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 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 reducing agents on physicochemical properties and gel-forming ability of surimi produced from frozen fish

Effects of different reducing agents (cysteine, ascorbic acid and sodium bisulfite) at various levels on physicochemical properties of protein, transglutaminase activity and gel properties of surimi produced from frozen croaker, lizardfish, threadfin bream and bigeye snapper were studied. Addition of cysteine resulted in the highest increase in the breaking force and the deformation of surimi gels, compared with other reducing agents. The optimum levels of cysteine were 0.05, 0.1, 0.05 and 0.1% (w/w) for surimi from frozen croaker, lizardfish, threadfin bream and bigeye snapper, respectively. Surimi from frozen croaker with cysteine added showed a similar breaking force and deformation to that produced from fresh fish. With addition of cysteine, an increase in sulfhydryl content with a concomitant decrease in disulfide bond content was generally observed. Ca²⁺ ATPase activity also increased, indicating the renaturation of the myosin molecule. T_max of peak 1 (myosin peak) of all surimi sols in the presence of cysteine was shifted to higher temperature. The increased transglutaminase activity was observed with addition of cysteine. Therefore, reducing agents, especially cysteine, recovered the denatured muscle proteins and activated the transglutaminase in the muscle, leading to the increased gel-forming ability of surimi produced from frozen fish.     

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.     

Effect of phosphate compounds on gel-forming ability of surimi from bigeye snapper (Priacanthus tayenus)

The properties of surimi gel from bigeye snapper (Priacanthus tayenus) added with various phosphate compounds (sodium pyrophosphate, PP; sodium tripolyphosphate, TPP; and sodium hexametaphosphate, HMP) at different levels (0%, 0.05%, 0.1%, 0.3% and 0.5% w/w) and heated under various conditions were studied. Kamaboko and directly heated gels from bigeye snapper surimi added with 0.05% PP had the increase in breaking force and deformation by 17.35% and 11.52%, and 13.54% and 3.53%, respectively, compared with the control gel (without PP addition). At the same level used (0.05%), TPP had no influence, but HMP exhibited a detrimental effect on kamaboko gel. The addition of PP (0.025%) in combination with 50 mmol CaCl₂/kg increased the breaking force by 38.68% as compared with the control gel (without additives), suggesting that the sufficient amount of CaCl₂ could enhance the setting of the gel. Generally, the marked decrease in breaking force with the coincidental increased expressible moisture was observed when the excessive amount of phosphate compounds was used (p<0.05). Microstructure study revealed that a gel with a fine network was formed with addition of PP. Therefore, the addition of PP in combination with CaCl₂ could increase the gel strength as well as water holding capacity of surimi gel.     

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.     

Gel‐forming properties of surimi produced from bigeye snapper,Priacanthus tayenus and P macracanthus,stored in ice

The influence of iced storage of two species of bigeye snapper, Priacanthus tayenus and P macracanthus, on the gel‐forming ability of the resulting surimi was investigated. Upon iced storage, whole fish underwent deterioration faster than beheaded/eviscerated fish. Total volatile base and trimethylamine contents of whole fish were higher than those of beheaded/eviscerated fish, particularly after 9 days of storage (P < 0.05). P macracanthus muscle was more susceptible to proteolytic degradation than P tayenus muscle. Ca²⁺‐ATPase activity decreased as the storage time increased (P < 0.05), indicating the denaturation of myosin. A marked decrease in Ca²⁺‐ATPase activity was found in whole fish kept for more than 6 days in ice (P < 0.05). Breaking force and deformation of surimi gels from both species decreased, with a concomitant decrease in whiteness, as the storage time increased (P < 0.05). Beheading and evisceration of fish retarded the deterioration. However, the gel‐forming ability of surimi produced from both species decreased continuously throughout iced storage (P < 0.05), probably owing to the denaturation and degradation of myofibrillar proteins. © 2002 Society of Chemical Industry     

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.     

