Ice Crystal Size Research Articles

Synergism effect of low voltage electrostatic field and antifreeze agents on enhancing the qualities of frozen beef steak: Perspectives on water migration and protein aggregation

In this study, a synergistic strategy utilizing low-voltage electrostatic field (LVEF) and antifreeze agents (4% sucrose +4% sorbitol) was proposed to reduce quality deterioration of prepared beef steak during freezing. The effects of the synergistic treatment on the water holding capacity, texture and muscle ultrastructure, myofibrillar protein (MP) aggregation was studied. Results showed that co-treatment significantly reduced thawing losses (about 41%) by preventing the migration of immobilized water to free water and reduced ice crystal size compared to air freezing (AF). In addition, co-treatment positively affected texture properties by shortening the gap between muscle fibers and maintaining the structural integrity of the sarcomeres. Moreover, synergistic treatment inhibited the unfolding of the MP structure and the formation of MP aggregates by strengthening non-covalent interactions. These results seem to demonstrate that LVEF can remarkably enhance the effects of cryoprotectants, which provides a new perspective on food cryoprotection. Industrial relevanceFreezing is the most common method of preserving prepared meat products, however, the formation of large ice crystals and the denaturation of muscle proteins are two major causes of quality deterioration during conventional air-freezing. In this study, a LVEF system was applied to the freezing process of prepared meat products, and a comparative and synergistic study was carried out with the current industry common chemical freezing protection methods (addition of antifreeze). The results showed that the synergistic treatment greatly promoted the nucleation of food products, shortened the phase transition time, reduced the ice crystal size and effectively reduced the thawing losses by approximately 41%. The green freezing system can be easily adapted to scenarios such as cold chain transport and cold storage. And the LVEF intensifies the interaction of antifreeze molecules with protein and water molecules, which seems to open up even more possibilities in cryopreservation.

Effects of frequencies ranging from 100 to 400 Hz on electromagnetic field assisted freezing of grass carp (Ctenopharyngodon idellus)

This study aimed to understand the effects of electromagnetic field (EMF) frequencies on the freezing of grass carp tissue. Frequencies ranging from 100 to 400 Hz with a fixed strength of 12 mT were applied during freezing. Results showed that the initial freezing point was significantly increased (p < 0.05) for treatment between 200 and 400 Hz compared with control, but the phase change duration was not affected. Reductions in ice areas and crystal sizes were also observed. The highest initial freezing point of −1.44 °C was obtained at 300 Hz with a 45% reduction in crystal size (19.29 μm). There were also no subsequent changes in the drip, texture, colour and pH values. These results indicated that the oscillation among ions due to applying EMF favoured ice crystallization, and frequencies between 200 and 400 Hz were suitable for improving the freezing process assisted by the electromagnetic field.

Experimental Study of the Effect of Ultrasound on the Freezing Process of Bo Chinh Ginseng

The main purpose of this study was to select the appropriate ultrasound parameters that support the freezing process of Bo Chinh ginseng. This process involves placing Bo Chinh ginseng in an open-air environment and ensuring that the transducer does not come into contact with the material. The research results show that the ultrasound power, ultrasound irradiation temperature and intermittency ratio all affect the freezing time, nucleation temperature, color and microstructure of the materials. When the ultrasound continuously operated during the freezing process, at a frequency of 20 kHz, there was a 29.1% reduction in the freezing time at a power level of 100 W as compared to freezing without the help of ultrasound irradiation. The irradiation temperature and nucleation temperature have a linear relationship (y=−0.35x−0.93) which can help to control the nucleation temperature, thereby changing the ice crystal size. Ultrasound-assisted freezing at a 0.6 intermittency ratio had the shortest freezing time. The microstructure of the material changed after ultrasound-assisted freezing and many microchannels and holes were generated. When frozen at a wave rate of 0.4, the microchannels that were created in the material effectively supported the process of water drainage in the drying sublimation stage. At the same time, ultrasound irradiation did not affect the color of the post-freezing material when compared to the color of the frozen material that did not undergo ultrasound irradiation.

