Ice Crystals Research Articles

Ice Recrystallization Unveils the Binding Mechanism Operating at a Diffused Interface.

Recrystallization of ice is a natural phenomenon that causes adverse effects in cryopreservation, agriculture, and in frozen food industry. It has long been recognized that ice recrystallization occurs through the Ostwald ripening and accretion processes. However, neither of these processes has been explored in microscopic detail by state-of-the-art experimental techniques. We carried out atomistic molecular dynamics (MD) simulations to explore ice recrystallization through the accretion process. Attempts have been made to elucidate the binding mechanism that is operating at the diffused ice-water interface. It is demonstrated that two ice crystals spontaneously recognize each other and bind together to form a large crystal in liquid water, resulting in ice recrystallization by accretion. Interestingly, the study reveals that the binding occurs due to the freezing of the interfacial water layer present between the two ice planes, even at a temperature above the melting point of the ice crystal. The synergistically enhanced ordering effect of two ice surfaces on the interfacial water leads to such freezing occurring during the binding process. However, proper crystallographic alignment is not necessarily required for the binding of the two crystals. Simulations have also been carried out to study the binding between an ice crystal and the model ice-binding surface (IBS) of an antifreeze protein above the melting point of the ice crystal. It is found that such binding at the IBS is accompanied by freezing of the interfacial water. This establishes that the synergetic ordering-driven freezing of interfacial water is a common binding mechanism at the diffused surfaces of ice crystals. We believe that this mechanism will provide a microscopic understanding of the process of recrystallization inhibition and thus help in designing suitable materials for potent applications in recrystallization inhibition.

Combining sulfite and freezing/thawing pretreatment to simultaneously improves methanogenesis, dewaterability, and pathogen inactivation of waste activated sludge: Depicting sulfite migration during ice crystal growth

Harmless treatment of waste activated sludge (WAS) is the primary goal for sludge management while bioresource recovery is raising wide scholarly and industrial interest due to the abundant resource potential in WAS. This study employed sulfite and freezing/thawing to pretreat WAS for its versatility in simultaneously enhancing methane production, improving dewaterability, and inactivating pathogenic microorganisms. The addition of 100 mg S/L of sulfite and subsequent freezing/thawing significantly promoted the release of organics from a low organic-contained WAS (volatile solid/total solid = 0.4), leading to a substantial increase in methane production by 10.99 %. The combined pretreatment significantly reduced the capillary suction time of sludge by 77.24 % and effectively inactivated pathogenic microorganisms to below detectable levels. From a micro level, sulfur aggregation was observed around sludge particles, which can be attributed to the process of ice formation. During this process, sulfite was continuously transferred to the aqueous phase surrounding the particles where were froze even slower. Moreover, the formation of capillary water ice crystals further compromised the protective function of extracellular polymeric substances (EPS) on sludge cells. Economic, and environmental analyses suggest this combined sulfite and freezing/thawing pretreatment has a potential for efficient sludge treatment towards energy recovery and safe disposal with high environmental and economic value.

Radiative effect of thin cirrus clouds in the extratropical lowermost stratosphere and tropopause region

Abstract. Cirrus clouds play an important role in the radiation budget of the Earth; nonetheless, the radiative effect of ultra-thin cirrus clouds in the tropopause region and in the lowermost stratosphere remains poorly constrained. These clouds have a small vertical extent and optical depth and are frequently neither observed even by sensitive sensors nor considered in climate model simulations. In addition, their short-wave (cooling) and long-wave (warming) radiative effects are often in approximate balance, and their net effect strongly depends on the shape and size of the cirrus particles. However, the CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere instrument (CRISTA-2) allows ultra-thin cirrus clouds to be detected. Here we use CRISTA-2 observations in summer 1997 in the Northern Hemisphere midlatitudes together with the Suite Of Community RAdiative Transfer codes based on Edwards and Slingo (SOCRATES) radiative transfer model to calculate the radiative effect of observed ultra-thin cirrus. Using sensitivity simulations with different ice effective particle size and shape, we provide an estimate of the uncertainty in the radiative effect of ultra-thin cirrus in the extratropical lowermost stratosphere and tropopause region during summer and – by extrapolation of the summer results – for winter. Cloud top height and ice water content are based on CRISTA-2 measurements, while the cloud vertical thickness was predefined to be 0.5 or 2 km. Our results indicate that if the ice crystals of these thin cirrus clouds are assumed to be spherical, their net cloud radiative effect is generally positive (warming). In contrast, assuming aggregates or a hexagonal shape, their net radiative effect is generally negative (cooling) during summer months and very likely positive (warming) during winter. The radiative effect is in the order of ±(0.1–0.01) W m−2 for a realistic global cloud coverage of 10 %, similar to the magnitude of the contrail cirrus radiative forcing (of ∼ 0.1 W m−2). The radiative effect is also dependent on the cloud vertical extent and consequently the optically thickness and effective radius of the particle size distribution (e.g. effective radius increase from 5 to 30 µm results in a factor ∼ 6 smaller long- and short-wave effects, respectively). The properties of ultra-thin cirrus clouds in the lowermost stratosphere and tropopause region need to be better observed, and ultra-thin cirrus clouds need to be evaluated in climate model simulations.

