Study of two different cold restructuring processes using two different qualities of hake (Merluccius capensis) muscle,with addition of microbial transglutaminase

BACKGROUND: Microbial transglutaminase (MTGase) can improve the mechanical and functional properties of restructured fish products without the need of thermal gelation. The present study seeks to determine whether, for different setting times, MTGase activity in restructured hake muscle made with pieces or with homogenised muscle can be affected by the quality of the protein in the raw materials. RESULTS: As regards mechanical properties, samples of both qualities subjected to the two different processes attained a suitable consistency after setting for 24 h at 5 °C. The quality of the protein in the sample is important when pieces are used for restructuring, but not when sample is homogenised. Also, there were strong correlations between residual MTGase activity up to 12 h and mechanical properties and electrophoretic band density. Water binding capacity (WBC) was not significantly altered by MTGase addition. CONCLUSION: The experimental combination of 10 g kg^?1 of MTGase, 15 g kg^?1 of sodium chloride and 7.5 g kg^?1 of sodium caseinate was suitable for the production of minimally processed raw restructured fish products made with two different qualities of fish protein and two different restructuring processes. In the restructured products made with pieces, the protein quality significantly affected final properties, but in finely homogenised product the protein quality was less important. Copyright © 2009 Society of Chemical Industry     

Low‐salt restructured fish products using microbial transglutaminase as binding agent

Low‐salt restructured silver carp products were obtained using mechanically deboned fish meat from filleting wastes of silver carp (Hypophthalmichthys molitrix). The additives used were NaCl at three levels (0 (control), 10 and 20 g kg^?1) and microbial transglutaminase (MTGase) also at three levels (0 (control), 3 and 6 g kg^?1). The fish meat was massaged with the additives at <15 °C for 1 h. The massaged fish paste was then packed into steel stainless tubes and cooked at 40 °C for 30 min followed by 90 °C for 15 min. Changes in mechanical properties (texture profile analysis and punch test), solubility, electrophoretic profile and expressible water were evaluated. Hardness was in the range from 26.3 to 52.4 N, cohesiveness varied from 0.185 to 0.318 and springiness varied from 0.418 to 0.768. Increasing the amount of both additives improved the mechanical and functional properties of the restructured silver carp products. MTGase activity was associated with a decrease in protein solubility and a decrease in the myosin band (SDS‐PAGE). Increasing NaCl decreased the amount of expressible water. The results indicated that it is feasible to obtain low‐salt restructured silver carp products with improved mechanical and good functional properties using 3 g kg^?1 MTGase and 10 g kg^?1 NaCl. © 2002 Society of Chemical Industry     

Use of microbial transglutaminase and sodium alginate in the preparation of restructured fish models using cold gelation: Effect of frozen storage

Changes in physicochemical properties of raw-appearing restructured models made from hake (Merluccius capensis) muscle, using cold gelation technology by addition of sodium alginate and microbial transglutaminase (MTGase), were studied during frozen storage at ? 15 °C.Among the more interesting results, addition of MTGase produced more protein aggregation in models processed by muscle homogenization and thus the protein network that formed in the gel was better than in samples with added sodium alginate. All samples presented enhanced changes in mechanical properties such as gel strength in the course of frozen storage. The protein network that formed was better organized as shown by the ultrastructure analysis and by protein aggregation data from the beginning of storage, and as a result Water Binding Capacity was greater in restructured models processed by muscle homogenization. Some of the models studied presented lipid oxidation during frozen storage, slightly more in the ones with MTGase added.Industrial RelevanceThe industrial relevance of the present work is to establish bases for using fish fillet trimmings and minced muscle to prepare restructured products that can be commercialized in a raw state and that could also support frozen storage in order to prolong the self-life in the market. The models studied here are not final products but the base with which to prepare them. One possibility of them is to process this kind of products with technologies normally used in whole fish muscle such as smoked fish fillets, carpaccios or marinated products. In addition, these raw restructured products can be commercialized to be cooked as a normal fresh fish fillet or pieces of fillet in a variety of preparations, and also products that contain a high amount of salt. Samples elaborated by binding larger muscle fragments imitate well the original fibrousness of the muscle so that it could be used to elaborate products similar to hamburgers or others that will be fried in batter.     

