Soluble Calcium Research Articles

Potensi Sari Kurma (Phoenix dactylifera) sebagai Peluruh Kristal Kalsium Oksalat Secara In Vitro

Dates (Phoenix dactilyfera) contain chemical compositions that can be used as traditional medicine for Calcium oxalate of kidney stone decay. Compound in palm juice can make Calcium oxalate dissolving is flavonoid and calium . The purpose of this study was to determine the effect of Palm dates juice dissolving calcium oxalate to determine the relationship between the concentration of dates palm juice with calcium solubility in kidney stones. To test its activities carried out in vitro using calcium oxalate which incubated for 3 hours with shaken out every 20 minutes at 37oC Determination of the solubility of calcium in date palm juice is by weighs insoluble calcium oxalate. Palm's juice concentration is divided into 60%, 50%, 40%, 30% and 20%. The results of these concentrations can be concluded that the juice of dates has the activity of dissolving calcium oxalate from kidney stones with average result weight in sequence 0.02 + 0.005 g; 0.02 + 0.005 g; 0.03 + 0.005 g; 0.04 + 0.005 g and 0.05 + 0.005 g. Positive control (batugin elixir) 60%, 50%,40%, 30% and 20% with in sequence result 0.08 + 0.001 g; 0.08 + 0.001 g; 0.08 + 0.005 g; 0.09 + 0.005 g; and 0.1 + 0.005 g. Negative Control result 0.11 g. The results obtained from the standard deviation are 0.031. Calcium oxalate that is not dissolved at most in the sample is 20% with an average of 0.05 + 0.005 g and the positive control is 20% of the batugine with an average of 0.1 + 0.005 g.Based on the weighing of calcium oxalate from each concentration the higher the concentration will cause the least insoluble calcium oxalate.

Lime Juice Enhances Calcium Bioaccessibility from Yogurt Snacks Formulated with Whey Minerals and Proteins.

Yogurt-based snacks originally with a calcium content between 0.10 and 0.17 mmol/g dry matter were enriched with a whey mineral concentrate and whey protein isolate or hydrolysate. Whey mineral concentrate was added to increase the total amount of calcium by 0.030 mmol/g dry matter. Calcium bioaccessibility was determined following an in vitro protocol including oral, gastric, and intestinal digestion, with special focus on the effect of lime juice quantifying calcium concentration and activity. Calcium bioaccessibility, defined as soluble calcium divided by total calcium after intestinal digestion amounted to between 17 and 25% for snacks without lime juice. For snacks with lime juice, the bioaccessibility increased to between 24 and 40%, an effect attributed to the presence of citric acid. Citric acid increased the calcium solubility both from whey mineral concentrate and yogurt, and the citrate anion kept supersaturated calcium soluble in the chyme. The binding of calcium in the chyme from snacks with or without lime juice was compared electrochemically, showing that citrate increased the amount of bound calcium but with lower affinity. The results indicated that whey minerals, a waste from cheese production, may be utilized in snacks enhancing calcium bioaccessibility when combined with lime juice.

Evaluation of soil amendments in perennial ryegrass pastures associated with white and red clover in small-scale milk production systems

Objective: evaluate the effect of the inclusion of lime and dolomite soil amendments in an established pasture of perennial ryegrass (Lolium perenne) cv. Tetragrain associated with white clover (Trifolium repens) cv. Ladino and red clover (Trifolium pratense) cv. Kendall. Methodology: Three treatments of soil amendments were implemented on a perennial ryegrass with white and red clover pasture A split plot experimental design was used. The treatments were: T1= control treatment (without soil amendment), T2= lime and T3= dolomite. The evaluated variables were: herbage mass (HM), dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD) and estimated metabolizable energy (eME). Results: There were significant differences in all evaluated variables, the interaction between experimental periods and treatments was not significant for any variable. The treatments did not affect herbage mass. As for the the soil, a decrease in pH is observed at the end of the experiment, and there was an increase in the total soluble calcium, magnesium and nitrogen and a decrease in aluminum. Implications: This study illustrates the use of soil amendments, which somehow modulate effects of the farmer practices on the pasture soils. Conclusions: Inclusion of soil amendments in pastures did not increase dry matter production, content of FDN, FDA or IVDMD, but increased crude protein and evaluated minerals, and decreases aluminum.

