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.     

Effects of adding fish gelatin on Alaska pollock surimi gels

Fish gelatin is a food additive obtained after hydrolysis of collagen from fish skin. The importance of fish gelatin as a food additive is increasing due to its increased commercial availability. Surimi is washed minced fish meat used as the raw material for seafood analogs like crabmeat substitutes. The most important attributes of surimi are gelling and whiteness. The objective of this work was to determine the effect of using fish gelatin as an additive in surimi to improve the mechanical and functional properties of gels. Surimi gels were prepared by mixing grade A or FA surimi (Alaska pollock) with salt (20 g/kg w/w) and commercial fish gelatin at 0 (control), 5, 7.5, 10, or 15 g/kg (w/w) previously dissolved in water (200 mL/kg surimi). The solubilized paste was incubated at 40 °C for 30 min followed by cooking at 90 °C for 15 min. Changes in mechanical properties (torsion test), a functional property (expressible water content) and color attributes of surimi gels were measured. Grade FA surimi gels containing 7.5–15 g/kg of fish gelatin showed an improved expressible moisture. However, gelatin added at 15 g/kg showed a disruptive effect detrimental to the mechanical properties. Color parameters were modified slightly. Whiteness attribute as affected by increasing the fish gelatin was instrumentally detected but not observed by sensory panelists. Gelatin did not change the overall color attributes and all gels remained in the grayish region. These results indicated that fish gelatin did not have an advantage for using as a functional additive in Alaska pollock surimi grades A or FA. However, it can be used at up to 10 g/kg without a negative effect on the mechanical properties.     

CHARACTERIZATION OF PROTEINASE RECOVERED FROM PACIFIC WHITING SURIMI WASH WATER

Pacific whiting surimi wash water (SWW) proteinase was recovered by ohmic heating, ultrafiltration, and freeze-drying. By these processes, 5.9-fold purification was achieved. The most efficient step was ohmic heating, which concentrated the proteinase by 4.8 fold. Specific activity of the recovered SWW proteinase on casein and Z-Phe-Arg-NMec was 28.2 and 0.17 U/mg protein, respectively. The SWW proteinase showed good hydrolytic activity towards casein, acid-denatured hemoglobin and myofibrils. Acidification increased specific activity on all substrates tested but reduced thermal stability. β-Mercaptoethanol, dithiothreitol and urea enhanced activity against Z-Phe-Arg-NMec. Proteinase activity on Z-Phe-Arg-NMec showed an optimum pH of 4.0. The recovered proteinase showed 18.5% residual activity after 7 week storage at 4C.     

Effect of Various Types of Egg White on Characteristics and Gelation of Fish Myofibrillar Proteins

ABSTRACT:  Three types of egg white protein (regular dried egg white [REW], special dried egg white [SEW], and liquid egg white [LEW]) were compared for their effect in surimi (CON), containing no egg white (EW). They were characterized for enzyme inhibition and time of EW addition, either with cryoprotectants prior to freezing or during gel preparation, using Pacific whiting surimi. In addition, the setting (suwari) effect and fish protein–EW protein interactions (dynamic rheological properties, total sulfhydryl groups, and fracture gel analysis) were evaluated using Alaska pollock surimi. After 12 mo frozen storage, adding 2% and 3% SEW to Pacific whiting surimi during chopping significantly ( P  < 0.05) increased the force and deformation values compared to adding the respective EW before freezing. The highest ( P  < 0.05) force (175.2 g) and deformation (9.0 mm) values after 12 mo were obtained when 3% SEW was added during chopping. Enzyme autolysis showed that addition of 2% EW protein was effective at inhibiting enzyme activity. During setting, adding 2% SEW maintained force (1047.4 g) and deformation (17.9 mm) values similar ( P  > 0.05) to CON (1055.1 g; 19.3 mm) and significantly ( P  < 0.05) better than 2% REW (666.1 g; 15.6 mm). Texture results corresponded well to other data where 2% SEW showed the lowest total sulfhydryl groups (48.3 mole/10⁵ g), and higher elastic modulus (G'), which suggests improved protein interaction for gel formation. Overall, the addition of 2% to 3% SEW improved gel textural properties of Pacific whiting and Alaska pollock fish protein.     

