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. 2022 Nov 23;17:100518. doi: 10.1016/j.fochx.2022.100518

Insight into muscle quality of white shrimp (Litopenaeus vannamei) frozen with static magnetic-assisted freezing at different intensities

Qinxiu Sun a,c,1, Honghong Zhang a,1, Xianqing Yang b,⁎, Qian Hou a, Yan Zhang a, Jiangpeng Su a, Xianhua Liu a, Qihang Wei a, Xiuping Dong d, Hongwu Ji a, Shucheng Liu a,c,⁎
PMCID: PMC9720240  PMID: 36478709

Highlights

  • •

    The effect of magnetic field freezing (MF) on white shrimp quality was studied.

  • •

    60 mT MF (MF-60) shortened the freezing time, reduced thawing/cooking loss.

  • •

    MF-60 helped to maintain the water holding capacity and texture properties.

  • •

    MF-60 reduced the mobility and loss of immobilized water and free water.

  • •

    The microstructure of MF-60 was less damaged by ice crystals.

Keywords: White shrimp, Magnetic field-assisted immersion freezing, Muscle quality, Ice crystal

Abstract

The effects of magnetic field-assisted immersion freezing (MF) with different intensities (20, 40, 60, and 80 mT) on the freezing process and muscle quality of white shrimp (Litopenaeus vannamei) were studied in the present study. The results showed that, compared with immersion freezing (IF), 60 mT MF (MF-60) shortened the total freezing time, reduced thawing loss and cooking loss, and helped to maintain the water holding capacity and texture properties of frozen shrimp samples. In addition, the increase in the L* value of frozen shrimp samples was also inhibited by MF-60. The result of water distribution revealed that MF-60 reduced the mobility and loss of immobilized water and free water. The microstructure of MF-60 was characterized by smaller pores, indicating that MF-60 promoted the generation of fine ice crystals. Overall, MF-60 was beneficial in reducing ice crystal size and inhibiting the loss of shrimp muscle quality loss during the freezing process.

Introduction

White shrimp (Litopenaeus vannamei) is one of the three excellent shrimp varieties with high yields in the world (Pan, Sun, Liu, Wei, Xia, Zheng, et al., 2021). The aquaculture scale of white shrimp is increasing due to its characteristics of fast growth, high-density breeding tolerance, and strong environmental adaptability (Kureshy & Davis, 2002). The production of white shrimp is 5.8 million tons in 2020, accounting for 51.72% of the total crustaceans farming production (FAO, 2022). However, fresh shrimp is usually more prone to decay than most other food products due to a large amount of nonprotein nitrogen, autolytic enzymes, and microorganisms in its body, which leads to its rapid postmortem deterioration and shorter storage period (Zhang, Cao, Lin, Deng, & Wu, 2019). Freezing is a commonly used preservation method for shrimp because it can inhibit the physiological and biochemical processes of shrimp, minimize microbial growth, and maintain product quality. However, during the traditional freezing process, the large and irregular ice crystals formed due to the slow freezing speed can easily damage food tissue cells, resulting in lost flavour and nutritional value, affecting the further processing and consumption of aquatic products, seriously restricting the promotion of aquatic products and the development of related industries (Dang, Gudjónsdóttir, Tómasson, Nguyen, Karlsdóttir, & Arason, 2018). The size, shape, and distribution of ice crystals in frozen products determine the quality of frozen products, which depends on the ice crystal nucleation rate and growth (Kiani & Sun, 2011). For decades, optimization of the freezing process has focused on improving heat transmission efficiency. However, the main disadvantage of this method (such as cryogenic rapid freezing) is the high total cooling cost, and some products are prone to freeze-fracture when directly exposed to extremely low temperatures. Recently, people began to pay attention to nucleation and proposed several nucleation control technologies (Dalvi-Isfahan, Hamdami, Xanthakis, & Le-Bail, 2017). From the point of view of regulating the formation of crystal nuclei and the growth of ice crystals, the freezing rate is accelerated, so that the heat transfer rate is greater than the water penetration rate, to form a large number, small volume, and uniform distribution of intracellular ice crystals, and to protect food tissues.

Among them, magnetic field-assisted freezing (MF) can not only change the nucleation of ice crystals, but also produces no pollution and has low energy consumption (Liu, Song, Yao, & Bennacer, 2018). It will not change the internal pressure of food or produce oxidized substances in the freezing process, which is a new green food freezing technology. Recently, researchers have found that MF can change the molecular properties of water and promote the formation of fine and uniform ice crystals, thus improving the quality of frozen food (Sutariya, & Sunkesula, 2021). The mechanism by which MF shortens the freezing phase transition time remains unclear until now, with the main speculative results shown in Fig. 1A. As shown in Fig. 1A, there are stronger and weaker hydrogen bonds between water molecules, with the stronger bonds becoming more tightly connected and the weaker bonds weakening or breaking under the influence of a magnetic field. As a result, the macromolecular clusters are transformed into small clusters or freed into free monomeric molecules by the magnetic field. Smaller water clusters will increase the amount of non-freezing water and better maintaining the quality of products (Owada & Kurita, 2001). Furthermore, the rearrangement of hydrogen bonds can greatly affect some of the properties of water that control freezing kinetics (such as freezing point, specific heat capacity, and thermal conductivity) and then control the nucleation of ice crystals (Otero, et al., 2016). Currently, MF-related studies have been conducted involving water and sodium chloride, vegetable, fruits, meat, and biomaterials (Tang et al., 2019, Jin et al., 2020, Otero and Pozo, 2022, Tang et al., 2020); however, few studies focusing on magnetic field-assisted techniques in shrimp processing have been reported. Since magnetic fields have different effects on foods with different characteristics (e.g. moisture content, carbohydrate composition and protein composition), it is necessary to find the appropriate magnetic field intensity conditions for white shrimp as different frozen foods corresponding to different optimum magnetic field intensities (Miñano et al., 2020). Therefore, specific research is needed on the magnetic field action parameters that can effectively improve the shrimp freezing efficiency and muscle quality. Moreover, as the actual MF magnetic field intensity was not clear in most studies, the heat generated by the magnetic field had not been eliminated to cause food freezing environmental temperature fluctuation, greatly reducing most of the trial’s credibility. Therefore, the effect of MF on food has also generated certain controversy. To verify the effect of MF on the freezing progress and quality of white shrimp, we designed a magnetic field assisted immersion freezer that can generate a uniform magnetic field, the actual magnetic field strength for food freezing can be measured in real time, and the thermal effects of magnetic field generation can be eliminated. Magnetic fields are classified according to their intensity as weak (<1 mT), medium intensity (1 mT ∼ 1 T), strong (1 T ∼ 20 T) and ultra-strong (>20 T) (Zhang, Li, & Zhang, 2019). Abie et al. (2021) utilized a lower magnetic field of 2 mT to freeze meat samples with unsatisfactory results, while Otero and Pozo (2022) used a greater static magnetic field of 150-200 mT, 107 to 359 mT to freeze potatoes and saline with disappointing performances, too (Abie et al., 2021, Otero and Pozo, 2022). In contrast, 10 mT and 60 mT magnetic field assisted freezing were observed to considerably diminish the size of ice crystals generated during freezing of cherry and mouse oocytes, respectively (Tang et al., 2020, Baniasadi et al., 2021). To investigate the effect of static magnetic field intensity on the muscle quality of frozen white shrimp, a medium magnetic field intensity range of 20 ∼ 80 mT was designed. The effects of different freezing magnetic field intensities on the freezing rate, ice crystal size, visual appearance, moisture characteristics, and physicochemical characteristics of white shrimp were investigated in the present study in the hope of finding appropriate MF parameters that can improve the quality of frozen shrimp (Fig. 1B).

