Unfrozen Samples Research Articles

Insights into the potential mechanism of diversified freezing techniques' influence on quality of golden pompano (Trachinotus ovatus): Focus on freezing speed, ice crystal morphology, water migration, and texture properties

The influences of air freezing (AF), liquid nitrogen freezing (LNF), immersion freezing (IF), magnetic field-assisted immersion freezing (MIF), and ultrasound-assisted immersion freezing (UIF) on the freezing time, water holding capacity, texture profile analysis (TPA), and microstructure of the golden pompano (Trachinotus ovatus) muscle was investigated. The findings indicated that the MIF and UIF groups were more effective in reducing the freezing time than other freezing method, with 84.35% and 85.81% shorter than that of AF, respectively. Among all the treatments, MIF had the best muscle integrity and closely packed myogenic fibers, which were more beneficial for maintaining the water holding capacity, textural properties, and color of the golden pompano muscle. Among all the groups, the MIF quality was the closest to unfrozen samples. Therefore, MIF effectively reduced the size of ice crystals, and inhibited the quality deterioration of frozen golden pompano.

Diffusion coefficients in scaffolds made with temperature controlled cryoprinting and an ink made of sodium alginate and agar

Temperature Controlled Cryoprinting (TCC), is a tissue engineering technique wherein each deposited voxel is frozen with precise control over cooling rates and the direction of freezing. This control allows for the generation of ice crystals with controlled shape and orientation. Recently we found that the macroscale fidelity of the TCC print is substantially improved by using a 3D printing ink composed of a mixture of two compounds: one that solidifies through chemical crosslinking (sodium alginate) and another that solidifies through physical (thermal) effects (agar). In this study we examine the hypothesis that the combination of sodium alginate and agar, affects also the fidelity of the microstructure and thereby the diffusivity of the scaffold. The ability of this technology to generate controlled diffusivity within the tissue scaffold was examined with a directional solidified TCC sample using fluorescence recovery after photobleaching (FRAP) and scanning electron microscope (SEM). We find that the diffusion coefficient in m2/s × 10−10 is: 1.62 ± 1.27 for the unfrozen sample, 2.40 ±1.54 for the rapidly frozen sample and 9.72± 4.50 for the slow frozen sample. This points to two conclusions. One is that the diffusivity is slow frozen samples is higher than that in unfrozen samples and in rapidly frozen sample. A second observation is that a relatively narrow range of diffusivity variance was obtained when using 2%w/v sodium alginate and 2%w/v of agar. However, when the concentration of agar was reduced to 0.5w/v a much wider spread of diffusivities was measure, 4.07±1.65. This suggests that the addition of agar has also an effect on the microscale fidelity, and consequently the diffusivity. The anisotropic diffusion properties of TCC-printed directional solidification samples were also validated through both FRAP and SEM.

Effect of long-term supercooling preservation using a stepwise algorithm on the freshness of kimchi cabbage

Kimchi cabbage is a Korean traditional fermented vegetable that is rich in nutrients and probiotics. Temperature changes caused microbial growth adversely affect the quality of kimchi. Therefore, controlling the preservation temperature is important to prevent over-fermentation of kimchi. Supercooling has emerged as an alternative storage method; however, maintaining the supercooled state of food is challenging. In this study, a stepwise cooling algorithm for supercooling preservation was developed and applied. All samples were maintained in a supercooled state, and no ice nucleation was detected. Assessments of CO2 content, pH, and titratable acidity revealed that supercooled samples exhibited more delayed fermentation than refrigerated samples. However, moisture content and hardness of the unfrozen (refrigerated and supercooled) samples were not significantly different. Microbial analysis and community composition indicated that the supercooling treatment delayed kimchi fermentation by approximately three months. Conclusively, supercooling is effective for maintaining the freshness of kimchi cabbage during long-term storage. This study contributes to the optimization of kimchi preservation strategies, offering potential benefits for both consumers and producers in terms of product quality, shelf life, and food safety.