Effect of dietary fibre and MTGase on the quality of mackerel surimi gels

BACKGROUND: The effects of microbial transglutaminase (MTGase; 5 g kg^?1) and dietary fibre (inner pea fibre and chicory root inulin, 20 and 40 g kg^?1) on gels from surimi made with Atlantic (Scomber scombrus) and chub mackerel (Scomber japonicus) were studied with the purpose of achieving a better understanding of the underlying phenomena and improving gels. RESULTS: MTGase addition improved textural properties (namely, cohesiveness increased from 0.19–0.41 to 0.59–0.72) and increased pH and water‐holding capacity (WHC). Moreover, MTGase reduced the elastic and viscous modules and darkened gels; protein solubility declined, meaning greater protein aggregation, according to electropherograms. MTGase had no unequivocal effect upon the gels' microstructure. Pea fibre increased hardness (an increase of almost 60% with 40 g kg^?1) and related parameters, the elastic and viscous modules and WHC. Pea fibre reduced extractable protein in sodium dodecyl sulfate and urea (in the absence of MTGase) as well. Scanning electron microscopy revealed different structures for gels containing pea fibre. Regarding inulin, it worsened textural quality and WHC. CONCLUSION: A combination of MTGase and pea fibre can improve a poor quality surimi. Copyright © 2009 Society of Chemical Industry     

Effect of Konjac Glucomannan (KGM) and Carboxymethylcellulose (CMC) on some Physico-Chemical and Mechanical Properties of Restructured Gilthead Sea Bream (Sparus aurata) Products

The development of restructured fish products and the application of new food ingredients have been used to create attractive new products and also to upgrade low-value species. The aim of this study was to evaluate the effect of konjac gum (KGM) and carboxymethylcellulose (CMC) fibres on the mechanical and physico-chemical properties of microbial transglutaminase treated restructured fish products from gilthead sea bream as well as to evaluate the effect of heat treatment and storage time. Water holding capacity, mechanical properties and colour attributes in fresh and heat-treated samples after 15 days of cold storage were measured. Results showed that these edible gums could be appropriate for making restructured products obtained from gilthead sea bream. In fresh formulations the addition of 10 g?kg^?1 of KGM or 10 g?kg^?1 of CMC presented a significant effect (p?≤?0.05) on water activity for fresh samples and the lowest value was obtained for 10 g?kg^?1 of KGM (0.975?±?0.002). Water holding capacity and adhesiveness increased due to the presence of these gums in fresh and heat-treated samples. For heat-treated samples, KGM significantly reduced (p?<?0.05) hardness, cohesiveness and chewiness. Cryo-scanning electron microscopy revealed different structures for gels containing fibres. The use of these fibres did not induce significant changes in colour parameters. Fresh or heat-treated samples stored for 15 days at 4°C showed changes in relation to the parameters investigated.     

Production of Restructured Meat using Microbial Transglutaminase without Salt or Cooking

To produce restructured meat, microbial transglutaminase (MTGase) was evaluated for its ability to introduce covalent crosslinks between protein molecules. Pork muscle cubes were mixed with MTGase and held at 5°C for 2 hr for the enzyme reaction. Restructured products were analyzed for binding strength without cooking. MTGase treatment resulted in effective binding of meat pieces provided there was addition of salt (NaCl). To ensure proper binding without NaCl, some food proteins with MTGase were also investigated. Meat cubes in combination with MTGase and sodium caseinate showed acceptable bind, and sodium caseinate appeared to be a superior substrate for the crosslinking to meat proteins than soy protein, whey protein, or gelatin. These results suggest a useful method for producing restructured meat which can be distributed in the raw, chilled state.     

1H and 23Na MRI studies of Atlantic salmon (Salmo salar) and Atlantic cod (Gadus morhua) fillet pieces salted in different brine concentrations

BACKGROUND: Applicability of magnetic resonance imaging (MRI) to quantitative analysis of sodium in salted fish products is usually impaired by the partial ²³Na MRI ‘invisibility’ phenomena as well as high investment costs of the MRI equipment. RESULTS: Salmon and cod fillet pieces, unsalted and brine salted (50, 100, 150, 200 and 250 g kg^?1 NaCl) for 48 h, were studied using ¹H and ²³Na MRI. Based on MRI results, T₁ and T₂ relaxation times were calculated for ¹H and the T₂ time for ²³Na nuclei. In addition, water diffusion images for all fillet samples and reference brine solutions were obtained. Variation of the nuclear magnetic resonance relaxation times and water diffusion constants with brine concentration is discussed in terms of the muscle structural changes. Sodium MRI visibility factors for the MRI method used were determined for all fish samples. CONCLUSION: Observed changes in proton and sodium NMR relaxation times with the salt content reflect complex counteraction of several factors related to the muscle structural changes. Sodium MRI visibility factors appear to be dependent on a number of experimental factors in a complex matter, making quantitative sodium analysis by the MRI technique used non‐trivial. Copyright © 2007 Society of Chemical Industry     

