Comprehensive analysis of ozone water rinsing on the water-holding capacity of grass carp surimi gel

Various factors affecting the gel properties of surimi: A review

As an important aquatic prepared food, surimi products are favored by consumers due to their unique viscoelastic properties and high nutritional value. Gel properties are the main indicators to measure the quality of surimi products. The gelation of surimi mainly involves intramolecular (conformational change) and intermolecular (chemical force) changes. Factors such as processing treatments, raw fish species and exogenous additives affect surimi protein structure, chemical forces and endogenous enzyme activities, which further affect the gel properties of surimi products. This review focuses on the mechanism of surimi heat-induced gel, mainly including protein chain expansion and aggregation through various chemical forces to form a three-dimensional network structure. In addition, the mechanism and application of different factors on the gel properties of surimi were also discussed, providing a reference for the selection of fish species, the control of heating conditions in the gel process of surimi products, the selection of additives and other measures to improve the gel performance.

Phase behavior of the gelation process of myofibrillar protein-curdlan blended system: Discussion based on rheology and gel properties

The phase behavior in protein-polysaccharide blended systems is the main factor affecting the physical properties of composite gels; however, the phase behavior at room temperature and during heated gelation is lacking discussion. In this research, extracted grouper myofibrillar protein (MP) and curdlan (CUR) were used as models for the MP-CUR blended system. The phase behavior of the MP-CUR blended system was analyzed using rheology and microstructure analysis, and the accuracy of the phase behavior analysis was verified by measuring the physical indices such as gel properties of the MP-CUR composite gels. At room temperature, MP and CUR showed good co-solubility, so the blended system with 0.8% CUR content obtained the best apparent viscosity, structural recoverability, and other rheological properties. After heating gelation, MP and CUR had strong thermodynamic unaffinity leading to phase separation, and the best storage modulus was obtained for the MP-CUR blended system with 0.6% CUR content. Therefore, it is concluded that 0.6% CUR content is the critical concentration for the MP-CUR blended system. The results were also confirmed by the best gel properties of 0.6% CUR composite gel when the physical properties of the composite gel were determined. The phase behavior evaluation was used to determine the appropriate polysaccharide concentrations as a means to improve the physicochemical properties of the composite gels and to exploit the value of polysaccharides in protein-based food applications.

Emerging technologies in seafood processing: An overview of innovations reshaping the aquatic food industry

Seafood processing has traditionally been challenging due to the rapid spoilage rates and quality degradation of these products. With the rise of food science and technology, novel methods are being developed to overcome these challenges and improve seafood quality, shelf life, and safety. These methods range from high-pressure processing (HPP) to edible coatings, and their exploration and application in seafood processing are of great importance. This review synthesizes the recent advancements in various emerging technologies used in the seafood industry and critically evaluates their efficacy, challenges, and potential benefits. The technologies covered include HPP, ultrasound, pulsed electric field, plasma technologies, pulsed light, low-voltage electrostatic field, ozone, vacuum cooking, purified condensed smoke, microwave heating, and edible coating. Each technology offers unique advantages and presents specific challenges; however, their successful application largely depends on the nature of the seafood product and the desired result. HPP and microwave heating show exceptional promise in terms of quality retention and shelf-life extension. Edible coatings present a multifunctional approach, offering preservation and the potential enhancement of nutritional value. The strength, weakness, opportunity, and threat (SWOT) analysis indicates that, despite the potential of these technologies, cost-effectiveness, scalability, regulatory considerations, and consumer acceptance remain crucial issues. As the seafood industry stands on the cusp of a technological revolution, understanding these nuances becomes imperative for sustainable growth. Future research should focus on technological refinements, understanding consumer perspectives, and developing regulatory frameworks to facilitate the adoption of these technologies in the seafood industry.