Enhancement of gel strength of bigeye snapper (Priacanthus tayenus) surimi using oxidised phenolic compounds

Effects of different oxidised phenolic compounds (ferulic acid, OFA; tannic acid, OTA; catechin, OCT and caffeic acid, OCF) at different levels (0–0.25% of protein content) on the properties of gels from bigeye snapper (Priacanthus tayenus) surimi were investigated. Breaking force and deformation of surimi gel varied with types and amounts of oxidised phenolic compounds. Gels added with 0.20% OFA, 0.05% OTA, 0.15% OCF and 0.05% OCT exhibited the marked increases in both breaking force and deformation, compared with the control (P < 0.05). Those increases were associated with lower expressible moisture content. No increases in both breaking force and deformation were observed when ferulic acid without oxygenation at alkaline pH was added, regardless of amount added (P > 0.05). No changes in the whiteness of gel were found with addition of OFA (P > 0.05), but the decreases in whiteness were noticeable as other oxidised phenolics were incorporated (P < 0.05). Different microstructures were obtained among gels with different oxidised phenolics. The physicochemical properties of natural actomyosin suggest that oxidised phenolics could induce conformational changes and the cross-linking through amino groups or the induction of disulphide bond formation. Therefore, the addition of oxidised phenolic compounds at the optimum level could increase the gel strength of surimi gel.     

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.     

Impact of lecithin incorporation on gel properties of bigeye snapper (Priacanthus tayenus) surimi

Gelling characteristics of bigeye snapper (Priacanthus tayenus) surimi functionalised by lecithin at different concentrations were investigated. Lecithin at ≤1 g 100 g⁻¹ had no impact on breaking force and deformation (P > 0.05). Expressible drip tended to decrease with increasing lecithin level up to 1 g 100 g⁻¹. Lecithin at 1–3 g 100 g⁻¹ improved the whiteness (P < 0.05). Jointed clusters were formed in the gel microstructure with 1 g 100 g⁻¹ lecithin. Gel without and with 1 g 100 g⁻¹ lecithin had the same texture profile and likeness scores (texture, odour and flavour) (P > 0.05). Peroxide value, TBARS content and rancid odour score of gels were changed considerably during refrigerated storage (4 °C/polyethylene bag) for 15 days but lower values of all indices were noticeable in gel with lecithin. Therefore, lecithin at 1 g 100 g⁻¹ was the optimum concentration for stabilising the texture, improving the water holding capacity, whitening the colour and retarding the lipid oxidation of bigeye snapper surimi gel.     

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.     

Pig plasma protein: potential use as proteinase inhibitor for surimi manufacture; inhibitory activity and the active components

The inhibitory activities of pig plasma protein (PPP) against proteinases and autolysis were studied. Using casein as a substrate, it was shown that PPP exerted inhibitory activity against Pacific whiting (PW) proteinase, papain and trypsin. At levels of 10 and 20 mg ml⁻¹, PPP showed higher inhibitory activity than beef plasma protein (BPP) or egg white against PW proteinase (P < 0.05). The inhibitory activity was proportional to the concentration of PPP used up to 10 mg ml⁻¹. PPP and BPP showed marked inhibition of autolysis of PW surimi at concentrations of 10–30 mg g⁻¹. Egg white showed lower inhibition than PPP or BPP against autolysis of surimi (P < 0.05). Myosin heavy chain (MHC) in Pacific whiting surimi was better retained when higher concentrations of PPP were used, while no changes in actin were observed. Inhibitory activity staining on sodium dodecyl sulphate (SDS) substrate gels incubated with papain or trypsin indicated that residual protein bands with apparent molecular weights of 60 000–63 000 may be the active inhibitory components in PPP. These bands were found in PPP and bovine plasma fraction IV‐1, although only under non‐reducing conditions. © 2000 Society of Chemical Industry     

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.     