An effective medium theory-based unified model for estimating thermal conductivity of unfrozen and frozen soils

Soil thermal conductivity (STC) is a crucial parameter in modeling land surface processes. However, the current STC models are developed separately for unfrozen and frozen soils, leading to inconsistent understanding. In this study, we propose a unified model based on the work of Ghanbarian and Daigle (2016) originally developed for unfrozen soils. The unified model comprises three parameters: critical volume fraction (ϕc), scaling exponent (t), and a compensating factor (α), and considers dry soil as the low-conductivity component (weighted by air volume fraction) and saturated soil as the high-conductivity component (weighted by volumetric liquid content for unfrozen state and total water content for frozen state). Specifically, ϕc represents a critical point where high-conductivity component begins to govern the behavior of effective STC, characterized by t. α allows for accurate calibration of saturated STC. Using a dataset of 90 unfrozen samples (693 measurements) and 74 frozen samples (255 measurements), pedotransfer functions (PTFs) for the three parameters were trained. The unified model successfully reproduces the sharp rise in STC at low moisture conditions during wetting and the increase during freezing. Compared to an empirical model (Côté and Konrad, 2005a) and a theoretical model (Tian et al., 2016), the unified model demonstrates higher predictive skill for unfrozen and frozen soils, achieving Nash-Sutcliffe efficiency coefficients of 0.96 and 0.90, respectively. This work contributes to a more consistent and comprehensive understanding of STC in cold environments and has the potential to be integrated into land surface models.

Regulation of the Ice Ⅰ to Ice III high pressure phase transition meta-stability in milk and its bactericidal effects

This study was focused on a novel approach of creating perturbations under high pressure (HP) meta-stable Ice Ⅰ to Ice Ⅲ phase transition and its bactericidal effects. Experiments were carried out under subzero high pressure processing conditions using Escherichia coli suspended in milk, and the microbial inactivation before and after the meta-stable state regulation was compared. The phase transition position of unperturbed milk was 302 MPa/–37.5 °C. The volume change resulting from the phase transition was employed as the perturbation mechanism. Glucose (5 %, 20 %) and sodium chloride solutions (5 %, 20 %) were used as regulatory sources. Glucose solutions accelerated the phase change of the milk better than the sodium chloride solution and resulted in an optimum phase transition position of milk at 243 MPa/–30.6 °C. The induced perturbations accelerated meta-stable transformation and enhanced the microbial destruction. At 330 MPa/3s, compared to the unfrozen samples, the lethality of E. coli in the frozen-regulated samples significantly increased by 1.79 log. The relationship between the E. coli inactivation within the phase change pressure range and the pressure was not continuous, but a segmented one, both before and after meta-stable state regulation. A higher level of E. coli destruction was accomplished by a 5 min pressure-holding of frozen samples at 220 MPa and 280 MPa as compared to the one-pulse and two-pulses treatments without holding time. The maximum lethality of 6.73 log was achieved at 280 MPa/5 min in the frozen-regulated application.

Thermal Conductivity of Frozen and Unfrozen Gas-Saturated Soils

Arctic permafrost often contains gas-saturated horizons. The gas component in freezing and frozen soils can exist under different pressures, which are expected to affect their properties and behavior. The effect of pore gas pressure on the thermal conductivity of frozen and unfrozen silt loam saturated with methane or carbon dioxide at pressures below the hydrate formation conditions is observed in the current study. The variable gas pressure and temperature conditions are simulated in a specially designed pressure cell, which allows thermal conductivity measuring in pressurized samples at positive and negative temperatures. The experiments using natural samples collected near the gas emission crater (Yamal Peninsula) show that thermal conductivity is sensitive to pore gas pressure even at high moisture contents. The thermal conductivity of methane-saturated soil becomes 4% and 6% higher in frozen and unfrozen samples, respectively, as the gas pressure increases from 0.1 MPa to 2 MPa. In the case of CO2 saturation, the respective thermal conductivity increase in frozen and unfrozen samples reaches 25% and 15% upon pressure change from 0.1 to 0.9 MPa. The results stimulate further special studies of the effects of gas type and pressure on the thermal properties of closed gas-saturated taliks, of which the pore pressure is increasing during freezing up.

Quantitative analysis perspective: Ice growth and super-chilling state of frozen dough under quick freezing

Ice crystal growth and dough quality under quick freezing were investigated in this study. The ice growth state (content and location) was analysed by the enthalpy balance method and electron microscopy analysis. The superchilling state was judged based on the quantitative analysis of ice crystals. The yeast fermentation performance and dough rheological properties of the frozen dough were assessed. The results showed that the −40 and −80 °C treatments led to quick dough freezing compared with the −20 °C freezing condition. Superchilled dough could be created at −40 °C (less than 35 min) or −80 °C (20 min). The yeast is intolerant to low temperature (−80 °C) based on the results of the dough system and the solution system. Moreover, for dough leavening performance, the freezing temperature and time should be taken into consideration. The elastic modulus and viscous modulus of the dough decreased after the freezing treatment, while the rheological characteristics of the superchilled samples were close to those of the unfrozen samples, which implies that the superchilling treatment maintained the gluten network structure of the dough.