Effect of cellulose on gel properties of heat-induced low-salt surimi gels: Physicochemical characteristics, water distribution and microstructure

The processing of surimi products requires the addition of high levels of salt, which makes it a high-salt food that poses a risk to human health. The search for exogenous additives to reduce the salt content of surimi products while ensuring their quality characteristics is crucial. Therefore, the effect of different species of cellulose on enhancing the quality characteristics of low-salt surimi gels was investigated and the best-modified cellulose was identified. Carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), and microcrystalline cellulose (MCC) were selected for this study to compare with high-salt control and low-salt control. The results showed that cellulose could induce conformational transitions of proteins and promote the formation of an ordered and dense surimi gel network and the minimum porosity of 15.935% was obtained in the MCC-treated group. The cellulose-treated group conferred good textural properties to the surimi gels, significantly improved gel strength and water retention capacity (p < 0.05), and reduced the amount of water lost after cooking treatment (p < 0.05). Low-field NMR results showed that cellulose reduced the release of water, converting more free water to immobile water, thus increasing the water proton density. The higher energy storage modulus G' in the presence of cellulose indicated a more stable surimi gel system dominated by springiness. In summary, cellulose could confer better quality characteristics to low-salt surimi gels and MCC performance was superior to other cellulose species. This study helps the understanding of the mechanism of cellulose-surimi action on the development of high-quality low-salt surimi gels.

Effect of oat β-glucan on gel properties and protein conformation of silver carp surimi

BACKGROUND

Polysaccharides are the most widely used additives to enhance the quality of surimi gels. Oat β-glucan (OG), a functional polysaccharide, is known to affect the gelation characteristics of surimi. However, it has been rarely reported. Therefore, the effect of OG at different levels on gelling properties, protein conformation, and microstructures of silver carp surimi gels were investigated.

RESULTS

An increase in the OG content from 0 to 1.0% significantly improved the hardness, springiness, chewiness, puncture properties, storage modulus, and loss modulus of surimi gels. Moreover, the incorporation of OG (0-1.0%) facilitated the unfolding of proteins, resulting in the conformational transformation from α-helix to β-sheet and β-turn. Consequently, surimi-OG gels displayed a denser network structure with smaller and more uniform voids. Furthermore, partial free water in the gel network was converted into immobile water, increasing the water-holding capacity. However, a further increase in the OG concentration (1.0-2.0%) resulted in a looser and more uneven network structure with large and numerous cavities. In addition, the whiteness of composite gels decreased with increasing content of OG.

CONCLUSION

The addition of 1.0% OG dramatically improved the gelation performance of silver carp surimi, providing a theoretical foundation for the exploitation and manufacture of functional surimi products. © 2023 Society of Chemical Industry.

Effects of chickpea protein-stabilized Pickering emulsion on the structure and gelling properties of hairtail fish myosin gel

The effects of different amount (0-12%) of chickpea protein-stabilized Pickering emulsion (CPE) on the gelling properties, intermolecular interactions, microstructure, and physicochemical stability of hairtail fish myosin gels were investigated. The myosin gel with 6%-9% CPE demonstrated significantly higher viscoelasticity, gel strength, hardness, water-holding capacity and whiteness, compared to the control (P < 0.05). In addition, Raman spectroscopy showed that CPE changed the microenvironment of the myosin, which promoted the changes in protein secondary structures, disulfide bond conformation and the local environments of the composite gels. The addition of 6%-9% CPE also enhanced the disulfide bond and hydrophobic interaction of myosin gels which induced more compact gel network structures. Furthermore, CPE improved the lipid oxidative stability and freeze-thaw stability of myosin gel. The results indicated that CPE could improve the gelling properties of myosin, making it a potential new additive and lipid substitute for the development of new emulsion gel products.