Fig. 1.

Fig. 1

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Microscopic diagram of water molecules during magnetic field freezing (A), article thought chart (B).

Materials and methods

Chemicals

Acetic acid (purity, ≥ 99.5%), chloroform (purity, ≥ 99.0%), ethanol (purity, ≥ 99.7%), xylene (purity, ≥ 99.0%), methanal (purity, ≥ 36.0%), hematoxylin-eosin solution, neutral gum, were purchased from Sinopharm Chemical Reagent ltd. (Shanghai, China), HE dye solution set, were purchased from Solarbio corporation (Beijing, China). All chemicals and reagents were of analytical grade.

MF equipment

The MF equipment (Fig. 2A) consists of magnetic field generator, heat dissipation system, freezing chamber, monitoring system, and control panel (Fig. 2A. 12). (1) The magnetic field generator consists of a Helmholtz coil (Fig. 2A. 7) and a DC power supply (Fig. 2A. 10), which allows the generation of a uniform magnetic field (Fig. 2B). The intensity of the magnetic field for the freezing chamber could be changed by adjusting the supply voltage (0–150 V) or current (0–15 A). (2) The heat dissipation system consists mainly of a separate cryostat circulator (Fig. 2A. 1) and a cooling water pipe around the Helmholtz coil (Fig. 2A. 6). The cooling water continuously removes the heat generated by the Helmholtz coil magnetisation so that it does not transfer heat to the freezer and destabilise the actual freezing temperature. (3) The freezing chamber is made up of a cylindrical chamber with a diameter of 12 cm and a height of 20 cm, in insulation, a cooling circulation system, and a freezing support. The cooling fluid (90% ethanol) is driven by the cooling circulation system to provide a uniform and stable freezer temperature. As shown in Fig. 2B, the freezing rack is 12 cm in diameter and 10 cm in height, nested in the freezing chamber. (4) The monitoring system includes the monitoring of temperature and magnetic field intensity. The temperature is monitored by a T-thermocouple connected to a computer (UT 325, Uni-Trend Technology Limited, Dongguan, China). Before putting the sample in the chamber, the digital Tesla meter (PF-045B, Litian Magnetoelectric Co., ltd., Sichuan, China) is used to confirm that the magnetic field intensity for the freezing chamber uniformly reaches the target intensity.

Fig. 2.

Fig. 2

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Schematic of the magnetic field freezer (A), schematic representation of the position and magnetic field intensity of the shrimp in the freezing rack (B), schematic diagram showing the Shrimp tissue and corresponding determination (C). For Fig. 2A: 1. Low-temperature constant temperature circulator; 2. Control panel of low-temperature constant temperature circulator; 3. Liquid chamber; 4. Cooling Tube; 5. PF-045B digital Tesla meter; 6. Cooling water pipe; 7. Helmholtz magnetic field coil; 8. Heat-insulating layer; 9. Insulation cover; 10. Direct-current power supply; 11. UT 325 multi-channel temperature tester; 12. Control panel for the magnetic field; 13. Condensing tube; 14. Electric pump; 15. Reservoir; 16. Compressor; 17. Fan; 18. Evaporator; 19. Electric box.

Preparation of shrimp

Live white shrimp samples of uniform size (30–40 pieces/kg) were purchased from Dongfeng Aquatic Market (Zhanjiang, China). They were transported to the laboratory with oxygenation and water. Shrimp samples were killed suddenly by crushed ice, decapitated, and selected for freezing with a weight of 13 ± 0.5 g and a body length of 10 ± 0.5 cm. After the samples body surface was blotted dry with filter paper, it was individually placed into a zipped polypropylene bag and then sealed. All samples were randomly divided into six aliquots and transferred to a 4 °C freezer for 12 h to stabilize the temperature of the samples from each group. A sample without freezing treatment (fresh) served as the control group, and the remaining five groups were frozen by different methods. For immersion freezing (IF) and MF, the shrimp samples were placed in a fixed position of a magnetic field freezer (XO-120L-Ⅱ, Nanjing Xianou Co., ltd., Nanjing, China). For each treatment eight shrimp samples were placed vertically in a fixed position on the freezing rack according to their corresponding numbers, with 1 cm reserved above and below each (Fig. 2B). This ensures that each sample is subjected to the same magnetic field. The magnetic field intensities were set to 0 mT (IF), 20 mT (MF-20), 40 mT (MF-40), 60 mT (MF-60), and 80 mT (MF-80). Before the white shrimp samples were subjected to MF treatment, they all waited for the magnetic field to stabilise before being frozen for the next batch. When the sample centre temperature reached −18 °C, the samples were transferred to a −18 °C refrigerator awaiting measurement.

Shrimp samples were segmented according to the number of muscle segments and named segments 1–6, respectively, and different segments were fixed for measurement of specified indexes (Fig. 2C). Shrimp samples with heads removed were used to measure thawing losses and cooking losses. And segment 1–5 was for water holding capacity (WHC), LF NMR (low-field nuclear magnetic resonance) and magnetic resonance imaging (MRI) determination, segment 2 was for the geometric center temperature and colour determination, segment 2–3 was for TPA (Texture profile analysis) measured, and segment 6 was for light microscopy and SEM (scanning electron microscopy) observation.

Determination of freezing time

The change of sample centre temperature with time was measured by a T-thermocouple connected to a computer (UT 325, Uni-Trend Technology Limited, Dongguan, China). The temperature probe was inserted into the geometric center of shrimp samples, which is the center of the second ventral segment of shrimp samples (Fig. 2C). The temperature of the freezer chamber was also recorded in real time (determination frequency:1 s/time) with the T-thermocouple.

Scanning electron microscopy

To visually visualize shrimp sample microstructure, vertical fibers from the muscle cross-section of the last muscle segment of shrimp samples were taken for light microscopy. As shown in Fig. 4A, vertical fibers were mainly located in the middle of the shrimp samples, near the intestinal glands and nerve lines. The second ventral segment of the shrimp sample was cut into 3 × 2 × 1 mm3 slices with a knife pre-cooled to −18 ℃. They were then freeze-dried using a vacuum freeze dryer (Labconco, Kansas, MO, USA) to prepare samples for SEM analysis. The samples were dried for 72 h at −60 ℃ with the condensing plate. Next, the dried samples were coated using a gold–palladium alloy coater (Bal-tec Co., Manchester, NH, USA). The microstructure of shrimp samples was examined using an SEM (SU8010, Hitachi, Tokyo, Japan) at an accelerating voltage of 5 kV, and the samples were observed at 300 × magnification.

Fig. 4.

Fig. 4

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Sampling sites diagram of shrimp muscle for SEM (A), SEM images of shrimp frozen by different treatments (B), light microscopy images of shrimp frozen by different treatments (C). IF: immersion freezing; MF: magnetic field-assisted freezing at different intensities.

Light microscopy

The microstructure of shrimp samples was measured according to the method of Yang, Liu, Sun, Zheng, Wei, Xia, et al. (2022). The second abdominal segment muscle (0.5 cm × 0.5 cm × 1.0 cm) of shrimp samples was fixed with Carnoy's solution (10% acetic acid, 30% chloroform, and 60% pure ethanol, v/v) for 48 h. And then it was dehydrated gradually with graded concentrations of alcohol (50%, 75%, 85%, 95%, and 100%), for 30 min each concentration. Subsequently, the samples were transparent with xylene, paraffin-soaked, and embedded. Then the paraffin-embedded tissues were sliced vertically by the slicer into 4 μm thick sections as in Fig. 4, then stained in hematoxylin-eosin solution. Finally, the vertical fibrous parts of the shrimp samples were observed with an optical microscope (Olympus BX41, Olympus Optical Co. ltd., Tokyo, Japan) (magnification 400×).

