequently utilized for various types of pasta making. This study aims at wider utilization of the ASKG in food industry and to improve the gel properties of the myofibrillar protein-based food system containing starch. Firstly, the influence of ASKG on pasting and retrogradation of potato starch (PS) was discussed. Also, the rheological properties, emulsification properties, microstructure, protein conformation, and textural properties of sheep meat myofibrillar protein (SMP)/ASKG and SMP-potato starch (PS)/ASKG composites were investigated. Besides, the sensory quality and texture of cooked sheep sausage were evaluated to explore the application of ASKG in real complex food system. The stronger hydrophobic interaction of protein and H-bonding formed between components, which may be attributed to transition of α-helix to β-conformation of the protein. The ASKG additive promoted the formation of a more compact and uniform gel network of composites, leading an increase of the water holding capacity (WHC), gel strength and springiness and emulsion stability of SMP composites. The SMP-PS/ASKG-0.5% composites kept the highest WHC about 66.5%, gel strength about 70.57 g, springiness about 0.73 g. Furthermore, ASKG has a retardation effect on the retrogradation of PS. ASKG could delay the water loss and the increase of hardness of sausage during five-day storage, suggesting a visible satisfactory capability of the ASKG to improve the gel texture and storage quality of cooked sheep sausage.

The effect of the purslane polyphenols on the structure of rabbit meat myofibrillar protein under malondialdehyde-induced oxidative stress.

The present research aimed to assess the protective effects of purslane polyphenols on rabbit meat myofibrillar protein (MP) under malondialdehyde (MDA)-induced oxidation. The major polyphenols in purslane extract were analyzed by ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). To analyze the protective mechanism of purslane polyphenol monomers on MP in the oxidation system, we determined the retained MDA content in the suspension and analyzed the structure and nuclear magnetic resonance (NMR) of MP. The UPLC-QTOF-MS identification analysis indicated that purslane polyphenols mainly contained chlorogenic acid, caffeic acid, ferulic acid, rutin, kaempferol, and quercetin. Polyphenols in purslane can prevent MDA from binding to MP effectively. Chlorogenic acid showed the best inhibitory effect, and the retention content of MDA decreased to 54.79%, which was significantly lower than those of other groups. Purslane polyphenols had protective effects on sulfhydryl groups, free amino groups, intrinsic tryptophan fluorescence, α-helix structure, and morphology of MP. Moreover, the carbonyl contents, increase in surface hydrophobicity, and random coil contents of MP were reduced. In addition, the NMR results indicated that polyphenols inhibited the oxidation of protein induced by MDA through competitive inhibition. PRACTICAL APPLICATION: This study showed the efficiency of purslane polyphenol monomers in protecting the structure and function of myofibrillar protein under malondialdehyde-induced oxidative stress and their potential to preserve the nutritional value of foods rich in proteins and lipids.

Changes in Gel Characteristics, Rheological Properties, and Water Migration of PSE Meat Myofibrillar Proteins with Different Amounts of Sodium Bicarbonate.

The changes in the gel and rheological properties and water-holding capacity of PSE meat myofibrillar proteins with different amounts of sodium bicarbonate (SC, 0−0.6/100 g) were studied. Compared to the PSE meat myofibrillar proteins with 0/100 g SC, the texture properties and cooking yield significantly increased (p < 0.05) with increasing SC; meanwhile, adding SC caused the gel color to darken. All samples had similar curves with three phases, and the storage modulus (G’) values significantly increased with the increasing SC. The thermal stability of the PSE meat myofibrillar proteins was enhanced, and the G’ value at 80 °C increased with the increasing SC. Because water was bound more tightly to the protein matrix, the initial relaxation times of T21 and T22 shortened, the peak ratio of P21 significantly increased (p < 0.05), and the P22 significantly decreased (p < 0.05), which implied that the mobility of the water was reduced. Overall, SC could improve the thermal stability of the PSE meat myofibrillar proteins and increase the water-holding capacity and textural properties of the cooked PSE meat myofibrillar protein gels.