Utility of dimethylsulfoxide to preserve synovial fluid samples for microcrystal detection and identification

Aims: To study whether the addition of dimethylsulfoxide (DMSO) to synovial fluid (SF) samples could be helpful to store frozen samples to improve the rates of detection and identification of crystals. Methods: Cross-sectional study of samples of SF consecutively obtained. Three aliquots were generated: one for immediate observation by a senior observer, and 2 to be frozen, one with 10% DMSO (DMSO+) and one without DMSO (DMSO–). Each aliquot was randomly allocated and blinded for further observation when once the samples were unfrozen 3 months afterward. Variables included for analysis were total leucocyte count, detection of crystals, identification of present crystals as monosodium urate (MSU) or calcium pyrophosphate (CPP), number of fields to the first crystal observation, and number of crystals per field. The vitality of leucocytes was evaluated using a trypan blue stain. All samples were examined using ordinary light and polarized light with a red compensator, and unfrozen samples by both senior and junior observers. Results: In the 30 reference samples of SF studied, the mean leucocyte count was 13.1 × 109/L, and 18/30 samples showed crystals (8 MSU, 10 CPP). Once unfrozen, leucocyte counts were 58% lower in DMSO aliquots vs. 22% in DMSO+ aliquots, with vitality (> 50% cells) reduced from 100% in the reference sample to 76.6% in the DMSO+ aliquots to none in the DMSO– aliquots. Agreement in the detection of crystals was much better in DMSO+ aliquots than DMSO– (kappa 1.00 vs. 0.69 and 0.65 vs. 0.11 for the senior and junior observers respectively). Moreover, 4/5 false-negative crystal detection in DMSO– aliquots showed CPP in the reference simple, even though a high density of crystals was observed in the reference sample. Conclusions: The addition of 10% DMSO to SF samples allows freezing and storage with a small loss of leucocyte counts and excellent agreement in the detection and identification of crystals. Cellular lysis may account for the false negative results in aliquots without DMSO, especially in the case of CPP, non-refringent crystals.

Differences between blood and cerebrospinal fluid glial fibrillary Acidic protein levels: The effect of sample stability.

Recent evidence has shown that the marker of reactive astrogliosis, glial fibrillary acidic protein (GFAP), has a stronger relationship with cerebral amyloid beta (Aβ) pathology in blood than in cerebrospinal fluid (CSF). This study investigates if pre-analytical treatment of blood and CSF contribute to these unexpected findings. Paired CSF and serum samples from 49 individuals (Aβ-negative = 28; Aβ-positive = 21) underwent a series of seven freeze-thaw cycles (FTCs). All samples were analyzed for GFAP and neurofilament light (NfL) using single molecule array technology including a fresh unfrozen sample from each patient. FTC significantly affected CSF GFAP concentration (-188.12 pg/ml per FTC) but not serum GFAP. In the same samples, NfL remained stable. Serum GFAP had a higher discrimination of Aβ burden than CSF GFAP, irrespective of FTC, which also included unfrozen samples. This study demonstrates large stability differences of GFAP in CSF and serum. However, this disparity does not seem to fully explain the stronger association of serum GFAP with Aβ pathology. Further work should investigate mechanisms of GFAP release into the bloodstream under pathological conditions.

Comparison of three rapid non-destructive techniques coupled with a classifier to increase transparency in the seafood value chain: Bioelectrical impedance analysis (BIA), near-infrared spectroscopy (NIR) and time domain reflectometry (TDR)

Bioelectrical impedance analysis (BIA), near-infrared (NIR) spectroscopy and time domain reflectometry (TDR) were compared as non-destructive techniques, coupled with a classifier based on partial least square discriminant analysis (PLS-DA), to assess added water detection in a seafood model: tuna. Three classification models were developed for each technology in unfrozen, thawed and in a combination of both stages to distinguish between added and non-added water samples. Results were acceptable for the unfrozen stage with all the technologies, giving TDR the best performance (accuracy = 0.95; error rate = 0.06). However, results on the model for thawed stage were not satisfactory, due to the behavior of water during the freezing-thawing process in both types of samples (with and without added water). For the combined model, NIR failed in the classification (accuracy = 0.68; error rate = 0.32), BIA gave acceptable results (accuracy = 0.72; error rate = 0.28) and TDR made a good classification (accuracy = 0.87; error rate = 0.12). • Non-destructive techniques and chemometrics help increasing food chain transparency. • BIA, NIR and TDR are suitable to detect added water in tuna unfrozen samples. • The best performance was obtained with TDR in unfrozen samples (accuracy = 0.95). • Results in thawed samples were not satisfactory with any technology.

