Temperature Dependency of Compression Properties of Fish-meat Gel as Affected by Added Starch

The influence of starch addition on the elastic properties of fish-meat gel was studied by measuring compression and stress relaxation properties and dynamic viscoelasticity. Samples with pregelatinized starch, with and without raw starch, and processed starch were used. Fish-meat gels with starch showed a higher modulus value at 80°C than at 90°C. The gelatinization of starch appeared to be prevented by surimi protein in the fish-meat gel, and so the sample that gelled at 90°C had a lower “packing effect” than the sample that gelled at 80°C. The optimum heating temperature indicated a higher “packing effect” on the surimi protein.     

Characteristics of surimi and kamaboko from sardines

Sardines of varying freshness (1 to 3 days in ice) were manually or mechanically processed into fish mince and surimi using 1 to 3 washing steps. Standard kamaboko gels were prepared by grinding thawed surimi with 3% NaCl and 5% potato starch, stuffing into sausage casings, holding at 37°C for 30 min and cooking at 90°C for 50 min.
Three washing steps decreased the yield of washed fish mince (21-27 g per 100 g of whole fish), and the protein recovery (50-55% of that present in the unwashed mince), but caused efficient lipid removal (80%) leading to surimi containing only 0.2-1.4% lipid. The texture and colour of the final kamaboko were also improved.
The texture parameters (folding score, rigidity, elasticity index and gel strength) of kamaboko prepared from very fresh sardines were markedly enhanced by gel setting during incubation at 37°C for 30 min or 4°C for 24 hr. Incubation at 60°C for 30 min led to soft, coarse gels. Omitting potato starch or replacement by spray dried egg white had little effect on texture.
The texture of kamaboko prepared from less fresh sardines was less firm and elastic, did not improve when incubation was carried out at 37 or 4°C before cooking, and was softer and coarser after incubation at 60°C. Partial or total replacement of potato starch by egg white, soy protein isolate or bovine serum albumin markedly improved the texture. Egg white also increased the colour lightness.     

ɛ-POLYLYSINE IMPROVES THE QUALITY OF SURIMI PRODUCTS

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.     

Participation of cysteine protease cathepsin L in the gel disintegration of red bulleye (Priacanthus macracanthus) surimi gel paste

BACKGROUND: Endogenous proteases, among them cysteine‐type proteases, are reported to contribute to gel disintegration, resulting in kamaboko of poor quality. Severe gel disintegration occurs in red bulleye surimi gel paste. The objective of this study was to clarify the participation of cysteine protease cathepsin L in the gel disintegration of red bulleye surimi. The surimi was made into kamaboko with and without cathepsin L inhibitors. To confirm its hydrolysis action, crude cathepsin L was also extracted and added to the surimi to make kamaboko. RESULTS: The gel strength of kamaboko obtained by both one‐step (50 °C, 2 h) and two‐step (50 °C, 2 h + 80 °C, 20 min) heating was very low in the absence of inhibitors. Protease inhibitors E‐64 and leupeptin were found to enhance the gel strength considerably. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the hydrolysis of kamaboko was promoted by crude cathepsin L and inhibited by E‐64 and leupeptin. The gel strength of two‐step heated kamaboko was increased from 12 to 110 and 130 g cm^?2 by E‐64 and leupeptin respectively at a concentration of 0.2 g kg^?1 surimi. CONCLUSION: Endogenous cathepsin L of red bulleye surimi participates in gel disintegration during kamaboko processing. It does so by degrading the myosin heavy chain of actomyosin and consequently hindering the gelation of red bulleye surimi. Copyright © 2009 Society of Chemical Industry     

Rheological and Textural Properties of Pacific Whiting Surimi Gels As Influenced by Chicken Plasma

