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.     

Effect of porcine plasma protein and setting on gel properties of surimi produced from fish caught in Thailand

Effects of porcine plasma protein (PPP) and high temperature setting on gel properties of surimi from bigeye snapper, bigeye croaker, threadfin bream and barracuda were investigated. PPP was effective in increasing breaking force and deformation of kamaboko gels set at 40°C for 30 min and heated at 90°C for 20 min. The optimum levels of PPP were 0.5, 0.5, 1.5 and 1.5 g/100 g and the optimum setting times were 2, 1.5, 1.5 and 2 h for bigeye snapper, bigeye croaker, threadfin bream and barracuda surimi, respectively. However, the addition of PPP significantly decreased whiteness (P<0.05). An increase in gel-forming ability of surimi with PPP coincided with a decrease in solubility in mixture of SDS, urea and β-mercaptoethanol, indicating the formation of nondisulfide covalent bond induced by both endogenous and plasma transglutaminase. The results supported that PPP improve the gelation of surimi in combination with setting.     

Effect of medium temperature setting on gelling characteristics of surimi from some tropical fish

Effects of setting at 25 °C on textural properties and cross-linking of myofibrillar proteins in surimi produced from threadfin bream (Nemipterus bleekeri), bigeye snapper (Priacanthus tayenus), barracuda (Sphyraena jello) and bigeye croaker (Pennahai macrophthalmus) were investigated. Increase in setting time (0–8 h) resulted in a higher breaking force and deformation for all surimi gels tested (P<0.05). Increased gel strength was associated with increase in non-disulfide bond formation and decreased heavy chain myosin. Proteins underwent degradation during setting; however polymerization occurred to a much higher extent, leading to a strengthened gel matrix. Therefore, setting at 25 °C, for an appropriate time, should be a promising means to improve gelling properties of surimi produced from tropical fish.     

Proteinase inhibitory activity of sarcoplasmic proteins from threadfin bream (Nemipterus spp.)

BACKGROUND: Thailand is the second largest surimi producer in the world and 50% of surimi is produced from threadfin bream. During surimi processing, sarcoplasmic proteins are removed through water washing and discarded in the waste stream. This study was aimed at investigating the proteinase inhibitory activity of sarcoplasmic proteins. RESULTS: Sarcoplasmic proteins from threadfin bream (TBSP) exhibited inhibitory activity toward trypsin but did not inhibit papain and chymotrypsin. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis under non‐reducing condition stained by trypsin inhibitory activity revealed three protein bands of molecular mass of 95, 41 and 37 kDa. Inhibitory activity of TBSP reached a maximum when subjected to 45 °C and completely disappeared at 60 °C. The breaking force and deformation of lizardfish surimi gel with added TBSP and pre‐incubated at 37° for 20 min increased with additional levels of TBSP (P < 0.05). Trichloroacetic acid–oligopeptide content of lizardfish surimi gel with added TBSP decreased with the addition of 4 g kg^?1 TBSP (P < 0.05). Retention of myosin heavy chain (MHC) increased when TBSP concentration was increased. TBSP effectively protected MHC from proteolysis at 37 °C to a similar extent as egg white powder, but efficacy of TBSP was not observed at 65 °C. CONCLUSION: TBSP could be applied to reduce proteolytic degradation of lizardfish surimi or other surimi associated with trypsin‐like proteinase, rendering an improvement in surimi gelation set at 37–40 °C. Copyright © 2009 Society of Chemical Industry     

Comparative study on physicochemical changes of muscle proteins from some tropical fish during frozen storage

Physicochemical changes of muscle from croaker, lizardfish, threadfin bream and bigeye snapper during storage at −18 °C were investigated for up to 24 weeks. Ca²⁺–ATPase activity decreased, whereas Mg²⁺–EGTA–ATPase activity increased throughout the storage. However, no marked changes in Mg²⁺–Ca²⁺–ATPase and Mg²⁺–ATPase activities were observed. Among all species tested, lizardfish muscle was most susceptible to those changes. Disulfide bond formation with the concomitant decrease in sulfhydryl group was found in all species. However, croaker and lizardfish contained higher disulfide bonds as storage time increased, compared to other species. Surface hydrophobicity increased in all species with the sharp reduction observed in lizardfish after 12 weeks. For all species, α-glucosidase and β-N-acetyl-glucosaminidase activities increased in association with the increased expressible drip. Therefore, extended frozen storage caused the denaturation of protein as well as the cell disruption in all species, but the degree of changes was dependent upon species.     