Experimental study on PVA reinforced salt-water ice under uniaxial-compression at arctic low temperatures

This paper proposed a new kind of reinforced salt-water ice with polyvinyl alcohol (PVA) powder and PVA fibre for cold-region constructions. A total of 53 ice stub columns were tested at −60 °C to evaluate the compression behaviour of PVA reinforced salt-water ice (PRSI). Key parameters in this testing program included the length of PVA fibre, the mass fraction of PVA fibre, the mass fraction of PVA powder, and the saponification of PVA powder. The failure modes and compressive stress-strain curves of ice columns at low temperatures were reported. Meanwhile, the influences of different parameters on ultimate compressive strength, ductility index, elastic modulus, peak strain, and workability were reported and discussed. These results indicated that the new reinforcing type improved the compressive strength of plain salt-water ice (PSI) from 10.1 to 29.6 MPa, and the ductility of PSI was also improved. Considering the mechanical properties and workability of PRSI, the optimized mix proportion was proposed. Reducing the size of ice crystals and eliminating the stress concentration at crack tip are the reasons to improve the compressive strength of PRSI. Adding PVA fibre mainly improved the ductility of PRSI rather than its compressive strength. Moreover, a four-phase microscopic model of PRSI at low temperature was proposed to explain the enhancement and failure mechanism of PRSI.

Backscattering Characteristics of Optical and Electromagnetic Waves in Joint Sensing of Cirrus Clouds by a Polarizing Lidar (0.355 µm) and a 94-GHz Radar

In this work, the problem of radiation scattering by ice crystals typical for cirrus clouds is solved for a 94-GHz radar (wavelength 3189 µm) and a lidar (wavelength 0.355 µm); the ice refractive indices are 1.7864 + 0.0032i and 1.3249 + 0i, respectively. The scattering matrices are calculated within the physical optics approximation and the discrete dipole approximation for the case of randomly oriented particles with sizes from 4 to 1000 µm. The ratio of the radar and lidar backscattering signals in the backward direction (the so-called radar–lidar ratio) is calculated for a wide range of the particle size for typical shapes of cirrus cloud ice crystals. It is shown that this ratio can be used for estimating the size of ice crystals in cirrus clouds.

Improved cryopreservation media formulation reduces costs of maintenance while preserving function of genetically modified insect cells.

Insect cell lines are an invaluable resource that facilitate various fundamental and applied research programs. Genetically engineered insect cell lines, in particular, serve as a platform through which the function of heterologously expressed proteins can be studied. However, a barrier to more widespread utilization and distribution of insect cell lines, genetically modified or not, is the technical and operational challenge associated with traditional cryopreservation methods, including their dependence on the use of liquid nitrogen facilities, animal or human serum products, and relatively high concentrations of permeating cryoprotectants (e.g., DMSO). Recent innovations in cryopreservation technologies have produced reagents with improved abilities to effectively preserve mammalian cell lines for long periods in regular laboratory deep freezers without using serum products, but their effectiveness in preserving genetically engineered insect cell lines has not yet been evaluated. In this study, we engineered Sf9 cells to express a dopamine receptor and used them as a model for evaluating the efficacy of a novel cryopreservation medium product, C80EZ®-INSECT, in not only preserving cell viability and proliferation efficiency but also maintaining the insect cell line's "functionality" after storage at -80°C. We found that the engineered Sf9 cells frozen using C80EZ®-INSECT with 5% DMSO alone and stored at -80°C for 6 mo displayed higher viability and growth rates than cells frozen using traditional fetal bovine serum (FBS)-based cryopreservation media with 10% DMSO that were stored at -80°C or in liquid nitrogen for the same period of time. We also found that after 6 mo of storage at -80°C or in liquid nitrogen the cells retained a responsiveness to dopamine comparable to that of the initial cell line, regardless of the cryopreservation reagent used. These results suggest that, due to the unique characteristics of C80EZ®-INSECT in preventing ice recrystallization and reducing ice crystal size and cellular apoptosis during cryostorage procedures, it is an effective cryopreservation reagent for genetically engineered Sf9 cells, and it practically eliminates the need for liquid nitrogen-based storage facilities and FBS-based cryopreservation formulations, as well as reduces the use of permeating cryoprotectants.