Gelation of Surimi by High Hydrostatic Pressure

The effects of high hydrostatic pressure (HHP) on gel strength of Pacific whiting and Alaska pollock surimi were determined by torsion. Pacific whiting gels were made with and without 1% beef plasma protein (BPP) as protease inhibitor. HHP treated whiting (1% BPP added) and pollock gels showed greatly increased strain values at all pressure/temperature combinations compared with heat-set controls. Stress values for the same samples were variable depending on treatment and species. A three-fold increase in strain and stress was found for HHP treated whiting gels made without inhibitor.     

USE OF CYSTEINE PROTEINASE INHIBITORS FROM INJURED TOMATO LEAVES IN WHITING SURIMI

Cooking surimi paste from Pacific whiting results in a gel with poor texture due mainly to myosin degradation caused by a cysteine proteinase. Cysteine and serine proteinase inhibitors were isolated from injured and methyl jasmonate treated tomato leaves. Tomato cysteine proteinase inhibitor was stable at 60C but inactivated at 90C, making it suitable for use in surimi. Tomato proteinase inhibitors (TPI), having 7.9 papain inhibitor units, inhibited autolysis about 95% in 10 g of Pacific whiting surimi. Gel strength of Pacific whiting surimi was improved by adding only 0.0 27% of TPI to the surimi formulation. Addition of TPI did not affect the color of whiting surimi gel, while egg white needed to prevent gel weakening caused the gels to have more yellow hue (P<0.05). SDS-PAGE showed that myofibrillar protein degradation was prevented during cooking when 0.027% of TPI was included in the surimi. TPI extracted from tomato plants has potential for use as food grade additive in Pacific whiting surimi.     

Assessment of Added Protein/Starch on the Functional Properties of Surimi Gels Manufactured from Atlantic Whiting

ABSTRACT: The functional properties (hardness, cohesiveness, color, and whiteness) of 5 food ingredients (2 whey protein concentrates [WPC 45 and WPC 76], whey protein isolate [WPI], egg white [EW], and potato starch [PS]) added to surimi gels were evaluated using 2 different thermal regimes. Hardness and cohesiveness of whiting surimi gels prepared using a rapid cook treatment (90°C for 15 min) did not significantly change on the addition of test ingredients. Hardness and cohesiveness of whiting surimi with added ingredients prepared using a suwari set treatment (0° to 4 °C for 12 h followed by 90°C for 15 min) were increased ( P < 0.05) on addition of additives with the exception of WPC 76, which decreased ( P < 0.05) surimi hardness and cohesiveness. Results showed that starch was more effective in improving the functional properties of surimi when compared with all other protein additives assessed.     

Proteinase in Pacific Whiting Surimi Wash Water: Identification and Characterization

A proteinase in Pacific whiting surimi wash water (SWW) was characterized to be cathepsin L based on molecular mass (M_r), substrate specificity, and SDS-substrate gel electrophoresis. The proteinase was highly active on Z-Phe-Arg-NMec, and the native M_r was 27,400 based on size exclusion (SEC)-HPLC. Acidification of the SEC-HPLC fractions showed a two-fold increase in activity on Z-Phe-Arg-NMec. SWW proteolytic activity was found at M_r 54,200 on SDS-substrate gel. However, acidification shifted the activity zone to M_r 39,500 corresponding to cathepsin L. No evidence of activity by calpain or cathepsin B or H was found in Pacific whiting SWW.     

