Alginate Gel Research Articles

Efficient Elimination of Inorganic/Organic Pollutants by Fe3O4/biochar@sodium Alginate Gel Beads.

The magnetic composite gel bead (Fe3O4-C@SA GB) adsorbent was prepared by sodium alginate (SA) crosslinking with pitaya peel-derived porous carbons (PPDPCs) and magnetic iron oxide nanoparticles (Fe3O4 NPs). The adsorption effects of Fe3O4-C@SA GBs on heavy metal ions (HMIs) and 17 β-estradiol (E2) in water are evaluated by classical kinetic models and isotherm models. The pseudo-second-order kinetic model shows that Fe3O4-C@SA GBs have maximum adsorption capacities of 9.62, 7.50, and 13.61 mg/g for Cu (II), Cd (II), and Pb (II), respectively. Meanwhile, the highest adsorption performance of the synthesized gel beads to E2 is of ca. 276.3 mg/g. In addition, the Fe3O4-C@SA GBs can still maintain a high level of adsorption efficiency after five adsorption cycles, displaying economic efficiency and reusability. Hence, this work provides useful insights into the efficient adsorption elimination of pollutants in sewage and the corresponding adsorption mechanisms.

Thermo-controlled microfluidic generation of monodisperse alginate microspheres based on external gelation.

Droplet-based microfluidic systems have received much attention as promising tools for fabricating monodisperse microspheres of alginate solutions with high accuracy and reproducibility. The immediate and simple ionotropic gelation of alginate, its biocompatibility, and its tunability of mechanical properties make it a favorable hydrogel in the biomedical and tissue engineering fields. In these fields, micron-sized alginate hydrogel spheres have shown high potential as cell vehicles and drug delivery systems. Although on-chip microfluidic gelation of the produced alginate droplets is common, several challenges remain. Complicated chemical and microfabrication processes are required, and the risk of microchannel clogging is high. In the current study, we present an easy-to-use microfluidic external gelation process to produce highly spherical and monodisperse microspheres from very low-concentrated alginate-RGD solution [0.5% (w/v)]. To accomplish this, gelatin, a thermo-sensitive and inexpensive biomaterial, was incorporated into the alginate solution as a sacrificial biomaterial that mediates the off-chip external gelation of the alginate with Ca2+, and avoids droplet coalescence. Utilizing the methodology mentioned above, we successfully generated monodisperse alginate microspheres (AMs) with diameters ranging from 27 μm to 46 μm, with a coefficient of variation of 0.14, from a mixture of Arg-Gly-Asp (RGD)-modified very low viscosity alginate and gelatin. These RGD-AMs were used as microcarriers for human umbilical vein endothelial cells. The described easy-to-use and cost-effective microfluidic off-chip external gelation strategy exhibits comparable advantages to on-chip external gelation and demonstrates superiority over the latter since clogging is impossible.

Methylene Blue Solid Alginate Gels for Photodynamic Therapy: The Peculiarities of Production and Controlled Release of the Dye

The purpose of this work is to establish the influence of the nature of solid alginate gels (alginic acid, AAG; calcium alginate, CAG) and the conditions of methylene blue (MB) introduction to alginate matrices upon its release into aqueous media. MB is an active photosensitizer, which is used in the photodynamic therapy of tumors and purulent wounds. Solid alginate gels based on AAG and CAG were obtained by adding hydrochloric acid and calcium chloride to sodium alginate. The dye was introduced into the matrix either at the stage of gelation or by immersing the gel in an aqueous solution of the dye. It has been shown that the strength of the dye’s attachment to AAG is higher than that of CAG, which leads to a higher rate of MB release from CAG into aqueous media. It has also been shown that, when introduced at the stage of gel formation, MB is released into both the water and buffer solutions. When MB is introduced by gel immersion into an MB solution, the dye may be released only into salt solutions. An alginate gel with immobilized MB can be used as a solid photosensitizing system with the controlled release of the photoactive agent into the wound cavity for photodynamic treatment.

