Polymerization Of Myosin Heavy Chain Research Articles

Comparative Effect of Cricket Protein Powder and Soy Protein Isolate on Gel Properties of Indian Mackerel Surimi.

This work comparatively investigated the effects of different levels (0, 1, 3, and 5%, w/w) of cricket protein powder (CP) and soy protein isolate (SPI) on the gel properties of mackerel surimi. Both SPI and CP enhanced the rheological properties of surimi pastes during heating, as indicated by the increase in G' and G″ and the decrease in tan δ. With increasing SPI content, the proteolytic inhibition, gel properties, water-holding capacity, and textural profiles of surimi gel were markedly enhanced. Molecular driving-force results showed that SPI markedly promoted the hydrophobic interaction, while disulfide bonds were dominant in CP-added gel. However, the whiteness of surimi gels tended to decrease with the increased levels of both additives, in particular CP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that SPI hindered the polymerization of myosin heavy chain while CP participated in the formation of non-disulfide covalent bonds with actin. Fourier transform infrared (FTIR) spectra indicated that CP and SPI did not influence the secondary structure of proteins in surimi. Scanning electron microscopy (SEM) demonstrated that CP or SPI induced the myofibrillar protein to form smoother and compact gel network structures. Overall acceptability of the mackerel surimi gel can be improved by the incorporation of 5% SPI while CP had a negative impact on several parameters. However, CP showed the remarkable ability to prevent the lipid oxidation of the gel after storage at 4 °C for 7 days. Overall, both SPI and CP demonstrated positive impacts on the gelling characteristics of mackerel surimi; however, SPI was more advantageous than CP in terms of the gel-strengthening effect and sensory qualities. This study offered a potential use for plant and insect proteins as functional and nutritional ingredients for the production of dark-fleshed fish surimi.

Effect of furcellaran incorporation on gel properties of sardine surimi

AbstractEffects of furcellaran, powder (FURP) and solution (FURS), incorporation (2‐8% based on surimi solid content) on gel properties of sardine (Sardinella albella) surimi were investigated. Breaking force, hardness, gumminess, chewiness, and whiteness of gels increased with increasing FURP or FURS contents (P < 0.05), where the highest values were observed in gel containing 8% FURS (P < 0.05). Expressible moisture content of gel decreased as levels of furcellaran increased (P < 0.05). The gel deformation, springiness, and cohesiveness were not affected by furcellaran (P > 0.05) as well as the polymerization of myosin heavy chain as visualised by SDS‐PAGE. FURP and FURS could enhance the interconnection between chains during heating as indicated by the higher G′. Addition of furcellaran, especially FURS, up to 6% increased sensory property of resulting gel (P < 0.05). Anywise, an abatement in overall likeness score was found in gel with 8% FURS. Finer and denser microstructural network was observed in gel containing 6% FURS when compared to control. Therefore, furcellaran, prepared as solution, at an appropriate level can improve the overall quality of sardine surimi.

Gelation and vibrational spectroscopy of tropical surimi induced by ascorbic acid and hydrogen peroxide.

The combined effect of ascorbic acid (AsA) and hydrogen peroxide (H2 O2 ) on gel-forming ability and structural changes of lizardfish (LZ) and threadfin bream (TB) surimi were investigated. Addition of 0.15% AsA and 0.1% H2 O2 greatly increased breaking force and distance of LZ surimi by 300% and 55%, respectively. Combination of 0.2% AsA and 0.15% H2 O2 resulted in the maximum TB surimi gel improvement with 150% and 90% increase in breaking force and distance, respectively. Browning reaction obviously occurred when combined AsA and H2 O2 was added, due to ascorbic acid oxidation. Polymerization of myosin heavy chain via disulfide bonds was promoted, and the formation of disulfide bonds was involved through oxidation of sulfhydryl groups with increasing AsA and H2 O2 . Fourier-transform infrared (FT-IR) spectroscopy revealed a decrease in α-helix and an increase in β-sheet content as AsA and H2 O2 increased in both species. A decrease of band area of aliphatic (2,800 to 3,000 and 1,450 cm-1 ), aromatic (1,208, 757, and ratio 850/830 cm-1 ), and change of disulfide bonds (525 and 540 cm-1 ) suggested an increase in hydrophobic interactions and disulfide bonds with addition of these additives. Based on principal component analysis (PCA), textural characteristics were positively correlated with β-sheet content. Our study suggested that combination of AsA and H2 O2 greatly enhanced gelation of LZ and TB by increasing not only disulfide bonds but also hydrophobic interactions. PRACTICAL APPLICATION: The combined ascorbic acid and hydrogen peroxide can be used to improve gelation of two important tropical surimi species, namely threadfin bream and lizardfish surimi, without requirement of setting. The optimum concentration of each additive varied with fish species.

