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     

Impact of salted duck egg albumen powder on proteolysis and gelling properties of sardine surimi

The influences of salted duck egg albumen powder (SDEAP) as salt replacer at various levels (0.5–2.5%) on autolysis and gelling properties of sardine surimi were investigated. SDEAP had high salt (33.67%) and protein contents (64.52%) with trypsin inhibitory activity of 5,975 kunits/g solid. SDEAP was white in color with L*‐value of 96.72. It had low moisture content (3.98%) and water activity (0.38). Autolysis of sardine surimi was drastically inhibited when SDEAP was incorporated with increasing levels as indicated by the more retained myosin heavy chain and the reduced trichloroacetic acid‐soluble peptide content. Breaking force and deformation of surimi gel increased, while expressible moisture content decreased as the levels of SDEAP added were increased (p < .05). Gumminess, hardness, chewiness, springiness, and cohesiveness of surimi gels also increased as SDEAP levels increased (p < .05). Lightness and whiteness were higher in all surimi gels incorporated with SDEAP than the control (p < .05). For microstructure, surimi gels incorporated with SDEAP at all levels used had finer gel network with smaller voids and more connectivity than the control gel. Thus, SDEAP could be used as a salt replacer for sardine surimi gel preparation and it could improve the properties of resulting 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.     

Physicochemical properties, gel-forming ability and myoglobin content of sardine (Sardinella gibbosa) and mackerel (Rastrelliger kanagurta) surimi produced by conventional method and alkaline solubilisation process

Characteristics and gel properties of sardine and mackerel surimi produced by conventional washing process and alkaline solubilising process were investigated. The decrease in Ca²⁺-ATPase activity with the changes in the surface hydrophobicity was found in surimi produced by alkaline solubilising process (p<0.05), suggesting the denaturation of protein induced by this process. The alkal-ine solubilising process with prewashing could remove myoglobin most effectively from sardine muscle, whereas the process without prewashing resulted in the greatest myoglobin removal in mackerel muscle (p<0.05). Surimi conventionally prepared by water or NaCl washing showed the gel with greater breaking force and deformation than that from alkaline solubilising process (p<0.05). The hig-her expressible moisture was found in the gels of surimi pre-pared by alkaline process, indicating the poor water holding capacity of the gel matrix. The highest whiteness was found in the gel of sardine surimi produced by alkaline process with prewashing but the highest whiteness was obtained in the gel of mackerel surimi washed with distilled water.     

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.     

PHYSICAL PROPERTIES OF FISH PROTEINS COOKED WITH STARCHES OR PROTEIN ADDITIVES UNDER OHMIC HEATING

ABSTRACT

The texture, color and microstructure of surimi seafood gels were investigated to determine the interaction effects of fish proteins with starches or protein additives under ohmic heating, and to compare ohmically cooked gels with conventional water‐bath‐cooked gels. Gel properties were affected by the type of additive, concentration and cooking method. The effect of starch on gel texture was more pronounced at low concentrations. Compared to wheat starch, potato starch seemed to slightly improve gel strength; however, it decreased the gel whiteness. All nonfish protein additives resulted in better or equal textural properties of gels, whereas there was a slightly negative effect for gel color. Fast ohmic‐cooked gels mostly exhibited higher gel strength than conventionally cooked gels.

PRACTICAL APPLICATIONS

There is a discrepancy between current gel preparation (slow heating by water bath) and current practice of crabstick manufacturing (fast heating). The use of data generated from slow cooking gel preparation for the manufacture of fast cooking crabstick does not make sense. This study demonstrates how starch and protein additives behave at ohmic heating which mimics the fast cooking crabstick manufacture.

     

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     

Effects of Bambara Groundnut Protein Isolates and Microbial Transglutaminase on Textural and Sensorial Properties of Surmi Gel from Sardine (Sardinella albella)

Effects of different bambara groundnut protein isolates (BGPIs) at a level of 6 % (w/w) in combination with microbial transglutaminase (MTGase) at a concentration of 0.6 U g^?1 surimi on gel properties of sardine (Sardinella albella) surimi were investigated. In the absence of MTGase, all BGPIs showed the adverse effect on gel-forming properties of surimi, as evidenced by the decreases in breaking force and deformation (P?<?0.05). When MTGase was incorporated, the increases in breaking force and deformation were found for all BGPIs used. Water-holding capacity of all gels was improved when BGPIs were added in combination with MTGase (P?<?0.05). Whiteness of gels slightly decreased with the addition of BGPIs; however, MTGase had no impact on whiteness (P?>?0.05). Surimi gel added with BGPI prepared from defatted flour with heat treatment in the presence of ethylenediaminetetraacetic acid (DF-BGPI-HE) and MTGase showed well-ordered network and exhibited the lowest peroxide value and thiobarbituric acid-reactive substances than those containing other BGPIs. Gel containing DF-BGPI-HE had negligible beany flavour. Additionally, DF-BGPI-HE had the lower amount of volatile compounds after storage of 30 days at room temperature than other BGPIs. Thus, the addition of DF-BGPI-HE and MTGase was an effective means to render sardine surimi gel with improved gel property and caused no beany flavour in resulting gel.     