Determination of thawing loss and cooking loss

The frozen samples were weighed immediately before thawing (W0). Then, the frozen samples were thawed to a geometric centre temperature of 4 °C and blotted dry with filter paper, then weighed (W1) immediately. The thawing loss was calculated as follows:

Thawing loss (%)=W0-W1W0×100

The thawed sample was weighed (W1) and heated in a water bath at 85 °C until the central temperature of the shrimp samples reached 75 °C. The cooked sample was immediately blotted dry with filter paper and weighed (W2). The cooking loss was calculated using the following formula:

Cookingloss%=W1-W2W1×100

Water holding capacity

The WHC of shrimp samples was measured by centrifugation. Briefly, approximately 10 g of each thawed sample was weighed (m1) and then wrapped in filter paper and transferred to a 10 mL centrifuge tube. The tubes were centrifuged in a centrifuge separator (1736 R, Labogene, Seoul, Korea) at 5000 r/min at 4 ℃ for 10 min. Next, the filter paper was removed, and the shrimp samples were weighed (m2). Each sample group was measured three times. The WHC was calculated as follows:

WHC (%)=1-m1-m2m1×100

Low-field nuclear magnetic resonance and magnetic resonance imaging analysis

LF NMR relaxation measurements were conducted with an NMI20-060H-I analyser (Niumag Electric Corporation, Shanghai, China). Approximately 10 g of thawed shrimp samples (4 ℃) were put into a 35 mm diameter plastic dish. The NMR detection frequency was set to 22.6 MHz, for each sample. Four scans were obtained at a 2 s interval with 5000 echoes in total. The transverse relaxation curve was measured using the Carr-Purcell-Meiboom-Gill pulse sequence mode and the CONTIN algorithm.

MRI measurements were analysed by multi-layer spin-echo pulse sequence imaging according to the method of Yang et al. (2022). The proton density imaging sequences were adopted and the test parameters were as follows: repetition time = 2000 ms, echo time = 40 ms. To present the water distribution visually, grey level images were converted to colour images by the Niumag NMR V3.0 image processing software.

Determination of texture properties

TPA was performed using a TA.XT Plus texture analyser (Stable Micro Systems ltd., UK) after determining cooking loss. The second and third abdomens of each shrimp sample were compressed by a P/0.5 cylindrical probe. Settings for TPA were as follows: constant test speed, 1.0 mm/s; sample deformation, 40%; hold-time between cycles, 5 s; and trigger force, 5 g. Hardness, springiness, and gumminess were calculated from the force–time curves generated by the in-built software Texture Exponent 32.

Determination of colour

The colour parameters of the shrimp samples were measured using a colourimeter (ZE-6000, Juki Corp, Tokyo, Japan). The colourimeter was calibrated with a white reference tile (L* = 95.26, a* = –0.89, b* = 1.18), then placing the colourimeter vertically near the second abdominal segment of the shrimp samples. Each sample was measured repeatedly-three times. The average value for each sample was calculated.

Statistical analysis

All data were analysed statistically with SPSS software (version 26.0, SPSS Inc., Chicago, IL, USA) and presented as mean ± deviation. One-way analysis of variance and Waller-Duncan’s test were used to measure the significance of the main effects (P < 0.05). Data regarding changes in moisture characteristics and physicochemical properties of white shrimp were analysed using a mixed procedure in which triplicates were included as random effects and the different freezing treatments (fresh, IF, MF-20, MF-40, MF-60, and MF-80) as fixed effects. For each batch of white shrimp sample, all experiments were carried out in triplicate.

Results and discussion

Changes in freezing time

A typical cooling curve is shown in Fig. 2A, but no super-cooling was detected in the freezing curves of all samples. As illustrated in Fig. 2A, the temperature of the different treatment groups in this experiment was stable at −35 °C, indicating that the heat dissipation system and insulation of the instrument effectively isolated the thermal effects caused by the Helmholtz coil. To better understand the influence of the freezing conditions on the freezing process, the freezing curve was divided into three stages: pre-cooling stage (4 – −1 °C), phase transition stage (-1 – −5 °C), and sub-cooling stage (-5 – −18 °C) (Otero, et al., 2016). Statistical analysis was performed on the time changes required for the samples to pass through each stage, as shown in Fig. 2B. During the pre-cooling process, sample temperature decreased rapidly because of the significant temperature difference between the sample and ambient temperature. There were no significant differences in the pre-cooling time among all the treatments (P > 0.05), indicating that freezing at different magnetic field intensities did not significantly change the heat transfer rate during the pre-cooling stage. During the phase transition, the sample temperature decreased slowly due to the formation of ice crystals releasing a large amount of latent heat, and the phase transition time of the samples was significantly changed by different magnetic field intensities. Compared with IF, MF significantly shortened the phase transition time of the samples (except for MF-20, whose phase transition time was not significantly different from that of IF). Similar to us, Watanabe, Kanesaka, Masuda, and Suzuki (2011) also found that the freezing process of tuna and agar samples was not significantly affected by a 20 mT static magnetic field combined with a 0.12 mT oscillating magnetic field (1 MHz) freezing. Owada and Kurita (2001) also found that the combination of static (10 mT) and oscillating (0.5 mT, 50 Hz) MF with an electric field (600 kV/m) did not improve the heat transfer in unfrozen chicken and gold anomala. This demonstrates that lower magnetic field intensity had no significant effect on freezing rate. With the increase in magnetic field intensities, the phase transition time of the sample first decreased and then increased, and the phase transition time of MF-60 was the shortest, which was 42.11% shorter than that of the IF sample (P < 0.05). In the sub-cooling phase, because most of the water inside the muscle was frozen, the heat transfer coefficient increased and the temperature decreased rapidly. The sub-cooling time showed a similar change to the phase transition time, and MF-60 showed the shortest sub-cooling time, which was 37.17% shorter than that of the IF sample (P < 0.05). Tang et al., 2019, Tang et al., 2020 also found that MF clearly reduced phase transition times on frozen cherries, blueberries, and pork. This may be due to the energy change in hydrogen bonding and Van der Waals forces within and between water molecule clusters caused by the static magnetic field, which transforms large water clusters into small clusters or free water molecules, leading to faster energy exchange and shorter freezing time (Lu et al., 2022). In addition, no subcooling was observed in the freezing curves of all samples. This may be because that the −35 °C immersion freezing of individual frozen shrimp samples was so fast that such small changes were not observed. And subsequent experiments at slightly higher temperatures will be used to demonstrate the effect of magnetic fields on subcooling. In summary, the length of phase transition period and total freezing time were significantly shorter in the present samples.