ROSUVASTATIN CALCIUM PRONIOSOME POWDER: A NOVEL APPROACH TO IMPROVE INTESTINAL ABSORPTION AND BIOAVAILABILITY

Objective: The main objective of the present study was to develop proniosomal formulations to enhance the oral bioavailability of rosuvastatin calcium by improving solubility, dissolution, and/or intestinal permeability.
 Methods: Proniosomal powder formulations were prepared with rosuvastatin calcium drug varying the Span 40 and cholesterol ratio in the range of 0.8:0.2–0.2:0.8 using maltodextrin as carrier by slurry method. The prepared proniosomal powder was filled into capsules. The bioavailability enhancement of proniosomes loaded with drug was studied focusing on non-ionic surfactants composition and drug:Span 40 ratio. Prepared proniosomes were characterized for their particle size distribution, zeta potential, entrapment efficiency, in vitro dissolution study, and thermal characteristics to understand the phase transition behavior. Further, the formulated proniosomes were subjected to stability behavior, ex vivo permeation studies using rat intestine followed by in vivo studies.
 Results: Physicochemical studies help in optimization of formulations. Enhancement in dissolution is due to incorporation of rosuvastatin calcium into the non-ionic surfactant and change in the physical state from crystalline to amorphous, thus improving oral bioavailability. Ex vivo studies show significant permeation enhancement across gastrointestinal membrane compared to control.
 Conclusion: Proniosomes provide a powerful and functional way of distribution of inadequately soluble rosuvastatin calcium drug which is proved from in vivo studies based on the enhanced oral delivery.

Label-free quantitative proteomic analysis of insect larval and metamorphic molts

BackgroundMolting is an essential biological process occurring characteristic times throughout the life cycle of holometabolous insects. However, it is not clear how insects determine the direction of molting to remain status quo or to initiate metamorphosis. To explore the functional factors that determine the direction of molts, liquid chromatography-mass spectrometry was used to identify the molecules involved in larval and metamorphic molting, and the differentially expressed proteins (DEPs) were compared in the two processes.ResultsThere were 321 and 1140 DEPs identified in larval and metamorphic molting process, respectively. Bioinformatics analyses show that the amino sugar pathway was up-regulated in both processes. The up-regulated protease contributed to the metamorphosis. In addition, several proteins with different expression patterns in larval-larval and larval-pupal transitions, including Endochitinase, GRIM-19 (Genes associated with retinoid-IFN-induced mortality-19), IDE (Insulin-degrading enzyme), Sorcin (Soluble resistance related calcium binding protein), OBP (Odorant-binding protein-2 precursor), TRAP1(Tumor necrosis factor receptor associated protein-1), etc., were further identified by parallel reaction monitoring, which may play diverse functions in larval-larval and larval-pupal transitions.ConclusionsThese results provide a proteomic insight into molecules involved in larval and metamorphic molts, and will likely improve the current understanding of determination of direction of molts.

Bioavailability, mobility and leaching of phosphorus in a Mediterranean agricultural soil (ne Spain) amended with different doses of biosolids.

The precipitation of sparingly soluble calcium phosphate in calcareous soils decreases the bioavailability of macronutrients, which makes their addition by way of fertilisers necessary. Sludge resulting from treating urban wastewater does not only provide significant amounts of phosphorus, but also helps lower the pH, thus increasing its bioavailability. The loss of part of soil nutrients due to irrigation or rain can contaminate groundwater. In order to assess the movement of phosphorus, a experiment was conducted on percolation columns, to which different doses of wastes were applied. The pH decreased by as much as 0.89 units, as well as the assimilable and soluble P, in intervals of 20cm of depth, obtaining maximum values of 254mg Pkg-1 and 1455μg Pkg-1 respectively, and the P present in the leached water collected, which did not surpass 95μg PL-1. The intent was to learn which was the majoritarian inorganic formed crystalline phase that immobilised the movement of phosphorus through the percolation column. The results obtained by the diffraction of X-rays are not conclusive, although they point to the formation of octacalcium phosphate. The diffractograms of the studied samples have similar diffraction lines to those of apatites.