Encapsulation and release of salidroside in myofibrillar protein‑sodium alginate gel: Effects of different M/G ratios of sodium alginate

Myofibrillar protein‑sodium alginate (MP-SA) gels play a pivotal role in the development of functional food gels. Salidroside (SAL) is promising component but suffers from low bioavailability, necessitating effective delivery systems. This study introduces M/G ratio factor into classical theoretical MP-based gel models, and use for the SAL delivery. The findings indicate that SA significantly enhances gel properties and functions. Scanning electron microscopy, liquid chromatography, and low-field nuclear magnetic resonance confirmed that the addition of SA improved microstructure, water retention, and thus reduced SAL loss during processing. Digestion simulations revealed the influence of SA type on SAL release kinetics. Molecular docking showed that SA with lower M/G ratio binds more readily to MP, a key determinant of gel performance. These insights provide a novel theoretical basis for MP-SA gels and offer a new perspective on the delivery of bioactive compounds in functional foods.

Inkjet-based facile fabrication of a copper ferrocyanide-embedded magnetic alginate microadsorbent for highly enhanced cesium removal

For the first time, simple and facile fabrication of a magnetic alginate microadsorbent via piezoelectric inkjet technology was developed for the selective removal of 137Cs via magnetic separation. Through the ejection of an alginate solution containing potassium ferrocyanide and magnetic nanoparticles (MNPs) into a Cu2+ solution via an inkjet device, the fabrication of a copper ferrocyanide-embedded magnetic alginate microadsorbent (CuFC-MAM) with an average size of 39.38 μm was easily achieved in a one-pot fabrication process; here, the Cu2+ ions acted as both a cross-linker for the gelation of alginate and a Cu source for the in situ synthesis of CuFC with potassium ferrocyanide. The Cs adsorption behavior of CuFC-MAM was effectively fitted by the pseudo-second-order kinetic model and Langmuir isotherm. Owing to the increased specific surface area of CuFC-MAM, its pseudo-second-order rate constant and maximum adsorption capacity were 76.54 and 1.486 times greater than those of CuFC-embedded magnetic alginate macroadsorbents fabricated without inkjet devices. Compared with other Cs adsorbents, CuFC-MAM presented the highest maximum capacity and Kd value; these results were attributed to the high content of CuFC in CuFC-MAM (50.15%). In addition, our CuFC-MAM exhibited an excellent removal efficiency of radioactive Cs, exceeding 99% from seawater.

One-step preparation of orange-red Emitting carbon dots for visual detection of copper ions in the water environment

In this study, p-aminophenol and o-phenylenediamine were used as materials in a straightforward one-step hot solvent approach for generating a nitrogen-doped carbon dot. Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and UV–Vis analysis were used to analyze the resultant CDs composites. Furthermore, fluorescence and absorption spectroscopy were used to assess the optical characteristics. Following the addition of Cu2+, CDs’ fluorescence was quenched statically, resulting in the formation of a non-fluorescent complex. Based on this, a highly selective fluorescent technique was developed with a detection limit of 2.71 μM and a relevant linear range of 10–100 μM for Cu2+. More convenient to carry and detect sodium alginate gel beads doped with carbon dots were prepared for visual detection of Cu2+. Using this method, Cu2+ ions from various environmental sources can be detected rapidly, cheaply, environmentally friendly, and selectively.

Microscopic mechanism of oxygen consumption inhibitor delaying the oxidation of coal