Changes in microstructure of shrimp

As shown in Fig. 4B, the holes in the image were left by the sublimation of ice crystals and therefore correspond to their form and size. For IF, many holes with heterogeneous sizes were formed between the muscle fibers, indicating that IF formed large and irregular ice crystals between the muscle fibers. For the MF-20 sample, although the diameter of the holes left by the ice crystals was still large, the size of the holes became uniform. Of all the frozen samples, MF-60 showed a more complete microstructure, characterised by the smallest and most uniform pores, indicating that MF-60 promoted the generation of fine and uniform ice crystals, which also further illustrated why there was less water loss for MF-60 after freeze-thawing. Baniasadi et al. (2021) also found that MF-60 maintained the ultrastructure of frozen mouse vitrified cumulus oocytes complexes effectively. Longer freezing times often result in the production of a small number of large extracellular ice crystals, while shorter freezing times often produce many small ice crystals located both intracellularly and extracellularly (Lorentzen, Hustad, Lian, Grip, Schrødter, Medeiros et al., 2020). The freezing times of the different magnetic field intensity treatment groups in this study corresponded to the results of ice crystal morphology size. As what mentioned before, the magnetic field transforms large water clumps into smaller ones, which may provide more sites for the nucleation of ice crystals, making them smaller and more evenly distributed (Lin et al., 2013).

As can be seen in Fig. 4C, the pink sections are stained muscle fibers and the white sections are empty spaces. Among all the samples, IF had the largest interfascicular space, this may be because the large ice crystals formed during freezing damaged the muscle tissue and prevented the extracellular water absorption after thawing. In the IF sample, the perimysium was separated from the muscle bundle, and the surface of the perimysium was rough, which might be caused by large ice crystals penetrating the perimysium (Cheng et al., 2020). There was no significant difference in microstructure between MF-20 and IF samples, which corresponded to the results of thawing loss and cooking loss, indicating that MF-20 could not significantly inhibit the damage of ice crystals to muscle tissue. Although there was little difference in the interfascicular space between MF-40, MF-80, and MF-60, the perimysium of mF-40 and MF-80 was coarser than that of MF-60, which further indicated that MF-60 could inhibit the destruction of muscle tissue by freezing. The interfascicular space of MF-60 samples was relatively small and the perimysium was relatively smooth, indicating that the ice crystal formation of MF-60 caused less damage to muscle cells, so that most of the water in the intercellular space could be reabsorbed by cells after thawing. The optical microscope results correspond to the morphology of the ice crystals as revealed by the SEM images. It is also possible that this is since the magnetic field can reduce the fluidity of the membrane, thereby enhancing its rigidity (Wang et al., 2014).

Changes in thawing loss

Water loss can affect the weight, appearance, and sensory properties of meat products (Huff-Lonergan & Lonergan, 2005). Freezing and thawing can change the water fraction and distribution of meat, so thawing loss can be used as an important indicator to evaluate meat quality (Leygonie, Britz, & Hoffman, 2012). As can be seen in Fig. 2C, the thawing losses of the IF and MF-20 samples were the greatest (P < 0.05), while there was no significant difference between the two groups (P > 0.05), indicating that the low magnetic field intensity has no significant effect on the thawing loss of the samples. With increasing magnetic field intensity, the thawing loss of the samples first decreased and then increased, and the MF-60 sample showed the lowest thawing loss (P < 0.05). This indicates that an appropriate magnetic field intensity is beneficial for promoting the generation of fine and uniform ice crystals and reducing the damage of muscle tissue by large ice crystals, which in turn reduces the thawing loss of frozen shrimp samples; however, an excessively high or too low magnetic field intensity was not beneficial in reducing the thawing loss of shrimp samples. Qin, Dong, and Li (2020) thought that under the action of a magnetic field, the magnetic force leads to the decrease of Gibbs free energy, resulting in smaller ice crystal radius smaller, reduced ice crystal damage to tissue cells, and reduced thawing loss. Zhou, Lu, Zhou, Song, Jiang, and Xia (2000) also found that the magnetic field intensity below 50 mT would not significantly change the distance between water molecules and intermolecular hydrogen bonding. Overall, the MF of shrimp samples was effective in reducing thawing loss, and the effect of the MF-60 was the most significant.

Changes in cooking loss

Cooking loss refers to the loss of a significant amount of liquid and a small amount of soluble material during heating. Partial dehydration during freezing may also be reflected by an increase in the cooking loss value, reducing the stability of the protein network and affecting protein water interactions (Solo-de-Zaldívar, Herranz, Borderías, & Tovar, 2014). As shown in Fig. 2D, the fresh sample has the lowest cooking loss among all samples, which is supported by the fact that the fresh samples were stable in protein structure and the interaction between protein and water was not disrupted. Freezing resulted in various degrees of increase in the cooking loss of the samples, which may be because, during the freezing process, the stress caused by the nucleation and growth of ice crystals, resulted in physical damage to the network, damaged the protein network, and the relationship of the protein network and water (Liang, Qu, Liu, Wang, & Jia, 2020). Compared with IF, the cooking loss was reduced by MF, providing further evidence that magnetic fields can control the nucleation and growth of ice crystals and inhibit the cryodenaturation of proteins. The cooking loss of the MF-60 sample was much lower than that of other frozen samples, which was only 48.17% higher than that of the fresh sample. This may be because fast freezing can keep the stability of shrimp myosin more effectively, hence maintaining the structure of shrimp muscle. Owada and Kurita (2001) thought that, during the MF process, an appropriate magnetic field intensity can reduce the size of the free water cluster, increase the amount of non-freezable bound water, and better preserve the stability of the protein structure. In addition, they also considered that small clusters of water were able to form hydrogen bonds with the polar groups of the tertiary structure of proteins and carbohydrates and attach them tightly. Therefore, MF would reduce the number of free water and thus the number and size of ice crystals.

Changes in water holding capacity

Water holding capacity refers to the ability of muscles to retain their original moisture when acted upon by external forces. It not only affects the taste, nutritional composition, tenderness, colour, and other edible quality of meat, but also directly affects the yield of meat products, which has important economic value. As illustrated in Fig. 2E, the water holding capacity of the fresh sample is much higher than that of the other samples (P < 0.05). A decrease in water holding capacity was observed in all frozen samples, and the IF samples had the lowest water holding capacity, which was 34% lower than that of the fresh sample (P < 0.05). The water holding capacity of MF-60 was the highest among all frozen samples, and was 1.57% higher than the MF-80 sample (P < 0.05). The change in water holding capacity is related to the structural integrity of muscle fiber cells and the change of the protein molecular structure. During the freezing process, the formation of ice crystals leads to the separation of bound water and protein molecules, resulting in the aggregation of protein side chains and denaturation. In addition, the concentration of solute in cells accelerates protein denaturation and reduces the water holding capacity of the muscle. In this study, the rapid freezing rate of MF-60 promoted the formation of uniform ice crystals inside and outside the cells and inhibited protein denaturation caused by freezing. Hu (2022) also found that MF caused less change to the secondary structure of beef protein than conventional freezing. Lin et al. (2012) thought that the cryoprotective effect of static MF was because the magnetic field enhances the biophysical stability of cell membranes, thereby reducing dehydration damage during freezing.

Changes in water distribution of shrimp

LF NMR is a non-destructive method that is currently widely used to determine moisture distribution in foods (Sun et al., 2019). As shown in Fig. 5, four different water populations can be observed at 0–1 ms (T2b1), 1–10 ms (T2b2), 10–100 ms (T21), and 100–1000 ms (T22). T2b1 and T2b2 represent strongly bound water (binds very strongly to macromolecules) and weakly bound water (binds strongly to macromolecules), respectively. T21 represents the immobilised water present in the dense network of myofibrillar proteins, and T22 represents free water present in the space between fiber bundles, dependent on capillary forces (Sun, Sun, Xia, Xu, & Kong, 2019). The transverse relaxation times T2 (Fig. 5C–F) and peak area percent contents P2 (Fig. 5B) were obtained by processing the LF NMR curves. T2 represents the binding capacity of the sample to water molecules, and the shorter the value of T2, the stronger the binding capacity of the sample to water molecules, and vice versa. P2 represents the relative water content of the corresponding group, and the larger P2, the higher the relative water content of the reconstituted group, and vice versa.

