Search

Surimi is a good source of myofibrillar proteins, stabilized with the addition of cryoprotectants during long-term frozen storage. Cryoprotectants have been found to be effective in protecting physical, functional and structural properties of myofibrillar proteins during frozen storage of surimi. Sucrose, sorbitol, polydextrose, lactitol, maltodextrin, litesse, sodium lactate, trehalose and phosphates are among the most-studied cryoprotectants used in the storage of surimi. These antifreezing agents reduce viscosity, improve moisture retention and enhance the protein stability during frozen storage. These factors are inevitably modified as the consequences on the surimi quality and the preservation of myofibrillar proteins from aggregation. This review highlights the preserving role of cryoprotectants on physical, functional and structural changes in surimi. Furthermore, it also discusses about the effect of different components on the quality of surimi gel and a comprehensive discussion on factors affecting the quality of surimi gel such as physicochemical properties, fish species and storage conditions. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the cryoprotective effect of a ovalbumin (OVA) and β-cyclodextrin (βCD) mixture (3:1, OVA/βCD) on the structure, rheology and gelling properties of myofibrillar proteins (MPs) during 90 days of frozen storage. A mixture of OVA/βCD at different concentrations (0, 2, 4, and 6%) was added to MPs and stored at −18 °C for 90 days. The addition of OVA/βCD significantly decreased the sulfhydryl contents while it increased the surface hydrophobicity, which was closely connected with tertiary structural changes. Circular dichroism analysis showed that the addition of OVA/βCD enhanced the stability of the secondary structure by inhibiting the decline in the α-helix. Rheological properties analysis indicated that 6% OVA/βCD treatment showed better storage modulus (G') and loss modulus (G"). In addition, treatment of OVA/βCD showed better gel forming properties than the control group (0%), helping to form a homogeneous and denser gel network. The results proved that 6% OVA/βCD could be act as a promising cryoprotectant, which can improve the structure and gel behavior of Culter alburnus MPs during frozen storage. Moreover, OVA/βCD could be a potential alternative to conventional cryoprotectants at the industrial level to increase the economic and commercial values of seafood products. [ABSTRACT FROM AUTHOR]

Summary: The effect of egg white protein (EWP) and β‐cyclodextrin (β‐CD) mixture was analysed on the myofibrillar proteins (MP) of Culter alburnus during a frozen storage at −18 °C for 60 days. Different proportions of EWP:β‐CD mixture (0%, 2%, 4% and 6%) were added into MP to analyse their effect against oxidative changes. During the study, sulphydryl contents and Ca‐ATPase activity (0.297 to 0.136 mmol g−1) decreased. Moreover, protein denaturation also prompted the surface hydrophobicity (11.47 to 32.06 μg) and carbonyls (26.36 to 49 mg.28 nmol mg−1) of control MP. A significant decline was observed in emulsifying properties. Besides, EWP:β‐CD showed remarkable stability against oxidative changes, by significantly reducing the carbonyls (26.26 to 37.69 nmol mg−1) and surface hydrophobicity (11.51 to 20.31 μg) and also the decline of Ca‐ATPase activity (0.29 to 0.19 mmol g−1). It can be concluded that EWP:β‐CD (6%) is an efficient approach against oxidative changes in MP from Culter alburnus. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze the effect of Kanjoc oligo-glucomannan (KOG) on functional and structural changes in silver carp surimi during fluctuated (FLUC) frozen storage. During this study, KOG was prepared and added 1 and 3% in surimi and myofibrillar protein (MP) and compared with a positive control (PC) of sucrose and sorbitol mixture added samples. The results showed that the water holding capacity (WHC), textural and structural properties decreased during FLUC-I and FLUC-II, indicating that it could be due to protein denaturation induced by the formation of irregular crystallizations and recrystallization. Moreover, it was noted that the addition of KOG (3%) enhanced the stability of α-helix content (58–47%) during FLUC-I and (60–50%) during FLUC-II by inhibiting the hydrophobic residue exposure and change in aromatic amino acids. Meanwhile, KOG (3%) enhanced the textural properties by inhibiting the freeze induced protein denaturation. During FLUC frozen storage, the KOG (3%) was found to be a more effective concentration than conventional cryoprotectant mixture (PC). At industrial level, KOG (3%) could be used as a potential alternative to conventional cryoprotectants to attain prolonged commercial and economic values of silver carp. • Kanjoc oligo-saccharides (KOG) analyzed as cryoprotectant in silver carp surimi. • KOG significantly reduced the protein changes during fluctuated frozen storage. • Dense and compact gel was formed after incorporating KOG (3%). • KOG (3%) improved the physicochemical and structural properties of surimi gel. • KOG (3%) proved to be as a potential alternative to conventional cryoprotectants. [ABSTRACT FROM AUTHOR]