Effectiveness of l-arginine/l-lysine in retarding deterioration of structural and gelling properties of duck meat myofibrillar protein during freeze-thaw cycles

This study aimed to investigate the protective effects of l-arginine (L-arg) and l-lysine (L-lys) on the structure and gel properties of myofibrillar protein (MP) in duck meat during several freeze-thaw (F-T) cycles. The analysis of the Ca2+-ATPase activity as well as total sulfhydryl and carbonyl contents demonstrated that L-arg and L-lys could slow down the oxidative denaturation of MP during F-T cycles. Circular dichroism, fluorescence spectroscopy, and rheology measurements indicated that L-arg and L-lys improved the stability of the secondary and tertiary structure of MP and preserved its gel properties. In summary, L-arg and L-lys had the potential to preserve the structural stability and gel properties of MP during F-T cycles.

Effect of sodium bicarbonate on solubility, conformation and emulsion properties of pale, soft and exudative meat myofibrillar proteins

To investigate the effects of sodium bicarbonate on aggregation and emulsion properties of pale, soft and exudative (PSE) meat myofibrillar proteins, the changes in pH, turbidity, particle size, free sulfhydryl, surface hydrophobicity, emulsifying ability, and emulsion stability were studied. The pH, solubility, proportion of free sulfhydryl groups, surface hydrophobicity, emulsifying ability, and emulsion stability significantly increased (P < 0.05) with an increase in sodium bicarbonate concentration from 0 g/kg to 6 g/kg. In contrast, zeta potential, turbidity, and particle size significantly decreased (P < 0.05). In summary, the addition of sodium bicarbonate increased the pH of PSE meat myofibrillar proteins and enhanced the electrostatic repulsion between the proteins, causing the absolute value of zeta potential to increase, leading to greater exposure of sulfhydryl and hydrophobic groups and formation of smaller aggregations, enhancing its solubility, emulsifying ability and emulsion stability. Thus, sodium bicarbonate could improve the processing performance of PSE meat.

Influence of content and degree of substitution of carboxymethylated cellulose nanofibrils on the gelation properties of cull cow meat myofibrillar proteins

Cull cow meat myofibrillar protein (CCMP) filled with carboxymethylated cellulose nanofibrils (cCNF) was initially characterized to study the effect of cCNF on the gelation properties of CCMP. Before heating, with the increased degree of substitution (DS) of cCNF, the ζ-potential and hydrophobicity of CCMP-cCNF solution increased at the same filler mass fractions (ϕm). During heating, the process of gelation was shortened after adding cCNF, especially samples filled with cCNF of high DS. After heating, the cCNF with lower DS led to the lower liquid loss of gels, and the effect was amplified with increased ϕm of cCNF. Similarly, the network structure of CCMP-cCNF with low DS was more compact and the ability to anti-deform was stronger according to scanning electron microscopy and texture analysis. Also, an Interpenetrating Polymer Network was formed. Overall, ϕm of cCNF had a positive effect on the gelation properties of CCMP by water channel blocking and physical entanglement, while cCNF with higher DS weakened this effect due to electrostatic repulsion. This study may provide a theoretical foundation about the development of restructured meat products.

The effect of linalool, limonene and sabinene on the thermal stability and structure of rabbit meat myofibrillar protein under malondialdehyde-induced oxidative stress

