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Efficient thawing can preserve the quality of frozen hairtail (Trichiurus lepturus) close to that of fresh hairtail. In contrast to air thawing (AT) and radio-frequency thawing (RT), this study looked at how graphene oxide (GO) and graphene magnetic (GM) nanoparticles paired with RT affect the microstructure and protein conformation of hairtails after thawing. The results suggested that GM-RT can reduce the myofibrillar protein (MP) damage and be more effective than other thawing treatments, like AT, RT, and GO-RT, in maintaining the microstructure of hairtail. The particle size and zeta potential showed that GM-RT could reduce the aggregation of MP during the thawing process compared to other thawing methods. Moreover, the texture of the hairtail after GM-RT exhibited higher hardness (1185.25 g), elasticity (2.25 mm), and chewiness (5.75 mJ) values compared to other thawing treatments. Especially compared with RT, the GM-RT treatment displayed significant improvements in hardness (27.24%), a considerable increase in springiness (92.23%), and an increase in chewiness (57.96%). GO-RT and GM-RT significantly reduced the centrifugal loss. The scanning electron microscopy results demonstrated that the effect of GM-RT was more akin to that of a fresh sample (FS) and characterized by a well-organized microstructure. In conclusion, GM-RT effectively diminished the MP aggregation and improved the texture of thawed fish. It can be regarded as a viable alternative thawing technique to enhance MP stability, which is vital for preserving meat quality. [ABSTRACT FROM AUTHOR]

BACKGROUND: The consumption of frozen foods inevitably involves a thawing process. Protein conformation changes during a short thawing process and the quantification of their effects remains challenging. Molecular dynamics simulations can be used to evaluate the conformational changes of protein occurring in food processing. RESULTS: In the present study, four different thawing methods were used [i.e. magnetic nanometer combined with microwave thawing (MT‐Mag), magnetic nanometer combined with radio frequency thawing (RT‐Mag), radio frequency thawing (RT) and microwave thawing (MT)] to change the conformation of myosin heavy chain (MHC). The results obtained showed that, compared with the fresh sample, the hydrogen bond number and radius of gyration of the RT‐Mag and RT groups were less decreased. Visual molecular dynamics STRIDE analysis showed that the content of the α helix was relatively high in the RT‐Mag and MT‐Mag groups. CONCLUSION: These simulation results indicate that RT‐Mag can be used as an effective method for promoting the thawing process of fish and better stabilizing the protein structure. These conclusions provide a theoretical realization for understanding the protein conformational transition during the thawing process and the realization of quantification and also provide guidance for choosing better thawing conditions without loss of nutritional properties. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The effect of ultrasonic power (UP) treatment on muscle quality and properties of myofibrillar protein (MP) was investigated. Six ultrasonic powers (0, 160, 200, 240, 280, and 320 W) were used to thawing Bonito fillets. Raman spectra, protein solubility, surface hydrophobicity, and sulfhydryl (SH) groups were used to research the secondary and tertiary structure of protein. Water migration was studied using Low‐field NMR. Microscopic structural was performed to observe the fiber state. The results showed that 280 W can keep protein stability compared with other thawing powers. The cooking loss had no significant difference (p >.05) in all samples. The thawing loss was reduced by ultrasonic treatment. In addition, the myofibril surface was smoother and no fracture at 280W. Meanwhile, the intracellular water was maintained stably. Therefore, appropriate ultrasonic power might be an alternative method to enhance the properties of the MP and the quality of meat during the thawing. Practical applications: In recent years, new thawing methods have been found by more and more researchers, so it is important for frozen food to thawing. In this work, different ultrasonic powers were used to explore protein stability and moisture migration during thawing bonito. The protein structure is more stable. [ABSTRACT FROM AUTHOR]

To evaluate the physicochemical properties and structure of thawed fillets, following six treatments were used: conventional thawing, microwave thawing, microwave or ultrasound combined with vacuum thawing, magnetic nanoparticles combined with microwave or far‐infrared thawing. The thawing loss, cooking loss, pH, color, texture change, water‐holding capacity, and water migration of fish fillets were determined. The total volatile base nitrogen and thiobarbituric acid were used to determine the degree of protein degradation and lipid oxidation. Microscope observations and scanning electron microscope (SEM) were used to observe fiber microstructure. Results indicated that both microwave combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing had desirable physicochemical properties as compared to other thawing methods. The lower total volatile base nitrogen and thiobarbituric acid values had less effect on protein degradation and lipid oxidation of thawing process. Besides, both microwaves combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing samples had no significant difference in immobilized and bond water compared with fresh sample. SEM and microscopic observation showed that the myofibril bundles were arranged regularly and smoothly in microwave combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing samples compared with other thawed methods. Thus, the microwave combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing as potential thawing methods could be used to maintain the quality of thawed fish fillets. Practical Application: Largemouth bass (Micropterus salmoides) is a good source of animal protein. The fish needs to be frozen for circulation because of geographical and seasonal factors, so thawing methods can directly affect the quality of thawed fish. The results showed that the microwave combined with vacuum and the magnetic nanoparticles combined with far‐infrared thawing could better maintain the quality of thawed fish. [ABSTRACT FROM AUTHOR]