Rheological properties of Pacific whiting surimi, in the absence and presence of chicken plasma (CP) at different levels (0.3–3.0%, w/w), were studied by dynamic rheological (small strain) and torsion fracture measurements, respectively. The surimi paste exhibited two major distinctive rheological transitions during heating (1°C/min) from 20 to 90°C with peaks observed at 33 and 56°C. The abrupt loss of G′ upon heating from 47 to 57°C, and the occurrence of small peak of phase angle at the same temperature range were prevented by the addition of CP. Nevertheless, the final G′ of the surimi paste added with CP was lower than that of the control. But shear fracture stress of both kamaboko and modori gels increased as the CP levels increased and shear strain increased with the addition of CP up to 2% (P < 0.05). CP inhibited the degradation of myosin heavy chains (MHC) caused by endogenous proteinases as indicated by more retained MHC and lowered TCA-soluble peptide content. Whiteness of gels decreased somewhat with increasing CP levels. CP, thus, could be a helpful additive for improving gelling properties of Pacific whiting surimi     

Characteristics of Sarcoplasmic Proteins and Their Interaction with Surimi and Kamaboko Gel

ABSTRACT:  This study examined the effect of adding common carp sarcoplasmic proteins (Sp- P) on the gel characteristics of threadfin bream surimi and kamaboko while maintaining constant moisture and myofibrillar levels. Based on the temperature sweep test, which is involved in heating of surimi gel from 10 to 80 °C to monitor the viscoelastic properties, at temperature range of 40 to 50 °C, the decrease level (depth of valley) in storage modulus (G') thermograph was in proportion to the concentration of added Sp- P. Storage modulus (G') showed greater elasticity after adding Sp- P compared with the control without Sp- P. Furthermore, the breaking force and distance and consequently gel strength of the resultant kamaboko were improved significantly ( P > 0.05). Thus, added Sp- P did not interfere with myofibrillar proteins during sol–gel transition phase but associated with textural quality enhancement of resultant kamaboko; however, addition of Sp- P from the dark muscle of the carp decreased the whiteness of the resultant surimi. Furthermore, according to the SEM micrographs, the gel strength could not be associated with either the number of polygonal structures/mm² or the area of the polygonal structures in the kamaboko gel microstructure.     

Alternative Techniques for Producing a Quality Surimi and Kamaboko from Common Carp (Cyprinus carpio)

ABSTRACT: The demand for surimi and kamaboko is increasing in the world at the same time as the supply of the fish traditionally used has declined. In an effort to increase the range and hence supply of fish used, factors increasing the quality of surimi and kamaboko from common carp were investigated. The best surimi and kamaboko characteristics were produced by a modified conventional method (MCM) rather than traditional method (TM), alkaline‐aided method (AAM), and pH modified method (PMM). MCM processing used centrifugation instead of decanting and filtering to optimize dewatering and remove the sarcoplasmic proteins (Sp‐P). The temperature sweep test, at the end of sol–gel transition stage (at 75 °C), showed significantly (P < 0.05) greater G′ for the kamaboko from MCM than that from other methods tested. Furthermore, the greatest and the least gel strengths were obtained with MCM and TM kamaboko, respectively. The protein recovery was about 67%, 74%, 87%, and 92% for TM, AAM, MCM, and PMM, respectively. TM and MCM resulted in the removal of Sp‐P as determined by SDS‐PAGE. The superiority of MCM kamaboko gel characteristics was supported by scanning electron micrographs (SEM) of the gel, which showed a significantly (P < 0.05) greater number of polygonal structures than for the TM kamaboko, which had the fewest and largest polygonal structures. The pH‐shifting methods improved the textural quality of the resultant kamaboko compared with TM. However, a simple modification (centrifugation compared with decanting) by MCM in the surimi process can further improve the quality of the surimi and kamaboko gels. Furthermore, because it removed Sp‐P and still preserved gel strength, it suggests that Sp‐P are not required for gel strength.     

Thermal Gel Degradation (Modori) in Sardine Surimi Gels

Sardine (Sardina pilchardus) surimi gels set (50°C or 60°C), or set and cooked (50°C or 60°C + 90°C) for different times were studied in order to evaluate modori (thermal gel degradation). The texture data of the set gels were similar to data obtained previously in gels set at lower temperature that produced good kamaboko gels. However, in gels set at 50°C and 60°C modori occurred upon cooking. Microscopically the set gels exhibited globular aggregated structures that became more compact when modori occurred. Results suggested that at modori temperature protein-protein bonding caused massive protein coagulation preventing the formation of a fibrillar matrix upon cooking.     