Production of low-salt restructured fish products from Mexican flounder (Cyclopsetta chittendeni) using microbial transglutaminase or whey protein concentrate as binders

Mexican flounder (Cyclopsetta chittendenni) is an abundant fish specie usually caught as shrimp by-catch in the north of the Gulf of Mexico, but due to its small size is mostly discarded after dying during catching and handling operations. The objective of this work was to determine the feasibility of obtaining low-salt restructured fish products using flounder flesh as raw material. Two levels of salt (10 and 20 g/kg) were tested and microbial transglutaminasa (MTGase) (3 g/kg) or whey protein concentrate (WPC) (10 g/kg) were used as binders. Changes in mechanical properties (texture profile analysis and puncture test), expressible water and colour attributes were measured. Good gels from Mexican flounder were obtained at both salt levels. The use of MTGase improved the mechanical properties at both salt levels. However, WPC improved the mechanical properties of gels obtained only with 20 g salt/kg. The restructured fish products showed a light greyish colour adequate for commercialization.     

Quality of dried white salted noodles affected by microbial transglutaminase

To examine the potential application of microbial transglutaminase (MTGase) in oriental noodle making, the effects of various MTGase addition levels on the rheological, textural and structural properties of noodles were investigated using good quality (‘Red Bicycle’) and poor quality (‘Sandow’) wheat flours. Addition of MTGase at 5–20 g kg^?1 levels, but not at 1 g kg^?1 level, to the two different wheat flours decreased rapid visco‐analyser (RVA) parameters of hot paste viscosity and final viscosity while increasing breakdown. For fresh white salted noodle dough sheets, the storage modulus (G′) and loss modulus (G″) increased significantly at 1 g kg^?1 MTGase addition for both types of flour, but there was no clear trend with higher levels of MTGase. For dried white salted noodles, textural parameters (tensile force, hardness and gumminess) generally increased, cooking loss was little affected and the yield of the cooked noodle was significantly decreased by MTGase. Color was slightly adversely affected. Scanning electron microscopy (SEM) results indicated that physical properties of dry noodles were improved through the formation of cross‐links [ε‐(γ‐glutamyl)lysine] by MTGase. Copyright © 2005 Society of Chemical Industry     

Reduction of sodium and increment of calcium and ω‐3 polyunsaturated fatty acids in dry fermented sausages: effects on the mineral content,lipid profile and sensory quality

BACKGROUND: A combined technological approach was applied in the development of healthier dry fermented sausages: a partial substitution of the pork back fat by pre‐emulsified linseed oil and a partial replacement of sodium chloride with calcium ascorbate at two different levels, leading to low amounts of salt (14gSalt and 10gSalt, with 14 g and 10 g NaCl per kg of mixture, respectively). RESULTS: The developed products (14gSalt and 10gSalt) showed adequate results for a_w (0.85 and 0.87) and pH (4.98 and 5.21), and low lipid oxidation values (1.4 × 10^?4 and 1.5 × 10^?5 g malondialdehyde (MDA) kg^?1). The lipid modification led to a significantly higher supply of ω‐3 (23.3 g kg^?1) compared to the control (3.2 g kg^?1). Simultaneously, reductions of 38% and 50% in sodium content and a calcium supply of 4 and 5.2 g kg^?1 were achieved in the 14gSalt and 10gSalt formulations, respectively, compared to the control products (26 g salt and 0.87 g kg^?1 Ca). Instrumental analysis of colour and texture and sensory studies demonstrated that the organoleptic quality of the new formulations was similar to that of traditional products. CONCLUSIONS: The developed dry fermented sausages showed healthier properties than traditional ones owing to their reduced sodium and higher calcium content and a significant supply of ω‐3 fatty acids. © 2012 Society of Chemical Industry     

Texture and colour properties of proteins recovered from whole gutted silver carp (Hypophthalmichthys molitrix) using isoelectric solubilisation/precipitation