Fig. 5.

Fig. 5

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LF NMR curve (A), relative content of water components P2 (%) (B), and transverse relaxation time T2 (ms) (C–F), MRI image of shrimp frozen by different treatments (G), changes in fresh shrimp and shrimp frozen by different treatments. IF: immersion freezing; MF: magnetic field-assisted freezing at different intensities. Different lowercase letters indicate significant differences (P < 0.05).

As can be seen in Fig. 5C–D, no significant differences were observed in the transverse relaxation time T2b1 and T2b2 among all the samples (P > 0.05). Correspondingly, there were no significant differences in P2b1 and P2b2 among all groups (P > 0.05). This may be because immobilised water is tightly bound to macromolecules, and common cold and heat processing or mechanical treatments did not significantly change the state of bound water (Mcdonnell et al., 2013). The transverse relaxation time of immobilised water (T21), the most abundant water in shrimp, was slightly affected by freezing treatments. As illustrated in Fig. 5E, freezing resulted in varying degrees of increase in T21 of the samples compared to the control, indicating that freezing weakened the binding of immobilised water to other components and increased the mobility of immobilised water. This may be due to the denaturation of myofibrillar proteins by freezing, which alters hydration (Li, Qin, Zhang, Li, Prinyawiwatkul, & Luo, 2018). The increased water mobility may also be related to the deterioration of the tight and continuous myofibril network during the freezing process, resulting in the dissociation of partial hydrogen and ionic bonds of myofibril protein, and the exposure of hydrophobic groups caused by mechanically damaged protein molecules (Liang, Qu, Liu, Zhu, & Wang, 2020). Among all the frozen samples, the T21 value of MF-60 was the shortest, which was not significantly different from that of the control group (P > 0.05). This may be because MF-60 inhibited the production of large ice crystals, reduced the damage of ice crystals to the structure of the muscle fiber network, inhibited the unfolding and denaturation of protein molecules, reduced the exposure of hydrophobic groups, and thus inhibited the increased mobility of immobilised water. Correspondingly, the immobilised water content (P21) of MF-60 was significantly higher than that of the other freezing treatment groups (P < 0.05), indicating that MF-60 effectively inhibited the conversion of immobilised water to free water in frozen shrimp samples. These results indicated that the application of an appropriate magnetic field intensity could delay the increase of water mobility of the shrimp samples, which may be because magnetic fields can induce the formation of small ice crystals (Fig. 5G). The change trends of T22 in all the samples were similar to those of T21. Freezing led to the increase of T22, and the T22 of the appropriate magnetic field intensity-assisted frozen sample increased minimally. Moreover, too large or too small magnetic field intensity could not effectively restrain the increase of T22, which was proposed that there was a window effect for the magnetic field action. As illustrated in Fig. 5B, comparing with the fresh sample, the P22 of the frozen samples increased in different degrees, with MF-60 being the smallest. The increase in free water could be attributed to the conformational changes of the myofibrillar protein and the rupture of muscle bundles in which water is confined. Jia, Orlien, Liu, and Sun (2020) suggested that the water population described by the T22 component was related to the water holding capacity and that this extramuscular fibrous water contributed to potential drip loss. Consistently, the change in free water content in this study corresponded with the water holding capacity results.

MRI, as a rapid and noninvasive imaging technique, can non-destructively detect the internal distribution of water in food matrices. Pseudocolour images after T2-weighted images of different samples are presented in Fig. 5G. In the pseudocolour image, red indicates high H-proton density, while blue indicates low H-proton density, and the brighter the colour in the image (pseudocolour map colour approaches red), the stronger the water proton signal representing this region, and the higher the water content.

As can be seen in the image, the colour of the fresh sample was the reddest and brightest, indicating that the fresh sample had the strongest water holding capacity. It was observed that the size of the brighter region decreased after freezing, which indicated that a longer water relaxation signal was lost during freezing. Among all frozen samples, the image of the IF samples was the bluest and the lowest, indicating that IF reduced the water retention of shrimp compared with other freezing treatments. With the increase of magnetic field intensity, the brightness inside the pseudocolour image gradually increased first and then decreased, and the brightness of the MF-60 was the highest, indicating that there were more muscle water molecules in the shrimp muscle, and the water storage capacity was enhanced. These results may be related to changes in muscle tissue structure and protein-water interaction (Zhang, Cheng, Wang, Yi, & Li, 2021). Cheng, Wang, Yang, Lin, Wang, and Tan (2020) also found that the denaturation of muscle proteins caused by the freezing process leads to the conversion of some immobilised water into free water. Then, the free water gradually emerges to the surface, resulting in dripping loss and reducing the brightness of the pseudocolour image of the sampler. The MRI results in this experiment correspond to those of LF NMR.

Changes in texture properties of shrimp

The textural properties of foods play a crucial role in the quality of food and determine consumer acceptance of the product (Liang, Qu, Liu, Wang, & Jia, 2020). The changes in hardness, springiness, and gumminess of the different samples are shown in Fig. 2F. Hardness is mainly related to muscle tissue integrity and protein structure stability. As can be seen from Fig. 2F, freezing leads to a decrease in hardness, which may be due to the aggregation and water loss caused by partial degeneration of myofibrils caused by ice crystal formation and growth during freezing. Yuan, Hua, Tang, Zhang, and Sun (2016) thought that myofibril content and connective tissue strength in muscle are the main components leading to the change of muscle texture properties. Concurrently, these changes may be related to the loss of muscle fiber to muscle fiber and/or muscle fiber to muscle septum attachment. Therefore, muscle protein denaturation may be an important reason for the muscle texture change (Romotowska, Gudjonsdottir, Karlsdottir, Kristinsson, Arason, Jonsson, et al., 2016). As shown in Fig. 2F, the hardness of shrimp samples increased first and then decreased with the increase of magnetic field intensity. Among all the frozen groups, the IF and MF-20 groups had the smallest hardness (P < 0.05), and MF-60 had the biggest hardness (P < 0.05), which was closest to the fresh sample. Leng, Zhang, Tian, Xu and Li (2022) also obtained results in a study of static magnetic field-assisted freezing of fish, in which an appropriate intensity of magnetic field was found to be beneficial in maintaining the texture of the fish.

Similar to the change in hardness, freezing caused varying degrees of decrease in the springiness and gumminess of the frozen samples compared to the control, with those of MF-60 being the highest among all the frozen samples (P < 0.05). This may be because the ice crystals formed by freezing caused water loss and redistribution in the sample, leading to a decrease in the springiness and gumminess properties. Berizi, Hosseinzadeh, Shekarforoush, and Barbieri (2017) also stated that the change in textural properties is inseparable from the loss of dripping water and the change in water holding capacity.

