Walleye Pollack Research Articles

加熱に伴うスケトウダラ肉糊中のミオシン重鎖の変化とＴＧａｓｅ製剤の影響

Walleye pollack frozen surimi was ground with 3.0% NaCl in the presence and absence of 0.3% food additive containing transglutaminase. The salt-ground meat was heated at 25°C or 40°C for various durations, followed by heating at 90°C for 30min to obtain kamaboko gels.Quality of the kamaboko gel was evaluated from the changes in the breaking strength and breaking strain as a function of preheating time, as previously reported. In the present study, the crosslinking profile of myosin heavy chains of the same kamaboko gel was investigated. The results were as follows: (1) The addition of the additive containing transglutaminase remarkably accelerated the cross-linking reaction of myosin heavy chains in the salt-ground meat, accumulating cross-linked products with larger molecular sizes. (2) When such cross-linked products were accumulated in a large quantity, the breaking strength increased at a much higher rate than the increase in breaking strain of the same kamaboko gel.Considering the rate of progressing of the cross-linking reaction between myosin heavy chains in the gel, the quality of the kamaboko thus formed was shown to be clearly different from that of the ordinary product.

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.

一重，二重網地コッドエンドの漁獲選択性

Mesh selectivity experiments were carried out using single and double codends in order to reduce the capture of small sizes of fish by northern trawlers in the Pacific coast of the Kuril Islands in September 1991. The mesh selectivity of the single codend was compared with that of the double codend commonly used in the experimental area. The estimated selection curves indicate the double codend has a for lower mesh selectivity for Walleye pollack and flounders than the single codend. It is suggested from underwater observations by video camera that the overlapped meshes decrease the mesh area, resulting in the low efficiency of mesh selection. From the results obtained the single codend of the presently employed mesh size is desirable to release undersized fish.

スケトウダラ塩漬肉の乾燥中に起こる筋原繊維タンパク質の変性に及ぼすソルビトールの影響

Meat blocks from walleye pollack were soaked in solutions containing 0.5-1.5M NaCl, 0.5-1.0M sorbitol. or their combinations with varied ratios for 24 hours at 4°C. After soaking, the cured meats were subjected to dehydration at 15°C. Changes in weight, NaCl and sorbitol concentrations of the meat, and myofibrillar Ca-ATPase activity together with crosslinking of myosin heavy chain of the same meat were investigated as a function of dehydration time. The results were as follows: (1) The meats containing 0.40-0.70M NaCl, 0.37-1.02M sorbitol, or combinations of 0.38-1.68M NaCl and 0.34-0.85M sorbitol were subjected to the dehydration process. (2) The rates of reduction of the weight of cured meats agreed well with the increase in NaCl and sorbitol concentration of the same meats induced by the dehydration. (3) The rate of dehydration of the cured meats was not related to the rate of denaturation of myofibrillar protein of the same meats. It is thus likely that the water retention ability of the meat is controlled by the concentration of NaCl and sorbitol, and their relative proportion in the meat, which was prepared by curing.

スケトウダラ筋肉の塩漬中に起こる筋原繊維タンパク質の変性に及ぼすソルビトールの影響

Meat blocks from walleye pollack were soaked in solutions containing 0.5-1.0M NaCl (N), 0.5-1.5M sorbitol (S), or their combinations with varied ratios for 24 hours at 4°C. During soaking, the increase in N and S of the meat, and the denaturation of myofibrillar protein as measured by the loss of Ca-ATPase activity and the cross-linking of myosin heavy chain of the same meat were investigated. The results were as follows: (1) The permeation of N into the meat depended on the concentration of N but not on the copresence of S concentration. (2) The permeation of S depended on the concentration of S, although the rate of permeation varied with the copresence of N concentration. (3) With increasing the concentration of N in the meat, the denaturation of myofibrillar protein accelerated, whereas increasing the concentration of S suppressed the same change. These findings suggest that the quality of meat block soaked in NaCl-sorbitol solution can be controlled by selecting the concentration and relative proportion of N and S in the soaking solution.