Two new multirotor uncrewed aerial vehicles (UAVs) for glaciogenic cloud seeding and aerosol measurements within the CLOUDLAB project

Abstract. Uncrewed aerial vehicles (UAVs) have become widely used in a range of atmospheric science research applications. Because of their small size, flexible range of motion, adaptability, and low cost, multirotor UAVs are especially well-suited for probing the lower atmosphere. However, their use so far has been limited to conditions outside of clouds, first because of the difficulty of flying beyond visual line of sight and second because of the challenge of flying in icing conditions in supercooled clouds. Here, we present two UAVs for cloud microphysical research: one UAV (the measurement UAV) equipped with a Portable Optical Particle Spectrometer (POPS) and meteorological sensors to probe the aerosol and meteorological properties in the boundary layer and one UAV (the seeding UAV) equipped with seeding flares to produce a plume of particles that can nucleate ice in supercooled clouds. A propeller heating mechanism on both UAVs allows for operating in supercooled clouds with icing conditions. These UAVs are an integral part of the CLOUDLAB project in which glaciogenic cloud seeding of supercooled low stratus clouds is utilized for studying aerosol–cloud interactions and ice crystal formation and growth. In this paper, we first show validations of the POPS on board the measurement UAV, demonstrating that the rotor turbulence has a small effect on measured particle number concentrations. We then exemplify the applicability for profiling the planetary boundary layer, as well as for sampling and characterizing aerosol plumes, in this case, the seeding plume. We also present a new method for filtering out high-concentration data to ensure good data quality of POPS. We explain the different flight patterns that are possible for both UAVs, namely horizontal or vertical leg patterns or hovering, with an extensive and flexible parameter space for designing the flight patterns according to our scientific goals. Finally, we show two examples of seeding experiments: first characterizing an out-of-cloud seeding plume with the measurement UAV flying horizontal transects through the plume and, second, characterizing an in-cloud seeding plume with downstream measurements from a POPS and a holographic imager mounted on a tethered balloon. Particle number concentrations and particle number size distributions of the seeding plume from the experiments reveal that we can successfully produce and measure the seeding plume, both in-cloud (with accompanying elevated ice crystal number concentrations) and out-of-cloud. The methods presented here will be useful for probing the lower atmosphere, for characterizing aerosol plumes, and for deepening our cloud microphysical understanding through cloud seeding experiments, all of which have the potential to benefit the atmospheric science community.

Biobased Aerogels Fabricated by the Ice Crystal Method for Smoke Purifying

Biobased Aerogels Fabricated by the Ice Crystal Method for Smoke Purifying

Survivability of amorphous ice in comets depends on the latent heat of crystallization of impure water ice

Abstract Comets are believed to have amorphous rather than crystalline ice at the epoch of their accretion. Cometary ice contains some impurities that govern the latent heat of ice crystallization, Lcry. However, it is still controversial whether the crystallization process is exothermic or endothermic. In this study, we perform one-dimensional simulations of the thermal evolution of kilometer-sized comets and investigate the effect of the latent heat. We find that the depth at which amorphous ice can survive significantly depends on the latent heat of ice crystallization. Assuming the cometary radius of 2 km, the depth of the amorphous ice mantle is approximately 100 m when the latent heat is positive (i.e., the exothermic case with Lcry = +9 × 104 J kg−1). In contrast, when we consider the impure ice representing the endothermic case with Lcry = −9 × 104 J kg−1, the depth of the amorphous ice mantle could exceed 1 km. Although our numerical results indicate that these depths depend on the size and the accretion age of comets, the depth in a comet with the negative latent heat is a few to several times larger than in the positive case for a given comet size. This work suggests that the spatial distribution of the ice crystallinity in a comet nucleus depends on the latent heat, which can be different from the previous estimates assuming pure water ice.