RECOVERY OF PROTEINASE FROM PACIFIC WHITING SURIMI WASH WATER

A proteinase from Pacific whiting surimi wash water (SWW) was recovered by ohmic heating, ultrafiltration, and freeze drying with overall yield of 0.83 g protein/L SWW and 78% recovery of activity. Ohmic heating conditions were optimized for the maximum recovery of the enzyme. Different applied voltages (50, 70, 90 V) showed no differences in efficiency for removing protein and retaining cathepsin Lactivity. Cathepsin L activity reached its maximum after ohmic heating to 55C whereas cathepsin B activity decreased constantly with increased temperature. A constant reduction in protein content was observed with the increase in temperatures from 45C to 60C and holding time up to 5 min. The highest retention of both total and specific activity of cathepsin L was obtained with the treatment at 55C for 3 min. Under these conditions, 193% activity was recovered from SWW although a large amount of the activity was lost by the subsequent steps of ultrafiltration and freeze drying.     

A NONLINEAR PROGRAMMING TECHNIQUE TO DEVELOP LEAST COST FORMULATIONS OF SURIMI PRODUCTS

Optimization programming techniques were applied to develop the least cost formulations for Pacific whiting surimi-based seafood (PWSBS). To develop the quality constraint functions, texture and color of whiting surimi gels were determined by torsion test and colorimeter, respectively. Whiting surimi gels were produced by heating at 90C for 15 min with 2% NaCl, five final moisture contents (74, 76, 78, 80, 82%), and various combinations of beef plasma protein (0–2%), potato starch (0–8%), and two whey protein concentrates (0–8%). Due to the nonlinear constraint functions describing texture and color, a nonlinear programming search technique was required to solve the least cost model for PWSBS. Results for representative target quality constraints are reported in this study and show that whey protein concentrate both increases the texture properties and remains economically competitive with other ingredients which similarly influence functionality in PWSBS.     

TEMPERATURE-TOLERANT FISH PROTEIN GELS USING KONJAC FLOUR

Shear stress and strain values of surimi gels made from Alaska pollock and Pacific whiting were measured upon cooling, reheating, and freeze/thawing. Konjac flour was introduced to investigate its ability to maintain fracture properties of surimi gels against various temperatures. Gel colors (CIE L*,a*,b*) were also measured as affected by various levels of konjac flour. Konjac flour (5%) showed its ability to reinforce shear stress of gels 8-10 times in both whiting and pollock surimi. Gels with 4% konjac flour were the most heat-tolerant in both surimi. Surimi gels with konjac flour exhibited an ability to maintain consistent shear strain values against repeated freeze/thaw abuse. Konjac flour, up to 2%, increased lightness of gels, while yellow hue increased gradually up to 5%.     

酵母提取物对鱼糜凝胶品质的影响

以冷冻鱼糜为原料,采用两段式加热方式制备鱼糜凝胶,测定添加FA02、FA28、KK02、FA31 4 种酵母提取物鱼糜凝胶的穿刺特性、质地剖面分析参数、色度、持水性、气味特征、滋味特征及感官评分,研究酵母提取物种类对鱼糜凝胶品质的影响。结果表明：在鱼糜中添加1%的酵母提取物可提高鱼糜凝胶的破断强度、凹陷深度、硬度和咀嚼性,显著改善其气味、滋味和总体可接受性,但会降低鱼糜凝胶的白度和色泽评分;感官评价、电子鼻和电子舌分析可知,添加酵母提取物可明显降低鱼糜凝胶的异味（腥味及过熟味）,其中酵母提取物KK02去异味的效果最好,具有增强鱼糜凝胶鲜味、降低其酸味和咸味的作用。     

Rheological changes during thermal gelation of meat batters containing surimi from alaska pollack (Theragra chalcogramma) or sardine (Sardina pilchardus)