Ground deformation as a result of the foundation of a new module in the Spanish Antarctic Base Gabriel de Castilla, Deception Island, Antarctica

Since its inauguration in the 1989/90 campaign, the Spanish Antarctic Base Gabriel de Castilla (BAEGC) has supported an increasing volume of scientific projects, stimulating the expansion of its facilities. The permafrost soil on which they are located is affected by changing thermal and periglacial conditions that disturb its mechanical and physical characteristics. This paper analyzes the foundation behavior of a building (18.5x6.5x2.7 m length – width – height, around 104 kg in operation supported on 16 posts) through the geomechanical study (stresses and deformations) of the ground during the winter and southern summer seasons, supported by three types of foundations: piles, footings and slabs. These are commonly recommended as support elements inperiglacial soils affected by thermal-seasonal variations. The geotechnical properties have been obtained from stress-tests on soil samples collected in the surroundings of the BAEGC, General Marvá Army Engineers Laboratory (INTA). Considering the thermal variations in the tests on frozen and unfrozen samples, the geotechnical column type has been established and extended along the profile of the 2D domain. The stationary stress-strain equations with a constitutive Mohr-Coulomb rupture model have been solved using finite elements in MIDAS GTS-NX, for each season and each foundation, discretizing with a triangular or quadrangular mesh adapted to the 2D domain geometry with the foundation. The numerical results show that, in any tested case, there is no critical ground failure, and the foundation with the smallest displacement (about 0.036 m), both in summer and winter, is the 1.2 m foundation placed at 0.5 m depth on permafrost.

Corrigendum to: Efficacy of short-term cold storage prior to cryopreservation of spermatozoa in a threatened lizard.

Assisted reproductive technologies (ARTs) have a significant role to play in reptile conservation, yet are severely lacking. Previous attempts to cryopreserve spermatozoa in the threatened lizard Varanus panoptes achieved approximately 48% motile sperm post-thaw for samples frozen immediately after collection. However, the feasibility of extended cold storage before cryopreservation has not been tested. We held V. panoptes spermatozoa at either 25°C or 4°C for 8 days, assessing sperm motility at days 1, 2, 4 and 8. Subsamples were cryopreserved on days 1 and 4 following the previously reported protocol for this species. Percentage motility decreased rapidly at 25°C, but did not decrease significantly until 4 days after collection at 4°C, with >30% motility maintained after 8 days. There was no significant difference in post-thaw motility or viability of samples cryopreserved after 1 or 4 days storage at 4°C, yielding substantial results for both parameters (mean motility 23.8% and 28.1% and mean viability 50.1% and 57.5% after 1 and 4 days respectively). We demonstrate the capacity to extend sperm viability for up to 8 days in unfrozen samples and to produce acceptable post-thaw motility in samples frozen after 4 days of storage, contributing to the development of valuable ARTs for lizards and other reptiles.

Efficacy of short-term cold storage prior to cryopreservation of spermatozoa in a threatened lizard.

Assisted reproductive technologies (ARTs) have a significant role to play in reptile conservation, yet are severely lacking. Previous attempts to cryopreserve spermatozoa in the threatened lizard Varanus panoptes achieved approximately 48% motile sperm post-thaw for samples frozen immediately after collection. However, the feasibility of extended cold storage before cryopreservation has not been tested. We held V. panoptes spermatozoa at either 25°C or 4°C for 8 days, assessing sperm motility at days 1, 2, 4 and 8. Subsamples were cryopreserved on days 1 and 4 following the previously reported protocol for this species. Percentage motility decreased rapidly at 25°C, but did not decrease significantly until 4 days after collection at 4°C, with >30% motility maintained after 8 days. There was no significant difference in post-thaw motility or viability of samples cryopreserved after 1 or 4 days storage at 4°C, yielding substantial results for both parameters (mean motility 23.8% and 28.1% and mean viability 50.1% and 57.5% after 1 and 4 days respectively). We demonstrate the capacity to extend sperm viability for up to 8 days in unfrozen samples and to produce acceptable post-thaw motility in samples frozen after 4 days of storage, contributing to the development of valuable ARTs for lizards and other reptiles.