BACKGROUND: The effect of ultrasonic thawing (0, 160, 280, 400 W) on water‐holding capacity (WHC), physicochemical properties and structure of tuna myofibrillar proteins was investigated. RESULTS: Thawing time was shown to decrease and thawing loss to increase significantly (P < 0.05) as power increased (160–400 W), whereas there was no significant difference (P > 0.05) in cooking loss. Changes in T2 relaxation time were investigated using low‐field nuclear magnetic resonance. Ultrasonic thawing could significantly (P < 0.05) improve the immobilised water content compared to the control (0 W). surface hydrophobicity decreased significantly and then increased significantly (P < 0.05), whereas there was no significant difference (P > 0.05) in the reactive sulfhydryl content as power was increased. Tuna thawed at 280 W suffered fewer negative effects on its microstructure. Roman spectral date showed that the α‐helix changed to a random coil and β‐turn as power was increased (up to 400 W). CONCLUSION: The application of ultrasonic thawing at a specified power was showed to be a beneficial process when used in the seafood industry, but application of excessive power resulted in lower WHC and structural changes to myofibrillar proteins. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Serious quality deterioration can occur with suboptimal thawing, and thus innovative thawing technologies may have an important role in improving the final quality of frozen foods. In recent years, although several new thawing technologies have been extensively studied, such as ultra‐high pressure assisted thawing, ultrasound‐assisted thawing, high‐voltage electrostatic field thawing, ohmic thawing, and radio frequency thawing, more research is needed to make them more applicable to thawing of food industrially. A better evaluation of the impact of thawing is needed to help move new thawing technologies forward. This review discusses the principles involved, the applications to different types of foods, modeling of the various processes, new evaluation techniques, and patents obtained for the different systems. The benefits and weaknesses of these systems are also discussed to provide a more complete review of these new thawing techniques. This review will, hopefully, encourage additional work that may help reach the goal of having better food thawing systems. [ABSTRACT FROM AUTHOR]

Ultrasound assisted vacuum thawing (UVT) or microwave vacuum thawing (MVT) with red seabream fillets were compared to fresh, chill storage thawing, vacuum thawing, microwave thawing and ultrasound thawing. The thermal stability and gelation properties were studied with DSC and dynamic rheology, respectively. Raman spectra before and after H/D isotope exchange and intrinsic fluorescence were used to measure protein secondary and tertiary structure. Low-field NMR was done to measure water migration. The two thawing techniques both retained actin thermal stability and generally retained more stable tertiary structures than the other thawing methods. MVT showed a desirable viscoelasticity of muscle proteins and UVT had a relatively stable secondary structure. There were no significant changes in free water. Thus, UVT and MVT could be used to improve the physicochemical properties of proteins during thawing of fillets. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of CS@Fe 3 O 4 nanoparticles combined with microwave or far infrared thawing on microbial diversity of red seabream (Pagrus major) fillets in terms of thawing loss, pH, TVB-N, classical microbiological enumeration and high-throughput sequencing, and the same parameters were also studied for 24 h after thawing. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FT), CS@Fe 3 O 4 nanoparticles combined with microwave thawing (CMT) and CS@Fe 3 O 4 nanoparticles combined with far-infrared thawing (CFT). The results showed that CFT and CMT had lower values of pH and TVB-N compared to the FT and MT. Based on conventional microbial count analysis, CFT and CMT samples also maintained lower TVC, pseudomonas and LAB counts. Using high-throughput sequencing analysis, Compared with FT and MT, CFT and CMT samples showed a significant decrease in the proportion of the Pseudomonadaceae flora. However, the proportion of Pseudomonas, Bacillaceae and Thermaceae also increased significantly after 24 h of storage, which indicated that become the predominant microbiota in red seabream (Pagrus major) fillets. • Four thawing methods were studied in red seabream by high-throughput sequencing. • The thawing method of CS@Fe 3 O 4 nanoparticles plus microwave or far infrared was used. • CFT and CMT decreased the community richness and microbial communities bacterial diversity. [ABSTRACT FROM AUTHOR]