Effect of gellan incorporation on gel properties of bigeye snapper surimi

Effects of gellan on gelling properties of surimi from bigeye snapper (Priacanthus macracanthus) were investigated. Two forms of gellan, powder (GLP) and suspension (GLS), were incorporated into surimi to obtain different final concentrations (2–8% based on surimi solid content). Gels added with GLP or GLS had the increases in breaking force and hardness as the levels were increased (p < 0.05). The highest breaking force and hardness were observed in surimi gel containing 8% GLS (p < 0.05). Expressible moisture content and whiteness of resulting gels were increased as levels of GLP and GLS increased (p < 0.05). Electrophoretic studies showed that gellan at all levels had no effect on polymerization of myosin heavy chain. Addition of GLP and GLS could enhance the interconnection between chains during heating as indicated by the higher G’. Both GLP and GLS increased sensory property of surimi gel as the level of gellan increased up to 6% (p < 0.05). However, the decrease in overall likeness score was found in gel added with 8% GLS. Microstructure studies revealed that finer and denser network was observed in surimi gel containing 6% GLS in comparison with that of the control. Therefore, gellan, prepared as suspension, at an appropriate level could improve gel strength of bigeye snapper surimi with an increased acceptability.

Importance of salt and temperature in myosin polymerization during surimi gelation

To address the effect of absence of NaCl on myosin heavy chain polymerization during two-step surimi gelation (different setting temperatures/times −5°C/24h and 30°C/30min-followed by heating at 90°C/30min) were considered. In gel samples made without salt (Lot A), no myosin heavy chain (MHC) polymerization was observed, only aggregation, as indicated by the electrophoresis in polyacrylamide/agarose gel profile. Moreover, these gels were characterized by weakly stabilized protein networks as denoted by the dynamic oscillatory measurement and FTIR analysis, resulting in poor quality gels. On the other hand, in gels made with added salt, MHC polymerization occurred, as evidenced by the electrophoresis, and the gelation resulted in a well-stabilized protein network with good physicochemical properties.

The pepsin digestibility of thermal gel products made from white croaker (Pennahia argentata) muscle in associating with myosin polymerization levels.

Thermal gels were made from white croaker (Pennahia argentata) surimi at various polymerization levels of myosin heavy chains induced by suwari treatment at 38 °C for various time periods and subsequently heated at 85 °C for 20 min. Myosin heavy chain polymerization levels were also achieved in the presence of microbial transglutaminase (MTG) added at various concentrations in the surimi. The breaking strength and breaking strain rate were markedly increased during suwari treatment up to 60 min in accordance with the increased levels of myosin heavy chain polymerization. MTG enhanced myosin heavy chain polymerization during suwari treatment for 15 and 30 min, resulting in the increase of breaking strength. The solubilization in 8 M urea and pepsin digestibility of these gels as well as angiotensin I-converting enzyme (ACE) inhibitory activity of their pepsin digests were decreased with the increased levels of myosin heavy chain polymerization. These results suggest that myosin heavy chain polymerization affects not only rheological properties of thermal gels but also their functional properties for human health.

Nonprotein Nitrogenous Compounds and Gelling Property of Whitecheek Shark (C archarhinus Dussumieri ) Mince as Affected by Washing and Microbial Transglutaminase

Changes in nonprotein nitrogenous compounds and gelling properties of whitecheek shark (Carcharhinus dussumieri) meat during iced storage for 12 days were monitored. Total volatile base (TVB), trimethylamine (TMA) and ammonia contents increased, whereas urea content decreased during the storage (P < 0.05). TVB, TMA, urea and ammonia contents were lower in washed mince, indicating the removal of those compounds by washing. The addition of microbial transglutaminase (MTGase, 0.6 unit/g sample) was able to increase breaking force, deformation and water-holding capacity of both gels from mince and washed mince. Nevertheless, gel strengthening effect of MTGase was lowered when mince or washed mince were obtained from shark stored for an extended time. Polymerization of myosin heavy chain was enhanced when MTGase was incorporated but took place at a lower degree for mince and washed mince produced from unfresh shark. Washing process in combination with MTGase addition could therefore improve gel quality of shark meat. Practical Applications Shark meat is a good source of protein, which could be a suitable source for surimi production. However, the meat is considered to have a low market value because of undesirable odor, which is mainly from the decomposition of urea to ammonia during extended storage. Appropriate washing to remove those compounds, along with the use of microbial transglutaminase (MTGase), can be a promising means to improve the textural properties of gels from shark mince. Thus, shark meat can be better exploited, especially for the surimi industry.

