Functional Properties Of Myofibrillar Proteins Research Articles

Effects of dielectric barrier discharge plasma on the physicochemical and functional properties of myofibrillar proteins

Abstract The present study was designed to investigate the effects of dielectric barrier discharge (DBD) plasma on myofibrillar proteins extracted from beef. For this purpose, myofibrillar proteins were extracted from Longissimus dorsi muscle and treated with DBD plasma for 0, 5, 10, 15, and 20 min to evaluate free sulfhydryl and carbonyl, FTIR, and DSC profiles as well as pH, color, foaming capacity and stability, emulsion capacity and stability, and water binding capacity of myofibrillar proteins. Evaluation of the chemical changes revealed that protein oxidation was the main event occurring during exposure to DBD plasma. Moreover, mild oxidation during the first 10 min of exposure was found to improve the functional properties of myofibrillar proteins such that significant (p

Effects of high-intensity ultrasound, high-pressure processing, and high-pressure homogenization on the physicochemical and functional properties of myofibrillar proteins

Abstract High-Intensity Ultrasound (HIU), High-Pressure Processing (HPP), and High-Pressure Homogenization (HPH) were applied to myofibrillar protein suspensions (MPS) under selected conditions, with an untreated sample designated as the control. The results revealed that MPS subjected to HPP had increased solubility, but solubility was reduced with HIU and HPH (p Industrial relevance The modern meat industry is seeking novel technologies to modify and/or improve the quality of meat and meat products, hence adding value to products as well as meeting demands of consumers. High-intensity ultrasound (HIU), high-pressure processing (HPP) and high-pressure homogenization (HPH), were applied to myofibrillar proteins suspensions. Their effects on myofibrillar proteins (MP), and different outcomes were observed. HIU can be an effective technique to improve the quality of MP gels, but some technical problems, such as heterogeneous distribution of ultrasonic waves, must be improved; HPP was the most effective technique in modifying MP in a manner that improved yield of MP gels when heated, whereas HPH was not effective for gel-type meat product. The information derived from this study provided a direct comparison of the three techniques and their influences on MP and thermally induced gels. This provides a useful reference for meat scientists and processors when choosing innovative technologies for the manufacture of meat products.

The effectiveness of clove extracts in the inhibition of hydroxyl radical oxidation-induced structural and rheological changes in porcine myofibrillar protein

Oxidation is a major cause of protein quality deterioration during the storage and processing of food. This study investigated the effects of clove extract (CE) on structural and rheological changes in porcine longissimus myofibrillar proteins (MP) and the effects of oxidizing radicals produced by a Fenton reaction system (FRS). Increased oxidation time was accompanied by increased carbonyl content, reduced Ca-ATPase activity, decreased enthalpy of denaturation, decreased thermal transition temperatures (P<0.05), and increased protein susceptibility to thermal aggregation. The addition of CE significantly inhibited carbonyl formation (P<0.05), enhanced solubility and thermal stability, and improved the gel formation ability (storage modulus, loss modulus) of MP. The protective effect of CE on protein denaturation was demonstrated by its efficacy in maintaining Ca-ATPase activity and decreasing the degree of protein aggregation. Overall, the hydroxyl radical-induced loss of the structural and functional properties of MP was significantly reduced by the presence of CE.

Oxidation of Myofibrillar Proteins and Impaired Functionality: Underlying Mechanisms of the Carbonylation Pathway

The potential impact of protein oxidation on the functional properties of myofibrillar proteins (MP) was investigated in the present study. To accomplish this purpose, myofibrillar proteins were oxidized in vitro for 12 days at 37 °C in the presence of Cu(2+), Fe(3+), and Mb in combination with H(2)O(2) and analyzed at sampling times for chemical changes induced by oxidative reactions and functional properties. The oxidation measurements included specific protein carbonyls (α-aminoadipic semialdehyde, AAS), advanced lysine oxidation products (α-aminoadipic acid, AAA, and Schiff bases), and thiobarbituric acid-reactive substances (TBARS). The factors and mechanisms involved in the oxidative degradation of lysine residues through the carbonylation pathway are precisely described. According to the present results, intense lipid and protein carbonylation, principally induced by Cu(2+)/systems, leads to a fast and severe loss of MP functionality, including impaired water-holding, foaming, and gelling capacities. The implication of Mb in the oxidation events enhances the production of AAA and Schiff bases, compromising to a larger extent the solubility of MP and worsening the aggregation and the gelling capacity. The connection between the oxidation-induced chemical changes and the loss of protein functionality is thoroughly discussed.