スケトウダラ調味乾製品の遊離アミノ酸含量に及ぼすソルビトールの影響

スケトウダラ調味乾製品の遊離アミノ酸含量に及ぼすソルビトールの影響

塩漬および乾燥工程中のスケトウダラ魚肉のレオロジー的性質とミオシン重鎖の変化に及ぼすソルビトールの影響

The rheological properties of meat blocks examined by creep measurement with cross-linking of myosin heavy chain (HC) were investigated during soaking and dehydration. The meat block from walleye pollack was soaked in 0.5M NaCl (pH 7.0) solution with 0 ?? 1.0M sorbitol at 5°C for 24 hours. After soaking, the meat block was dehydrated at 20°C for 24 hours. Both values of elastic modulus and viscosity of meat blocks soaked in 0.5M NaCl solution with 1.0M sorbitol were higher than those of the blocks during soaking and dehydration without sorbitol. During soaking and dehydration, cross-linked myosin HCs of small molecular size in the blocks soaked in 0.5M NaCl solution with 1.0M sorbitol were formed in large quantities compared with those in the blocks without sorbitol. These results indicated that sorbitol in meat blocks affected the cross-linking of myosin HCs of those blocks and contributed to an improvement of elastic modules and viscosity of meat.

等級の異なるスケトウダラ冷凍すり身のかまぼこ品質に対する牛血しょう粉末添加の影響

Six kinds of walleye pollack frozen surimis of different grades were subjected to the preparation of kamaboko gels with and without the addition of 0.5% bovine plasma powder. The quality of the kamaboko gels thus obtained was evaluated by measuring the gel properties such as the breaking strength, breaking strain, gel strength, and spring constant. It was found that the addition of bovine plasma powder remarkably enhanced the gelling ability of all kinds of frozen surimis, although the apparent increment in gel properties of the kamaboko was larger in the frozen surimi of lower grade than that of higher grade. However, the quality of the kamaboko gel prepared from the frozen surimi of lower grade on addition of plasma was still remained inferior to that from the highest grade without the addition of plasma. These results also supported our previous conclusion that the gelling of frozen surimi with bovine plasma powder proceeded via slightly different way as compared to the case without plasma.

スケトウダラかまぼこゲルの物性に及ぼす鶏卵成分の影響

スケトウダラかまぼこゲルの物性に及ぼす鶏卵成分の影響

Interaction of Saponins with Salt Soluble Proteins from Walleye Pollack Meat

Interaction of Saponins with Salt Soluble Proteins from Walleye Pollack Meat

トランスグルタミナーゼを含む製剤を添加したスケトウダラかまぼこの品質

Kamaboko gels were prepared by adding 0.3% food additive containing transglutaminase in order to set, at a number of different temperatures from salt-ground meat of walleye pollack frozen surimi. The quality of the kamaboko gels thus formed was compared to kamaboko formed without the additive. The breaking strength of the kamaboko gel formed with the additive was much higher, whereas the breaking strain remained at a fairly low level. However, gelling of salt-ground meat in the presence of the additive varied somewhat depending on the setting temperature. In addition, solubility of the kamaboko gel formed with the same additive into SDS (sodium dodecylsulfate)-urea-mercaptoethanol mixture was much lower as setting time progressed, while the kamaboko gel without the additive was easily soluble into the same medium. These results indicate that kamaboko gel prepared in the presence of transglutaminase additive is evidently different from that product without the additive.

牛血しょう粉末を添加したスケトウダラかまぼこの品質

Kamaboko gels were prepared by adding 0.5% food additive, bovine plasma powder, by preheating at different temperatures from salt-ground meat of walleye pollack frozen surimi. The quality of kamaboko gel thus formed was compared to kamaboko formed without additive. The gelling property of the salt-ground meat with bovine plasma powder varied with the temperature of preheating. At 30°C and less, the breaking strength and breaking strain of the kamaboko gel formed with the additive was much higher, whereas the breaking strength and breaking strain of the kamaboko gel formed at 40°C and above remained low. However, the quality of the kamaboko gels formed with the bovine plasma powder was generally found to be similar to that of the products on the market by a sensory test, although gel strength and spring constant of products were slightly different.