The objective of this study was to use a thermal scanning rigidity monitor to analyse the changes occurring in rheological behaviour during thermal gelation induced by the presence of surimi in meat batters. These studies were conducted on systems prepared with pork meat to which varying proportions of surimi from Alaska pollack (Theragra chalcogramma (Pallas)) or sardine (Sardina pilchardus) (Walb) were added. The results indicated that gelation in pork proteins did not occur in the same way as in fish proteins. Whereas the addition of Alaska pollack surimi to the meat preparations produced scarcely any change with respect to the meat alone, the sardine surimi caused major alterations. These changes depended upon the proportion of protein from surimi added: addition of 100 g kg^?1 caused a protein matrix to form, inducing the formation of stiffer gels and the appearance of the setting phenomenon, although at higher temperatures than are found with fish proteins. Such behaviour was not apparent when the proportion of protein from surimi was raised to 200 g kg^?1.     

Optimum chopping conditions for Alaska pollock, Pacific whiting, and threadfin bream surimi paste and gel based on rheological and Raman spectroscopic analysis

Rheological and Raman spectroscopic properties of surimi from three species [Alaska pollock (AP) (cold water), Pacific whiting (temperate water), and threadfin bream (warm water)] were investigated as affected by various chopping conditions. Comminuting Alaska pollock surimi at 0 °C demonstrated superior gel hardness and cohesiveness when chopping time was extended to 15-18 min; however, long chopping time at higher temperatures resulted in a significantly decreased gel texture particularly at 20 °C. Warm water fish threadfin bream exhibited higher gel texture when chopping was done longer at higher temperature. Rheological properties were significantly affected by both chopping time and temperature. Species effect, based on their thermal stability, was readily apparent. Raman spectroscopy revealed a significant change in disulfide linkage and the reduction of secondary structure upon extended chopping. Dynamic oscillation rheology demonstrated the damage of light meromyoisn and lowering of onset of gelling temperature as the chopping time was extended. PRACTICAL APPLICATION: Chopping conditions to determine gel quality and manufacture surimi seafood are varied by all manufacturers. This paper covering three primary species for surimi with their suggested optimum chopping conditions: 15 min for Alaska pollock when chopped at 0 °C, 15 min for Pacific whiting at 15-20 °C, and 18 min for threadfin bream at 25-30 °C. The use of optimum chopping condition should maximize the value of each surimi and provide consistent quality to the end users.     

Linear Programming in Blending Various Components of Surimi Seafood

Shear stress, shear strain, whiteness of surimi gels made with high and low grades of Alaska pollock and Pacific whiting were investigated to determine linearity of their relationships. A canonical form of least square linear model in mixture design showed a greater linearity (r²0.99) for blending high and low grade surimi lots. Due to linearity without interaction (p<0.001), a least cost linear program provided optimum blending for surimi lots based on value, constraints, and decision variables. Linear programming to determine optimum formulation of surimi with starches and water content was not feasible due to interactions between surimi and starch, or starch and water.     

Color improvement by titanium dioxide and its effect on gelation and texture of proteins recovered from whole fish using isoelectric solubilization/precipitation

Whiteness is a critical attribute for restructured fish products such as surimi seafood. However, the whiteness of gels made from proteins recovered from fish processing by-products or whole fish using isoelectric solubilization/precipitation is poor. The by-products and whole fish contain bones, scales, skin, etc. that affect gel color. Therefore, whiteness needs to be improved if marketable products are to be developed from recovered proteins. The objectives of this study were to determine effects of titanium dioxide (TiO₂) on: (1) color; (2) texture; and (3) viscoelasticity (G′) of gels made from isolated carp proteins and Alaska pollock surimi. Carp proteins were recovered with isoelectric solubilization/precipitation. TiO₂ was added to carp proteins at 0-0.5 g/100 g. TiO₂ was not added to surimi. Due to much higher (P < 0.05) yellowness (b^∗) and lower (P < 0.05) lightness (L^∗), the whiteness of carp gels without TiO₂ was lower (P < 0.05) than surimi gels. TiO₂ at ≥ 0.2 g/100 g resulted in better (P < 0.05) whiteness of carp gels than surimi gels without chalky and artificially white appearance. TiO₂ did not affect texture or viscoelasticity. This research demonstrates that whiteness of restructured fish products based on proteins recovered from whole fish via isoelectric solubilization/precipitation can be similar to the whiteness of surimi seafood.     