Molecular mobility and concentration of plant cells intracellular compartments, as derived from ice crystal size measured on cryo-SEM micrographs

Molecular mobility and concentration of plant cells intracellular compartments, as derived from ice crystal size measured on cryo-SEM micrographs

Dependence of Ice Crystal Size Distributions in High Ice Water Content Conditions on Environmental Conditions: Results from the HAIC-HIWC Cayenne Campaign

Abstract A new method that automatically determines the modality of an observed particle size distribution (PSD) and the representation of each mode as a gamma function was used to characterize data obtained during the High Altitude Ice Crystals and High Ice Water Content (HAIC-HIWC) project based out of Cayenne, French Guiana, in 2015. PSDs measured by a 2D stereo probe and a precipitation imaging probe for particles with maximum dimension (Dmax) &gt; 55 μm were used to show how the gamma parameters varied with environmental conditions, including temperature (T) and convective properties such as cloud type, mesoscale convective system (MCS) age, distance away from the nearest convective peak, and underlying surface characteristics. Four kinds of modality PSDs were observed: unimodal PSDs and three types of multimodal PSDs (Bimodal1 with breakpoints 100 ± 20 μm between modes, Bimodal2 with breakpoints 1000 ± 300 μm, and Trimodal PSDs with two breakpoints). The T and ice water content (IWC) are the most important factors influencing the modality of PSDs, with the frequency of multimodal PSDs increasing with increasing T and IWC. An ellipsoid of equally plausible solutions in (No–λ–μ) phase space is defined for each mode of the observed PSDs for different environmental conditions. The percentage overlap between ellipsoids was used to quantify the differences between overlapping ellipsoids for varying conditions. The volumes of the ellipsoid decrease with increasing IWC for most cases, and (No–λ–μ) vary with environmental conditions related to distribution of IWC. HIWC regions are dominated by small irregular ice crystals and columns. The parameters (No–λ–μ) in each mode exhibit mutual dependence.

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

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.

Investigating the influence of freezing rate and frozen storage conditions on a model sponge cake using synchrotron X-rays micro-computed tomography

Synchrotron X-rays micro-computed tomography was applied to visualize and quantify 3D ice crystal changes into a model sponge cake after freezing and subsequent frozen storage. Model sponge cake samples were submitted to two different freezing rates (fast: 17.2 °C min−1 and slow: 0.3 °C min−1), then stored at constant and fluctuating temperatures over a two weeks period. 3D images were acquired at frozen state thanks to a thermostated cell (CellStat) and processed using a grey level based segmentation method. Image analysis revealed that the ice volume fraction is conserved during storage but ice crystal size and location change whatever the freezing rate and the storage conditions. Maximum local thicknesses increase both inside (from 20 µm to 50 µm) and outside (from 47 µm to 70 µm) the matrix during the fourteen days storage period. Both specific surface areas between starch and ice (SSAice/starch) and between air and ice (SSAair/ice) also evolve with storage duration: SSAice/starch decreases up to − 30 % while SSAair/ice increases up to + 13 % depending on the freezing rates and the storage conditions. These results highlighted that, during storage, ice crystals evolve according to two different mechanisms depending on the freezing rate: fast freezing leads to a local redistribution of water both within the starch matrix and within the pores, while slow freezing results in both local redistribution within the starch matrix and water migration towards the pores. In addition, stable storage temperatures favor local water redistribution whereas water migration from the starch matrix towards the pores was greater in the case of fluctuating storage temperatures. This study shows that freezing and frozen storage conditions have a synergistic effect on the microstructure evolution of sponge cake due to recrystallization phenomena.

Nanoarchitectonics of RGO-Wrapped CNF/GO Aerogels with Controlled Pore Structures by PVA-Assisted Freeze-Casting Approach for Efficient Sound and Microwave Absorption.

Acoustic absorption materials play an important role in eliminating the negative effects of noise. Herein, a polyvinyl alcohol (PVA)-assisted freeze-casting was developed for controllably fabricating reduced graphene oxide wrapped carbon nanofiber (RGO@CNF)/graphene oxide composite aerogel. During the freeze-casting, PVA was used as an icing inhibitor to control the size of ice crystals. While the concentration of PVA increased from 0 to 15 mg ⋅ ml-1 , the average pore size of the aerogel was reduced from 154 to 45 μm. Due to the modulation of the pore size and composition, the propagation path and friction loss for sound were optimized, especially at low frequency. For instance, the normalized sound absorption coefficient of RGO@CNF/GO-10 achieves 0.79 (250-6300 Hz). The sample also exhibits a desirable microwave absorbing property whose maximum reflection loss is -47.3 dB (9.44 GHz, d=3.0 mm). Prospectively, this synthetic strategy can be extended to develop other forms of elastic aerogel with a controlled pore size.