Cryogenic vs. Mechanical freezing impact on the quality of the sea bass (Dicentrarchus labrax) during long-term storage

In this study, we compared the long-term impact of cryogenic and mechanical freezing on sea bass quality. Mechanical freezing (MF) and cryogenic freezing (CF) were conducted at -40 °C and -80 °C, respectively, with air velocities of 2 m s-1 and 0.5 m s-1. Frozen samples were stored at -20 °C for 60 days. We assessed quality attributes, including exudate loss, texture, TBA value, color, enthalpy, microstructure, and protein denaturation, over this period. Exudate loss increased significantly during storage, with no significant difference between freezing methods. The cutting force, L*, b*, chroma (C*), and total color difference (ΔE) were mainly influenced by storage time rather than freezing methods, as p values were >0.05. MF samples were notably less green (p < 0.05) than CF samples, as indicated by higher a* value. Lipid oxidation occurred post-freezing and during storage, with the TBA value at the 0th month being 11 % lower for cryogenic freezing compared to mechanical freezing, reducing to just 2 % after the 2nd month. CF exhibited slightly higher enthalpy than MF, although not significant. Furthermore, the deconvolution data suggested that protein denaturation was impacted not only by freezing storage but also by the freezing treatment and freezing methods to some extent. Microstructure analysis showed that CF produced smaller ice crystals and maintained tissue integrity (inter-fibre distance) better than MF (p value = 0.000), a benefit that persisted during storage (p value = 0.009). Overall, fish quality attributes were more affected by the freezing treatment and storage conditions than by the freezing methods.

Tough, Antifreezing, and Piezoelectric Organohydrogel as a Flexible Wearable Sensor for Human-Machine Interaction.

Piezoelectric hydrogel sensors are becoming increasingly popular for wearable sensing applications due to their high sensitivity, self-powered performance, and simple preparation process. However, conventional piezoelectric hydrogels lack antifreezing properties and are thus confronted with the liability of rupture in low temperatures owing to the use of water as the dispersion medium. Herein, a kind of piezoelectric organohydrogel that integrates piezoelectricity, low-temperature tolerance, mechanical robustness, and stable electrical performance is reported by using poly(vinylidene fluoride) (PVDF), acrylonitrile (AN), acrylamide (AAm), p-styrenesulfonate (NaSS), glycerol, and zinc chloride. In detail, the dipolar interaction of the PVDF chain with the PAN chain facilitates the crystal phase transition of PVDF from the α to β phase, which endows the organohydrogels with a high piezoelectric constant d33 of 35 pC/N. In addition, the organohydrogels are highly ductile and can withstand significant tensile and compressive forces through the synergy of the dipolar interaction and amide hydrogen bonding. Besides, by incorporating glycerol and zinc chloride, the growth of ice crystals is inhibited, allowing the organohydrogels to maintain stable flexibility and sensitivity even at -20 °C. The real-time monitoring of the pulse signal for up to 2 min indicates that the gel sensor has stable sensitivity. It is believed that our organohydrogels will have good prospects in future wearable electronics.

Towards spatiotemporal-resolved spectroscopic measurement of freezing desalination using femtosecond laser filaments

Freezing desalination can produce freshwater from seawater or industrial wastewater by ice crystallization with low energy consumption and less corrosion, and is promising for alleviating current stress on the world's water supply. However, the salt rejection dynamics during the freezing process is less understood due to the lack of real-time, high spatiotemporal-resolved detection methods. Here we present a proof-of-principle, quantitative, and simultaneous multi-salt detection approach for the measurement of salt rejection dynamics in salt-contaminated water at the ppm level using an ultrashort-pulsed femtosecond laser propagating in the filamentation regime. We show that this approach of filament-induced plasma spectroscopy possesses the abilities for both monitoring the change of salt concentration in the remaining unfrozen water during the freezing process and imaging the spatial concentration distributions of metal contaminants on the resultant ice surface. With this approach, we find that the initial salt concentration in water plays an essential role in the efficiency of the freezing desalination process, which shows a metal-species-dependent characteristic. Our results pave the way towards real-time, online, and high spatiotemporal-resolved detection of salt rejection dynamics of freezing desalination by ultrashort-pulsed lasers.