Changes in the colour of shrimp

As illustrated in Table 1, freezing led to an increase in the brightness value L* of shrimp muscle. The L* value of MF was lower than that of IF, and the L* value of MF-60 was the lowest, which was 37.68% higher than that of fresh samples (P < 0.05). The rise and fall of L* value correlated to high and low thawing loss levels, respectively. The higher the thawing loss, the higher the moisture density on the sample's surface, generating a water layer that enhances light refraction and raises the L* value (Li et al., 2020, Li et al., 2022). The increase in L* value is more deeply entrenched in the fact that the ice crystals formed by freezing damage the structure of the muscle tissue, limiting part of the free water that flows out after thawing from being absorbed (Sun et al., 2019). Furthermore, the L* value of the MF-80 samples was higher than the MF-60 and close to the MF-40, corresponding to a larger thawing loss. This also demonstrates that the L* value does not diminish with increasing magnetic field intensity and that it has the optimum magnetic field intensity for quick freezing. Concurrently, the structural changes in muscle during freezing, such as the disruption of protein conformation, can increase light scattering and thus the L* value of muscle. In the present study, an appropriate magnetic field intensity controlled the formation of crystal nuclei, reduced the size of ice crystals formed, inhibited freezing denaturation of proteins, and reduced the increase of the L* value caused by freezing. The microstructure (Fig. 4) and thawing loss (Fig. 3D) reveal that smaller ice crystals of the MF-60 samples generated less muscle damage and reduced thawing loss, which resulted in lower L* value than the other frozen samples. Lin, Chang, Lin, Hsieh, and Huang (2015) thought that the cryoprotective effect of magnetic fields may be due to the improved biophysical stability of cell membranes during cooling. However, there was no significant difference in the redness a* and yellowness b* values of shrimp meat among all treatment groups (P > 0.05), indicating that the different freezing treatments did not significantly destroy the pigment-protein of shrimp muscle. Similar results were also found by Hu (2022), who investigated the effects of infrared dehydration and MF on frozen beef. This may be because the short freezing time did not lead to significant oxidation of the pigmented proteins, so the a* and b* values of the samples from each group were not significantly different.

Table 1.

Colour of fresh shrimp and shrimp frozen by different treatments.

Treatment L* a* b*
Fresh 28.73 ± 0.59e 0.17 ± 0.06a 3.67 ± 0.11a
IF 36.37 ± 0.15a 0.10 ± 0.10a 3.70 ± 0.17a
MF-20 36.27 ± 0.29ab 0.13 ± 0.15a 3.67 ± 0.05a
MF-40 35.64 ± 0.06bc 0.10 ± 0.17a 3.73 ± 0.30a
MF-60 34.57 ± 0.35d 0.17 ± 0.06a 3.70 ± 0.26a
MF-80 35.40 ± 0.17c 0.17 ± 0.15a 3.90 ± 0.17a
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IF: immersion freezing; MF: magnetic field-assisted freezing at different intensities. Different lowercase letters in the same column indicate significant differences (P < 0.05).

Fig. 3.

Fig. 3

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Visual appearance (A), Freezing curve (B), freezing time (s) (C), thawing loss (%) (D), cooking loss (%) (E), water holding capacity (%) (F), and texture properties (G) of shrimp samples frozen by different treatments. IF: immersion freezing; MF: magnetic field-assisted freezing at different intensities. Different lowercase letters in the same indicator indicate significant differences (P < 0.05).

Visual appearance

The purpose of MF treatment on white shrimp samples is to improve the muscle quality, however, for consumers, visual appearance is the most important consideration when making a purchasing decision. Melanosis, which is let on by polyphenol oxidase (PPO), drastically reduces the product's visual qualities, which leads to low consumer acceptability (Li, 2022). As shown in Fig. 3A, the first row shows the visual appearance of white shrimp samples after freezing, and the second row shows the visual appearance of them after thawing for 12 h. After freezing, there was essentially no change between the various white shrimp samples, and when compared to fresh samples, the thawed samples were nearly virtually identical. PPO is present mostly in the head and thorax of shrimp, however, the white shrimp samples in this experiment had been de-headed, which dramatically decreased the occurrence of melanosis (Sae-Leaw & Benjakul, 2019). This significantly decreased the likelihood of melanosis in the shrimp. The least PPO was found in the white shrimp muscle, and as the samples were frozen and thawed in less than a day, so there was no difference between the thawed and fresh samples (Sae-Leaw & Benjakul, 2019).

Conclusions

In this study, a dedicated experimental system for MF of white shrimp samples was set up by combining static magnetic fields with immersion freezing, and the potential of MF to improve muscle quality of frozen white shrimp samples was explored by comparing IF and different static magnetic field intensities assist freezing. The results revealed that MF could accelerate the process of freezing, with MF-60 being the most efficient. Compared to any other freezing treatment, MF-60 reduced the thawing loss, and cooking loss, and helped to maintain the colour, water holding capacity, and texture properties of frozen shrimp. In addition, MF-60 could significantly inhibit the mobility and loss of immobilised water and free water. MF-60 produced the smallest and most uniformly sized ice crystals, which is demonstrated by the characteristic microstructure of fine and distributed pores in the MF-60 sample. Therefore, the appropriate MF intensity of 60 mT was beneficial in reducing the size of ice crystals and protecting the quality of frozen shrimps. In summary, MF is a novel freezing technique to improve the quality of frozen white shrimps, and the subsequent should revolve around the effect of MF on the properties of water molecules and protein structure, to elucidate the mechanism of magnetic field assisted freezing. Also, to further apply MF technology to quality control of frozen shrimps, more efficient and energy-saving equipment needs to be developed.

CRediT authorship contribution statement

Qinxiu Sun: Data curation, Writing – original draft, Visualization. Honghong Zhang: Data curation, Writing – original draft, Visualization. Xianqing Yang: Conceptualization, Methodology, Writing – review & editing. Qian Hou: Investigation, Validation. Yan Zhang: Investigation, Validation. Jiangpeng Su: Investigation, Validation. Xianhua Liu: Investigation, Validation. Qihang Wei: Investigation, Validation. Xiuping Dong: Supervision. Hongwu Ji: Supervision. Shucheng Liu: Conceptualization, Methodology, Writing – review & editing.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This study was supported by the Ocean Young Innovative Talents Project of Zhanjiang [grant number 2021E05015]; Young Innovative Talents Project of Guangdong General Universities [grant number 2020KQNCX028]; Fund of Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, China [grant number NYJG202102]; Doctoral Research Initiation Project of Guangdong Ocean University [grant number R20047]; Modern Agro-industry Technology Research System of China [grant number CARS-48]; and Guangdong Innovation Team of Seafood Green Processing Technology [grant number 2019KCXTD011].

Contributor Information

Qinxiu Sun, Email: sunqinxiugo@163.com.

Honghong Zhang, Email: zhh13612349597@163.com.

Xianqing Yang, Email: yxqgd@163.com.

Shucheng Liu, Email: lsc771017@163.com.

Data availability

No data was used for the research described in the article.