Polysaccharide-Derived Ice Recrystallization Inhibitors with a Modular Design: The Case of Dextran-Based Graft Polymers.

Ice recrystallization inhibitors inspired from antifreeze proteins (AFPs) are receiving increasing interest for cryobiology and other extreme environment applications. Here, we present a modular strategy to develop polysaccharide-derived biomimetics, and detailed studies were performed in the case of dextran. Poly(vinyl alcohol) (PVA) which has been termed as one of the most potent biomimetics of AFPs was grafted onto dextran via thiol-ene click chemistry (Dex-g-PVA). This demonstrated that Dex-g-PVA is effective in IRI and its activity increases with the degree of polymerization (DP) (sizes of ice crystals were 18.846 ± 1.759 and 9.700 ± 1.920 μm with DPs of 30 and 80, respectively) and fraction of PVA. By means of the dynamic ice shaping (DIS) assay, Dex-g-PVA is found to engage on the ice crystal surfaces, thus the ice affinity accounts for their IRI activity. In addition, Dex- g-PVA displayed enhanced IRI activity compared to that of equivalent PVA alone. We speculate that the hydrophilic nature of dextran would derive PVA in a stretch conformation that favors ice binding. The modular design can not only offer polysaccharides IRI activity but also favor the ice-binding behavior of PVA.

Initial ice growth control mechanism for CMC-Na in model systems

In this study, CMC-Na solutions with different DS and concentrations were frozen at −20 °C and −40 °C. At the macroscopic level, the nucleation temperature and nucleation start time were analysed by freezing curves, and the morphology, size, and quantity of ice crystals after recrystallization were captured dynamically at the microlevel. The results show that CMC-Na can effectively accelerate the nucleation process, shorten the phase transition time, and evenly promote the formation of numerous distributed small ice crystals, and there is no significant difference in the effect of CMC-Na at different freezing temperatures. At the microlevel, a high concentration of CMC-Na can inhibit the recrystallization process more effectively, probably because it is readily attached to the surface of ice crystals, and the reduction in surface tension increases the free energy, which prevents the growth of ice crystals. When CMC-Na is added to the ice cream system, it can reduce the nucleation temperature, increase the degree of supercooling, and promote the internal generation of abundant ice crystals. At the same annealing rate, CMC-Na can effectively inhibit the occurrence of recrystallization, which is consistent with the conclusion of the solution system.

Static magnetic field assisted freezing of four kinds of fruits and vegetables: Micro and macro effects

Novel food freezing technology assisted by static magnetic field (SMF) has emerged in recent years. However, few papers have compared the effects of SMF on different kinds of foods under the same experimental conditions. This study investigated the effects of 0 to 45 mT SMF intensities on apple, peach, cucumber and Indian jujube from micro and macro scales. The parameters including ice crystal size, time through -1 ∼ -5 °C, drip loss and texture were compared. The results show that SMF tended to decrease the ice crystals size for four kinds of fruits and vegetables, and the optimal SMF intensity varied with the types of foods. The beneficial effect of SMF on reducing ice crystal size did not always appear in macro-scale freezing. Positive effects of SMF on macro-scale parameters only appeared in Indian jujube, and stronger intensity brought better quality.