This study aimed to assess the protective effects of the main components of Zanthoxylum bungeanum Maxim. essential oil (ZBMEO) on the characteristics of rabbit meat myofibrillar protein (MP) under MDA (malondialdehyde) induced oxidation. The MP suspensions were mixed with various concentrations (5 mM, 25 mM and 50 mM) of linalool, limonene, sabinene under MDA-induced oxidation. The retained MDA contents were determined, and the thermal stability and structure of rabbit meat myofibrillar protein were analyzed. Linalool, limonene and sabinene can prevent MDA from binding to MP effectively. The addition of linalool, limonene and sabinene led to the increase in the sulfhydryl and free amine contents, and the decrease in the carbonyl content and surface hydrophobicity compared to control MP. Also, the addition had protective effects on maintaining the secondary structure and morphology of MP under MDA-induced oxidation. The Differential scanning calorimetry (DSC) and SDS-PAGE analysis indicated that linalool, limonene, sabinene had an obvious protective effect on MHC and actin. The above results suggest that linalool, limonene and sabinene could reduce the oxidative damage of MDA to MP, which might have the potential in protecting the structure and physicochemical properties of the protein in foods.

Effect of multiple freeze‐thaw cycles on protein and lipid oxidation in rabbit meat

SummaryFrozen storage is chosen to be the preferred method in meat preservation. However, multiple freeze‐thaw (F‐T) cycles will occur during the transfers or distribution processes under poor cold‐chain conditions. This study investigated the effects of multiple freeze‐thaw (F‐T) cycles on water mobility, microstructure damage, protein oxidation and lipid oxidation in rabbit meat during seven F‐T cycles through 56 days. Scanning electron microscopy results indicated that the increase of F‐T cycles induced the rupture of endomysia and the increase of gaps between fibres. Low‐field nuclear magnetic resonance (LF‐NMR) results showed that the peak area of T21 and T22 decreased with increasing number of repeated F‐T cycles, indicating that immobile water shifted to free water, and free water mobility increased. During repeated freeze‐thaw process, the peroxide value, thiobarbituric acid‐reactive substances, non‐haem iron content and carbonyl groups of rabbit meat gradually increased, whereas haem content, haem iron content and sulfhydryl content of rabbit meat gradually decreased. In addition, the results of Fourier transform infrared, sodium dodecyl sulphate polyacrylamide gel electrophoresis, and intrinsic fluorescence spectroscopy indirectly proved that multiple F‐T cycles could cause α‐helix structure disruption, protein aggregation and degradation, and tryptophan oxidation of rabbit meat myofibrillar protein (MP). Overall, multiple repeated F‐T cycles changed moisture migration, damaged microstructure and promoted lipid and protein oxidation of rabbit meat.

Partial substitution of NaCl with chloride salt mixtures: Impact on oxidative characteristics of meat myofibrillar protein and their rheological properties

The effects of partial substitution of NaCl using chloride salt (KCl, MgCl2, and CaCl2) mixtures with different formulas on oxidative characteristics, physicochemical and gel properties of the pork meat myofibrillar protein (MP) were investigated. In a hydroxyl-radical-induced oxidative system, the mixtures of NaCl, KCl, and MgCl2 increased the carbonyl content of MP in substitution degree of 25% and 50%; and all chloride salts mixtures raised MP's disulfide bond level. In addition, chloride salt mixtures significantly lower MP gel's storage modulus, water-holding capacity, and gel strength, especially at the substituted ratio of 50%, due to the more disorderly and aggregated structure were observed in MP gels. The MP gel containing 0.45 M NaCl, 0.075 KCl, and 0.025 M MgCl2 exhibited superior qualities due to its compact pore structure. Thus, that NaCl was partially substituted by KCl and MgCl2 at a lower substituted ratio (25%) is promising to improve the functional properties of low-sodium MP gel products.