Gelation characteristics of tropical surimi under water bath and ohmic heating

Gelation characteristics of tropical surimi, namely threadfin bream (TB), bigeye snapper (BS), goatfish (GF) and lizardfish (LF) prepared in the absence and presence of 10 g kg^?1 egg white proteins were evaluated using either ohmic (OH) or water bath (WB) heating. LF and GF surimi exhibited higher endogenous proteolytic activity than BS and TB. Ohmic heating markedly minimized proteolysis of LF and GF surimi as evidenced by a reduction of trichloroacetic acid (TCA)-soluble oligopeptide content of gels and more retention of myosin heavy chain (MHC). Ohmic heating increased breaking force and deformation of TB and BS surimi by 1.3 and 1.6 times, respectively, as compared to water bath heating. However, TB surimi gels heated by a higher applied voltage gradient of 16.7 V cm^?1 exhibited lower breaking force than those heated at 6.7 V cm^?1. Gels heated ohmically contained lower total sulfhydryl concentration, indicating the greater extent of disulfide bond formation as compared to gels heated in a 90 °C water bath. The rapid heating method with shorter heating time could improve water holding capacity and preserve color of tropical surimi gels when compared to water bath heating.     

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     

Identification by GeLC‐MS/MS of Trypsin Inhibitor in Sarcoplasmic Proteins of Three Tropical Fish and Characterization of Their Inhibitory Properties

Sarcoplasmic proteins from 3 fish species were fractionated by 50% to 70% ammonium sulfate precipitation. Lyophilized fractionated sarcoplasmic proteins of threadfin bream (TB‐SP), bigeye snapper (BS‐SP), and yellow croaker (YC‐SP) showed 80% to 92% trypsin inhibitory activity. Trypsin inhibitory activity staining gel electrophoresis revealed bands at 32, 33, 37, 45, 48, and 50 kDa for the 3 species, and a band at 95 kDa was observed for TB‐SP and YC‐SP. Alpha‐1‐antitrypsin with molecular mass of 45 to 50 kDa was identified in YC‐SP by gel‐based liquid chromatography‐tandem mass spectrometry (GeLC‐MS/MS). Other major protein bands appeared on trypsin activity staining included phosphorylase, glyceraldehyde‐3‐phosphate dehydrogenase, and creatine kinase with molecular mass of 95 and 35 to 40 kDa, respectively. But, these 3 proteins did not show true trypsin inhibitory activity. Trypsin inhibitory activity of fractionated sarcoplasmic proteins showed good stability, with >80% activity retained at 60 °C and up to 0.6 M NaCl. TB‐SP showed the highest inhibitory activity against autolysis of washed threadfin bream mince at 65 °C. Addition of 0.5% or 1% TB‐SP improved textural properties of threadfin bream surimi gels preincubated at 37 or 65 °C followed by heating at 90 °C. Therefore, TB‐SP could be a promising protein ingredient for enhancing surimi gel texture.     

Whey protein concentrate: Autolysis inhibition and effects on the gel properties of surimi prepared from tropical fish

Effects of whey protein concentrate (WPC) on autolysis inhibition and gel properties of surimi produced from bigeye snapper (Priacanthus tayenus), goatfish (Mulloidichthys vanicolensis), threadfin bream (Nemipterus bleekeri) and lizardfish (Saurida tumbil) were investigated. WPC (0–3%) showed inhibitory activity against autolysis in all surimi at both 60 and 65 °C in a concentration-dependent manner. Myosin heavy chain (MHC) of surimi was more retained in the presence of WPC. Breaking force and deformation of kamaboko gels of all surimi increased as added levels of WPC increased (P < 0.05). This was associated with lower levels of protein degradation, as evidenced by the decrease in trichloroacetic acid-soluble peptide content (P < 0.05). WPC at 3% (w/w) significantly decreased the whiteness of gels. However, water-holding capacity of kamaboko gels was improved with increasing concentration of WPC. The microstructure of surimi gels generally became denser with the addition of WPC.     

Porcine plasma protein as proteinase inhibitor in bigeye snapper (Priacanthus tayenus) muscle and surimi

Porcine plasma protein (PPP) showed inhibitory activity towards trypsin, papain, digestive enzymes and modori‐inducing proteinases from bigeye snapper. Among the fractions prepared, fraction IV‐1 exhibited the highest inhibitory activity against all proteinases tested and the autolysis of fish muscle. At a level of 0.5% (w/w), both PPP and fraction IV‐1 effectively prevented the degradation of myosin heavy chain in fish muscle. The inhibitory activity of fraction IV‐1 was stable up to 60 °C. Incorporation of fraction IV‐1 significantly increased the breaking force, deformation and water‐holding capacity of surimi gel from bigeye snapper (P < 0.05). However, no increase in breaking force and deformation was found when fraction IV‐1 was added at a level above 0.3% (w/w) (P > 0.05). No significant change in whiteness of surimi gel was observed with the addition of fraction IV‐1 (P > 0.05). © 2001 Society of Chemical Industry     