四种非肌肉蛋白对冷冻竹荚鱼鱼糜凝胶能力的影响研究

探讨了四种常用的非肌肉蛋白对竹荚鱼鱼糜凝胶特性的影响,对不同鱼糜加热过程中凝胶强度、持水力、白度、SDS-PAGE电泳图谱以及微观结构的变化进行比较。实验结果表明,血浆蛋白对冷冻竹荚鱼的蛋白酶有很强的抑制效果,最佳添加量为1%。卵清蛋白及乳清蛋白在5%高浓度时其凝胶增强效果与1%的血浆蛋白添加效果近似,大豆蛋白的效果较差,四种蛋白对鱼糜白度、持水力影响不大。非肌肉蛋白应用于竹荚鱼鱼糜的品质改善中,对凝胶劣化有一定的抑制,这对竹荚鱼鱼糜的品质控制具有一定意义。     

Effect of furcellaran incorporation on gel properties of sardine surimi

Effects of furcellaran, powder (FURP) and solution (FURS), incorporation (2-8% based on surimi solid content) on gel properties of sardine (Sardinella albella) surimi were investigated. Breaking force, hardness, gumminess, chewiness, and whiteness of gels increased with increasing FURP or FURS contents (P < 0.05), where the highest values were observed in gel containing 8% FURS (P < 0.05). Expressible moisture content of gel decreased as levels of furcellaran increased (P < 0.05). The gel deformation, springiness, and cohesiveness were not affected by furcellaran (P > 0.05) as well as the polymerization of myosin heavy chain as visualised by SDS-PAGE. FURP and FURS could enhance the interconnection between chains during heating as indicated by the higher G′. Addition of furcellaran, especially FURS, up to 6% increased sensory property of resulting gel (P < 0.05). Anywise, an abatement in overall likeness score was found in gel with 8% FURS. Finer and denser microstructural network was observed in gel containing 6% FURS when compared to control. Therefore, furcellaran, prepared as solution, at an appropriate level can improve the overall quality of sardine surimi.     

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.     

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.     

Thermal Gel Degradation (Modori) in Sturgeon (Acipenseridae) Surimi Gels

Sturgeon meat has been found to be suitable as surimi raw materials. The present study determined the modori phenomenon in sturgeon surimi gels and identified its relationship with cathepsins. In all heat‐treated gels (25 to 90 °C, at 5 °C intervals), the 40 °C‐incubated sturgeon surimi gel showed the weakest gel properties and water‐holding capacity (P < 0.05), a rough protein gel network under SEM, and the highest protein solubility and trichloroacetic acid‐soluble peptides content (P < 0.05). SDS‐PAGE indicated that the myosin heavy chain band of sturgeon surimi gels was almost completely degraded at 40 °C. Moreover, the highest cathepsin L activity was observed in 40 °C‐treated sturgeon surimi gels (P < 0.05). Our results suggested that the modori phenomenon in sturgeon surimi gels occurred at 40 °C, which was partially attributed to cathepsin L, thereby allowing for the better exploitation and utilization of sturgeon surimi.     

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     

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.     

Impact of microbial transglutaminase on gelling properties of Indian mackerel fish protein isolates

Impacts of microbial transglutaminase (MTGase) (0–0.6 units/g sample) on gel properties of Indian mackerel unwashed mince, surimi and protein isolates with and without prewashing were studied. Generally, lower myoglobin and lipid contents were found in protein isolate with and without prewashing, compared to those of unwashed mince and surimi (P < 0.05). Protein isolate had the decreased Ca²⁺-ATPase and protein solubility, indicating protein denaturation. When MTGase was incorporated, breaking force and deformation of all gels markedly increased, especially as MTGase levels increased (P < 0.05). At the same MTGase level, gel from protein isolate with prewashing exhibited the highest breaking force and deformation (P < 0.05). The addition of MTGase could lower the expressible moisture content of most gels. No change in whiteness of gel was observed with the addition of MTGase (P > 0.05), but gel from protein isolate gels had decreased whiteness as MTGase at high level was added. The microstructure of protein isolate gels without prewashing showed a similar network to unwashed mince gels, whilst a similar network was observed between surimi gel and gel from protein isolate with prewashing. Nevertheless, a larger void was noticeable in gels from protein isolates. All gels incorporated with MTGase (0.6 units/g) showed a slightly denser network than those without MTGase. Thus, gel with improved properties could be obtained from protein isolate from Indian mackerel with added MTGase.     

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     

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     

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     

不同蛋白添加剂对秘鲁鱿鱼鱼糜凝胶特性的影响

为了改善秘鲁鱿鱼鱼糜的凝胶特性,本文研究了添加不同种类的蛋白添加剂（卵清蛋白,猪血浆蛋白,乳清蛋白,大豆蛋白）对秘鲁鱿鱼鱼糜凝胶破断力,凹陷距离,凝胶强度,色泽的影响,并通过SDS-PAGE电泳分析其肌原纤维蛋白的降解情况。结果发现:添加卵清蛋白可显著增强鱿鱼鱼糜的破断强度和凝胶强度（p<0.05）,添加乳清蛋白和大豆蛋白对秘鲁鱿鱼鱼糜破断强度和凝胶强度的提高没有明显的促进作用,而添加猪血浆蛋白粉则对秘鲁鱿鱼鱼糜的破断强度和凝胶强度有一定的降低作用。添加各种蛋白粉的鱿鱼鱼糜凝胶凹陷度变化不大。而添加几种蛋白粉均会使鱼糜凝胶的白度降低,其中添加猪血浆蛋白粉对鱼糜白度的影响最大。通过SDS-PAGE分析,秘鲁鱿鱼鱼糜在添加蛋白后肌球蛋白的变化不明显。这表明蛋白添加剂的蛋白酶抑制剂作用效果不大。