Impacts of the ice-particle size distribution shape parameter on climate simulations with the Community Atmosphere Model Version 6 (CAM6)

Abstract. The impacts of the ice-crystal size distribution shape parameter (μi) were considered in the two-moment bulk cloud microphysics scheme of the Community Atmosphere Model Version 6 (CAM6). The μi's impact on the statistical mean radii of ice crystals can be analyzed based on their calculating formulas. Under the same mass (qi) and number (Ni), the ratios of the mass-weighted radius (Rqi, not related to μi) to other statistical mean radii (e.g., effective radiative radius) are completely determined by μi. Offline tests show that μi has a significant impact on the cloud microphysical processes owing to the μi-induced changes in ice-crystal size distribution and statistical mean radii (excluding Rqi). Climate simulations show that increasing μi would lead to higher qi and lower Ni in most regions, and these impacts can be explained by the changes in cloud microphysical processes. After increasing μi from 0 to 5, the longwave cloud radiative effect increases (stronger warming effect) by 5.58 W m−2 (25.11 %), and the convective precipitation rate decreases by −0.12 mm d−1 (7.64 %). In short, the impacts of μi on climate simulations are significant, and the main influence mechanisms are also clear. This suggests that the μi-related processes deserve to be parameterized in a more realistic manner.

Effects of ultrasound–assisted freezing on the quality of large yellow croaker (Pseudosciaena crocea) subjected to multiple freeze–thaw cycles

Repeated freezing and thawing due to temperature fluctuations irreversibly damage the muscle tissue cells of fish, thereby reducing their economic quality. In this study, the effects of ultrasound-assisted immersed freezing (UIF) technology on the changes in the quality of large yellow croaker (Pseudosciaena crocea) subjected to 0 to 5 freeze–thaw cycles were investigated. The results showed that the quality deterioration inevitably occurred after repeated freeze–thaw cycles. However, UIF significantly delayed the changes in the water holding capacity (WHC), immobilized water content, color and texture properties of fish. Compared to the control group (air freezing, AF), the thawing loss in the UIF group was reduced by 1.09 % to 4.54 % (P < 0.05), the centrifuging loss was reduced by 0.39 % to 1.86 % (P < 0.05), the migration of immobilized water content was reduced by 4 % to 5 % (P < 0.05). Moreover, SEM and LM images illustrated that the microstructures of muscle tissue in UIF group were more uniform and denser than that of the AF group after freeze–thaw cycles, and that the ice crystal size from UIF group were smaller and more regular than that of AF group. Furthermore, UIF did not caused more excessive protein oxidation of myofibrillary protein, but significantly delayed the lipid oxidation of fish muscle. The results indicated that UIF technology effectively inhibits the deterioration of fish quality affected by multiple freeze–thaw cycles, thus providing a reference for controlling the deterioration of aquatic products due to temperature fluctuations in the industry.

Depolarization Ratio for Randomly Oriented Ice Crystals of Cirrus Clouds

The depolarization ratio and backscattering cross sections have been calculated for shapes and size of ice crystals that are typical in cirrus clouds. The calculations are performed in the physical-optics approximation. It is shown that the depolarization ratio approaches some constant when the size of the crystals becomes much larger than the incident wavelength. For the transparent ice crystals, when absorption is absent, the magnitude of this constant strongly depends on crystal shapes. This fact allows inferring the crystal shape from magnitudes of the depolarization ratio in lidar signals. For the lidar wavelengths, where absorption of light is considerable, the depolarization ratio of lidar signals can be used for inferring crystal sizes. Such results are important for the development of algorithms interpreting the signals obtained by both ground-based and space-borne lidars.

Assessment of oligofructose and glycerol supplementation on glass transition temperature and quality of frozen yogurt

Frozen yogurt is one of the most common types of dairy functional food. It has the characteristics of both yogurt and ice cream. The present study was planned to see the effects of oligofructose and glycerol supplementation on glass transition temperature and other structural properties of probiotic frozen yogurt. Frozen yogurt was prepared with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis) and yogurt starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus). Furthermore, in frozen yogurt mixture oligofructose (2%, 4%, and 6%), and glycerol (1%, 2%, 3%, and 4%) were supplemented. The results have shown that oligofructose supplementations have increased the total solids, overrun, and stickiness, while decreased the hardness significantly (p < .05). Oligofructose also has shown a non-significant effect on melting rate, air cell size, ice crystal size (p > .05). However, the glycerol supplementations have increased the melting rate while decreased the glass transition temperature significantly (p < .05). The oligofructose and glycerol can be used to improve the textural properties of frozen yogurt. Novelty impact statement The probiotic frozen yogurt with different ingredients and combinations of prebiotics (fructooligosaccharides, oligofructose, inulin, etc.) were prepared and its quality was analyzed in various previous studies but the combined effect of prebiotic with cryoprotectant (glycerol) was not investigated so far. So, in the current study, the oligofructose and glycerol's effect on frozen yogurt texture, melting rate, air cell size, ice crystal size, and on glass transition temperature were evaluated and the results are discussed in this manuscript.