CHITOSAN AFFECTS TRANSGLUTAMINASE-INDUCED SURIMI GELATION

Effect of chitosan on barred garfish (Hemiramphus far) surimi gel was studied in the presence of EDTA and microbial transglutaminase (MTGase). An increase in breaking force of surimi gels added with 1.0% prawn shell chitosan indicated the gel enhancing effect of chitosan on the heat‐induced gelation of fish myofibrillar proteins. However, gel‐forming ability of surimi containing chitosan was inhibited in the presence of EDTA, especially at higher concentration. Therefore, the enhancing effect of chitosan was possibly mediated through the action of endogenous transglutaminase (TGase) during setting, resulting in the formation of protein‐protein and protein‐chitosan conjugates. In general, addition of MTGase remarkably increased both breaking force and deformation of surimi gel (P<0.05). However, enhancing effect of MTGase was retarded in the presence of chitosan, resulting in lower magnitude of breaking force and deformation (P<0.05). Scanning electron microscopy showed that chitosan particles were uniformly dispersed in the gel matrix. A tightly associated gel network was formed in surimi containing MTGase, whereas a large number of voids were noted in gels with EDTA. These results suggest that chitosan acted as a surimi gel enhancer in combination with endogenous TGase in fish muscle, but hindered gel formation in the presence of MTGase.     

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.     

Effect of chitin and chitosan on gelling properties of surimi from barred garfish (Hemiramphus far)

The addition of chitin/chitosan significantly increased the breaking force and deformation of gels prepared from barred garfish surimi (P < 0.05). Addition of 7B chitosan with 65.6% degree of deacetylation (% DD) at the level of 15 mg g⁻¹ resulted in the maximum increases in both breaking force and deformation of suwari and kamaboko gels compared to the control and gels containing chitin or chitosan with other % DD (P < 0.05). A chitosan concentration of 10 mg g⁻¹ was found to render the highest breaking force of kamaboko gel compared to other concentrations tested (P < 0.05). Kamaboko gel containing chitosan had an increased breaking force as the calcium chloride concentration increased (P < 0.05), indicating the role of endogenous transglutaminase in cross‐linking of protein–protein and protein–chitosan conjugates. Therefore the incorporation of chitosan and calcium chloride greatly improved the gelling properties of surimi from barred garfish without changes in colour. © 2000 Society of Chemical Industry     

Skin gelatin from bigeye snapper and brownstripe red snapper: Chemical compositions and effect of microbial transglutaminase on gel properties

Fish skin gelatin was extracted from the skin of bigeye snapper (Priacanthus macracanthus) and brownstripe red snapper (Lutjanus vitta) with yields of 6.5% and 9.4% on the basis of wet weight, respectively. Both skin gelatins having high protein but low fat content contained high hydroxyproline content (75.0 and 71.5 mg/g gelatin powder). The bloom strength of gelatin gel from brownstripe red snapper skin gelatin (218.6 g) was greater than that of bigeye snapper skin gelatin (105.7 g) (P<0.05). The addition of microbial transglutaminase (MTGase) at concentrations up to 0.005% and 0.01% (w/v) increased the bloom strength of gelatin gel from bigeye snapper and brownstripe red snapper, respectively (P<0.05). However, the bloom strength of skin gelatin gel from both fish species decreased with further increase in MTGase concentration. SDS-PAGE of gelatin gel added with MTGase showed the decrease in band intensity of protein components, especially, β- and γ- components, suggesting the cross-linking of these components induced by MTGase. Microstructure studies revealed that denser and finer structure was observed with the addition of MTGase.     

EFFECT OF CHICKEN PLASMA PROTEIN AND SOME PROTEIN ADDITIVES ON PROTEOLYSIS AND GEL-FORMING ABILITY OF SARDINE (SARDINELLA GIBBOSA) SURIMI

The effect of chicken plasma protein (CPP) and various protein additives on autolysis and gel‐forming ability of sardine (Sardinella gibbosa) surimi was investigated. CPP and other protein additives showed inhibitory activity toward autolysis of sardine surimi incubated at 70C in a concentration‐dependent manner. Porcine plasma protein (PPP) and egg white (EW) were more effective in proteolysis prevention than CPP and other protein additives. Breaking force and deformation of both modori and kamaboko gels increased when CPP and other protein additives were added at levels up to 2% (P < 0.05). Nevertheless, PPP and EW showed a greater gel‐strengthening effect than CPP and other protein additives (P < 0.05). Addition of CPP and other plasma proteins resulted in decreased whiteness, especially with increasing amount (P < 0.05). However, no change in whiteness was observed with gels containing EW and soy protein isolate (SPI) (P > 0.05). Proteolysis of sardine surimi can be retarded by the addition of CPP and protein additives, leading to increased gel‐forming ability.     

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