The Effects of Lipid Oxidation Product Acrolein on the Structure and Gel Properties of Rabbit Meat Myofibrillar Proteins

We investigated the effect of acrolein, a byproduct of lipid oxidation, on the structure and gel properties of myofibrillar proteins (MPs) isolated from rabbit meat. As the acrolein concentration increased, the protein carbonyl compounds significantly accumulated (p < 0.05), and the total sulfhydryl content was significantly lost (p < 0.05). The results of circular dichroism spectra, surface hydrophobicity, UV absorption spectra and intrinsic fluorescence spectra evidenced that acrolein caused the disruption of α-helix structure, the exposure of hydrophobic sites and the unfolding of MPs. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis suggested that medium (0–1 mM) and high (5–10 mM) concentrations of acrolein could induce protein cross-linkage and protein aggregation, respectively. These structural changes could affect gelling properties of MPs involving gel strength and water holding capacity (WHC). The results of Raman spectroscopy indicated that moderate oxidative modification caused protein unfolding as well as the decline of α-helix structure and the increase of β-sheets structure in gels, thereby influencing the gel properties. Moderate oxidative modification (0–1 mM) improved gel strength and WHC, while excessive oxidative modification (5–10 mM) resulted in decreased gel properties.

Effect of peroxyl radicals on the structure and gel properties of isolated rabbit meat myofibrillar proteins

SummaryWe investigated the effect of peroxyl radicals (ROO·), which are products of lipid peroxidation, on the structure and gel properties of myofibrillar proteins (MPs) isolated from rabbit meat. 2,2′‐Azobis(2‐amidinopropane) dihydrochloride (AAPH) was heated to stably derive ROO·. As the AAPH concentration increased, the protein carbonyl compounds significantly accumulated (P &lt; 0.05), and the total sulfhydryl content was significantly lost (P &lt; 0.05). Circular dichroism spectra, UV absorption spectra, intrinsic fluorescence spectra and surface hydrophobicity revealed that ROO· caused protein unfolding and conformational changes in MPs. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) analysis indicated that moderate (0–3 mm) and relatively high (5 and 10 mm) AAPH concentrations could lead to protein crosslinking and protein aggregation, respectively. These changes in protein structure could influence the gelling properties of MPs. Low‐level protein oxidation could increase gel strength and water holding capacity, whereas high‐level protein oxidation could reduce gel properties.

Effects of konjac glucomannan and acetylated distarch phosphate on the gel properties of pork meat myofibrillar proteins.

The effects of konjac glucomannan (KGM) and acetylated distarch phosphate (ADSP) on properties of pork meat myofibrillar protein (MP) were investigated using rotary rheometer, colorimeter, texture analyzer, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). The addition of KGM and ADSP resulted in increase in both storage modulus (G') and water holding capacity. Whiteness of MP gels was not influenced by the addition of KGM or ADSP, but the texture of MP gels changed apparently with the incorporation of KGM or ADSP. The temperature sweep showed that the increase in G' was associated with the gelatinization of ADSP and its synergistic effect with KGM. The FTIR indicated that the addition of KGM and ADSP enhanced the hydrogen bond in the gel system. The addition of KGM and ADSP changed the microstructures of MP gels, indicating the possible interactions among KGM, ADSP and MP. The images of CLSM showed that starch granules filled in the gap in the protein network, meanwhile the KGM evenly dispersed in the protein network structure.

Characterisation of novel fungal and bacterial protease preparations and evaluation of their ability to hydrolyse meat myofibrillar and connective tissue proteins

The catalytic capability of four commercially available food-grade fungal and bacterial protease preparations (AFP, FPII, F60K and HT) was evaluated over a range of pH, temperature and substrate conditions using esterase and caseinolytic activity assays and time course hydrolysis over 120 and 60min of myofibrillar and connective tissue proteins, respectively. The protease preparations displayed similar casein hydrolysis kinetics and were active in hydrolysing BODIPY-FL casein to varying extents at postmortem aging meat pH (5.0–6.0). All of the four proteases exhibited selective hydrolytic activity towards meat myofibrillar proteins including myosin and actin. Significant hydrolysis of two meat tenderisation protein markers troponin T and desmin by the four proteases was detected by western blot. The results obtained indicate that the new fungal protease preparations AFP and FPII, bacterial protease preparation HT and the new source of fungal protease preparation F60K have potential for use in meat tenderising applications.

