Search Results (38)

Glycopolypeptoids were synthesized and showed effective antifreeze activity, demonstrating their potential as novel antifreeze agents for cryopreservation. These polypeptide analogs offer improved stability and tunability compared with natural antifreeze glycoproteins (AFGPs) and existing synthetic mimics. Using the ring-opening polymerization of N-substituted N-carboxyanhydride monomers followed by click chemistry, glycopolypeptoids with controlled polymerization degrees and varied structures were designed and prepared. Their antifreeze performance was assessed via nanoliter osmometry and ice recrystallization inhibition assays, revealing a strong correlation between the molecular structure and antifreeze activity. The findings highlight glycopolypeptoids as a promising, cost-effective alternative to natural AFGPs, providing new insights into the development of biomimetic cryoprotectants. This study expands the understanding of synthetic antifreeze materials and offers a practical approach for improving cryopreservation efficiency in biomedical and industrial applications. Full article

Generally, small molecule alcohols and concentrated electrolyte ions can be introduced into the medium of hydrogels as anti-freezing agents to achieve significant anti-freezing properties. However, due to the exchange effect with the external environment, the anti-freezing agents may leak or change in composition causing contamination and unstable material performance during use. Here, cellulose and sodium polyacrylate (PAAS) were used to construct interpenetrating network hydrogels, with cellulose comprising up to 63% of the system. Sodium ions and carboxylic acid groups ionized from the polyacrylate network restricting the formation of water clusters through strong hydration and significantly reduced the ice crystal formation temperature. The rigid cellulose networks provided mechanical strength for the hydrogels. The new interpenetrating network hydrogels exhibited a low anti-freezing temperature (lowest at −56.12 °C), a high water content (over 82.5 wt%), and considerable toughness (up to 2.53 MJ m⁻³). The intrinsic anti-freezing hydrogel constructed in this work provides a new reference strategy for expanding the practicability of anti-freezing hydrogels. Full article

Construction in cold regions faces significant challenges due to delayed cement hydration and frost damage caused by sub-zero temperatures. This study investigated the effects of three antifreeze agents on the performance of composite cement under sub-zero temperatures. The setting time, compressive strength, freezing point, and hydration mechanisms were evaluated. The results revealed that CaCl₂ optimally accelerated hydration, while achieving the continuous development of compressive strengths through freezing-point depression and dense microstructure formation. NaNO₂ exhibited the lowest freezing point but delayed setting at high dosages, while Li₂CO₃ showed limited impact due to insufficient freezing point depression. Li₂CO₃ showed limited efficacy under continuous low temperatures but enabled strength recovery after the temperature transition from sub-zero to ambient conditions. This research provides a basis for the application of antifreeze agents in the composite cement system for construction in cold environments. Full article

Grapevines are widely cultivated and highly nutritious, making them economically significant among cultivated plants globally. However, important spring temperature fluctuations and frequent frost events in some production areas severely affect grape growth and yield. Therefore, enhancing the cold resistance of grapevines is of considerable importance for production. This study used the less cold-resistant grape varieties Vitis vinifera cv. Cabernet Sauvignon and Vitis vinifera cv. Chardonnay as test materials. They were treated with the antifreeze agents ‘GuoGuang KangXiu,’ ‘Biogas Liquid’, ‘SenHuo’, and ‘Ice Shield’ for 24 and 48 h before exposure to a low-temperature treatment of −2 °C. Compared to the control (water), all four antifreeze agents significantly reduced the relative conductivity and malondialdehyde content in the tender shoots of both grape varieties, increased the Fv/Fm ratio, enhanced osmotic adjustment substance levels, and improved antioxidant enzyme activity. Moreover, relative conductivity and malondialdehyde content were significantly lower, and the Fv/Fm ratio was higher when the antifreeze agents were applied 24 h before frost compared to 48 h. This suggests that all four antifreeze agents effectively improve grapevine cold resistance, with better results observed when applied 24 h before frost. Additionally, the antifreeze agents significantly increased the soluble solid content in berries and enhanced the levels of anthocyanins, total phenols, total tannins, total flavonoids, and total flavonols in the berries’ skin. They had minimal impact on the fruit set rate, cluster weight, and berries shape index, indicating that these agents can improve berries quality to some extent. Full article