Linear Heating Rate Affects Gelation of Alaska Pollock and Pacific Whiting Surimi

Shear stress of Alaska pollock surimi gels with and without beef plasma protein (BPP) increased as heating rate decreased, but shear strain was unaffected. An increase in shear stress was accompanied by an increase of cross-linked myosin heavy chain. Slow heating rates increased proteolysis in Pacific whiting surimi as shown by degradation of myosin heavy chain and low shear stress and shear strain. Proteolysis of whiting surimi was lessened by BPP to a greater extent at rapid heating rates (20 and 30°C/min) than at slow heating rates (1 and 5°C/min).     

膳食纤维对鱼糜凝胶工艺特性的影响

研究大豆膳食纤维(水不溶性膳食纤维)、聚葡萄糖(水溶性膳食纤维)以及两者的混合物对带鱼鱼糜凝胶工艺特性的影响.每种膳食纤维添加量均为0,10,20,30,50g/kg,分析鱼浆的质构特性、色差以及鱼糜凝胶的凝胶特性、持水性和白度等的变化情况.结果表明,大豆膳食纤维可以提高鱼糜凝胶的质构特性以及持水性但是会一定程度的降低凝胶的白度;添加5％的聚葡糖会使凝胶的质构特性和持水性显著降低但是可显著地增加鱼糜凝胶的弹性及白度;而两者混合物对鱼糜凝胶影响居于两者之间.     

Effects of Freeze-Thaw Abuse on the Viscosity and Gel-Forming Properties of Surimi from Two Species

The effects of cyclic freezing and thawing upon the quality of frozen surimi of two species were studied with respect to sol viscosity, sol rigidity changes during thermal processing and structural failure properties of the cooked gel. A torsion test, used to determine the strength of gels subjected to different thermal histories, revealed that increasing the number of freeze-thaw cycles reduced the strength and deformability of both sand trout and Alaska pollack surimis. Continuous monitoring of sol rigidity during thermal processing showed little changes in thermal transition temperatures caused by freeze-thaw abuse for either surimi but shifts occurred in overall rigidity levels. Particularly dramatic changes were induced in the Alaska pollack rigidity thermogram. The rigidity thermograms of sand trout and Alaska pollack were significantly different, as were their responses to freeze-thaw abuse and low temperature (4°C and 40°C) pretreatments.     

EFFECT OF SETTING CONDITIONS USING MICROBIAL TRANSGLUTAMINASE DURING OBTENTION OF BEEF GELS

Microbial transglutaminase (MTG) is a food additive widely used to improve the mechanical properties of beef, poultry and fish gels. The aim of this study was to determine the effect of incubation temperature on the mechanical properties of restructured beef gels treated with MTG. The restructured beef gels were obtained by adding 0.0% (untreated) or 0.3% MTG. Three incubation temperatures (40, 50 or 60C) for 30 min were used, followed by cooking at 90C for 15 min. Control samples without incubation were also prepared. Changes in the mechanical properties (texture profile analysis and puncture test), color attributes, expressible water and cooking loss were determined. Results indicated that the maximum mechanical properties can be obtained by incubating beef pastes at 50C for 30 min with minimal effect on color, expressible water and cooking loss when 0.3% of MTG is added.

PRACTICAL APPLICATIONS

Meat and poultry are considered nonsetting proteins, and consequently, an incubating treatment to allow optimal cross-linking has not been considered, and the products are usually obtained by direct cooking. Our results showed that beef gels containing 0.3% of microbial transglutaminase incubated at 50C showed higher mechanical properties than control gels without incubation. These results could be useful to improve the mechanical properties of beef gels.