Rheological characteristics of suwari and kamaboko gels made of surimi from Indian major carps

The gel strength, compressibility and folding characteristic of suwari (set) and kamaboko (set and cooked) gels prepared from rohu ( Labeo rohita ), catla ( Catla catla ) and mrigal ( Cirrhinus mrigala ) surimi were examined to understand the occurrence of suwari and modori phenomena in surimi from major freshwater carps. Suwari setting of gels did not take place at lower temperatures. Suwari gels showed good gel strength at 50 °C for rohu and at 60 °C for catla and mrigal after 30 min setting time. Incubation for 60 min decreased the gel strength at 60 °C for rohu and catla. Setting at 25 °C followed by cooking at 90 °C increased the gel strength. Increased setting temperature, however, decreased the gel strength of cooked gels. Gel strength and compressibility data were supported by folding characteristics. © 2002 Society of Chemical Industry     

GEL PROPERTIES OF BIGEYE SNAPPER (PRIACANTHUS TAYENUS) SURIMI AS AFFECTED BY SETTING AND PORCINE PLASMA PROTEINS

Effects of setting temperature, time, and addition of porcine plasma protein (PPP) on gel properties of surimi from bigeye snapper (Priacanthus tayenus) were investigated. Breaking force and deformation of the surimi gels increased as the setting time and temperature increased. The gel preincubated at 35C for 90 min in the presence of 0.5% PPP, followed by cooking at 90C for 20 min showed the maximum force and deformation. The decrease in solubility of the resultant suwari and kamaboko gels in solution containing sodium dodecyl sulfate, urea and β‐mercaptoethanol suggested that gel enhancement was mainly mediated through the formation of nondisulfide covalent bonds catalyzed by both transglutaminase (TGase) in fish muscle and porcine plasma. Addition of PPP slightly decreased the whiteness of the kamaboko gels.     

Mechanisms of gelation of sardine proteins: influence of thermal processing and of various additives on the texture and protein solubility of kamaboko gels

Surimi prepared from freshly caught sardines was mixed with NaCl and other additives and used to prepare kamaboko gels. Protein-protein interactions involved in the setting (at 4 or 37°C) and/or the cooking (at 90°C) gelation steps were investigated (i) by assessment of kamaboko texture as a result of the type and concentration of additive added; (ii) by partial solubilization of kamaboko gels in buffers containing mercaptoethanol, sodium dodecyl sulphate (SDS) and/or urea, followed by determination of the soluble protein constituents by polyacrylamide gel electrophoresis. Cooked gels of high elasticity and of varying rigidity and gel strength were obtained in the 73–80% water range. Adequate gel texture required a NaCl content of 1.7–3.5% and a pH range of 6.4–8.4. Low concentrations of reducing agents (mercaptoethanol, dithiothreitol, cysteine) or of divalent cations (Ca²⁺, Mg²⁺) improved the texture of gels obtained by setting at 37°C with and without subsequent cooking at 90°C. On the other hand, the addition of N -ethyl maleimide or of ethylene diamine tetra-acetate led to texture deterioration after cooking. These data demonstrate the involvement of disulphide bonds and of electrostatic interactions in surimi gelation. Gel solubilization experiments indicate that the aggregation of myosin heavy chains through various types of protein-protein interactions may be responsible for the elastic gel network formed during setting at 37°C (30 min) or 4°C (24h). Strengthening of the gel network after cooking appears to be due to additional disulphide and hydrophobic interactions.     

Heat-Induced Gelation Properties of Surimi From Mechanically Separated Chicken

Chicken surimi was prepared from fresh mechanically separated chicken meat using a sodium bicarbonate washing process. The heat-induced gelation properties were assessed under different conditions of pH, temperature, heating rate, protein and sodium tripolyphosphate (TPP) concentrations. Surimi gel strength increased (p < 0.05) after: reducing pH from 6.4 to 6.0, increasing temperature from 40°C to 80°C, reducing heating rate from 5°C/min to 1°C/min, increasing protein concentration from 4% (w/w) to 8% (w/w) or addition of 0.3% (w/w) TPP. Freeze thaw stability studies revealed that the gel strength of surimi decreased (p < 0.05) when subjected to frozen storage at – 18°C.     