This paper reviews recent advancements in the pipeline transport performance of paste backfill slurry in long-distance underground backfilling operations, with a primary focus on applications in metal mines. Key aspects, including flow performance, energy consumption during transport, and operational stability, are discussed in detail. Slurry concentration and rheological properties, including viscosity, yield stress, and flow behavior, as well as particle size distribution, are examined for their effects on transport efficiency. The relationship between these characteristics and pipeline resistance is also examined. Factors like pipeline orientation, configuration, diameter, length, elbow design, and elevation gradients are explored, demonstrating that careful design can optimize flow performance, reduce energy consumption, and minimize the risk of blockages and bursts. Additionally, the roles of commonly used additives, such as water reducers, foaming agents, antifreeze agents, and thickeners, are discussed in terms of their impact on slurry flowability, stability, and resistance losses. Optimal slurry regulation, strategic pipeline design, and effective additive utilization improve flow efficiency, extend service life, and reduce maintenance costs, thereby ensuring reliable backfill operations. Future research should focus on innovative pipeline designs, such as improving material selection and configuration to optimize flow stability and reduce energy consumption. Advanced additives, including thickeners and water reducers, could further enhance slurry flowability, reduce pipeline resistance, and improve system reliability. Full article

Antifreeze agents play a critical role in various fields including tissue engineering, gene therapy, therapeutic protein production, and transplantation. Commonly used antifreeze agents such as DMSO and other organic substances are known to have cytotoxic effects. Antifreeze proteins sourced from cold-adapted organisms offer a promising solution by inhibiting ice crystal formation; however, their effectiveness is hindered by a dynamic ice-shaping (DIS) effect and thermal hysteresis (TH) properties. In response to these limitations, antifreeze peptides (AFPs) have been developed as alternatives to antifreeze proteins, providing similar antifreeze properties without the associated drawbacks. This review explores the methods for acquiring AFPs, with a particular emphasis on chemical synthesis. It aims to offer valuable insights and practical implications to drive the realm of sub-zero storage. Full article

Currently, self-desiccating asphalt mixtures on roads mainly incorporate phase-change materials or salt-based slow-release agents individually for de-icing. However, pure phase-change material mixtures have limited anti-freezing efficiency and short heat-release duration, making them impractical for large-scale snow melting; meanwhile, salt-based slow-release agents suffer from rapid deterioration in de-icing performance. To address these issues encountered, herein, we introduce the phase-change/salt-based slow-release composite materials via the integration of these two materials and investigate their pavement and de-icing performance with the asphalt mixture. For the pavement performance, the optimal asphalt–aggregate ratio for the anti-icing asphalt mixture was found to be 5.1% For anti-bonding and de-icing performance, the electrical conductivity tests, bonding pull-off tests, and interfacial contact melting experiments were conducted. The results indicate that the latent heat of the TH-ME5 (phase-change material) can delay the decrease in environmental temperature and inhibit salt release from T-SEN (salt-based slow-release material), thereby extending the lifespan of the anti-icing asphalt mixture. These results demonstrate that the synergistic effect between the two components of the composite material not only enhance the snow-melting and de-icing performance of the asphalt pavement but also prolong the snow-melting time of the pavement in a low-temperature environment. Full article

In this study, ultrafiltration fractions (<3 k Da, LMH; >3 k Da, HMH) and solid-phase extraction fractions (hydrophilic hydrolysate, HIH; hydrophobic hydrolysate, HOH) from trypsin hydrolysate purified from croceine croaker (Pseudosciaena crocea) isolate were obtained to investigate the cryoprotective effects of the different fractions, achieved by means of maceration of turbot fish meat after three freeze-thaw cycles. Alterations in the texture, color, moisture loss, myofibrillar protein oxidation stability and conformation, and microstructure of the fish were analyzed after freezing and thawing. The results demonstrate that HIH maximized the retention of fish texture, reduced moisture loss, minimized the oxidation and aggregation of myofibrillar proteins, and stabilized the secondary and tertiary structures of myofibrillar proteins compared to the control group. In conclusion, the HIH component in the trypsin hydrolysates of croceine croaker significantly contributes to minimizing freeze damage in fish meat and acts as an anti-freezing agent with high industrial application potential. Full article