Addition of CPP-ACP to yogurt inhibits enamel subsurface demineralization

ObjectivesThe aim of this study was to investigate the capacity of an approved food additive with anticariogenic properties, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), when added to a processed, sugar-containing yogurt with added lactic-acid bacteria (probiotics), to prevent demineralization of enamel subsurface lesions in vitro. MethodsEnamel subsurface demineralised lesions were created in thirty extracted human third molars. These were then exposed to artificial saliva (AS) with: 1) Danone yogurt alone; 2) Danone yogurt with 0.2 % w/w CPP-ACP; or 3) Danone yogurt with 0.5 % w/w CPP-ACP at 37 °C for two weeks. The yogurt/AS was replaced with fresh preparations each day. At the completion of each treatment the enamel slabs were embedded, sectioned and analyzed using transverse microradiography to measure changes in enamel lesion depths and subsurface mineral content. Yogurt samples were analysed for soluble calcium (Ca) and inorganic phosphate (Pi) levels and pH. ResultsYogurt alone demineralized enamel subsurface lesions to produce significantly larger lesions. However, the addition of 0.2 % CPP-ACP to the yogurt resulted in significant reduction in demineralization compared with yogurt alone (p < 0.0001). The addition of 0.5 % CPP-ACP to the yogurt produced a net remineralization effect with a significant increase in lesion mineral content (p < 0.0001). The addition of CPP-ACP resulted in a significant (p < 0.0001) dose-related increase in Ca, Pi and pH. ConclusionsThe addition of CPP-ACP to a commercial yogurt exhibited a dose related protective effect with 0.5 % CPP-ACP producing remineralization of existing enamel subsurface lesions under the in vitro experimental conditions. Clinical significanceThe results of this study suggest that some processed yogurts with added sugar could result in enamel demineralization when frequently consumed by individuals with poor oral hygiene. The addition of CPP-ACP to these yogurts may help prevent demineralization and promote enamel subsurface lesion remineralization, and therefore, make them safer for teeth.

Occurrence and transformation of sodium and calcium species in mild liquefaction solid product of Hami coal during pyrolysis

To better understand the occurrence and chemical transformation of sodium and calcium species in mild liquefaction solid product (MLS) of Hami coal (HM) during pyrolysis, sequential chemical extraction combined with SEM-EDS and XRD analysis of low temperature ash were used in this work. Results show that the addition of polymer dispersant in sequential chemical extraction help to accurately determine the content of different occurrence modes of sodium and calcium species because of the hydrophobicity and high cohesiveness of samples. Compared with HM char, the smooth and compacted structure of MLS char makes it easier for calcium, sodium and sulfur to enrich on the surface of char during MLS pyrolysis. The release of sodium is much higher than that of calcium, and the release of both sodium and calcium in MLS during pyrolysis is lower than that in HM. Besides pyrolysis temperature, the transformation of calcium and sodium species is also greatly influenced by other minerals. Due to the enrichment of minerals and the addition of Fe-S catalyst in the liquefaction process, the chemical transformation behaviors of minerals during MLS pyrolysis are more complex than that of HM coal. For organic bound calcium (AS-Ca), besides partial volatilization into gas phase, it may convert into hydrochloric acid soluble calcium (HS-Ca). The content of HS-Ca decreases over 600 °C due to the decomposition of CaCO3, while the formation of CaS leads to a significantly increase of HS-Ca during MLS pyrolysis.

Preparation of CaO@TiO2-SiO2 Biomaterial with a Sol-Gel Method for Bone Implantation.