The purpose of this research was to investigate the cryoprotective role of EWP-XO in the prevention of oxidative and structural changes in the myofibrillar proteins (MPs). Different concentrations of egg white protein and xylooligosaccharide (EWP-XO) mixture (0, 2, 4 and 6%) were added to the MPs of Culter alburnus fish during frozen storage (−18 °C) of 60 days. During the study, it was observed that EWP-XO significantly (P <.05) reduced the Ca-ATPase activity, which is greatly related with tertiary structural changes. Meanwhile, carbonyl contents of MPs increased in line with frozen storage (control samples). Meanwhile, samples treated with 6% EWP-XO showed less increase in carbonyl content indicating the decreased protein oxidation. The addition of EWP-XO efficiently inhibited the decline in the sulfhydryl contents. Furthermore, through circular dichroism analysis it was confirmed that the addition of EWP-XO increased the secondary structural stability by preventing the reduction in α-helix content. Microstructural analysis confirmed the preservation of a well-structured protein network that reduced the porosity and protein aggregation of MPs gel. It was concluded that 6% EWP-XO was an effective cryoprotectant mixture, which preserved the functional and structural properties of Culter alburnus during 60 days of frozen storage period. [Display omitted] • Cryoprotective effect of EWP-XO was checked on myofibrillar proteins during frozen storage • EWP-XO significantly (P <.05) reduced the oxidative changes during frozen storage • 6% EWP-XO effectively inhibited protein denaturation and aggregation in frozen storage • 6% EWP-XO improved myofibrillar proteins gelling and structural properties • 6% EWP-XO is an effective concentration to exhibit cryoprotective role on MP [ABSTRACT FROM AUTHOR]

The cryoprotective effect of konjac oligosaccharide (KOG) on the silver carp surimi proteins during frozen storage was analyzed. Meanwhile, molecular dynamic simulation (MD) was carried out to examine the insight interaction of KOG with myosin. The Ca2+ - ATPase and gel strength decreased in all samples, despite the treatment with a sucrose (4%) + sorbitol (4%) mixture as PC and KOG (1 and 3%). The samples added with no cryoprotectants (C) showed a remarkable decline in Ca2+-ATPase activity and gel strength. The decline in these properties could be due to oxidative changes in myosin, ice crystallization, and protein denaturation. Most interestingly, KOG (3%) incorporated samples that presented significant constancy in Ca2+-ATPase and gel strength properties, this stability was further proved with a MD computational study. Our findings of homology and MD analysis affirmed that KOG could substitute water molecules and form hydrogen bonds with amino acid residues, thereby leading to protein stability. Overall, the KOG water substitution action played an efficient cryoprotective effect on frozen silver carp protein. Furthermore, this application could extend the role of KOG at the industrial level as an effective cryoprotectant. • The cryoprotective mechanism of konjac oligosaccharide was analyzed on myosin. • The addition of konjac oligosaccharide reduced the decline in Ca2+ATPase activity. • Konjac oligosaccharide could substitute water molecules and form hydrogen bonds. • Multiple noncovalent connections help stabilize proteins. [ABSTRACT FROM AUTHOR]