Effect of Endogenous Transglutaminase on Threadfin Bream Surimi Gelation

ABSTRACT: Transglutaminase(TGase) activity of threadfin bream mince was 99.6 units/g of dry weight. After washing and screw-pressed dewatering, 44% residual activity was retained. Covalent cross-linking of myosin heavy chain (MHC) was observed at both 25 and 40°C and supported by increased gel strength. When pre-incubation at 40°C was prolonged to 4 h, breaking force and MHC decreased due to endogenous proteinase(s). TGase activity towards MHC and synthetic substrates was effectively inhibited by iodoacetic acid (IAA). Autolytic activity and degradation of MHC was inhibited by phenylmethanesulfonyl fluoride (PMSF). Addition of 0.2% Ca²⁺ significantly improved breaking force and increased MHC cross-linking of surimi gels pre-incubated at 40°C for 2 h. Keywords: transglutaminase, myosin heavy chain, cross-linking, threadfin bream     

Transglutaminase-mediated setting in bigeye snapper Surimi

Effect of setting induced by endogenous transglutaminase (TGase) in two species of bigeye snapper, Priacanthus tayenus and Priacanthus macracanthus, on gel properties and protein cross-linking was investigated. Setting at either 25 or 40 °C, prior to heating at 90 °C resulted in the increase in both breaking force and deformation of surimi from both species, particularly when setting time increased (P<0.05). A decrease in solubility of surimi gels in a mixture of sodium dodecyl-sulfate, urea and β-mercaptoethanol suggested increased formation of non-disulfide covalent bonding which coincided with increased gel strength and the decrease in myosin heavy chain (MHC) polypeptide. The optimum conditions for setting of surimi sol was found to be 40 °C for 2 h for P. tayenus and 25 °C for 3 h for P. macracanthus. Assayed by monodancylcadaverine (MDC)-incorporation method, TGase from P. tayenus and P. macracanthus exhibited an optimum temperature at 40 and 25 °C, respectively. In addition, the breaking force and deformation of surimi from both species increased markedly with the addition of calcium chloride, while they decreased considerably in the presence of EDTA, N-methylmaleimide and ammonium chloride. The results confirmed that endogenous transglutaminase played an important role in gel enhancement of surimi from both species of bigeye snapper.     

PORCINE PLASMA PROTEINS AS GEL ENHANCER IN BIGEYE SNAPPER (PRIACANTHUS TAYENUS) SURIMI

Cohn's fraction I‐S from porcine plasma showed the highest transglutaminase activity, compared to fractions I. 11+III, IV, IV‐l. The optimum temperature for incorporating monodancylcadaverine into dimethylated casein was 45C. Plasma transglutaminase in fraction I‐S was activated by calcium chloride but was inhibited by N‐ethylmaleimide, ethylenediaminetetraacetic acid, and ammonium chloride. The addition of fraction I‐S into bigeye snapper surimi resulted in a substantial increase in gel breaking force and deformation, particularly in the presence of calcium chloride and thrombin. No changes in whiteness and water holding capacity were observed in surimi gel with the addition of 0–0.5% of fraction I‐S. Fraction I‐S was found to catalyze nondisulfide covalent cross‐linking of myosin heavy chain. The combination of endogenous and plasma transglutaminase enhanced surimi gelation.     

The effect of whitening agents on the gel-forming ability and whiteness of surimi

The effect of different concentrations of the whitening agents, calcium carbonate, titanium dioxide and soybean oil, on the gel‐forming ability and whiteness of a mixture of bigeye snapper and mackerel surimi was investigated. The whiteness of the surimi gels increased as the concentration of all whitening agents increased (P < 0.05). Titanium dioxide was a good whitening agent and it had no detrimental effects on gel‐forming ability, while oil reduced the gel breaking force and deformation. The addition of calcium carbonate did not result in a marked increase in whiteness, but it did increase the breaking force and deformation to some extent. The different whitening agents showed different influences on the whiteness and gelling characteristics of surimi gel.     