IMPROVEMENT OF PHYSICAL PROPERTIES OF BLACK TIGER SHRIMP (PENAEUS MONODON) MEAT GEL INDUCED BY HIGH PRESSURE AND HEAT TREATMENT

Breaking force and weight loss of the black tiger shrimp (Penaeus monodon) meat gel induced by pressure (600 MPa, 20 min, 28C) or pressure (400 MPa, 20 min, 28C) followed by heating (90C, 20 min) increased with the decrease in trichloroacetic acid-soluble peptide content when bovine plasma protein concentration (0–3% w/w) increased (P < 0.05). The gel prepared by pressure–heat treatment showed the higher breaking force but lower deformation than that prepared by only pressure (P < 0.05). The impact of microbial transglutaminase (MTGase, 0–2% w/w) and gelation conditions (setting, pressure, setting before/after pressure, setting and pressure followed by heating) on gel properties were also investigated. Breaking force and deformation increased with increasing MTGase concentration up to 0.15% (P < 0.05) mainly due to myosin heavy chain polymerization. The MTGase added gels prepared by pressure (400–600 MPa, 20 min, 28C) or combination with setting exhibited the greater breaking deformation than those induced by pressure–heat treatment (P < 0.05). PRACTICAL APPLICATIONS The production of gel product from shrimp meat or remainder, mostly small or broken shrimp, obtained from shrimp processing can lead to a new product with high market value. Due to the poor gel-forming ability of shrimp muscle protein, high pressure treatment in combination with bovine plasma protein or MTGase has been proven as a promising means to produce the gel with a unique appearance and improved textural properties. This finding indicates the feasibility for shrimp processing industry to maximize the utilization of shrimp.

Oxygen permeability and antioxidative properties of edible surimi films

The oxygen permeability (PO2) and antioxidative activity of edible surimi films were investigated. Surimi films with lower PO2 were successfully prepared by heating the film-forming solutions (pH 3) at 70°C for 20 min. On the other hand, it was revealed that surimi films themselves possess antioxidative properties based on 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity and reducing power. Sardine oils in surimi film pouches were stored for 40 days at 40°C in the dark. Both peroxide value and thiobarbituric acid reactive substances values increased slightly during the initial period of storage but decreased significantly at the later stage of storage, indicating that oxidation of sardine oil was effectively hindered by packing in surimi film pouches. Furthermore, polymerization of myosin heavy chain in surimi films was observed during the storage at 40°C.

기능성 어육단백질의 젤화 특성과 산업적 응용-1. 가열변성 중 화학결합에 미치는 pH의 영향

The effect of pH on surface hydrophobicity, sulfhydryl group, infrared spectrum, SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) pattern and enthalpy was investigated in recovered protein from mackerel and frozen blackspotted croaker by alkaline processing. Hydrophobic residue in myofibrillar protein exposed to the surface of protein, and hydrophobic interaction were the highest around 6. The surface hydrophobicity was different between myofibrillar protein and myofibrillar protein including sarcoplasmic protein (recovered protein). The peak at 1636 c was increased with pH, and the recovered protein was unfolded in alkali pH. Difference of surface and total sulfhydryl group at pH 7.0 and 10 was comparative high, and decrease of surface sulfhydryl group indicated formation of S-S bonds. Mackerel and frozen blackspotted croaker in alkaline pH showed bands of polymerized myosin heavy chain on SDS-PAGE pattern. The transition temperatures of recovered protein were 33.1, 44.3 and 65.5. Gelation of recovered protein from alkali processing was estimated by increase of -sheet structure by pH treatment, S-S bonds by oxidation of surface sulfhydryl group in heating, polymerization of myosin heavy chain in order.r.