Novel assistive technologies for efficient freezing of pork based on high voltage electric field and static magnetic field: A comparative study

To enhance the freezing rate and thawed product quality of pork tenderloin, an experimental study was conducted using the high voltage electric field and static magnetic field separately during freezing. Pork tenderloin pieces were frozen at −20 °C under several high voltage electric fields (10 kV/m (HVEF1), 30 kV/m (HVEF3), 50 kV/m (HVEF5)) and magnetic fields of 2 mT (MF2), 4 mT (MF4), 6 mT (MF6) and 8 mT (MF8). The effects of different methods on freezing rate, ice crystal size as well as the distribution, and product quality after thawing were investigated. The freezing time of pork tenderloin was reduced by 40.04% and 37.81% respectively, under the optimal electric and magnetic field conditions tested. The thawing loss decreased from 5.7% of conventional freezing to 1.7% of HVEF1 and 2.4% of MF2, respectively. In addition, both high-voltage electric field freezing and magnetic field freezing can better maintain the moisture state in the sample. The results for color and pH confirmed that the thawed product quality using HVEF1 and MF2 was superior to that obtained under other conditions. The myofibrillar protein in the thawed products obtained from HVEF1 and MF2 treatments was also found to be thermally more stable. It is noteworthy that the HVEF1 treated sample has the highest umami signal and the lowest salty signal. Considering the enhanced freezing efficiency and improved quality, application of HVEF1 is recommended as a viable strategy to produce high-quality frozen pork tenderloin. Industrial relevanceThe slow freezing rate of frozen meat products and serious deterioration of product quality are the key problems. Therefore, improving the efficiency of freezing is desirable. This study provides ideas for pork preservation. It caters to the need of industrial production of meat product where better efficiency freezing process is highly desirable, and the findings of this study is beneficial to the meat processing industry.

Maintaining the freeze thawing characteristics of tomato through development and evaluation of magnetic field‐assisted freezing system

This study was conducted to investigate the effect of application of developed electromagnetic field system on freezing characteristics and quality of whole frozen tomato fruit. The system was developed with an electromagnetic field generating apparatus for applying magnetic field in the range of 2.5 mT (0.025 kGauss) and 3.0 mT (0.030 kGauss) in the existing deep freezing system. Freezing experiments were conducted to analyze the freezing curve so as to determine the effect of electromagnetic field on effective freezing time and rate in comparison with ordinary freezing process. Sensory characteristics were evaluated on the basis of visual appearance, texture, and thawing loss after thawing of samples at room temperature. Results indicated that magnetic field resulted in complete freezing of tomato samples in much shorter period of time (220–260 min) as compared to ordinary freezing (1460 min) with prominent lowering of freezing point and extending degree of supercooling. Thawing loss was significantly (p < 0.05) lower for electromagnetically frozen samples. It was 0.02% for the tomato samples frozen under the effect of magnetic field as compared to control (1.73%). Electromagnetically frozen tomato samples exhibited freshness and textural characteristics in terms of hardness of cell structure as close to the fresh samples even upon thawing and thus may represent a veritable means to retain the quality of perishables for longer period of time. Novelty Impact Statement The application of magnetic field along with the existing freezing method results positively in enhancing the degree of supercooling and helped in reducing the damage to the food products caused by the formation of non-uniform and larger ice crystals while speeding up the freezing process. The samples frozen with applied magnetic field differed significantly from the samples frozen conventionally in terms of appearance, freshness, and thawing loss. The fast freezing controlled the ice nucleation, decreased the freezing period, and maintained the stability of size, shape, and distribution of ice crystals in the food product. Drip loss was observed to be 1.73% after thawing when tomatoes were frozen without the influence of magnetic field. By the application of magnetic field, it was reduced to 0.02% for the same samples under similar thawing conditions just after the completion of the freezing process.