The calcium phosphate spherical material with a hierarchical structure has been used as a bone implantation material. To improve the properties of the implant material, the compositions of calcium phosphate, silicon, and titanium are crucial. The presence of silicon on the surface of the phosphate–calcium material accelerates the bonding of the implant with the bone (osseointegration). The aim of this work was to develop a sol–gel method to prepare spherical calcium-phosphate@TiO2–SiO2 biomaterials for bone implantation. The CaO@TiO2–SiO2 biomaterial with a core–shell structure was synthesized by the sol–gel method. The biological properties of the materials were studied with a simulated body fluid (SBF). The sample had a spherical shape. The sample exhibited bioactive properties because an increase in the content of calcium and phosphorus ions in the shell and the presence of precipitated ions from the solution were detected on the surface. The TiO2–SiO2 framework was uniformly fixed on the CaO core. Heat treatment of the hybrid mesostructure led to the formation of mesoporous materials with a specific regular structure in the nanometer size in the shell, which is necessary for the fixation of biological cells when the sample is introduced into the biological medium. The formation of a calcium–phosphate layer on the materials and the release of soluble silicon and calcium ions into the SBF are the key factors for the rapid connection of these materials with tissue. The results demonstrate that the CaO@TiO2–SiO2 biomaterial with a core–shell structure is a good candidate for bone implantation.

Aesthetic Silver-Doped Octacalcium Phosphate Powders Exhibiting Both Contact Antibacterial Ability and Low Cytotoxicity.

Since the introduction of biomaterials, infection has been a serious problem in clinical operations. Although several studies have introduced hybrid materials of calcium phosphate and Ag0 nanoparticles (NPs) that exhibit antibacterial activity, released Ag+ ions and Ag0 NPs are highly cytotoxic and the materials require complex fabrication techniques such as laser irradiation. In this study, we introduce a simple one-pot synthesis method based on crystal-engineering techniques to prepare Ag+-substituted octacalcium phosphate (OCP–Ag) powder that simultaneously exhibits antibacterial activity, little change in color, and low cytotoxicity, thereby overcoming the shortcomings of calcium phosphate as a biomaterial. We used AgNO3-containing (NH4)2HPO4 aqueous solutions as reaction solutions in which Ag+ forms soluble complex [Ag(NH3)2]+ ions that are stable at Ag+ concentrations less than ∼30 mmol/L. Hydrolysis of soluble calcium phosphate in this solution led to pure OCP–Ag when the Ag+ concentration was less than ∼30 mmol/L. Crystallographic analysis showed that Ag+ substituted at the P5 PO4-conjugated sites and was uniformly distributed. When the concentration of Ag+ in the reaction solution was varied, the Ag+ content of the OCP–Ag could be controlled. The obtained OCP–Ag exhibited little color change or Ag+ release when immersed in various media; however, it exhibited contact antibacterial ability toward resident oral bacteria. The prepared OCP–Ag showed no substantial cytotoxicity toward undifferentiated and differentiated MC3T3-E1 cells in assays. Notably, when the Ag+ content in OCP–Ag was optimized (Ag: ∼1 at %), it simultaneously exhibited contact antibacterial ability, little color change, and low cytotoxicity.

Effect of Casein Phosphopeptides on In Vitro Solubilization of Calcium in Fortified Cheese Pizza

Cheese pizzas fortified with casein phosphopeptide (CPP) and calcium were subjected to an in vitro digestion to assess whether CPP could prevent the precipitation of calcium. The total calcium content of the cheese pizzas was adjusted to 1,000 mg per pizza (~370 g) with the addition of calcium originating from eggshells. Two levels of trypsin-digested caseins (367 and 459 mg), with a CPP content of ~20%, were added to each pizza. The in vitro digested pizzas were then centrifuged and the supernatant was mixed with Na2HPO3 at 37°C to estimate the possible soluble effect of CPP on calcium. After 24 h of reaction, the solution was centrifuged and the calcium content in the resultant supernatant was analyzed by inductively coupled plasma-atomic emission spectroscopy. One-way statistical analyses showed that CPP had a positive effect on the solubilization of calcium against phosphate (p&lt;0.05). Cheese pizza supplemented with 459 mg of CPP powder was able to prevent precipitation of calcium by 98.8%, whereas no CPP-added cheese pizza solubilized 86.4% of the calcium. A sensory test was also carried out, revealing that panelists could not discern the bitter taste of the CPP added to the pizzas.