Comparison of the Proteolytic Activities of New Commercially Available Bacterial and Fungal Proteases toward Meat Proteins

The hydrolytic activity of 3 commercially available protease preparations (bacterial protease G, fungal 31000, and fungal 60000) were examined using fluorescent-labeled casein, azo dye-impregnated collagen, and meat protein extracts from bovine M. semimembranosus and Achilles tendon, and compared to that of papain. Assays showed that all proteases exhibited little activity at low temperature (5 °C), and maximal activity at 45 °C. The pH, at which optimal activity was observed for each of the protease preparations, differed and ranged from pH 5.0 to 8.0. Kinetic parameters (K(M) and V(max) ) were also different between protease preparations, with the bacterial protease G and papain exhibiting significantly higher V(max) values (P < 0.001) and lower K(M) values (P < 0.01) for the casein substrate than the 2 fungal protease preparations. Meat protein hydrolysis was displayed on SDS-PAGE and proteins analyzed with mass spectrometry. The protease preparations were shown to have varying affinity toward different meat proteins. The bacterial protease G preparation was efficient at hydrolyzing most myofibril and collagen proteins, and appeared to be more efficient than papain at hydrolyzing collagen proteins. On the other hand the 2 fungal protease preparations showed a selective specificity toward meat myofibrillar proteins, and the fungal 60000 protease preparation exhibited high affinity toward collagen γ and collagen type I chain B proteins. The results generated in this study demonstrated that these commercial proteases have good potential for use in meat tenderization applications due to their mild and complementary effects on different meat proteins. Bacterial and fungal protease preparations exhibited varying affinities for hydrolyzing meat proteins. This selective moderate capability of microbial proteases compared to papain is potentially an advantage in avoiding over-tenderization in meat. On the other hand, the bacterial protease G preparation, which appeared to be more efficient at hydrolyzing connective tissue proteins than papain, could be beneficial in tenderizing meat with high connective tissue content. The synergistic effect of these protease preparations could be incorporated into a meat tenderizing formula to give the tenderizer a broad activity spectrum, thus able to target different cuts of meat.

Extração de proteínas miofibrilares de carne bovina para elaboração de filmes comestíveis

A utilização de proteínas miofibrilares de carne na elaboração de filmes comestíveis implica, inicialmente, na obtenção desta macromolécula, uma vez que ela é indisponível comercialmente. Assim, os objetivos deste trabalho foram a obtenção e caracterização de proteínas miofibrilares de carne bovina, em escala de laboratório, e a elaboração e caracterização da microestrutura de filmes à base dessas proteínas. As proteínas miofibrilares foram extraídas do músculo Semitendinosus bovino, pós rigor mortis, empregando-se uma técnica de extração por centrifugação diferencial em solução tampão, com diferentes concentrações salinas, segundo metodologia de EISELE & BREKKE [13] modificada neste trabalho. As proteínas, assim obtidas, foram liofilizadas (PML) e analisadas para determinação do teor de proteínas, de lipídios, de sais minerais, de cinzas e da umidade. A composição de aminoácidos foi determinada por cromatografia de troca iônica e o perfil eletroforético foi determinado em gel de poliacrilamida. Alguns filmes foram elaborados com 1g de PML/100g de solução, 60g de glicerol/100g de proteínas e ácido acético glacial para ajuste do pH=2,8. A microestrutura desses filmes foram analisadas por microscopia eletrônica de varredura. A PML, que apresentou teor de proteínas de 84,3%, foi composta de diversas frações de proteínas miofibrilares, com destaque para frações da miosina e da actina, segundo os resultados da eletroforese. Trabalhando-se a composição de aminoácidos, verificou-se que a maior contribuição energética das interações potenciais dos aminoácidos, foram as provenientes de ligações covalentes (58,3%), seguidas das interações iônicas (35,72%). A microestrutura do filme revelou uma estrutura pouco homogênea, porém coesa e densa e uma matriz protéica compacta e fina.