The effects of magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT) on the freshness and amines content of red seabream fillets were investigated. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FIRT), magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT). The quality of the fresh sample, the sample after thawing and thawed sample after being stored for 6 h were compared by measuring the freshness indexes such as the volatile amino nitrogen content, thiobarbituric acid content, pH value, total number of viable colonies, and the food safety evaluation indexes such as the formaldehyde, dimethylamine, trimethylamine and putrescine contents. The results showed that MNPFT and MNPMT can maintain better freshness than microwave and far-infrared thawing, and the increase in amines content was significantly inhibited. • Two methods of combined thawing have been proposed. • Effect of four thawing methods on the freshness and safety was analyzed. • Magnetic nanoparticles plus microwave or far infrared thawing works better. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different thawing methods on the quality of largemouth bass. The viscoelastic properties of proteins in Ultrasonics combined with microwave thawing (UMT) and Ultrasonics combined with far-infrared thawing (UIT) samples were closer to FS, which was an indication of good gelation and gel quality. Zeta potential, Raman spectra before and after H/D isotope exchange were used to measure the protein aggregation and the secondary structure of protein. Fourier transform Raman spectra and Raman spectra have been used to investigate the chemical changes in fish lipid during lipid oxidation. Results indicated that both UMT and UIT showed protein stability and gelation property. Thus, it was proved that UMT and UIT could be potentially used to improve the fish quality during thawing process. • Two novel thawing methods have been proposed. • The effects of five thawing methods on fish quality was studied. • UMT and UIT could maintain the quality of the largemouth bass fillets better. [ABSTRACT FROM AUTHOR]

This work was aimed to explore the effects of different thawing strategies on the properties of sea bass myofibrillar protein (MP) and organization structure. Results revealed that magnetic nanometer combined with radio frequency thawing (RT-Mag) and magnetic nanometer combined with microwave thawing (MT-Mag) increased the α-helical content and decreased β-sheet content, while RT-Mag had minimal effect on the secondary protein structure. Low-field nuclear magnetic resonance and SEM analysis revealed that RT-Mag and radio frequency thawing (RT) reduced the mobility and loss of immobilized and non-mobile water, had the most compact and ordered network structure. Decreases in the T max and enthalpies were observed in the thawing treatments expect for RT-Mag during the thawing process. The appearance of polymerized protein band of SDS-PAGE indicated that RT-Mag and MT-Mag occurred a mild oxidation. In addition, the changes of particle size indicated that MP pretreated by RT-Mag and MT-Mag had less aggregation and degradation. The UV second derivative showed that the effect of RT-Mag treatment was closer to that of FS, and the improvement effect of protein aggregation and oxidation was better. Therefore, RT-Mag of New thawing method can be used as an alternative method to improve MP performance and meat quality. ● The two new thawing method of RT-Mag and MT-Mag were adopted. ● Protein structure and thermal stability of sea bass thawed by different methods were studied. ● RT-Mag and MT-Mag could improve MP performance and meat quality. [ABSTRACT FROM AUTHOR]

In order to evaluate the effects of magnetic nanoparticles plus microwave (MNPMT) or far-infrared (MNPFT) thawing on protein conformation changes and moisture migration of red seabream ( Pagrus major ) fillets, cold storage thawing, microwave thawing, MNPMT, far-infrared thawing and MNPFT were subjected to red seabream fillets. DSC and dynamic rheology were conducted to analyze physicochemical changes. Raman spectra before and after isotope H/D exchange, intrinsic fluorescence and UV second derivative spectra were carried out to explore myofibrillar protein structural changes. Low-field NMR was used to test water migration. SEM was performed to observe fiber microstructure. Results indicated that MNPMT and MNPFT both had a desirable thermal stability and gelation property. Besides, both showed stable protein secondary and tertiary structure. Immobilized water in them also had no significant changes compared with fresh sample. This research provided some novel thawing technologies for application in food industry. [ABSTRACT FROM AUTHOR]

Fish consumption and its processing products has attracted much attention nowadays due to the high nutritional value in fish. However, due to the large amount of water contained in fish, fish products are prone to decay, leading to a rapid decline in fish quality. Therefore, the rapid and effective detection of fish freshness will be crucial for the future seafood industry. Effective visualization of fish freshness under different thawing methods is of great significance in fish quality and conducive to the retention of fish nutrients. Electrical conductivity (EC) is a chemical index of freshness. The purpose of this study is to investigate the combination of hyperspectral imaging (HSI) and multivariate data to identify fish freshness. Multivariate linear stepwise regression (MLSR) algorithm and Partial least squares regression (PLSR) methods were used to calibrate and predict the whole spectrum. The PLSR and MLSR model of 7 characteristic wavelengths (445, 474, 580, 612, 711, 813, 974 nm) extracted by SPA were established, and the combination algorithm for obtaining the best prediction model was SPA coupled with PLSR. The parametric equation established by SPA-PLSR model (R2p of 0.8569 and RMSEP of 19.06) is transferred to each pixel of the image to generate the spatial distribution diagram of EC value. The ability of the models based on HSI to predict the freshness indicators were verified for largemouth bass fillets stored under different thawing methods. The study demonstrated that HSI is a potential non-invasive and non-destructive technique for the identification of fish freshness. • Ultrasonics combined with microwave thawing was assembled by the investigators. • Hyperspectral imaging was used for monitoring of EC value in fish fillet. • Seven effective wavelengths were selected by Successive projections algorithm. • Best calibration model was obtained based on SPA-PLSR. • Image visualization of EC was achieved by an image processing algorithm. [ABSTRACT FROM AUTHOR]