Effects of duration and temperature of frozen storage on the quality and food safety characteristics of pork after thawing and after storage under modified atmosphere

The aim of this study was to investigate the influence of the duration of frozen storage (12 and 24 weeks) and the storage temperature (−18 °C or − 80 °C) on the shelf life of pork in MAP for up to 14 days after thawing. Frozen meat was compared to unfrozen meat in different physicochemical and microbiological parameters. The parameters a*, b*, pH value, cooking loss, shear force and antioxidant activity showed no significant changes depending on the freezing process. The total moisture loss was significantly higher for frozen/thawed pork compared to unfrozen pork. The storage loss of all frozen samples showed higher values than the unfrozen samples on all examination days. The level of TBARS reached comparable values for all experimental groups. On examination days 7 and 14, significantly lower values of total plate count (TPC) and Pseudomonas spp. were measured for frozen pork compared to unfrozen pork. The temperature of frozen storage had no significant influence on the quality of pork.

Development of micro and macro fracture properties of cementitious materials exposed to freeze-thaw environment at early ages

The freeze–thaw cycles can affect the fracture properties of early age cementitious materials significantly. Considering the multiscale and multiphase nature of cementitious materials, it is of significance to study the fracture properties of cementitious materials across scales. This study investigates the development of fracture properties of cement paste subject to freeze–thaw cycles at the age of 1, 3, and 7 days at both macro and micro scales by using the three-point bending test method and the nano scratch technique, respectively. At micro scale, the fracture properties of the unreacted clinker, the hydrates and the interfacial transition zone (ITZ) between the clinker and the hydrates phases were measured. The developments of micro fracture properties of the three phases and the macro fracture properties of paste beams are evaluated and compared for both frozen and unfrozen samples. For the first time the nano-scratching technique was used to study the effect of the early age frost attack on the fracture properties of individual phase in cement paste. The findings in this study provide an insight into the fracture properties of cementitious materials from the microscopic point of view, and will benefit the further understanding of the mechanism of freeze–thaw damage to cementitious materials.

Effect of Red Lentil Flour Addition on Total Polyphenols Content and Antioxidant Capacity of Frozen Dough Bread

The fortification of frozen dough improved with addition of pulse flour - red lentil flour in various proportions (15% and 30%) was analyzed in order to raise the protein content, total polyphenol content (TPC) and antioxidant capacity (expressed using DPPH and CUPRAC methods) of wheat bread obtained from frozen dough. The high-protein, phenolic and flavonoid compounds potential of red lentil was considered for expanding the range of products obtained from frozen dough and physicochemical attributes (acidity, moisture porosity and ash content) were analyzed. Results showed that the bread formulated with 30% red lentil flour had the highest antioxidant capacity. The protein content showed higher values for samples with fortification, freezing treatment not affecting the content. The results denoted that enrichment of wheat dough with red lentil flour significantly increases the levels of polyphenols and the antioxidant activity of the final products. A strong increasement of phenolic compounds content was observed for the frozen samples, differences between fermented and unfermented samples and frozen and unfrozen samples varying significantly.

Effects of Freezing and Thawing Procedures on Selected Clinical Chemistry Parameters in Plasma.

Introduction: Measurements from frozen sample collections are important key indicators in clinical studies. It is a prime concern of biobanks and laboratories to minimize preanalytical bias and variance through standardization. In this study, we aimed at assessing the effects of different freezing and thawing conditions on the reproducibility of medical routine parameters from frozen samples. Materials and Methods: In total, 12 pooled samples were generated from leftover lithium heparinized plasma samples from clinical routine testing. Aliquots of the pools were frozen using three freezing methods (in carton box at -80°C, flash freezing in liquid nitrogen, and controlled-rate freezing [CRF]) and stored at -80°C. After 3 days, samples were thawed using two methods (30 minutes at room temperature or water bath at 25°C for 3 minutes). Ten clinical chemistry laboratory parameters were measured before (baseline) and after freeze-thaw treatment: total calcium, potassium, sodium, alanine aminotransferase, lactate dehydrogenase (LDH), lipase, uric acid, albumin, c-reactive protein (CRP), and total protein. We evaluated the influence of the different preanalytical treatments on the test results and compared each condition with nonfrozen baseline measurements. Results: We found no significant differences between freezing methods for all tested parameters. Only LDH was significantly affected by thawing with fast-rate thawing being closer to baseline than slow-rate thawing. Potassium, LDH, lipase, uric acid, albumin, and CRP values were significantly changed after freezing and thawing compared with unfrozen samples. The least prominent changes compared with unfrozen baseline measurements were obtained when a CRF protocol of the local biobank and fast thawing was applied. However, the observed changes between baseline and frozen samples were smaller than the measurement uncertainty for 9 of the 10 parameters. Discussion: Changes introduced through freezing-thawing were small and not of clinical importance. A slight statistically based preference toward results from slow CRF and fast thawing of plasma being closest to unfrozen samples could be supported.