BACKGROUND: According to an FAO report, carp are the cheapest and by far the most commonly consumed fish in the world. Carp have minimal growth requirements, yet rapid growth rates. Although carp are generally considered unsuitable for human consumption in the USA, they have rapidly started populating major bodies of fresh water in the USA to the extent that commercial processing becomes of interest. However, typical mechanical means of meat recovery from carp are impractical owing to the bony nature of the carp carcass. Therefore the aim of the present study was to devise processing strategies to recover fish meat from carp that could be used in the development of human food products. RESULTS: Isoelectric solubilisation/precipitation at acidic and basic pH values was applied to whole gutted silver carp. Depending on the solubilisation pH, protein and fat recovery yields were approximately 420–660 and 800–950 g kg^?1 respectively. The process effectively removed impurities such as bones, scales, skin, fins, etc. from whole gutted carp. The proteins were concentrated to approximately 900 g kg^?1, while the fat was reduced by 970–990 g kg^?1. Functional additives (potato starch, beef plasma protein, transglutaminase and polyphosphate) improved (P < 0.05) the texture of carp protein‐based gels such that it was generally comparable to the texture of Alaska pollock surimi gels. Although titanium dioxide improved (P < 0.05) the whiteness of carp gels, it was lower (P < 0.05) than the whiteness of Alaska pollock surimi gels. CONCLUSION: Isoelectric solublisation/precipitation allows protein and lipid recovery from whole gutted carp. However, if the proteins are used as a gelling ingredient in fish food products, functional additives are recommended. Copyright © 2008 Society of Chemical Industry     

Negative effect of combining microbial transglutaminase with low methoxyl pectins on the mechanical properties and colour attributes of fish gels

The objective of this work was to determine the effect of combining different concentrations of microbial transglutaminase (MTGase) and types of low methoxyl (LM) pectin on the mechanical properties (textural profile analysis, puncture test) and the colour attributes of fish restructured products. A disruptive effect was observed when LM pectin and MTGase were added to fish gels. Adding 1% MTGase with LM32 pectin significantly decreased the hardness (3.85 kg), springiness (0.631) and chewiness (0.434 kg). When LM32 pectin and 0.1% MTGase were added together, significant decreases of the three puncture test parameters were observed. The chroma of fish gels decreased significantly when 0.3% MTGase was added. Fish gels containing the LM35 pectin had higher chroma values than all other fish gels with the same level of MTGase. Hue value was increased in all fish gels after increasing the MTGase level. The results obtained showed that LM pectin is not suitable for use in products containing MTGase.     

Comparative study on protein cross-linking and gel enhancing effect of microbial transglutaminase on surimi from different fish

BACKGROUND: Microbial transglutaminase (MTGase) has been used to increase the gel strength of surimi. Nevertheless, its effectiveness varies with fish species. The aim of this study was to elucidate the effect of MTGase at different levels on protein cross‐linking and gel property of surimi from threadfin bream, Indian mackerel and sardine in the presence and absence of endogenous transglutaminase. RESULT: Breaking force of all surimi gels increased as MTGase levels (0–0.6 U g^?1) increased except for threadfin bream surimi gel, where the breaking force decreased at 0.6 U g^?1 (P < 0.05). In the presence of EDTA, the gel strengthening effect was lower, suggesting the combined effect of endogenous transglutaminase with MTGase. With the addition of MTGase, the gel with the highest increase in breaking force showed highest decrease in myosin heavy chain. When cross‐linking activity of MTGase on natural actomyosin (NAM) was determined, the highest decreasing rate in ε‐amino group content with the concomitant increased formation of cross‐linked proteins was found in NAM from threadfin bream. The reactivity of muscle proteins toward MTGase‐induced cross‐linking was in agreement with surimi gel strengthening. CONCLUSION: The composition and properties of muscle proteins of varying fish species more likely determined protein cross‐linking induced by MTGase, thereby affecting their gel properties. Copyright © 2011 Society of Chemical Industry     

Rheological investigation of alginate chain interactions induced by concentrating calcium cations