The effect of kappa-carrageenan oligosaccharides was analyzed on the gelling abilities of grass carp myofibrillar proteins (MP) during 60 days frozen storage. Four gel treatments were prepared: control without additives (C), a positive control with sucrose: sorbitol (PC), and two batches with 1 and 2% of kappa-carrageenan (KC). All MP gels showed a significant decline in the functional and structural properties. Water holding capacity (WHC) and textural properties of control MP gel was significantly reduced due to oxidative changes, whereas weak cross-linking between amino acid molecules and denaturation of myosin observed. In contrast, PC and KC showed a significant control on the reduction of functional properties due to the enhanced inter/intra-molecular interactions and less formation of ice crystals. Addition of KC (2%) significantly restricted the decline in WHC from 95.45 to 75.47%, which is well associated with high hydrogen proton density. Besides that, low field nuclear magnetic resonance (LF-NMR) analysis exhibited a restricted increase in T 22 relaxation time in samples added with KC (2%). Overall, MP gel with KC (2%) proved to be an effective alternative in comparison with PC and could be efficient in the production and commercialization of fish and other seafood products. • Oligosaccharides could be an effective alternative to the traditional cryoprotectants. • Kappa-carrageenan (KC) improved the viscoelastic properties of MP gel. • KC enhanced WHC properties of grass carp MP gel. • Better textural profile characteristics were observed in MP gels with KC. • KC restricted the water mobility in protein molecules. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the impact of egg white protein (EWP) and β-cyclodextrin (βCD) mixture (3:1) on the structural and functional properties of myofibrillar proteins (MP) from silver carp during 60 days of frozen storage. Different concentrations of EWP-βCD were prepared and incorporated with MP. It was analyzed that α-helix content significantly decreased (P < 0.05) during frozen storage. EWP-βCD substantially enhanced the stability of α-helix content with the minimum increase of β-turn and random coils. Furthermore, rheological studies revealed that MP with increased EWP-βCD concentrations (4 and 6%) improved the inter-molecular protein interactions and enhanced the viscoelastic properties during the gelation process. Moreover, this addition improved the textural properties compared to control. It was also observed from microstructural analysis that MP gelling properties were decreased, which showed coarser and porous structure in control MP (0%). Meanwhile, MP gel treated with EWP-βCD (6%) showed a more compact and well-established network of proteins. All experimental analysis confirmed that EWP-βCD (6%) showed better cryoprotective properties in the preservation of the functional and structural properties of silver carp MP during frozen storage, and could be effective in the industrial storage of fish and associated products. • Myofibrillar proteins subjected to frozen storage, stored for 60 days at −18 °C. • EWP-βCD significantly (P < 0.05) reduced the changes textural properties. • 6% EWP-βCD improved myofibrillar proteins gelling and structural properties. • 6% EWP-βCD is an effective concentration to exhibit cryoprotective role on MP. [ABSTRACT FROM AUTHOR]

This study focused on the effects of egg white protein (EWP) and β-cyclodextrin (βCD) mixture (3:1, EWP/βCD) at 0, 2, 4 and 6% concentrations on fish (Culter alburnus) myofibrillar proteins (MP) during 60 days of frozen storage (−18 °C) by analyzing functional, rheological and structural changes in MP and MP gels. After 60 days of storage, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy revealed a decrease in the MP α-helix content, and EWP/βCD addition improved the MP secondary structural properties by inhibiting protein aggregation induced by exposure of hydrophobic residues. Particularly, the 6% EWP/βCD treatment significantly decreased (P < 0.05) the pores and spaces of MP gels formed during frozen storage, resulting in a denser network. Moreover, compared with the control (0%), EWP/βCD addition significantly increased (P < 0.05) the gel hardness, springiness, gumminess and cohesiveness as well as whiteness and water holding properties. Dynamic rheological analysis showed that 6% EWP/βCD also increased the MP storage modulus (G') and loss modulus (G"). This research provides useful information for increasing the commercial life of fish products by frozen storage and contributes to the potential application of EWP/βCD as a low-sweetness cryoprotectant for Culter alburnus fish. Image 1 • Effect of EWP/βCD was analyzed in myofibrillar protein of culter alburnus during 60 days of frozen storage. • EWP/βCD decreased the protein denaturation and aggregation during frozen storage. • Well-established and interconnected MP gel network was formed with addition of 6% EWP/βCD. • Over all EWP/βCD improved the functional, rheological and structural properties of MP. [ABSTRACT FROM AUTHOR]