不同食用蛋白的添加对鲤鱼鱼糜流变和凝胶特性的影响

目的:研究大豆分离蛋白(soybean protein isolated,SPI)、乳清分离蛋白(whey protein isolate,WPI)、花生分离蛋白(peanut protein isolate,PPI)的添加对鲤鱼鱼糜流变和凝胶性质的影响。方法:利用流变仪、质构仪、色差计等对添加不同蛋白鱼糜的弹性模量、黏性模量、凝胶强度、破断强度、凹陷深度、持水性以及白度进行测定,并采用相关性分析法研究各指标之间的相互关系。结果:不同添加量的SPI、WPI和PPI均能有效地改善鱼糜的弹性模量、黏性模量、破断强度、凝胶强度和持水性,但会降低破断深度和白度,但各测定指标间存在显著相关(p<0.05)。SPI和PPI的添加对鱼糜的流变性、破断强度、凝胶强度的提高效果更好,添加量为8%时,鱼糜的凝胶强度均达到最大值,其中SPI组可达3806.70 g·mm,比对照组增加了34.63%;WPI对鱼糜的保水性效果最好,添加量为8%时,失水率仅为12.6%;白度随着蛋白添加量的增加而降低,其中PPI组与WPI组引起的白度降低较少,且差异不显著(p>0.05)。结论:在实际鱼糜制品的生产中,应根据产品的特征选择适合的蛋白种类和合理的添加量,来提高鱼糜制品的品质。     

Factors Affecting Separation of Low Fat Flesh from Fatty Fish by Cryo-shattering

Our previous report on separating low fat flesh from fatty fish by cryo-shattering indicated that at appropriate temperatures, fat content in particles increased with particle size. The effect was temperature dependent; that effect of low temperature on fracture stress and elastic modulus of model fish flesh was further examined at - 60°C to - 196°C. The fish flesh showed abrupt changes in compression and tensile fracture stress at about - 90°C and - 150°C; such changes strongly affected fat content-particle size relations (FCPSR). Using measured fracture stress and elastic modulus values, FCPSR was successfully simulated when Bond's equation was linked with an empirical equation to estimate work index values.     

The properties of surimi and kamaboko gels from nine British species of fish

This paper describes the preparation and properties of surimi and derived kamaboko gels from a range of British-caught species of teleost (or bony) fish including white fish (fillets, trimmings and skeletons), fatty fish and an elasmobranch (or cartilaginous) fish. The data include yields, moisture and fat contents, water-binding capacities, pH values and Hunter L,a,b colour values as well as sensory and instrumentally measured indices of texture.
Cod, haddock and whiting fillets and trimmings of haddock and whiting yielded surimi and derived gels with functional properties most closely approaching those of the Alaska pollack surimi used as a standard. Saithe gave a gel which was firm and elastic but which had a low water-binding capacity and was dark in colour. The fatty fish yielded surimi with some potentially useful functional properties but colour and water-binding capacity were inferior to pollack surimi.     

Effect of high-temperature setting on gelling characteristic of surimi from some tropical fish

The effect of setting at 40 °C on the textural properties and the changes in myofibrillar proteins in surimi produced from threadfin bream (Nemipterus bleekeri), bigeye snapper (Priacanthus tayenus), barracuda (Sphyraena jello) and bigeye croaker (Pennahai macrophthalmus) was investigated. An increase in the time of setting generally resulted in higher breaking force and also the deformation of both suwari and kamaboko gels. Maximum increases in gel‐breaking force were obtained in 1 h for threadfin bream, 2 h for bigeye snapper, 1.5 h for barracuda and 3 h for bigeye croaker. Extended setting time caused decreases in breaking force and deformation in all surimi, except that produced from bigeye croaker. Gel strengthening was associated with an increase in non‐disulphide covalent bond formation. Degradation of proteins occurred with prolonged setting. Therefore, setting at 40 °C for an appropriate time is a promising means to improve the gelling property of surimi produced from tropical fish.     