Pressed Composites Based on Gypsum and Magnesia Binders Modified with Secondary Resources

The results of the studies aimed at increasing the water resistance of the pressed building materials based on gypsum and magnesia binders due to their modification with active dispersed fillers from secondary resources are presented. The gypsum binder modification was carried out by the joint introduction of carbonate-containing sludge from it into the chemical treatment of thermal power plants and monoammonium phosphate, and of magnesia cement - silica fume and finely ground burnt mines. Physical and mechanical characteristics of the materials’ control samples were determined according to the standards and generally accepted methods. The increase in water resistance of the pressed modified composites was evaluated by changing the softening coefficient. It is shown that when using gypsum binders, an increase in the water resistance of products based on them can be achieved by changing the structure formation of the pressed material and the formation on the elements’ surface of its fine-crystalline structure of the sparingly soluble calcium phosphates’ screening protective films. The increase in water resistance of pressed products made of modified magnesia binders is explained by the appearance of insoluble hydro silicates, hydro aluminates and hydro aluminosilicates of magnesium, in the structure of the hardened artificial stone as well as the formation of a complex combined structure containing coagulation, condensation and crystallization phases. The technical characteristics of the materials obtained are sufficient for their use, in particular, in the building envelope. The possibility of replacing a significant amount of binders with secondary resources has been identified. This allows not only to increase the water resistance of the pressed products on the basis of the proposed modified binders, but also to reduce their cost, as well as free up the land allocated for dumps.

Physicochemical properties of skim milk powder dispersions prepared with calcium-chelating sodium tripolyphosphate, trisodium citrate, and sodium hexametaphosphate

Due to health benefits of proteins, the demand for protein beverages has grown rapidly. Translucent protein drinks with neutral pH may have advantages over acidic beverages that may cause dental erosion, and skim milk powder (SMP) is an affordable protein ingredient. Dissociating casein micelles by calcium chelators is a well-known method to reduce SMP dispersion turbidity, but much is to be studied for physicochemical properties as affected by chelator type and concentration. The objective of the present study was to characterize physicochemical properties of dispersions with 5% (wt/vol) SMP after addition of 0 to 30 mM sodium tripolyphosphate, trisodium citrate, or sodium hexametaphosphate. The turbidity was decreased with increasing chelator concentration, with the lowest turbidity observed in the SMP dispersions with sodium hexametaphosphate. The smallest hydrodynamic diameter was observed at an intermediate chelator concentration, resulting from the balance of casein micelle dissociation and aggregation of dissociated caseins induced at an elevated ionic strength. Heating at 90°C for 5 min increased turbidity but lowered hydrodynamic diameter of SMP dispersions, with some exceptions. The morphology of SMP dispersions differed for each chelator and was also affected by chelator concentration and heating. Trisodium citrate was the most effective to demineralize colloidal calcium phosphate in casein micelles, but the amount of dissolved calcium was not directly correlated with the decreased turbidity, indicating different chelating mechanisms by each chelator. Analysis of serum calcium and phosphorus concentrations also suggested that the type and concentration of soluble and insoluble calcium phosphates and their partitioning in the serum and casein micelles were dynamically changed by the studied parameters to affect dispersion turbidity and structures of casein micelles. Findings from the present study may be used to formulate translucent beverages incorporating SMP and other casein micelle ingredients.