Influence and effect mechanism of disulfide bonds linkages between protein-coated lipid droplets and the protein matrix on the physicochemical properties, microstructure, and protein structure of ovalbumin emulsion gels

In this study, disulfide bonds between the interfacial protein film formed on the lipid particles and the protein in ovalbumin emulsion gels were blocked with 0, 1, 3, 5 and 10 mM of the N-ethylmaleimide (NEM) to explore the influence and effect mechanism of disulfide bonds between the interfacial proteins on the physicochemical properties, microstructure, and protein structure of sunflower oil-ovalbumin emulsion gels. Ovalbumin emulsion gels with NEM-treated ovalbumin emulsion (N-OE) had lower hardness, free sulfhydryl content, water holding capacity (WHC), and surface hydrophobicity, but higher spin-spin relaxation time (T₂) than ovalbumin emulsion gels with NEM-treated ovalbumin substrate solution (N-OSS). In addition, N-OE and N-OSS had lower hardness, free sulfhydryl content, WHC and surface hydrophobicity, as well as a more coarse and disordered microstructure than non-NEM treated ovalbumin emulsion gel (control group). The free sulfhydryl content, hardness, WHC, and surface hydrophobicity of the ovalbumin emulsion gels all decreased as the NEM concentration rose (p < 0.05), whereas the amide A band changed to higher wave numbers. These results collectively indicated that the reduction of disulfide between the interfacial layer and the proteins inhibited the hydrophobic effect, the formation of hydrogen bonds, and prevented the formation of larger aggregates. Thus the disulfide bonds between the interfacial proteins contribute to the hardness enhancement and water stabilization of the ovalbumin gel.

The migration and loss of water in emulsified surimi gels prepared with different phase states of lipids: Effect of freeze-thawing treatments

The freeze-thawing (FT) stability generally correlates well with the economic value and acceptability of frozen surimi-based products. However, quality changes of emulsified surimi gels under FT conditions are still unclear. Therefore, the gel properties of samples with different phase states of lipids (lard, lard + soybean oil, and soybean oil) were investigated at FT conditions. Results showed that the soybean oil evidently improved the rheological behaviors of sols/gels compared to the lard group. The moisture content of samples with different lipids decreased by 2.40%-2.71% after 4 FT cycles. With increasing FT cycles, the water-holding capacity decreased accompanied by the increase of cooking loss. Spin-spin relaxation spectra and hydrogen proton density images proved the occurrence of water migration of gels during these processes. Better gel integrity was observed in samples consisting of soybean oil, where the proportion of pores was lower than those with lard regardless of FT treatments. Additionally, the intermolecular forces of gels also changed under FT treatments. There results suggested that the lipids with different phase states affected the migration and loss of water in emulsified surimi gels under FT cycles. PRACTICAL APPLICATION: The quality changes of heating-induced surimi gel products under frozen storage have been ignored, especially the emulsified surimi gels. This study discloses the changes of the gel properties in emulsified gel products with different phase states of lipids after FT treatments, which provides critical insights into the quality improvement of this novel emulsified surimi product during processing, storage, and transportation.

High gelatinous salted duck egg white protein powder gel: Physicochemical, microstructure and techno-functional properties

Salted duck egg is one of the most popular products, and China is one of the major countries consuming salted duck egg products. However, due to the high salt content of salted egg white and low physical and chemical properties such as gel, many factories generally only use salted egg yolk and discard salted duck egg white (SDEW) as a waste liquid when processing. This is not only a waste of resources, but also a pollution to the environment. In this paper, protein powder was prepared from salted egg white. Then xanthan gum (XG) was added to make it co-gel with ovalbumin to achieve the purpose of preparing high gelatinous salted egg white protein powder. The results showed that the optimum conditions of SDEW-XG composite gel were as follows: the xanthan gum content was 0.08% (w/w), the reaction pH was 6.5, and the heating temperature was 100°C. Under these conditions, the gel strength reaches the maximum value. Meanwhile, compared with the protein powder without xanthan gum, the addition of xanthan gum significantly affected the secondary structure of the protein powder of SDEW and improved the water holding capacity of the gel. In conclusion, the addition of xanthan gum can significantly improve the gel quality of SDEW protein powder, which provides a theoretical basis for the quality improvement of salted egg white.