スケトウダラすり身加圧ゲルの性状に及ぼすアンモニウム塩の影響

To investigate the effect of ammonium ion on the quality of pressure-induced gel, walleye pollack surimi was ground with NaCl, or NaCl containing a small amount of (NH4)2 SO4 or NH4Cl. The salt-ground meat was then treated under 300 MPa at 0°C for 10 min followed by storage at 5°C for 120 hours, and breaking strength and breaking strain together with subunit composition of myofibrillar protein were evaluated. Transglutaminase activities and ε-(γ-glutamyl) lysine contents were also measured. The results obtained were as follows: (1) Transglutaminase activity of the salt-ground meat was mostly inactivated by the pressure-treatment, (2) The rates of formation of cross-linked myosin heavy chain (60% of total protein) and of ε-(γ-glutamyl) lysine (2.7mg/g) in the pressure-induced gel were virtually identical with those in the setting gel from the same surimi, (3) The breaking strength of the pressure-induced gel reached more than twice that of the setting gel, (4) Addition of ammonium salts to the salt-ground meat largely suppressed the formation of cross-linked myosin heavy chain and of ε-(γ-glutamyl) lysine, while the breaking strength of the pressure-induced gel remained at half the level of that of the gel formed without ammonium salts. These results suggested that intermolecular hydrophobic interaction between myofibrillar proteins, which was formed through the pressure-treatment, might contribute to the production of an elastic gel.

Conformational Changes in Actomyosins from Fish and Pork Muscles by Ultraviolet Irradiation.

To obtain information about actomyosin denaturation due to ultraviolet (UV) irradiation, changes in some properties of walleye pollack, sardine, flying fish, and pork actomyosins by UV irradiation were examined. It was revealed that UV irradiation significantly increased the surface hydrophobicity of all the actomyosins regardless of heating, markedly reducing the total SH content at the same time, while there was a tendency for the surface SH content to decreased after an initial increment in the following order of instability: walleye pollack, sardine, flying fish>pork. From differential scanning calorimetry (DSC) data, it was suggested that UV irradiation prompted the unfolding of actomyosin.

Comparison of Reactivity of Transglutaminase to Various Fish Actomyosins.

It was found that all fish muscles analyzed contained transglutaminase (TGase) in an activity range of 2.41-0.10unit/g of wet weight. White croaker muscle has the highest activity, followed in descending order by carp, walleye pollack, chum salmon, atka mackerel, and rainbow trout.The reactivity of carp TGase to various fish actomyosins was investigated in terms of the velocity of polymerization of myosin heavy chain using a medium containing 5mg/ml actomyosin, 5mM CaCl2, 0.5M NaCl, and 0-0.05 unit carp TGase at pH 7.5 and 25°C. The rates of polymerization were significantly different according to the source of actomyosin, ranging from 13.5 to 0.1h-1•unit-1. The highest value was obtained from the actomyosin of walleye pollack, followed by those of rainbow trout, chum salmon, atka mackerel, white croaker, and carp. These results suggest that the TGase-mediated cross-linking reaction of myosin heavy chain may be mainly regulated by the conformational factor of the substrate actomyosin, depending on the species of fish.The combined effects of both factors, TGase content and reactivity, provided new insight into the species-specific set gel-formability of fish muscle pastes.