Tailoring an egg white protein double network emulsion gel as a novel fat substitute for improving freeze-thaw stability of minced meat gel

This work aimed to investigate the effect of double network emulsion gel (DNEG) as a substitute for pork back fat (PBF) on the freeze-thaw stability of minced meat gel (MMG). We used slow acidification with glucono-δ-lactone (GDL) to induce egg white protein (EWP) gelation, while CaCO3 was affected by acidification to release Ca2+ to cross-link sodium alginate (SA), resulting in the gradual formation of DNEG networks. The MMG prepared using DNEG substitute for PBF had fine hardness and color after 5 freeze-thaw cycles (FTCs). This was due to the excellent plasticity of DNEG, which made it more capable of filling the voids of minced meat products, thus reducing the space for ice crystal growth. As a result, MMG prepared with DNEG could pass through the maximum ice crystal formation zone faster and avoid damage due to the formation of larger ice crystals. Notably, DNEG provided a barrier for the migration of immobilized water to bulk water in the sample. After several freeze-thaw treatments, the water holding capacity of samples prepared with DNEG decreased significantly slower, which slowed down the oxidation and decomposition of meat proteins. In summary, this study revealed the role of fat substitute DNEG as a favorable filling material for improving the freeze-thaw stability of minced meat products, and provided a technical reference for the development of healthy and storable meat products.

To What Extent Do Low-Voltage Electrostatic Fields Play a Role in the Physicochemical Properties of Pork during Freezing and Storage?

Low-voltage electrostatic fields (LVEF) are recognized as a new technology that can improve the quality of frozen meat. To determine the extent to which LVEF assistance affects the quality of frozen pork for long-term storage, pork was frozen and stored at -18 and -38 °C for up to 5 months. Water-holding capacity, muscle microstructure, and protein properties were investigated after up to 5 months of frozen storage with and without LVEF assistance. In comparison to traditional -18 and -38 °C frozen storage, LVEF treatment inhibited water migration during frozen storage and thawing. As a result, thawing losses were reduced by 15.97% (-18 °C) and 3.38% (-38 °C) in LVEF-assisted compared to conventional freezing methods. LVEF helped to maintain the muscle fiber microstructure and reduce muscle protein denaturation by miniaturizing ice crystal formation by freezing. As a result of this study, LVEF is more suitable for freezing or short-term frozen storage, while a lower temperature plays a more significant role in long-term frozen storage.

Controlling the Architecture of Freeze-Dried Collagen Scaffolds with Ultrasound-Induced Nucleation.

Collagen is a naturally occurring polymer that can be freeze-dried to create 3D porous scaffold architectures for potential application in tissue engineering. The process comprises the freezing of water in an aqueous slurry followed by sublimation of the ice via a pre-determined temperature-pressure regime and these parameters determine the arrangement, shape and size of the ice crystals. However, ice nucleation is a stochastic process, and this has significant and inherent limitations on the ability to control scaffold structures both within and between the fabrication batches. In this paper, we demonstrate that it is possible to overcome the disadvantages of the stochastic process via the use of low-frequency ultrasound (40 kHz) to trigger nucleation, on-demand, in type I insoluble bovine collagen slurries. The application of ultrasound was found to define the nucleation temperature of collagen slurries, precisely tailoring the pore architecture and providing important new structural and mechanistic insights. The parameter space includes reduction in average pore size and narrowing of pore size distributions while maintaining the percolation diameter. A set of core principles are identified that highlight the huge potential of ultrasound to finely tune the scaffold architecture and revolutionise the reproducibility of the scaffold fabrication protocol.

Plant Cryopreservation: Principles, Applications, and Challenges of Banking Plant Diversity at Ultralow Temperatures.