References

  1. Abie S.M., Münch D., Egelandsdal B., Bjerke F., Wergeland I., Martinsen Ø.G. Combined 0.2 T static magnetic field and 20 kHz, 2 V/cm square wave electric field do not affect supercooling and freezing time of saline solution and meat samples. Journal of Food Engineering. 2021;311 doi: 10.1016/j.jfoodeng.2021.110710. [DOI] [Google Scholar]
  2. Baniasadi F., Hajiaghalou S., Shahverdi A., Pirhajati V., Fathi R. Static magnetic field halves cryoinjuries of vitrified mouse COCs, improves their functions and modulates pluripotency of derived blastocysts. Theriogenology. 2021;163:31–42. doi: 10.1016/j.theriogenology.2020.12.025. [DOI] [PubMed] [Google Scholar]
  3. Berizi E., Hosseinzadeh S., Shekarforoush S.S., Barbieri G. Microbial, chemical, textural and sensory properties of coated rainbow trout by chitosan combined with pomegranate peel extract during frozen storage. International Journal of Biological Macromolecules. 2017;106:1004–1013. doi: 10.1016/j.ijbiomac.2017.08.099. [DOI] [PubMed] [Google Scholar]
  4. Cheng S., Wang X., Yang H., Lin R., Wang H., Tan M. Characterization of moisture migration of beef during refrigeration storage by low-field NMR and its relationship to beef quality. Journal of the Science of Food and Agriculture. 2020;100:1940–1948. doi: 10.1002/jsfa.10206. [DOI] [PubMed] [Google Scholar]
  5. Cheng H., Song S., Jung E.Y., Jeong J.Y., Joo S.T., Kim G.D. Comparison of beef quality influenced by freeze-thawing among different beef cuts having different muscle fiber characteristics. Meat Science. 2020;169 doi: 10.1016/j.meatsci.2020.108206. [DOI] [PubMed] [Google Scholar]
  6. Dalvi-Isfahan M., Hamdami N., Xanthakis E., Le-Bail A. Review on the control of ice nucleation by ultrasound waves, electric and magnetic fields. Journal of Food Engineering. 2017;195:222–234. doi: 10.1016/j.jfoodeng.2016.10.001. [DOI] [Google Scholar]
  7. Dang H.T.T., Gudjónsdóttir M., Tómasson T., Nguyen M.V., Karlsdóttir M.G., Arason S. Influence of processing additives, packaging and storage conditions on the physicochemical stability of frozen Tra catfish (Pangasius hypophthalmus) fillets. Journal of Food Engineering. 2018;238:148–155. doi: 10.1016/j.jfoodeng.2018.06.021. [DOI] [Google Scholar]
  8. FAO . FAO; Rome: 2022. The state of world fisheries and aquaculture 2022 – sustainability in action; p. 44.http://www.fao.org/3/ca9229en/ca9229en.pdf [Google Scholar]
  9. Hu R. A Novel Synergistic Freezing Assisted by Infrared Pre-dehydration Combined with Magnetic Field: Effect on Freezing Efficiency and Thawed Product Qualities of Beef. Food and Bioprocess Technology. 2022;14 doi: 10.1007/s11947-022-02825-0. [DOI] [Google Scholar]
  10. Huff-Lonergan E., Lonergan S.M. Mechanisms of water-holding capacity of meat: The role of postmortem biochemical and structural changes. Meat Science. 2005;71(1):194–204. doi: 10.1016/j.meatsci.2005.04.022. [DOI] [PubMed] [Google Scholar]
  11. Jia G., Orlien V., Liu H., Sun A. Effect of high pressure processing of pork (longissimus dorsi) on changes of protein structure and water loss during frozen storage. LWT-Food Science and Technology. 2020;135(3) doi: 10.1016/j.lwt.2020.110084. [DOI] [Google Scholar]
  12. Jin S., Sun S., Jiang X., Zhao Y., Wang Y., Deng Y. Effect of static magnetic field on the freezing process of deionized water and 0.9% NaCl solution. Journal of Food Processing and Preservation. 2020;44(9):e14663. [Google Scholar]
  13. Kiani H., Sun D.W. Water crystallization and its importance to freezing of foods: A review. Trends in Food Science and Technology. 2011;22(8) doi: 10.1016/j.tifs.2011.04.011. 407–426 (20) [DOI] [Google Scholar]
  14. Kureshy N., Davis D.A. Protein requirement for maintenance and maximum weight gain for the Pacific white shrimp, Litopenaeus vannamei. Aquaculture. 2002;204(1–2):125–143. doi: 10.1016/S0044-8486(01)00649-4. [DOI] [Google Scholar]
  15. Leng D., Zhang H., Tian C., Xu H., Li P. The effect of magnetic field on the quality of channel catfish under two different freezing temperatures. International Journal of Refrigeration. 2022 doi: 10.1016/j.ijrefrig.2022.05.008. S014070072200161X. [DOI] [Google Scholar]
  16. Leygonie C., Britz T.J., Hoffman L.C. Impact of freezing and thawing on the quality of meat: Review. Meat Science. 2012;91(2):93–98. doi: 10.1016/j.meatsci.2012.01.013. [DOI] [PubMed] [Google Scholar]
  17. Li D., Qin N., Zhang L., Li Q., Prinyawiwatkul W., Luo Y. Degradation of adenosine triphosphate, water loss and textural changes in frozen common carp (Cyprinus carpio) fillets during storage at different temperatures. International Journal of Refrigeration. 2018;98:294–301. doi: 10.1016/j.ijrefrig.2018.11.014. [DOI] [Google Scholar]
  18. Li D., Zhao H., Muhammad A.I., Song L., Guo M., Liu D. The comparison of ultrasound-assisted thawing, air thawing and water immersion thawing on the quality of slow/fast freezing bighead carp (Aristichthys nobilis) fillets. Food Chemistry. 2020;320 doi: 10.1016/j.foodchem.2020.126614. [DOI] [PubMed] [Google Scholar]
  19. Li T., Kuang S., Xiao T., Hu L., Nie P., Ramaswamy H.S., Yu Y. The effect of pressure-shift freezing versus air freezing and liquid immersion on the quality of frozen fish during storage. Foods. 2022;11(13):1842. doi: 10.3390/foods11131842. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Li Y. Efficacy of freeze-chilled storage combined with tea polyphenol for controlling melanosis, quality deterioration, and spoilage bacterial growth of Pacific white shrimp (Litopenaeus vannamei) Food Chemistry. 2022;370 doi: 10.1016/j.foodchem.2021.130924. [DOI] [PubMed] [Google Scholar]
  21. Liang Y., Qu Z., Liu M., Wang J., Jia F. Effect of curdlan on the quality of frozen-cooked noodles during frozen storage. Journal of Cereal Science. 2020;95 doi: 10.1016/j.jcs.2020.103019. [DOI] [Google Scholar]
  22. Liang Y., Qu Z., Liu M., Zhu M., Wang J. Further interpretation of the strengthening effect of curdlan on frozen cooked noodles quality during frozen storage: Studies on water state and properties. Food Chemistry. 2020;346(2) doi: 10.1016/j.foodchem.2020.128908. [DOI] [PubMed] [Google Scholar]
  23. Lin C., Chang W., Lee S., Feng S., Lin C. Influence of a static magnetic field on the slow freezing of human erythrocytes. International Journal of Radiation Biology. 2012;89(1):51–56. doi: 10.3109/09553002.2012.717731. [DOI] [PubMed] [Google Scholar]
  24. Lin S.L., Chang W.J., Lin C.Y., Hsieh S.C., Huang H.M. Static magnetic field increases survival rate of dental pulp stem cells during DMSO-free cryopreservation. Journal of Bioelectricity. 2015;34(4):302–308. doi: 10.3109/15368378.2014.919588. [DOI] [PubMed] [Google Scholar]
  25. Lin C.Y., Chang W.J., Lee S.Y., Feng S.W., Lin C.T., Fan K.S., Huang H.M. Influence of a static magnetic field on the slow freezing of human erythrocytes. International Journal of Radiation Biology. 2013;89(1):51–56. doi: 10.3109/09553002.2012.717731. [DOI] [PubMed] [Google Scholar]