Protein cross-linking ability of sarcoplasmic proteins extracted from threadfin bream

Sarcoplasmic proteins extracted from threadfin bream (TB, Nemipterus sp.) contained transglutaminase (TGase) activity exhibiting a pH optima at 7.5. Activity increased with CaCl₂ and reached the maximum at 5 mmol/L, showing the Ca²⁺-dependent characteristic. TGase activity staining on native-polyacrylamide gel electrophoresis (native-PAGE) showed two fluorescent bands catalyzing incorporation of monodansylcadavarine (MDC) into di-methylated casein (DMC). However, both fluorescent bands showed only one major protein band with a molecular weight of about 66 kDa on sodium dodecylsulfate-PAGE (SDS-PAGE), suggesting the presence of isozymes. The TB sarcoplasmic protein (TBSP) concentrated using a 30-kDa ultrafiltration membrane induced cross-linkings of bovine serum albumin when incubated at 25 °C for 6 h. Addition of the concentrated TBSP at 1.6 g protein/100 g along with 0.1 g CaCl₂/100 g resulted in a 1.8-fold increase in the breaking force of the proteinase-laden lizardfish surimi pre-incubated at 37 °C for 20 min. TBSP effectively minimized proteolysis of lizardfish surimi at 37 °C. TBSP could be a promising protein additive that improves textural properties of proteinase-laden surimi.     

Changes in physico-chemical properties and gel-forming ability of lizardfish (Saurida tumbil) during post-mortem storage in ice

Changes in physico-chemical properties and gel-forming ability of lizardfish muscle (Saurida tumbil), stored in ice, were investigated up to 15 days. Heading and eviscerating, prior to iced storage, retarded myosin heavy chain degradation and formaldehyde formation. Additionally, denaturation of myosin and troponin was slightly impeded as monitored by the lower decrease in Ca²⁺-ATPase and lower increase in Mg²⁺–EGTA-ATPase, respectively. Gel-forming ability of surimi, prepared under different setting and/or heating conditions, decreased as storage time increased (P<0.05). However, superior breaking force and deformation of surimi gel, from headed/eviscerated fish, to that from whole fish was observed throughout the storage. Whiteness of surimi gel from headed/eviscerated fish was much higher than that from whole fish, especially when the storage time increased. Therefore, storage time and pretreatment were found to be crucial factors, determining the changes in physico-chemical properties and gel-forming ability of lizardfish during iced storage.     

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.     

Cross-linking activity of sarcoplasmic fraction from bigeye snapper (Priacanthus tayenus) muscle

Addition of sarcoplasmic fraction from bigeye snapper (Priacanthus tayenus) into natural actomyosin in combination with setting at 40°C resulted in the cross-linking of myosin heavy chain (MHC). Higher amount of sarcoplasmic fraction and extended setting time resulted in a higher cross-linking, indicating the presence of endogenous transglutaminase (TGase) in bigeye snapper muscle. TGase activity was activated by calcium ion and reducing agents (β-mercaptoethanol and dithiotreitol), but was inhibited by N-ethylmaleimide (NEM), NH₄Cl and EDTA. TGase in the sarcoplasmic fraction was not stable when heated at temperature above 40°C, particularly with an increasing heating time. TGase was stable at pH ranging from 5.0 to 7.0, in which more than 70% activity was retained. Therefore, sarcoplasmic fraction possessed a cross-linking activity caused by TGase and its recovery for further uses should be considered.     

鱼种和亲水胶体对鱼糜制品凝胶性质的影响

考察了添加复合亲水胶体对鲢鱼、带鱼、金线鱼等鱼糜制品凝胶特性的影响。结果发现,添加亲水胶体后,带鱼鱼糜制品凝胶强度从58.38 g·cm提高至107.27 g·cm,金线鱼鱼糜制品从328.68 g·cm下降至137.55 g·cm,但鲢鱼鱼糜制品没有明显变化。另一方面,添加亲水胶体后鱼糜制品的硬度、粘结性、咀嚼性等发生下降,但水分含量、持水性、蒸煮吸水率均有显著提高。而且,添加亲水胶体后带鱼鱼糜制品中肌球蛋白重链的降解受到一定的抑制。SEM结果发现亲水胶体可以填充到带鱼和鲢鱼鱼糜制品中,但在金线鱼鱼糜凝胶结构中容易形成胶体块状,导致凝胶强度下降。      

Elucidating Factors Affecting Floatation of Fish Ball

ABSTRACT:  Factors affecting floatation of fish ball in water were investigated. The density of threadfin bream (TB) surimi paste significantly decreased ( P < 0.05) as moisture content, temperature, or salt concentration increased. The ability of surimi paste to float or sink in water was observed according to changes in density. In gel texture measurement, when surimi was thawed for 1 h before chopping at 5 °C with 2% salt, the highest breaking force and deformation values were obtained. Apparent viscosity of surimi paste decreased as moisture content increased or salt concentration increased, and chopping temperature decreased. Setting gels in salt solution (5 or 10%) significantly reduced ( P < 0.05) stickiness, which is the tendency to stick to one another.