In order to inhibit the coal-oxygen complex that triggers spontaneous coal combustion, a retardant consisting of sodium alginate solution, sodium bicarbonate, inorganic salt MgCl2 and deoxidiser that can achieve multiple effects of hysteresis and oxygen depletion was developed. Taking the sulfur-containing side-chain reactive group of coal molecule -CH2-SH as the object of study, the Gaussian 16W procedure and density-functional-transfer theory (DFT) were applied to investigate the electrostatic potential and reaction tendency, oxygen adsorption capacity, front-line orbitals, natural bonding capacity, and oxygen adsorption capacity of the reactive group before and after the formation of the complexes with Na+ and Mg2+, using the solvation effect at the level of B3LYP/6-31G(d, p), respectively. The changes of electrostatic potential and reaction tendency, oxygen adsorption, front orbitals, natural bonding orbitals and charge transfer before and after the formation of complexes between -CH2-SH reactive groups and Na+, Mg2+, respectively. Comparative analysis of the interaction with oxygen before and after the formation of coordination blocking structure of coal and inorganic salts in gaseous environment, aqueous environment and retarded oxygen-depleting sodium alginate blocking solution environment, respectively. The calculated results show that the side chain of the aromatic ring of the raw coal is the active site for easy adsorption of oxygen, and the stability of the coordination blocking structure is significantly enhanced under the environment of hysteretic oxygen-depleting sodium alginate gel blocking agent, and the adsorption of oxygen before and after the coal molecule combines with Na+ and Mg2+ is the weakest under the environment of hysteretic oxygen-depleting sodium alginate gel blocking agent; The absolute value of the HOMO orbital energy increases the most, and the energy level difference (ELUMO - EHOMO) of the complexes increases the most; the natural bonding orbital analysis reveals that the lone pair of electrons of S atoms in -CH2-SH under the environment of hysteresis oxygen depletion sodium alginate gel blocker has a strong coordination effect with Na+ and Mg2+. In the hysteresis oxygen depletion sodium alginate gel resist environment, the stability of the coordination blocking structure is strengthened due to the moderateness of the dielectric constant, and its oxygen depletion also reduces the number of O2 molecules, which further reduces the adsorption and collision chances between the two, and a more desirable blocking effect can be obtained. The results reveal the micro-mechanism of the hysteresis oxygen depletion inhibitor in preventing spontaneous combustion of coal, which can provide a reference for further improving the inhibition effect of the inhibitor.

Small molecular weight alginate gel porogen for the 3D bioprinting of microvasculature.

In order to recreate the complexity of human organs, the field of tissue engineering and regenerative medicine has been focusing on methods to build organs from the bottom up by assembling distinct small functional units consisting of a biomaterial and cells. This bottom-up engineering requires bioinks that can be assembled by 3D bioprinting and that permit fast vascularization of the construct to ensure survival of embedded cells. To this end, a small molecular weight alginate (SMWA) gel porogen is presented herein. Alginate is a biocompatible biomaterial, which can be easily converted into small porogen gels with the procedure reported in this article. The SMWA porogen is mixed with photo-crosslinkable hydrogels and leached from the hydrogel post-crosslinking to increase porosity and facilitate vascularization. As a proof of concept, this system is tested with the commonly used biomaterial Gelatin Methacryloyl (GelMA). The SMWA porogen-GelMA blend is proven to be bioprintable. Incubating the blend for 20min in a low concentration phosphate buffered saline and sodium citrate solution significantly reduces the remaining porogen in the hydrogel . The intent to completely leach the porogen from the hydrogel was abandoned, as longer incubation times and higher concentrations of phosphate and citrate were detrimental to endothelial proliferation. Nonetheless, even with remnants of the porogen left in the hydrogel, the created porosity significantly improves viability, growth factor signaling, vasculogenesis, and angiogenesis in 3D bioprinted structures. This article concludes that the usage of the SMWA porogen can improve the assembly of microvasculature in 3D bioprinted structures. This technology can benefit the bottom-up assembly of large scaffolds with high cell density through 3D bioprinting by improving cell viability and allowing faster vascularization.