Chain interactions of sodium alginate during its gelation were investigated by a new gelation method which was based on a Ca²⁺-concentrating gelling process (CCGP) produced by water evaporation of an alginate solution containing CaCl₂. For two commercially available sodium alginate samples (low viscosity (LA) and medium viscosity (MA)) having different molecular weight distributions but the same G/M blocks, the critical Ca²⁺ concentrations for their gelation were found to be 4.6 (for LA) and 4.5 (for MA) μmol/mL after evaporating water from 1% of alginate solutions containing 4 μmol/mL of CaCl₂. The CCGP gelation method for alginate under the above conditions were confirmed by rheological measurements and the observed highly ordered and uniform mesh structure of the CCGP-formed alginate gels shown in cryo-SEM images. Combinations of LA and MA at different ratios (0:4, 1:3, 2:2, 3:1, 4:0 on weight basis) were studied using the CCGP gelation method to further the understanding of the alginate chain interactions during gelation. Different LA/MA mixtures exhibited different rheological properties in either non-gelled or gelled systems, indicating that the molecular weight distributions of the sodium alginates influence the alginate chain interactions mediated by Ca²⁺. Thus, an appropriate combination of LA and MA is required for a strong alginate interchain interaction during CCGP, and alginate products with desirable characteristics can be produced by manipulating the mixing ratios of sodium alginates having different molecular weight distributions even at the same total composition and distribution of G/M blocks.     

Use of dairy proteins and microbial transglutaminase to obtain low-salt fish products from filleting waste from silver carp (Hypophthalmichthys molitrix)

Restructured fish products from the filleting waste from silver carp (Hypophthalmichthys molitrix) were obtained using sodium caseinate (1%), whey protein concentrate (WPC) (1%) or MTGase (0.3%) at different levels of salt (0%, 1% or 2%). The restructured products were obtained by incubating at 40 °C for 60 min and then at 90 °C for 20 min. Changes in the mechanical properties were studied by measuring changes in the textural profile analyses, punch test and torsional test analyses and expressible water. The mechanical properties increased when the salt level was also increased. The mechanical properties of non-salted and low-salt products were increased by using dairy proteins. Sodium caseinate had a greater effect in improving mechanical properties than WPC. MTGase increased expressible water. The results obtained showed that the mechanical properties of low-salt restructured fish products can be improved by using dairy proteins combined with MTGase, with a slight increase in expressible water.     

Effect of pretreatments and drying temperatures on sweet potato flour

Effect of pretreatments with 1 w/v% sodium hydrogen sulphite (NaHSO₃) and 1 w/v% calcium chloride (CaCl₂) and drying temperatures (55, 60 and 65 °C) on sweet potato flour were investigated. Flour treated with CaCl₂ had higher amounts of ascorbic acid and β‐carotene (10.61–12.54 and 3.26–3.46 mg 100 g^?1 wet basis, respectively) than that treated with NaHSO₃ (9.47–11.47 and 3.05–3.43 mg 100 g^?1 wet basis, respectively). Total phenolic content and water absorption index (wet basis) were highest at 65 °C when treated with NaHSO₃ (10.44 mg 100 g^?1 and 2.49 g g^?1 respectively) and CaCl₂ (9.52 mg 100 g^?1 and 2.85 g g^?1 respectively). Swelling capacity (wet basis) was highest at 60 °C when treated with CaCl₂ (2.96 g g^?1) whereas when treated with NaHSO₃ (2.85 g g^?1) it was highest at 55 °C. Freeze‐dried samples treated with NaHSO₃ had higher lightness and total phenolic content while CaCl₂‐treated samples had higher β‐carotene and ascorbic acid. The results showed that good quality flour could be produced after soaking in CaCl₂ and dried at 65 °C.     

Cryoprotective additives and cryostabilisation effects on muscle fillets of the freshwater teleost fish Rohu carp (Labeo rohita) during prolonged frozen storage