Freeze-thaw cycles significantly impact construction by altering soil properties and stability, which can lead to delays and increased costs. While soil-stabilizing additives are vital for addressing these issues, stabilized soils remain susceptible to volume changes and structural alterations, ultimately reducing their strength after repeated freeze-thaw cycles. This study aims to introduce a different approach by employing magnesium chloride (MgCl₂) as an antifreeze and soil stabilizer additive to enhance the freeze-thaw resilience of clay soils. We investigated the efficiency of MgCl₂ solutions at concentrations of 4%, 9%, and 14% on soil by conducting tests such as Atterberg limits, standard proctor compaction, unconfined compression, and freeze-thaw cycles under extreme cold conditions (−10 °C and −20 °C), alongside microstructural analysis with SEM, XRD, and FTIR. The results showed that MgCl₂ reduces the soil’s liquid limit and plasticity index while enhancing its compressive strength and durability. Specifically, soil treated with a 14% MgCl₂ solution maintained its volume and strength at −20 °C, with similar positive outcomes observed for samples treated with 14% and 9% MgCl₂ solutions at −10 °C. This underlines MgCl₂’s potential to enhance soil stability during initial stabilization and, most importantly, preserve it under cyclic freeze-thaw stresses, offering a solution to improve construction practices in cold environments. Full article

Antifreeze peptides have become effective antifreeze agents for frozen products, but their low quantity of active ingredients and high cost limit large-scale application. This study used the glycosylation of fish collagen peptides with glucosamine hydrochloride catalyzed by transglutaminase to obtain a transglutaminase-catalyzed glycosylation product (TGP) and investigate its antifreeze effect on tilapia. Compared with the blank group, the freshness (pH value of 6.31, TVB-N value of 21.7 mg/100 g, whiteness of 46.28), textural properties (especially hardness and elasticity), and rheological properties of the TGP groups were significantly improved. In addition, the protein structures of the samples were investigated using UV absorption and fluorescence spectroscopy. The results showed that the tertiary structure of the TGP groups changed to form a dense polymer. Therefore, this approach can reduce the denaturation and decomposition of muscle fibers and proteins in fish meat more effectively and has a better protective effect on muscle structure and protein aggregation, improving the stability of fish meat. This study reveals an innovative method for generating antifreeze peptides by enzymatic glycosylation, and glycosylated fish collagen peptide products can be used as new and effective green antifreeze agents in frozen foods. Full article

The development of nontoxic and efficient antifreeze agents for organ cryopreservation is crucial. However, the research remains highly challenging. In this study, we designed and synthesized a series of peptoid oligomers using the solid-phase submonomer synthesis method by mimicking the amphiphilic structures of antifreeze proteins (AFPs). The obtained peptoid oligomers showed excellent antifreeze properties, reducing the ice crystal growth rate and inhibiting ice recrystallization. The effects of the hydrophobicity and sequence of the peptoid side chains were also studied to reveal the structure–property relationship. The prepared peptoid oligomers were detected as non-cytotoxic and considered to be useful in the biological field. We hope that the peptoid oligomers presented in this study can provide effective strategies for the design of biological cryoprotectants for organ preservation in the future. Full article

Aquatic products are gaining popularity due to their delicacy and high nutrient value. However, they are perishable, with a short shelf-life. Frozen storage is associated with adverse effects, leading to protein oxidation and degradation, thereby altering the protein’s structural integrity and subsequently influencing the palatability of protein-based food products. To address these challenges, novel antifreeze peptides have gained significant attention. Antifreeze peptides are a class of small molecular weight proteins or protein hydrolysates that offer protection to organisms in frozen or sub-frozen environments. They offer distinct advantages over conventional commercial antifreeze agents and natural antifreeze proteins. This review provides an overview of the current state of research on antifreeze agents, elucidates their characteristics and mechanisms, and examines their applications in aquatic products. Furthermore, the article offers insights into the prospective development and application prospects of antifreeze peptides. Full article