Inhibitory effect of oxidized lipid on the thermal gelation of Alaska pollack ( Theragra chalcogramma) surimi

The influence of incorporated oxidized lipid on the thermal gelation of Alaska pollack ( Theragra chalcogramma) surimi was investigated. Cod liver oil was intentionally oxidized by aeration at 45 °C in the dark for up to 7 days. Cod liver oil oxidized for 2 days (2-CLO) or 5 days (5-CLO) was incorporated at a level of 10% into surimi and suwari gels and kamaboko gels were prepared. The addition of oxidized lipid, especially 5-CLO, inhibited the normal gelation of surimi and it was more profound for the kamaboko gels. SDS–PAGE patterns revealed that the polymerization of myosin heavy chain was inhibited by the addition of 5-CLO. The inhibitory substances for surimi gelation were found to be present mostly in the water-soluble fraction of 5-CLO.

Gel forming ability of fish meat oxidized during washing

: In order to examine the effect of meat oxidation on the gel forming ability before grinding the meat with salt, fish meat was washed with CuCl2 solution, and the gel strength as well as total sulfhydryl (SH) groups and sodium dodecylsulfate–polyacrylamide gel electrophoresis (SDS-PAGE) patterns were analysed. Washing with CuCl2 solution resulted in a decrease in the total SH content of fish meat and the formation of myosin heavy chain (MHC) dimer through disulfide bonding. The plot of logarithmic gel strength versus protein concentration after heating the washed meat at 80°C in the presence of 3% NaCl to form a gel illustrated that the gel forming ability of meats washed with CuCl2 solution was weaker than the control meat. The gel of meat washed with CuCl2 showed the polymerization of MHC and MHC dimers through disulfide bonding much more than the control meat gel, although a small decrease in the SH group content after heating. Further washing with ethylene diamine tetra-acetic acid (EDTA) solution to remove CuCl2 from the CuCl2-washed meat also resulted in similar behavior for MHC polymerization and SH content as the CuCl2-washed meat, and the gel was still weaker than the control gel. It was found that the oxidation of SH groups during washing with CuCl2 solution accompanied by MHC dimer formation in the meat results in the weakening of its gel forming ability.

Inhibiting effect of polymerization and degradation of myosin heavy chain during preheating at 30oC and 50oC on the gel-forming ability of walleye pollack surimi

To confirm the contribution of polymerization and degradation of myosin heavy chain (MHC) during preheating to the gel-forming ability of fish meat paste, walleye pollack surimi paste was preheated at 30∞C and 50∞C prior to heating at 80∞C in the presence of various inhibitors. At 30∞C, ethyleneglycol bis(2-aminoethyl ether)-N,N,N¢,N¢-tetraacetic acid (EGTA) and ethylenedi- aminetetraacitic acid (EDTA) inhibited gel formation as well as the polymerization of MHC, whereas dithiothreitol (DTT) and leupeptin promoted gel formation, which was accompanied by the enhance- ment of MHC polymerization and decreased MHC degradation, respectively. At 50∞C, leupeptin inhib- ited MHC degradation and improved gel strength, whereas EGTA, EDTA and DTT had no effect on MHC polymerization and degradation and did not affect gel formation. The results demonstrate that the gel strength of cooked gel (80∞C) is not affected by preheating at 30∞C and 50∞C and does not inhibit polymerization and degradation. Results suggest that the gel strength of cooked gel is depen- dent on the polymerization and degradation of MHC during preheating.

Contribution of the polymerization of protein by disulfide bonding to increased gel strength of walleye pollack surimi gel with preheating time

ABSTRACT: To clarify the contribution of polymerization of myosin heavy chain (MHC) by disulfide bonding to increased gel strength of cooked gel via preheating, the pastes of walleye pollack surimi (SS and C grades) were preheated at 25°C and 40°C for a variety of hours prior to heating at 80°C for 20 min. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) patterns of cooked gels were analyzed with and without reducing the samples, which were solubilized in 8 M urea–2% SDS solution. The formation of polymers by disulfide bonding in cooked gels was almost constant in each of the SS and C grade surimi gels despite the period of preheating. Therefore, it was suggested that polymerization by disulfide bonding occurred during cooking at 80°C and not during preheating.

ɛ‐POLYLYSINE IMPROVES THE QUALITY OF SURIMI PRODUCTS

ABSTRACT To apply ɛ‐polylysine (PL) as a natural food preservative for the preparation of surimi products, effects of added PL on the textural properties and shelf‐life of kamaboko gels were investigated. Kamaboko gels were prepared by setting at 30C for 1 h, then heating at 80C for 20 min. Breaking force and breaking strain of kamaboko gels increased slightly with increasing PL concentration up to 0.2% and decreased at 0.4%. However, the protein subunit component composition of kamaboko gels did not vary with the amount of PL added, indicating that PL did not promote the polymerization of myosin heavy chain. The increased pH value of surimi to around 7.6 as the result of the incorporation of 0.2% PL was found to be attributable to the increased textural properties of kamaboko gels. The shelf‐life of kamaboko gels was significantly extended by the addition of 0.2% PL in surimi, especially at 5C and 10C storage.