Progressive loss of plant diversity requires the protection of wild and agri-/horticultural species. For species whose seeds are extremely short-lived, or rarely or never produce seeds, or whose genetic makeup must be preserved, cryopreservation offers the only possibility for long-term conservation. At temperatures below freezing, most vegetative plant tissues suffer severe damage from ice crystal formation and require protection. In this review, we describe how increasing the concentration of cellular solutes by air drying or adding cryoprotectants, together with rapid cooling, results in a vitrified, highly viscous state in which cells can remain viable and be stored. On this basis, a range of dormant bud-freezing, slow-cooling, and (droplet-)vitrification protocols have been developed, but few are used to cryobank important agricultural/horticultural/timber and threatened species. To improve cryopreservation efficiency, the effects of cryoprotectants and molecular processes need to be understood and the costs for cryobanking reduced. However, overall, the long-term costs of cryopreservation are low, while the benefits are huge.

Use of ultrasound and NIRs as tools for monitoring ice formation in superchilled meat

This study aimed to gain a deeper understanding of the ice crystal formation during the superchilling process (SC) of meat by using non-destructive methods. Ultrasound inspection was performed considering the ultrasonic pulse velocity (UPV), while Near Infrared Spectroscopy (NIR) measurements were carried out with a spectral range of 950–1650 nm. Signals from both methodologies were periodically taken during the controlled freezing of 8 beef cubic samples of (6 cm3). Obtained results revealed that both methods have the ability to detect the ice crystal formation during the SC process, and particularly during the period of thermal arrest. Hence, these results evidence that ultrasound inspection and NIR, combined with Multivariate Statistical Process Control charts, could be implemented as quality control procedures during the SC process of muscle foods, allowing a more accurate control of the process and thus, minimizing the potential deleterious effects of ice crystals formation in meat.

Graph-Neural-Network-Based Unsupervised Learning of the Temporal Similarity of Structural Features Observed in Molecular Dynamics Simulations.

Classification of molecular structures is a crucial step in molecular dynamics (MD) simulations to detect various structures and phases within systems. Molecular structures, which are commonly identified using order parameters, were recently identified using machine learning (ML), that is, the ML models acquire structural features using labeled crystals or phases via supervised learning. However, these approaches may not identify unlabeled or unknown structures, such as the imperfect crystal structures observed in nonequilibrium systems and interfaces. In this study, we proposed the use of a novel unsupervised learning framework, denoted temporal self-supervised learning (TSSL), to learn structural features and design their parameters. In TSSL, the ML models learn that the structural similarity is learned via contrastive learning based on minor short-term variations caused by perturbations in MD simulations. This learning framework is applied to a sophisticated architecture of graph neural network models that use bond angle and length data of the neighboring atoms. TSSL successfully classifies water and ice crystals based on high local ordering, and furthermore, it detects imperfect structures typical of interfaces such as the water-ice and ice-vapor interfaces.

Tunable tip singularity of a water droplet freezing on surfaces under forced convection

Typically, a water droplet on surfaces freezes with a tip singularity on the top in an experimental environment, and the magnitude of the singular tip is thought to be a constant of ∼ 131°. Interestingly, we observed that the tip magnitude can be variable from 131° to 180° (i.e., disappearing) under a ubiquitous convection environment. Especially, dependent on the competition between heat conduction (influenced by contact angle and substrate temperature) and convection, the traditional concave freezing front and a newly found convex freezing front were both observed during the freezing process, respectively corresponding to the emergence and disappearance of the singular tip. Additionally, an analytical model was proposed to clarify the variable mechanisms of tip singularity and the quantitative relationship between the magnitude of tip and the curvature of the ice-water interfaces during freezing. This study advances our understanding of freezing dynamics and ice crystal geometry. Simultaneously, the inhibition effect of convection on the singular ice crystals may provide a promising method for mitigating mechanical damage caused by sharp ice crystals during cryopreservation.

Ice templated and ice seed tailored hydrogels for highly efficient solar evaporator

In recent years, freshwater resources have become a global concern, and solar vapor generation (SVG) has garnered significant attention from researchers. Herein, a novel hydrogel solar evaporator was prepared by incorporating lignin and CuS-rGO into a chitosan-gelatin matrix. The anisotropic and isotropic morphologies of the hydrogel were prepared by pathway control on the solidification velocities of ice crystals and ice seeds. It presented that the anisotropic morphology can improve the refraction of light and increase the utilization rate of light by forming a light trap, leading to higher water evaporation rate. Additionally, ice seed was introduced during the freezing process, producing an anisotropic hydrogel with curled layer structure that endowed lower enthalpy of water evaporation and faster water transfer rate, resulting in high evaporate of 3.62 kg m−2 h−1 under one solar irradiation with photothermal conversion efficiency of 97.7 %. Finally, the gel also demonstrated good mechanical properties, long-term working stability and harsh environment tolerance, which make it ideal for outdoor applications. The hydrogel evaporator had potential to generate 25.24 kg m2 water per day that could meet the huge demand for freshwater as sources.