  26. Liu B., Song J., Yao Z., Bennacer R. Effects of magnetic field on the phase change cells and the formation of ice crystals in biomaterials: Carrot case. Journal of Thermal Science & Engineering Applications. 2018;9(3) doi: 10.1115/1.4035936. [DOI] [Google Scholar]
  27. Lorentzen G., Hustad A., Lian F., Grip A.E., Schrødter E., Medeiros T., Siikavuopio S.I. Effect of freezing methods, frozen storage time, and thawing methods on the quality of mildly cooked snow crab (Chionoecetes opilio) clusters. LWT-Food Science and Technology. 2020;123 doi: 10.1016/j.lwt.2020.109103. [DOI] [Google Scholar]
  28. Lu N., Ma J., Sun D.W. Enhancing physical and chemical quality attributes of frozen meat and meat products: Mechanisms, techniques and applications. Trends in Food Science and Technology. 2022;124:63–85. doi: 10.1016/j.tifs.2022.04.004. [DOI] [Google Scholar]
  29. Mcdonnell C.K., Allen P., Duggan E., Arimi J.M., Casey E., Duane G., Lyng J.G. The effect of salt and fibre direction on water dynamics, distribution and mobility in pork muscle: A low field NMR study. Meat Science. 2013;95(1):51–58. doi: 10.1016/j.meatsci.2013.04.012. [DOI] [PubMed] [Google Scholar]
  30. Miñano H.L.A., de S. Silva A.C., Souto S., Costa E.J.X. Magnetic fields in food processing perspectives, applications and action models. Processes. 2020;8(7):814. doi: 10.3390/pr8070814. [DOI] [Google Scholar]
  31. Otero L., Pozo A. Effects of the application of static magnetic fields during potato freezing. Journal of Food Engineering. 2022;316 doi: 10.1016/j.jfoodeng.2021.110838. [DOI] [Google Scholar]
  32. Otero L., Rodriguez A.C., Perez-Mateos M., Sanz P.D. Effects of magnetic fields on freezing: application to biological products. Comprehensive Reviews Food Science Food Safety. 2016;15(3):646–667. doi: 10.1111/1541-4337.12202. [DOI] [PubMed] [Google Scholar]
  33. Owada N, Kurita S, inventors. 2001. Super-quick freezing method and apparatus therefor. US Patent 6250087 B1.
  34. Pan Y., Sun Q., Liu Y., Wei S., Xia Q., Zheng O., Liu S., Ji H., Deng C., Hao J. The relationship between rheological and textural properties of shrimp surimi adding starch and 3D printability based on principal component analysis. Food Science & Nutrition. 2021;9:2985–2999. doi: 10.1002/fsn3.2257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Qin Y., Dong B., Li W. Experimental study of the frosting characteristic of water on a cold surface in the magnetic field. Experimental Thermal and Fluid Science. 2020;114(4) doi: 10.1016/j.expthermflusci.2020.110044. [DOI] [Google Scholar]
  36. Romotowska P.E., Gudjonsdottir M., Karlsdottir T.B., Kristinsson M.G., Arason S., Jonsson A., Kristinsson H.G. Effect of brining and frozen storage on physicochemical properties of well-fed Atlantic mackerel (Scomber scombrus) intended for hot smoking and canning. LWT-Food Science and Technology. 2016;72:109–205. doi: 10.1016/j.lwt.2016.04.055. [DOI] [Google Scholar]
  37. Sae-Leaw T., Benjakul S. Distribution and characteristics of polyphenoloxidase from pacific white shrimp (Litopenaeus vannamei) Journal of Food Science. 2019;84(5):1078–1086. doi: 10.1111/1750-3841.14593. [DOI] [PubMed] [Google Scholar]
  38. Sun Q., Sun F., Xia X., Xu H., Kong B. The comparison of ultrasound-assisted immersion freezing, air freezing and immersion freezing on the muscle quality and physicochemical properties of common carp (Cyprinus carpio) during freezing storage. Ultrasonics Sonochemistry. 2019;51:281–291. doi: 10.1016/j.ultsonch.2018.10.006. [DOI] [PubMed] [Google Scholar]
  39. Sun Q., Zhao X., Zhang C., Xia X., Sun F., Kong B. Ultrasound-assisted immersion freezing accelerates the freezing process and improves the quality of common carp (Cyprinus carpio) at different power levels. LWT-Food Science and Technology. 2019;108:106–112. doi: 10.1016/j.lwt.2019.03.042. [DOI] [Google Scholar]
  40. Sutariya S.G., Sunkesula V. Food freezing: emerging techniques for improving quality and process efficiency a comprehensive review. Innovative Food Processing Technologies. 2021:36–63. doi: 10.1016/B978-0-08-100596-5.23035-7. [DOI] [Google Scholar]
  41. Solo-de-Zaldívar B., Herranz B., Borderías A.J., Tovar C.A. Effect of freezing and frozen storage on restructured fish prototypes made with glucomannan and fish mince. Food Hydrocolloids. 2014;41:233–240. doi: 10.1016/j.foodhyd.2014.04.019. [DOI] [Google Scholar]
  42. Tang J., Shao S., Tian C. Effects of the magnetic field on the freezing parameters of the pork. International Journal of Refrigeration. 2019;107:31–38. doi: 10.1016/j.ijrefrig.2019.07.019. [DOI] [Google Scholar]
  43. Tang J., Zhang H., Tian C., Shao S. Effects of different magnetic fields on the freezing parameters of cherry. Journal of Food Engineering. 2020;278 doi: 10.1016/j.jfoodeng.2020.109949. [DOI] [Google Scholar]
  44. Wang Z., Hao F., Ding C., Yang Z., Shang P. Effects of static magnetic field on cell biomechanical property and membrane ultrastructure: Cell mechanical property in SMF. Bioelectromagnetics. 2014;35(4):251–261. doi: 10.1002/bem.21847. [DOI] [PubMed] [Google Scholar]
  45. Watanabe M., Kanesaka N., Masuda K., Suzuki T. Proceedings of the 23rd IIR International Congress of Refrigeration: refrigeration for sustainable development. 2011 August 21-26. Prague, Czech Republic. 2011. Effect of oscillating magnetic field on supercooling in food freezing. [Google Scholar]
  46. Yang Z., Liu S., Sun Q., Zheng O., Wei S., Xia Q.…Xu J. Insight into muscle quality of golden pompano (Trachinotus ovatus) frozen with liquid nitrogen at different temperatures. Food Chemistry. 2022;374 doi: 10.1016/j.foodchem.2021.131737. [DOI] [PubMed] [Google Scholar]
  47. Yuan G., Hua L., Tang W., Zhang X., Sun H. Effect of chitosan coating combined with pomegranate peel extract on the quality of Pacific white shrimp during iced storage. Food Control. 2016;59(1):818–823. doi: 10.1016/j.foodcont.2015.07.011. [DOI] [Google Scholar]
  48. Zhang B., Cao H.J., Lin H.M., Deng S.G., Wu H. Insights into ice-growth inhibition by trehalose and alginate oligosaccharides in peeled Pacific white shrimp (Litopenaeus vannamei) during frozen storage. Food Chemistry. 2019;278:482–490. doi: 10.1016/j.foodchem.2018.11.087. [DOI] [PubMed] [Google Scholar]
  49. Zhang L., Li Z., Zhang X. Effects of static magnetic fields on eukaryotic cytoskeleton. Chinese Science Bulletin. 2019;64(8):748–760. doi: 10.1360/N972018-00648. [DOI] [Google Scholar]
  50. Zhang W., Cheng S., Wang S., Yi K., Li D. Effect of pre-frying on distribution of protons and physicochemical qualities of mackerel. Journal of the Science of Food and Agriculture. 2021;101(11):4838–4846. doi: 10.1002/jsfa.11130. [DOI] [PubMed] [Google Scholar]
  51. Zhou K.X., Lu G.W., Zhou Q.C., Song J.H., Jiang S.T., Xia H.R. Monte Carlo simulation of liquid water in a magnetic field. Journal of Applied Physics. 2000;88(4):1802–1805. doi: 10.1063/1.1305324. [DOI] [Google Scholar]

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Data Availability Statement

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