Food waste is a major issue that is increasingly affecting our environment. More than one-third of food is wasted, resulting in over $400 billion in losses to the U.S. economy. While composting and other small recycling practices are encouraged from person-to-person, it is not enough to balance the net loss of 80 million tons per year. Currently, one of the most promising routes for reducing food waste is through microbial fermentation, which can convert the waste into valuable bioproducts. Among the compounds produced from fermentation, 2,3-butanediol (2,3-BDO) has gained interest recently due to its molecular structure as a building block for many other derivatives used in perfumes, synthetic rubber, fumigants, antifreeze agents, fuel additives, and pharmaceuticals. Waste feedstocks, such as food waste, are a potential source of renewable energy due to their lack of cost and availability. Food waste also possesses microbial requirements for growth such as carbohydrates, proteins, fats, and more. However, food waste is highly inconsistent and the variability in composition may hinder its ability to be a stable source for bioproducts such as 2,3-BDO. This current study focuses specifically on post-consumer food waste and how 2,3-BDO can be produced through a non-model organism, Bacillus licheniformis YNP5-TSU during non-sterile fermentation. From the dining hall at Tennessee State University, 13 food waste samples were collected over a 6-month period and the compositional analysis was performed. On average, these samples consisted of fat (19.7%), protein (18.7%), ash (4.8%), fiber (3.4%), starch (27.1%), and soluble sugars (20.9%) on a dry basis with an average moisture content of 34.7%. Food waste samples were also assessed for their potential production of 2,3-BDO during non-sterile thermophilic fermentation, resulting in a max titer of 12.12 g/L and a 33% g/g yield of 2,3-BDO/carbohydrates. These findings are promising and can lead to the better understanding of food waste as a defined feedstock for 2,3-BDO and other fermentation end-products. Full article

To effectively resolve the inherent conflict between dust control and ice prevention on truck roads during North Surface Coal Mine winters, initially, via monomer preference experiments, the optimal monomers for wetting, moisturizing, and condensing functions were identified as sodium dodecylbenzene sulfonate (B), glycerol (N), and polyacrylamide (R). In parallel, through compound synergistic experiments, the constituent elements of an anti-freezing agent were determined, referred to as F. Subsequently, a four-factor three-level orthogonal test was conducted employing the monomers B, N, R, and the anti-freezing agent F. This evaluation focused on four principal control parameters: penetration rate, evaporation resistance, viscosity, and freezing point. The results led to the identification of the optimal antifreeze and dust suppressant formulation, designated as B2N3R1F3. Within the North Open-Pit Coal Mine, the self-developed dust suppressant was applied to the field test section. Multiple parameters were examined for 6 consecutive days, encompassing the water content of the pavement geotechnical soil, the concentrations of total dust and exhaled dust, and the particle size distribution of dust within this road section. The field test results show that: the average water content of the road surface within the dust suppressant test section measured at 12%; the dust reduction efficiency of total dust and exhaled dust is 93% and 91%; the proportion of dust particles with a size exceeding 500 μm increased by 54.6%. These comprehensive findings provide a empirical framework for the effective resolution of the practical challenge of simultaneously managing dust control and frost protection on truck roads within surface coal mines. Full article

Quality degradation due to the formation and growth of ice crystals caused by temperature fluctuations during storage, transportation, or retailing is a common problem in frozen surimi. While commercial antifreeze is used as an ingredient in frozen surimi, its high sweetness does not meet the contemporary consumer demand for low sugar and low calories. Therefore, the development of new green antifreeze agents to achieve an enhanced frozen-thawed stability of surimi has received more attention. The aim of this study was to develop a cryoprotectant (a mixture of citric acid and trehalose) to enhance the frozen-thawed stability of surimi by inhibiting the oxidative denaturation and structural changes of frozen-thawed mirror carp (Cyprinus carpio L.) surimi myofibrillar protein (MP). The results showed that the amounts of free amine, sulfhydryl, α-helix, intrinsic fluorescence intensity, and thermal stability in the control significantly decreased after five F-T cycles, while the Schiff base fluorescence intensity, amounts of disulfide bonds and surface hydrophobicity significantly increased (p < 0.05). Compared to sucrose + sorbitol (SS), the natural deep eutectic solvents (NADES) effectively inhibited protein oxidation. After five F-T cycles, the α-helix content and Ca²⁺-ATPase activity of the NADES samples were 4.32% and 80.0%, respectively, higher, and the carbonyl content was 17.4% lower than those of the control. These observations indicate that NADES could inhibit oxidative denaturation and enhance the structural stability of MP. Full article