Assessment of flavor characteristics in snakehead (Ophiocephalus argus Cantor) surimi gels affected by atmospheric cold plasma treatment using GC-IMS

The gel formation ability of freshwater surimi is weak, resulting in its poor flavor and quality. Atmospheric cold plasma (ACP), a widely developed non-thermal processing technology in the food industry, is considered to have potential applications in maintaining and improving the flavor characteristics of surimi gels. In this study, the effect of ACP on snakehead surimi gels flavor at different treatment times was investigated by sensory evaluation and gas chromatography-ion mobility spectrometry (GC-IMS) analysis. The results showed that ACP could better maintain and improve the original appearance and tissue state characteristics of surimi gels, scoring about 1-2 points higher than the ACP-untreated group. GC-IMS analysis demonstrated the obvious difference in the volatile organic compounds (VOCs) among the treatment groups. Specifically, the samples treated for 120 s with ACP exhibited the most unique aroma characteristics, which probably related to the highest thiobarbituric acid reactive substances values (73.28 μmol MDA/kg sample). Meanwhile, the reduced TCA-soluble peptides content indicated that ACP could inhibit protein degradation to maintaining the tissue state and flavor characteristics of the surimi gels. In conclusion, the advantages of ACP treatment, such as little damage to nutrients, and maximum retention of original sensory properties, provide new ideas for its application in the flavor characteristics of the snakehead surimi gels.

Gelation Process Optimization of Shrimp Surimi Induced by Dense Phase Carbon Dioxide and Quality Evaluation of Gel

Dense phase carbon dioxide (DPCD) is a new non-thermal method to induce surimi gel. However, the gel quality is affected by many factors, such as DPCD treatment time, temperature, and pressure, which makes it complicated to determine its operating parameters. Box-Behnken and backward linear regression were used to optimize the conditions (temperature, pressure, and treatment time) of DPCD-induced shrimp surimi gel formation, and a model between shrimp surimi gel strength and treatment conditions was developed and validated in the present study. Meanwhile, the heat-induced method was used as a control to analyze the effect of DPCD on the quality of shrimp surimi gel in the present study. The results showed that DPCD treatment affected the strength of shrimp surimi gel significantly, and the pressure of DPCD had the greatest influence on the gel strength of shrimp surimi, followed by time and temperature. When the processing pressure was 30 MPa, the temperature was 55 °C, and the treatment time was 60 min, the gel strength of the shrimp surimi was as high as 197.35 N·mm, which was not significantly different from the simulated value of 198.28 N mm (p > 0.05). The results of the gel quality properties showed that, compared with the heat-induced method, DPCD reduced the nutrient and quality loss of the shrimp surimi gel, and increased the gel strength and gel water-holding capacity. The results of low-field nuclear magnet resonance showed that DPCD increased the binding capacity of shrimp surimi to bound water and immobilized water, and reduced their losses. Gel microstructure further demonstrated that DPCD could improve shrimp surimi gelation properties, characterized by a finer and uniformly dense gel network structure. In summary, DPCD is a potential method for inducing shrimp surimi to form a suitable gel. The prediction model established in this study between DPCD treatment temperature, pressure, time, and gel strength can provide a reference for the production of shrimp surimi by DPCD.

Compare with different vegetable oils on the quality of the Nemipterus virgatus surimi gel

To enhance the quality and flavor of surimi‐based products, we investigated the effects of vegetable oils (peanut, soybean, corn, coconut, olive, and safflower seed oils) on the texture, water‐holding capacity (WHC), microstructure, and flavor of the Nemipterus virgatus surimi gel. The results showed that 6 kinds of vegetable oils could improve the whiteness and flavor of gels. However, peanut, olive, and coconut oils enriching oleic acid or lauric acid were easy to accumulate with an average diameter of more than 0.15 μm. Thus, the gel with the oil showed a loose network structures with large cavities, and the texture was deteriorated, accompanied by decreased WHC (p < .05). Compared with other vegetable oils, soybean, corn and safflower seed oils enriching linoleic acid were emulsified with protein forming a stable interfacial protein film. The gel with the oil showed an increase in the WHC and bound water content. Furthermore, the oil droplets with an average diameter of less than 0.15 μm were evenly distributed in the gel matrix, and the gel exhibited dense network structures with small cavities and smooth surface. In general, soybean and safflower seed oils can be used as a potential additive to improve the quality and flavor of surimi‐based products.