Single-particle measurements of filamentous influenza virions reveal damage induced by freezing.

Clinical isolates of influenza virus produce pleiomorphic virions, ranging from small spheres to elongated filaments. The filaments are seemingly adaptive in natural infections, but their basic functional properties are poorly understood and functional studies of filaments often report contradictory results. This may be due to artefactual damage from routine laboratory handling, an issue which has been noted several times without being explored in detail. To determine whether standard laboratory techniques could damage filaments, we used immunofluorescence microscopy to rapidly and reproducibly quantify and characterize the dimensions of filaments. Most of the techniques we tested had minimal impact on filaments, but freezing to -70 °C, a standard storage step before carrying out functional studies on influenza viruses, severely reduced their concentration, median length and the infectivity of the whole virion population. We noted that damage from freezing is likely to have affected most of the functional studies of filaments performed to date, and to address this we show that it can be mitigated by snap-freezing or incorporating the cryoprotectant DMSO. We recommend that functional studies of filaments characterize virion populations prior to analysis to ensure reproducibility, and that they use unfrozen samples if possible and cryoprotectants if not. These basic measures will support the robust functional characterizations of filaments that are required to understand their roles in natural influenza virus infections.

The Influence of Nanosilica on Unconfined Compressive Strength of Frost-Susceptible Soil

In engineering practice there are numerous methods to improve the mechanical properties of subsoil. The paper presents the analysis of changes in the unconfined compressive strength of frost-susceptible soils stabilised with nanosilica (NS). Tests were conducted on samples of fine-grained soil at the maximum dry density (MDD) and optimum moisture content (OMC). Four variants of samples were prepared: soil without additive, soil with 1% NS, soil with 3% NS and soil with 5% NS. Due to the frost-susceptible character of the soil, tests were conducted on non-frozen samples and on samples subjected to ten cycles of freezing and thawing. Cyclic freezing and thawing of soil mixtures allowed for determination of the additive effectiveness in the temperature conditions encountered during the winter season. Based on the research results of unfrozen samples, it was determined that the addition of nanosilica leads to the increase in their unconfined compressive strength. On the other hand, the strength of pure soil samples after ten cycles of freezing and thawing decreased. This is a commonly known trend that results from the soil and soil mixtures freezing. However, in the same conditions, the unconfined compressive strength of samples stabilised with nanosilica demonstrated a significant increase with the increase of the additive content. The highest values were noted for samples stabilised with 5% addition of nanosilica. In order to explain the obtained results, further tests are required. However, the preliminary research has shown the effectiveness of nanosilica as an independent additive stabilising frost-susceptible soils, although it is not commonly used in engineering practice.

Sphingosine-1-phosphate reduces atresia of primordial follicles occurring during slow-freezing and thawing of human ovarian cortical strips.

We aimed in this study to explore if sphingosine-1-phosphate (S1P) reduces apoptosis of primordial follicles during cryopreservation of human ovarian cortical samples. Ovarian cortical tissue fragments obtained from young patients who underwent laparoscopic excision of benign ovarian cysts were used for the experiments. The samples were slow-frozen and thawed with and without S1P at 200 and 400 μM, cultured for 1 day, and then were fixed and processed for both histomorphological assessment and detection of apoptosis with immunohistochemistry using apoptosis marker cleaved caspase-3. Follicle counts were expressed as the mean number of follicles per mm2 . The mean number of primordial follicles and in vitro estradiol (E2) and anti-mullerian hormone (AMH) production of the slow-frozen and thawed samples were significantly reduced compared with fresh unfrozen samples. S1P treatment at 400 μM but not 200 μM concentration resulted in a significant increase in the number of surviving primordial follicles and in vitro E2 and AMH productions of the samples compared with their counterparts slow-frozen without S1P. We found that that there was a significant decrease in the number of primordial follicles with their oocytes stained positive for cleaved caspase-3 in the slow-frozen samples S1P 400 μM in comparison with the samples slow-frozen without S1P. These results suggest that S1P may ameliorate follicle atresia occurring in human ovarian cortical samples during cryopreservation.