Responsibility of Myosin S-1 and Rod for the Polymerization of Myosin Heavy Chain through Disulfide Bonding upon Heating of Actomyosin

Responsibility of Myosin S-1 and Rod for the Polymerization of Myosin Heavy Chain through Disulfide Bonding upon Heating of Actomyosin

EFFECTS OF CHITOSAN ON GELLING PROPERTIES OF LOW QUALITY SURIMI

ABSTRACT In order to produce a strong and elastic gel from low quality walleye pollock surimi, use of chitosan was examined. The strength of gels was nearly doubled by the addition of 1.5% chitosan when salted surimi pastes were set below 25C. In contrast, chitin did not cause any changes in the physical texture of gels. When salted surimi pastes containing 1.5% chitosan were set at 20C, a large decrease in the proportion of myosin heavy chain was observed with a concomitant increase in components with molecular weights heavier than myosin heavy chain. Since the addition of EGTA, an inhibitor of transglutaminase, to surimi reduced gel strength and minimized myosin heavy chain polymerization, it is suggested that the enhancing effect ofchitosan on the gel formation of walleye pollock surimi could be due to the activity of the endogenous transglutaminase known to be present in this surimi.

コイ・ミオシン加熱時のＳＳ結合による高分子化に及ぼすシステインの促進効果

When carp myosin was heated at 80°C with cysteine, the polymerization of protein through SS bonding (SS polymerization) was promoted. The SS polymerization was promoted even in the presence of both EDTA and cysteine, though it was not promoted in the presence of only EDTA. Cysteine was oxidized into cystine. Cystine also accelerated the SS polymerization of myosin heavy chain during the heating, and it was reduced into cysteine.From these results, it was suggested that acceleration of SS polymerization of myosin heavy chain by adding cysteine is due to the promotion of intermolecular SS bonding by the oxidative effect of cystine which was produced from cysteine during the heating.

The Subfragment Responsible for the Polymerization of Myosin Heavy Chain through SS Bonding during the Heating of Carp Myosin.

To decide the subfragment in carp myosin responsible for the polymerization of myosin heavy chain (HC) through SS bonding during the heating at 80°C, carp myosin was digested with α-chymotrypsin into S-1 and rod, and was heated. From the SDS-PAGE patterns (3% polyacrylamide gel) of the heated samples solubilized in 8M urea-2% SDS, two components were found to be produced. The one was observed on the top of the polyacrylamide gel, and the other was just over HC and was 260 kDa in molecular mass. By treating each component with 10% 2-mercaptoethanol, it was found that the former component was made only from S-1 (80 kDa) and the latter was only from rod (130 kDa).Therefore, it was concluded that in the polymerization of HC through SS bonding during the heating of myosin, SH groups on rod is responsible for the formation of HC dimer and those on S-1 is responsible for the HC polymer formation.

Participation of the Superoxide Radical in the Beneficial Effect of Ascorbic Acid on Heat-induced Fish Meat Gel (Kamaboko)

The influence of ascorbic acid (AsA) on the proteins in raw meat paste (surimi) of walleye pollack during the formation of a gel by incubating at 40°C, or 40°C and 90°C was examined by SDS-polyacrylamide gel electrophoresis. AsA significantly enhanced the decrease in the amount of myosin heavy chain (MHC), by promoting the polymerization of MHC via disulfide bridging. Diethylenetriaminepentaacetic acid, a chelator, and tiron, a scavenger of the superoxide radical, both inhibited the promoting effect of AsA on MHC polymerization in surimi. Therefore, the superoxide radical generated via the metal-catalyzed autoxidation of AsA participated in the polymerization of MHC. The production of the cysteine (Cys) thiyl radical due to superoxide in a 10 mM Cys solution was confirmed by electron spin resonance spectroscopy, in which superoxide was generated by photo-activation of riboflavin. These results suggest that the polymerization of MHC by AsA proceeds through a radical-radical reaction of the thiyl radicals of Cys residues that are generated by superoxide radicals.