Asian Carp, an Alternative Material for Surimi Production: Progress and Future

Asian carp is a general designation for grass carp, silver carp, bighead carp, and black carp. These fish species belong to the family Cyprinidae. In 2018, more than 18.5 million tons of Asian carp were produced globally. Asian carp can be used for producing surimi, a stabilized myofibrillar protein concentrate that can be made into a wide variety of products such as imitation crab sticks, fish balls, fish cakes, fish tofu, and fish sausage. Surimi is usually made from marine fish, but Asian carp have been widely used for surimi production in China. The quality of surimi is affected by various factors, including the processing methods and food additives, such as polysaccharides, protein, salt, and cryoprotectant. With an impending shortage of marine fish due to overfishing and depletion of fish stocks, Asian carp have a potential to serve as an alternative raw material for surimi products thanks to their high abundancy, less emissions of greenhouse gases from farming, desirable flesh color, and sufficient gel forming ability. The utilization of Asian carp in surimi production could also contribute to relieving the overflow of Asian carp in the United States.

Improvement of gelation properties of silver carp surimi through ultrasound-assisted water bath heating

The present work investigated the effects of water bath heating coupled with different ultrasound treatments on the gel properties, protein conformation, microstructures and chemical interactions of silver carp surimi at low/high salt levels. Results showed that the gel strength, hardness, springiness and water holding capacity (WHC) of surimi gels at low salt concentration were inferior to those at high salt content, regardless of the treatments. Compared with the traditional water bath heating, ultrasonic-assisted treatments significantly improved the gelation properties of surimi at the same salt level. In fact, ultrasound treatment also facilitated the unfolding of α-helix structure of the protein, with the resulting exposure of internal groups further enhancing hydrophobic interactions and hydrogen bonds between protein molecules, thereby leading to the formation of denser microstructures with smaller holes. Furthermore, the most noteworthy ultrasonic treatment group was ultrasound-assisted preheating (U + W) group, whose gelation performance under low salt condition, was comparable with that of the traditional two-stage heating (W + W) group with high salt content. Overall, ultrasound-assisted water bath preheating proved to be a feasible approach to improve the gel properties and microstructures of low-salt surimi gels.

Effect of ultrasound assisted konjac glucomannan treatment on properties of chicken plasma protein gelation

The effect of ultrasound assisted konjac glucomannan treatment on the properties of chicken plasma protein gelation was investigated in this study. There were four gelation groups as follows: untreated plasma protein gelation (Control), gelation added konjac glucomannan (KGG), gelation by ultrasound treatment alone (UG) and gelation added konjac glucomannan combined with ultrasound treatment (KGUG). The data showed that the gelation strength and water-holding capacity of the treated groups were significantly increased compared with those of Control. The strongest bonding water was present in KGUG, followed by KGG and UG in low-field nuclear magnetic resonance. The storage energy (G') and loss energy modulus (G″) of KGUG showed the largest rheological properties, and the G' value was higher than that of G″. Furthermore, the elastic and gelatinous properties of UG, KGG and KGUG played a dominant role in viscoelasticity. After konjac glucomannan addition, the particle size of KGG increased significantly. Compared with that of the Control and KGG, the average particle size of UG and KGUG decreased significantly after ultrasound treatment. The hydrophobicity and disulfide bonds mainly affected the formation of heat-induced gelation in these four groups. Furthermore, KGUG with the highest hydrophobicity and disulfide bonds revealed the best stability. Therefore, the gelation of chicken plasma protein by ultrasound assisted konjac glucomannan treatment had excellent gelling properties.