Influence of drying temperature upon some mechanical properties of beech wood

The paper presents the results obtained in an experimental study concerning the influence of drying temperature upon the mechanical properties of beech wood (Fagus sylvatica L.). Sound wood samples without red heart were cut from white (unsteamed) beech timber parts, dried at different temperatures: 20 °C, 80 °C, 90 °C, 100 °C, 115 °C and same relative air humidity: 50%. After performing classical tests for evaluation of some selected mechanical properties, the following conclusions could be drawn: all bending properties (static bending strength, modulus of elasticity and impact bending strength) increased with increasing temperature, confirming thus the benefiting effect of heat upon wood plasticity. The tensile strengths, both parallel and perpendicular to grain, increased with increasing temperature, but only in the range below 100 °C; as soon as the temperature exceeded this value, the tensile strengths began decreasing. As far as compression strength parallel to grain, shearing strength and splitting resistance is concerned, no significant influence of temperature could be established. However, it seems that these properties are negatively affected by kiln-drying, as even with low kiln-drying temperatures these strengths are much lower than in case of air-drying.     

Effect of microbial transglutaminase on autolysis and gelation of lizardfish surimi

In the absence of microbial transglutaminase (MTGase), the textural properties of lizardfish surimi (Saurida spp) improved when pre‐incubated at 4 and 25 °C for 24 and 4 h, respectively. MTGase optimally catalyzed incorporation of monodansylcadaverine (MDC) into surimi at 40 °C. Addition of MTGase appeared to reduce autolytic activity at 25 and 40 °C, but had no effect on autolytic activity at 65 °C. Breaking force and deformation of lizardfish surimi significantly improved when 0.1 unit MTGase g^?1 surimi (1.8 g kg^?1) was added and pre‐incubated at either 25 or 40 °C. Textural properties improved concomitant with cross‐linked polymers of myosin heavy chain and tropomyosin, but not actin. Addition of MTGase also improved the storage modulus (G′). The gel network of surimi mixed with MTGase and pre‐incubated at 40 °C readily formed during the pre‐incubation period, while formation of the gel network began at 48.1 °C in the absence of MTGase. Copyright © 2005 Society of Chemical Industry     

Setting Response of Alaska Pollock Surimi Compared with Beef Myofibrils

Physicochemical properties of surimi after preincubation at 25–50°C and beef myofibrils at 25–60°C for up to 8 hr prior to cooking at 80°C for 20 min were evaluated by a torsion test and sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Shear stress and true shear strain of surimi were more sensitive to pH changes than beef myofibrils. Maximum gel strength was found at = pH 7 for surimi and pH 6 for beef myofibrils. The myofibrils showed no setting effect at any preincubation temperatures examined, while surimi showed an optimum setting effect at 25°C. Incorporation of beef myofibrils into surimi resulted in decrease of shear stress and true shear strain values.     

Physicochemical changes in surimi with salt substitute

Protein endothermic transitions (thermal denaturation), rheological properties (protein gelation), and fundamental texture properties (shear stress and strain at mechanical fracture) of Alaska pollock surimi gels made with 0 (control), 1, 2, and 3 g/100 g of salt (NaCl) were determined and compared with equal molar concentration of salt substitute. Salt and salt substitute shifted the onset of myosin transition to higher temperature and resulted in larger myosin peaks (i.e., transition enthalpy). Endothermic transitions showed similar trends to rheological properties. The elastic modulus (G′) increased when salt or salt substitute was added to surimi, except at the highest concentration of salt and salt substitute. Salt and salt substitute also induced the onset of protein gelation (i.e., as measured by significant increase of G′) at lower temperature. Surimi gels with salt substitute and salt at equal molar concentrations had similar texture properties (shear stress and strain). Based on the present study, salt substitute can be used in the development of low-sodium surimi seafood products without significant change in gelation and texture.