Cellulose nanofibres mitigate chloride ion ingress in cement-based systems

This study pioneers the use of cellulose nanofibres (CNF) as a means to restricting the chloride-ion ingress in cement based systems. Three CNF variants, differing in their carboxylate content from 0.13 to 1.13 mmol/g of the nanofibre, were introduced to paste and mortar mixtures alike, at up to 1.2% by volume fraction of the dry nanofibre. The reference mixture was a plain system, prepared with CSA Type GU Portland cement. The ingress of chloride ions was investigated per the Rapid Chloride Penetration Test (ASTM C1202) and further assessed by colorimetry. Companion studies were conducted to measure changes to the air-void network and the pH environment within. The results demonstrate that adding CNF significantly impedes chloride-ion penetration, most likely due to a lower porosity in the 10 nm–140 nm range. Higher amounts of carboxyl groups, [COOH], uniformly led to higher CNF efficiency, both for easy workability and for restricting the chloride ingress. So that, for 0.50% fibre volume fraction, and the CNF variant grafted with 1.13 mmol of carboxylate/g, the mortar witnessed a 50% drop in the measured electrical charge as well as in the depth of chloride penetration. The study indicates that the [COOH] groups scavenge the soluble calcium cations Ca2+, from the aqueous phase of the cement paste without, however, altering the pH therein.

Effect of soluble calcium on enhancing nitrate retention by biochar

Batch experiments were conducted to test the hypothesis that nitrate (NO3−) could be immobilized by biochar via adsorption of CaNO3+ to the negatively charged biochar surfaces. The results show that addition of soluble Ca in both aqueous and soil systems enabled NO3− retention by the biochar material. Increase in the added Ca enhanced the retention rate and the optimal NO3− retention was gained at a Ca/NO3 molar ratio of 2 for the aqueous system. For the soil system, the Ca/NO3 molar ratio required to attain the optimal NO3− retention was much greater due to competition of other soil-borne ligands and soil colloids for the available Ca. At the same level of added Ca, the amount of NO3− being retained tended to increase with increasing dose of the biochar. More NO3− was retained in the soil system than in the aqueous system at the same dosage level of biochar due to additional adsorption of CaNO3+ by negatively changed soil organic and inorganic colloids. The findings obtained from this study have implications for developing effective methods for reducing NO3− leaching from soils.

Calcium and hydroxyapatite binding site of human vitronectin provides insights to abnormal deposit formation

The human blood protein vitronectin (Vn) is a major component of the abnormal deposits associated with age-related macular degeneration, Alzheimer's disease, and many other age-related disorders. Its accumulation with lipids and hydroxyapatite (HAP) has been demonstrated, but the precise mechanism for deposit formation remains unknown. Using a combination of solution and solid-state NMR experiments, cosedimentation assays, differential scanning fluorimetry (DSF), and binding energy calculations, we demonstrate that Vn is capable of binding both soluble ionic calcium and crystalline HAP, with high affinity and chemical specificity. Calcium ions bind preferentially at an external site, at the top of the hemopexin-like (HX) domain, with a group of four Asp carboxylate groups. The same external site is also implicated in HAP binding. Moreover, Vn acquires thermal stability upon association with either calcium ions or crystalline HAP. The data point to a mechanism whereby Vn plays an active role in orchestrating calcified deposit formation. They provide a platform for understanding the pathogenesis of macular degeneration and other related degenerative disorders, and the normal functions of Vn, especially those related to bone resorption.

The Problem of Expansion in Erosion and Sedimentation Extensions of Drinking Water in Libya: A Case Study of Kufra City

Corrosion problems that occur in all fields in engineering activities cause high negative economic impacts, therefore research into operations of different wear mechanisms is a prerequisite for mitigating the effects of corrosion problems can reduce economic loss. Groundwater is vital and the sole resource in most of the studied region in the city of kufra. In this study, some physical and chemical analysis studies were conducted on the water samples in the study area, which included: pH, total soluble salts, sulfate, chloride, calcium and magnesium. The values of these concentrations in the studied water samples indicate that they constitute a chemically suitable environment for corrosion and precipitation reactions, additionally, the pH values for the studied water samples ranged between (6.02 - 8.2), EC ranges between (266 - 3054) microseism/cm, temperature values ranged from 34.8 C0 to 37.4 C0, TDS between (270 - 1936 ppm). It was found that the Aggressiveness coefficient ranged between (9.03 to 11.58) and this indicates that the water in this region is highly corrosive and the Ryzner coefficient ranges between (8.98 -11.49), which indicates the water condition is the cause of corrosion. The Langelier coefficient index shows that the negative values are the cause of the increase in wear rate values from -2.73 to -0.89.