The effects of various cryoprotective additives separately and in combination were studied on the myofibrillar protein integrity, biochemical enzyme activity levels and muscle ultrastructure in the freshwater teleost fish Rohu carp (Labeo rohita). Fish muscle samples were divided into eight groups and immersed in different mixtures of cryoprotective additives (S1–S8), then frozen at ? 20 or ? 30 °C for 24 months. Electrophoretic studies revealed early (within 6 months) alteration of the myofibrillar proteins myosin light chain, α‐actinin and tropomyosin. Reduction of the storage temperature from ? 20 to ? 30 °C slowed down the degradative processes. Sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that fish muscle treated with cryoprotective mixture S8 (40 g L^?1 sorbitol/3 g L^?1 sodium tripolyphosphate/4 g L^?1 sodium alginate) showed minimal post mortem changes in myofibrillar proteins. Ultrastructural results also revealed post mortem damage to the muscle, seen earliest (within 6 months) in the sample frozen‐stored without additives (S2), as compared with the normal, unfrozen muscle (S1). The influence of cryoprotectants alone and in combination on fish muscle structural proteins, myosin and actin filaments (A and I bands), during prolonged frozen storage was investigated. After 12 months, samples frozen‐stored with various cryoprotective additives (S2‐S7), except S8, showed signs of myofibrillar disintegration. Beyond that time the degradative processes started showing up in all samples, with minimal muscle ultrastructural damage in sample S8. Again, reducing the storage temperature from ? 20 to ? 30 °C slowed down the degradative processes. Ultrastructural results correlated well with levels of biochemical enzymes (Ca²⁺ myofibrillar ATPase and succinic dehydrogenase) during frozen storage. This is the first report of the cryoprotective effects of these additives on this popular edible fish species. Of the various combinations of additives tested, cryoprotective mixture S8 was found to preserve the muscle structure longest under frozen storage conditions. However, even this mixture was only effective for 18 months at ? 30 °C. Beyond that time the myofibrillar degradative processes were apparent with correlative electrophoretic, biochemical and ultrastructural studies. Copyright © 2006 Society of Chemical Industry     

Effect of calcium salts on the texture,structure and sensory acceptance of osmotically dehydrated guavas

The effect of additives, calcium chloride and calcium lactate (5–25 g kg^?1), on the osmotic dehydration of guavas with sucrose solutions was studied, aiming at the structural preservation of processed fruits. The osmotic process was evaluated from the reduction in weight of the guavas, water loss and solids gain, and the samples were analyzed with respect to calcium content, texture (stress and strain at failure, relaxation time and residual stress), structure by light microscopy and sensory acceptance. Calcium salts had a strong influence on the texture and structure of the processed guavas, resulting in the maintenance of tissue structure when calcium lactate was used at concentrations up to 15 g kg^?1, and calcium chloride was used at 5 g kg^?1. The sensory acceptability of guava was related to the structural and texture results. Calcium treatments did not improve guava's sensory acceptance. Guavas treated with calcium lactate showed good sensory acceptance, presenting slight inferior scores only at concentrations above 20g kg^?1, while CaCl₂ treated guavas showed average scores statistically equal to the sucrose and calcium lactate treated fruits only at 5 g kg^?1. Copyright © 2007 Society of Chemical Industry     

Modification of the properties of milk protein films by gamma radiation and polysaccharide addition

This study has demonstrated that gamma radiation induced an improvement of barrier properties and tensile strength of films containing calcium caseinate, whey protein isolate and glycerol (1:1:1) through creation of a crosslinked β‐structure. Up to 32 kGy the effect was accompanied by an increase in rigidity and was larger with increasing radiation dose. The irradiation of protein solutions also caused improvement of puncture strength of films prepared with potato starch, soluble potato starch or sodium alginate addition (at a level of 50 g kg^?1 of total proteins). Addition of potato starch did not influence mechanical properties of films but significantly improved barrier properties. Addition of sodium alginate resulted in improvement of both puncture strength and barrier properties. Addition of sodium alginate to irradiated protein solution resulted in films revealing the greatest improvement in properties. Gels prepared using irradiated protein solutions mixed with calcium salt were stronger than gels prepared using non‐irradiated solutions owing to the preferred binding of calcium ions to the crosslinked protein network. Presence of sodium alginate and potato starch weakened the interaction of proteins with calcium ions owing to entrapment of proteins in the polysaccharide network, while addition of soluble potato starch promoted these interactions. Copyright © 2006 Society of Chemical Industry     

Using Salt and Microbial Transglutaminase as Binding Agents in Restructured Fish Products Resembling Hams

ABSTRACT: Restructured products were obtained from fish paste of silver carp ( Hypophthalmichthys molitrix ) by massaging and cooking in ham presses. Assayed were 3 levels of salt (0 as control, 1, or 2%) and 3 levels of microbial transglutaminase (MTGase). Changes on solubility of pastes, mechanical properties, WHC, and SDS-PAGE of the cooked product were evaluated. MTGase needed the addition of NaCl to improve the mechanical properties of these restructured products. Better textural properties were obtained with 2% NaCl. Adding 0.3% of MTGase and 1% NaCl obtained a low-salt, homogenous restructured meat block with 2773 g hardness, 29106 g/cm gel strength, 0.233 cohesiveness, and 11.6% extracted water.