Psychrophiles to control ice-water phase changes in frost-susceptible soils

The phase changes of soil water or porous media have a crucial influence on the performance of natural and man-made infrastructures in cold regions. While various methods have been explored to address the impacts of frost-action arising from these phase changes, conventional approaches often rely on chemicals, mechanical techniques, and the reuse of waste materials, which often exhibit certain limitations and environmental concerns. In contrast, certain organisms produce ice-binding proteins (IBPs) or antifreeze proteins (AFPs) to adapt to low temperatures, which can inhibit ice crystal growth by lowering the freezing point and preventing ice crystallization without the need for external intervention. This study explores the potential of three psychrophilic microbes: Sporosarcina psychrophile, Sporosarcina globispora, and Polaromonas hydrogenivorans, to induce non-equilibrium freezing point depression and thermal hysteresis in order to control ice lens growth in frost-susceptible soils. We hypothesize that the AFPs produced by psychrophiles will alter the phase changes of porous media in frost-susceptible soils. The growth profiles of the microbes, the concentration of released proteins in the extracellular solution, and the thermal properties of the protein-mixed soils are monitored at an interval of three days. The controlled soil showed a freezing point of − 4.59 °C and thermal hysteresis of 4.62 °C, whereas protein-treated soil showed a maximum freezing point depression of − 8.54 °C and thermal hysteresis of 7.71 °C. Interestingly, except for the controlled sample, all the protein-treated soil samples were thawed at a negative temperature (minimum recorded at − 0.85 °C). Further analysis showed that the treated soils compared to porous media mixed soil freeze (1.25 °C vs. 0.51 °C) and thaw (2.75 °C vs. 1.72 °C) at extensive temperature gap. This freezing and thawing temperature gap is the temperature difference between the beginning of ice core formation and completed frozen, and the beginning of ice core thawing and completed thawed for the treated soil samples selected from different incubation days. Overall, this study presents a novel bio-mediated approach using psychrophilic microbes to control ice formation in frost-susceptible soils.

STUDYING THE SOLUBILITY OF THE SYSTEM ZnSO4 - KNO3 - H2O

The solubility of the components in the ZnSO4 - KNO3 - H2O system was studied by the visual-polythermal method in the temperature range from -7.0°С to 42.0°С. The phase diagram delimits the fields of ice crystallization, KNO3, K2SO4·ZnSO4·6H2O, and ZnSO4. A solubility diagram was constructed, and a new compound K2SO4·ZnSO4·6H2O was separated. The new compound was identified by chemical, X-ray phase, thermogravimetric, and IR spectroscopic analysis.

The Influence of Whey Protein Isolate on the Quality Indicators of Acidophilic Ice Cream Based on Liquid Concentrates of Demineralized Whey.

The use of liquid whey concentrates in the composition of ice cream, especially in combination with other powdered whey proteins, is limited due to their understudied properties. This article shows the main rheological and thermophysical characteristics of ice cream mixes, as well as color parameters, microstructure, analysis of ice crystals and quality indicators of ice cream during storage. The most significant freezing of free water (p ≤ 0.05) was observed in the temperature range from the cryoscopic temperature to -10 °C. The microscopy of experimental ice cream samples based on hydrolyzed whey concentrates indicates the formation of a homogeneous crystalline structure of ice crystals with an average diameter of 13.75-14.75 μm. Microstructural analysis confirms the expediency of using whey protein isolate in ice cream, which ensures uniform distribution of air bubbles in the product and sufficient overrun (71.98-76.55%). The combination of non-hydrolyzed whey concentrate and 3% whey protein isolate provides the highest stability to preserve the purity and color intensity of the ice cream during storage. The produced ice cream can be classified as probiotic (number of Lactobacillus acidophilus not lower than 6.2 log CFU/g) and protein-enriched (protein supply from 15.02-18.59%).