Influence of the Capture Method on the Physicochemical and Functional Properties of Myofibrillar Proteins of Fin from Frozen, Stored Squid (Illex argentinus)

The physicochemical and functional properties of actomyosin from fins of frozen, stored squid caught either by jigging machines (AME1) or by trawling (AME2) were investigated. At time 0 SDS-PAGE, 10% of AMEl and AME2 showed the characteristic polypeptide bands of myofibrillar proteins and two components of 155 kDa and 55 kDa. Both the degradation of the myosin heavy chain and an increase in the 155-kDa component occurred earlier in AME2. Irrespective of the capture method used, no significant changes in protein solubility and a decrease (P < 0.05) in reduced viscosity were observed in both AMEl and AME2. Surface hydrophobicity (SoANS) of AMEl increased (P < 0.05) during the first month of storage and remained unchanged thereafter. The SoANS of AME2 was unchanged. The initial value of SoANS of AME2 was higher than that of AMEl. The emulsion activity index and the emulsion stability of AME2 increased (P < 0.05) during the first month of storage, whereas the emulsion activity index and emulsion stability of AMEl remained unchanged during the frozen storage period. These results indicate that the capture method influences the rate of autolysis and the functional properties of myofibrillar proteins of fin from frozen, stored squid.

Surface hydrophobicity and functional properties of myofibrillar proteins of mantle from frozen-stored squid ( Illex argentinus) caught either jigging machine or trawling

The surface hydrophobicity and functional properties of actomyosin from the mantle of frozen squid caught either by jigging machines (AME1) or by trawl (AME2) were investigated. Two components of 155 and 55 kDa were present in the gels at zero time of storage. Degradation of the myosin heavy chain and increase in the 155 kDa component occur earlier in AME2. Irrespective of the catch method used, no significant ( P>0.05) changes in protein solubility were observed. The reduced viscosity of both AME1 and AME2 decreased up to months 3 and 5 of frozen storage, respectively. At the beginning of storage, the superficial hydrophobicity of AME2 was 30% higher than that of AME1. So 1-anilino-8-naphthalene sulfonic acid of AME2 significantly increased during 3–5 months of storage period and that of AME1 at the end of storage. The emulsion activity index (EAI) of AME2 significantly ( P<0.05) increased during the first month and decreased after 3 months of storage. EAI of AME1 decreased at month 3 and remained unchanged thereafter. Emulsion stability (ES) of AME2 showed a behavior that was similar to its IAE and that of AME1 remained unchanged.

Physico-chemical and functional properties of myofibrillar proteins from different species of molluscs

The physico-chemical and functional properties of myofibrillar proteins from scallop ( Zygochlamys patagonica), bivalve molluscs ( Aulacomya ater ater), and squid ( Illex argentinus) were investigated. Actomyosins were studied by SDS-PAGE, Mg 2+-(Ca 2+-dependent) ATPase activity, reduced viscosity, and surface hydrophobicity determinations. The emulsion capacity (EC) of both soluble protein extracts and actomyosins was also determined. Densitometric analysis of the SDS-PAGE 10% gels showed that in comparison with the actomyosin from striated muscle of scallop, the actomyosins of Aulacomya, squid, and smooth plus striated muscle of scallop have a significant higher relative percentage of paramyosin and a lower relative percentage of myosin. The reduced viscosity of actomyosin from both striated and smooth plus striated adductor muscle of scallop was significantly lower than that of squid and Aulacomya. No significant differences were observed in the enzymatic activity of the actomyosins analysed. Surface hydrophobicity and EC of actomyosin from striated muscle of Aulacomya were lower than those corresponding to actomyosin of the other species. The highest values of EC were observed in extracts of squid mantle. In addition, the EC of the extracts was significantly higher than the EC of their respective actomyosins.

Myofibrillar protein from different muscle fiber types: implications of biochemical and functional properties in meat processing.

Texture, moisture retention, and tenderness of processed muscle foods are influenced by the functionality of myofibrillar protein. Recent studies have revealed large variations in processing quality between red and white muscle groups that can be attributed to differences in the functional properties of myofibrillar protein associated with the type of fiber. Myofibrillar proteins from fast- and slow-twitch fibers exhibit different biochemical and rheological characteristics and form gels with distinctly different viscoelastic properties and microstructures. The existence and wide distribution of the numerous myosin isoforms in different muscle and fiber types contribute to the various functional behaviors of myofibrillar protein. The different sensitivities of fast and slow myofibrillar proteins to pH, ionic environment, temperature, and other external factors have been well documented and illustrate the importance of adjusting meat processing conditions, according to fiber type profile to achieve maximum protein functionalities, and hence, uniform quality of the final muscle foods.

Functional Properties of Myofibrillar Proteins from Cold‐Shortened and Thaw‐Rigor Bovine Muscles

ABSTRACTPrerigor bovine sternomandibularis muscles were stored at 15, 0 and −29°C to examine cold‐shortening and thaw‐rigor effects on myofibrillar protein extractability and gelation properties of myofibrils and salt‐soluble protein (SSP). Frozen muscle that underwent severe contraction at thawing showed greater protein extractability (35%) than muscles stored at 0 and 15°C (27% extractability). Of the three tempered muscles, thaw‐rigor muscle produced the strongest myofibril gel and cold‐shortened muscle formed the most elastic SSP gel as determined by dynamic shear and penetration measurements. However, thermally induced changes in gel viscoelastic moduli for all protein samples followed similar patterns. Results indicated that physicochemical changes accompanying muscle contraction affected protein network formation during gelation.