Effects of nano fish bone on gelling properties of tofu gel coagulated by citric acid.

Tofu gel was made by using citric acid (0.14%) in combination with varied volumetric ratios (e.g., 0-4%) of nano fish bone (NFB). The gel properties were investigated by colorimetry, penetration tests, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. As the volumetric ratio increased from 0 to 3%, the soluble calcium concentrations of soymilk linearly increased from 1.78 to 6.42mg/mL. Correspondently, yield, moisture and texture values of the tofu gel increased continuously (p<0.05) while syneresis and whiteness decreased (p<0.05). Furthermore, ionic bonds, hydrophobic interactions and hydrogen bonds increased by 140%, 40% and 10%, respectively. With the addition of NFB, the α-helices of the soybean proteins changed to β-sheets and random coil structures. Additionally, the tofu gel network became more orderly and denser. The results confirmed that NFB can be utilized as a functional coagulant ingredient to improve the properties of acid-induced tofu gels.

Incorporating whey protein aggregates produced with heat and ultrasound treatment into rennet gels and model non-fat cheese systems

Native whey proteins (WP) are expulsed from cheese coagulation during syneresis. Although incorporating denatured WP aggregates into cheese gels has been previously proposed to improve the overall cheese yield, the effects of WP aggregate properties on gelation kinetics and protein retention are not yet fully understood. In this study, heat and power ultrasound were used to produce denatured whey protein aggregates with a wide range of sizes. The effects of size and hydrophobicity differences in WP aggregates produced by heat and heat coupled with ultrasound were investigated in relation to the kinetics of rennet gelation and protein retention in model non-fat cheddar cheeses. Rheological measurements showed that sufficiently large, denatured WP aggregates could avoid impairment of rennet gelation caused by native WP, irrespective of changes in the soluble calcium concentration or the surface hydrophobicity of the aggregates. WP aggregates formed by the combined heat and ultrasound treatment were more hydrophobic than the larger heat-treated aggregates and were better retained in the cheese. However, inclusion of sufficiently large aggregates in cheese milk conferred an openness to the cheese microstructure and showed promise in improving the otherwise rigid non-fat cheese.

Desiccation Cracking Behavior of Clayey Soils Treated with Biocement and Bottom Ash Admixture during Wetting–Drying Cycles

Desiccation cracking considerably impairs the hydraulic and mechanical properties of clayey soils that are critical to the long-term performance of infrastructure foundations and earth structures. Typical crack remediation methods are associated with high labor and maintenance costs or the use of environmentally unfriendly chemicals. Recycling waste materials and developing biomediated techniques have emerged as green, sustainable soil stabilization solutions. The objective of this study was to investigate the feasibility of soil crack remediation through use of bottom ash admixtures and microbial-induced calcite precipitation (MICP). We carried out cyclic wetting–drying tests to characterize the effects of bottom ash and MICP on the desiccation cracking behaviors of bentonite soils. Two groups of soil samples that contained different percentages of bottom ash (0%, 20%, 40% by weight) were prepared for cyclic water and MICP treatments, respectively. The desiccation cracking patterns captured by a high-resolution camera were quantified using image processing. We also employed scanning electron microscopy for microstructural characterizations. Experimental results revealed that cyclic water treatment resulted in more cracking, whereas cyclic MICP treatment improved soil strength owing to the precipitation of calcite crystals on the soil particle surface and inside the interparticle pores. Adding bottom ash to bentonite reduced the plasticity of the mixture, promoted the flocculation of clay particles by cation exchange, and also provided soluble calcium to enhance calcite precipitation. This study demonstrates the potential of bottom ash and MICP for crack remediation and brings new insights into the design and assessment of sustainable infrastructures under climate changes.