スケトウダラ肉糊のゲル形成能とミオシン重鎖の多量化に及ぼすソルビトールの影響

Walleye pollack surimi without any additives was ground with 2.5% NaCl, 0.3% sodium polyphosphate, and 0 ?? 8% sorbitol. The salt-ground meat was incubated at 20°C and 40°C for setting, and again at 90°C for 20min to prepare setting-heating gel. Breaking strength (BS) and breaking strain (bs) of the setting and setting-heating gels with the cross-linking of myosin heavy chain (HC) were investigated as a function of setting time.The values of BS and bs of the gels formed through setting with 0.8% sorbitol were higher than those of the gels formed by setting without sorbitol.During the setting at 20°C, cross-linked myosin HCs with small molecular sizes in the gels with 8% sorbitol were formed in a large quantity as compared with those in the gels without sorbitol. However, in the setting at 40°C, the increase of cross-linked myosin HC in the gels with 8% sorbitol was in a small quantity and was nearly identical to that of the gel without sorbitol.These results indicated that sorbitol in surimi affected the cross-linking of myosin HCs of the salt-ground meat and contributed to an improvement in gel formation of the meat.

ジュール熱を利用したスケトウダラの低温加熱ゲルの品質

ジュール熱を利用したスケトウダラの低温加熱ゲルの品質

カツオ，コイおよびスケトウダラの肉糊のゲル化とミオシン重鎖の多量化反応に及ぼすＣａＣｌ２の影響

Salt-ground meat of skipjack tuna, carp, and walleye pollack containing 0-20 mmol CaCl2/kg was incubated at 10-40°C for setting. During incubation, changes in breaking strength and the subunit composition of the myofibrillar protein of the setting gel were examined. The gel formation and the cross-linking reaction of the myosin heavy chain (HC) of the salt-ground meat were promoted by the addition of CaCl2. CaCl2 exerted its effect by increas-ing the HC polymers during setting of skipjack tuna and carp salt-ground meat. On the other hand, CaCl2 stimulated the formation of large size HC polymers in walleye pollack meat, which were components corresponding to HC polymers too large to be solubilized into SDS-urea buffer. Moreover, the degree of the stimulatory effects of CaCl2 on gel formation and the cross-linking reaction of HC of the salt-ground meat was found to be in the order of skipjack tuna>carp>walleye pollack, from largest to smallest. This order was essentially the same as for the thermal stability of the myofibrillar protein for these fish species.

魚肉筋形質タンパク質の高圧処理による組織化に対する諸要因の検討

For the purpose of the utilization of sarcoplasmic protein of fish (Sp-P) as a food material, the behavior of the Sp-P under a high pressure was examined. Sp-P from sardine, walleye pollack, flatfish, and horse mackerel was observed to be insolubilized and precipitated at a pressure above 1, 500kg/cm2. When the concentration of Sp-P was above 50mg/ml, the protein was texturized. The characteristics of the texturized product were affected by many factors such as fish species, pH, protein concentration, pressure, and treatment time. An observation under a scanning electron microscope and physical measurement revealed that the structure of the texturized material was porous but elastic, and it was quite different from that of the coagulum obtained from Sp-P by heat treatment. It is concluded that pressurization might be an advantageous treatment for the texturization of Sp-P.

Effects of Monovalent Cations on Cross-linking of Myosin in Suwari Gels from Walleye Pollack.

Salted pastes prepared from walleye pollack surimi by the addition of one of NaCl, KCl, and NH4Cl were incubated at 25°C to produce suwari gel and then cooked at 90°C for 20 min (cooked gel). It was found that the suwari and cooked gels having strong firmness were produced by the addition of NaCl to above 0.2M with a concomitant formation of cross-linked myosin polymers. The suwari and cooked gels containing KCl in the range of 0.1-0.8M were markedly lower in gel strength and in a degree of myosin cross-linking. The setting of the surimi paste containing KCl was not linked to the final cooked gel strength. The experiment using a fluorescent probe, monodansylcadaverine, for monitoring the TGase action during the setting demonstrated that the action on myosin heavy chains occurred significantly in the presence of NaCl, but not in KCl. Since the activity of crude TGase prepared from the surimi was not affected by the addition of KCl as well as NaCl when the acetylated casein was used as a protein substrate, it seems that reactive sites on myosin molecules will not be accessible to TGase in the presence of KCl. Surimi paste containing NH4Cl did not form suwari gel nor TGase-mediated myosin polymers.