Essential oil release from zein particles as modulated by inorganic coating and biopolymeric networking

Zein particles (ZPs) have emerged as a popular delivery carrier for hydrophobic bioactive substances. However, some lipophilic compounds are easily released from ZPs because of the low polarity compatibility between zein and the compounds. The loss of encapsulated substances is particularly evident for citrus essential oil (CEO), an extremely hydrophobic ingredient. The premature release of CEO from ZPs was mitigated by developing a modification approach using ZPs coated with calcium phosphate (CaP) and networked with Ca2+-alginate gel (CaAlg). The approach involved the preparation of ZPs (through the antisolvent addition procedure) in phosphate buffer, and supplementation of the particles consecutively with sodium alginate and Ca2+ ions (as CaCl2). This procedure resulted in retention of up to 28% of CEO within ZPs after the accelerated storage experiment. Under in vitro gastric and intestinal digestion condition, the CaP-coated and CaAlg-networked ZPs had a significantly lower release of CEO compared to their non-coated and non-networked counterparts. The morphology of the particles was investigated by scanning (SEM) and transmission (TEM) electron microscopies, as well as confocal laser scanning microscopy. SEM imaging showed that sodium alginate could facilitate the formation of CaP coating through preventing CaP crystallization. CaP coating also decreased the ZPs fusion/aggregation as evidenced by comparing the ζ-potential and microscopic morphology of the particles. Examination of the infrared spectra of the particles revealed that the formation of CaP coating occurred at Ca2+ ion concentrations ≥ 10 mM.

Simultaneous viscoelasticity and sprayability in antimicrobial acetic acid-alginate fluid gels

Acetic acid is a promising alternative to antibiotics for topical applications, particularly burn wounds, however its site specificity and retention are impaired by poor material properties. In this study, acetic acid was investigated as both the gelling agent and antimicrobial active in alginate fluid gels. The formed microstructure was found to be directly dependent on acetic acid concentration, leading to highly tuneable material properties. At clinically relevant concentrations of 2.5–5 % acetic acid, the fluid gels were elastically dominated at rest, with viscosities up to 7 orders of magnitude greater than acetic acid alone. These material properties imparted long term surface retention and microparticle barrier function, not seen with either acetic acid or alginate solutions. Most notably, sprayability was enhanced simultaneously with the increased viscosity and elasticity due to the introduction of a discretised microstructure, leading to a remarkable tenfold increase in spray coverage. Formulation was found not to inhibit antimicrobial activity, despite the less acidic pH, with common burn wound pathogens Staphylococcus aureus and Pseudomonas aeruginosa being equally susceptible to the fluid gels as to acetic acid solutions.

A novel technique for skull base reconstruction in craniofacial fibrous dysplasia surgery using three-dimensional printing and a dental alginate mold: illustrative case.

Fibrous dysplasia is a rare and benign skeletal lesion characterized by fibrous tissue proliferation due to an abnormal osteogenesis replacing normal bone. An 18-year-old male with fibrous dysplasia of the left sphenoid, ethmoid, orbit, and frontal bones was managed with excision and skull base reconstruction. After complete removal of the tumor, skull base reconstruction was commenced by making a reverse temporalis flap and placing it over the opened paranasal sinuses for a robust vascularized graft, followed by an abdominal fat graft, and then a pedicled pericranal flap was added to complete the multilayer onlay graft. To recreate the skull base, a mirror image of the contralateral skull base was constructed using three-dimensional (3D) printing, and the 3D-printed model was sterilized prior to the surgery. Intraoperatively, the model was then pressed onto dental alginate gel to make a negative mold. This was used to make the definitive flap using polymethylmethacrylate. Temporoplasty was also performed using polymethylmethacrylate to fill the defect left by the temporalis graft. The patient recovered well following the procedure. Appropriate, personalized skull base reconstruction techniques can be successfully done with 3D printing using alternative low-cost materials and implements, especially following resection of cases like craniofacial fibrous dysplasia. https://thejns.org/doi/10.3171/CASE24262.

Development of a Bio-Selecting Agent Based on Immobilized Bacterial Cells with Amidase Activity for Bio-Detection of Acrylamide

Actinobacteria cells Rhodococcus erythropolis 4-1 and Rhodococcus erythropolis 11-2 and Proteobacteria Alcaligenes faecalis 2, which have amidase activity, were immobilized by entrapping barium alginate and agarose into the gel structure, as well as by obtaining biofilms on thermally expanded graphite (TEG). The operational stability of such immobilized biocatalysts after storage in frozen and dehydrated form was determined, and a prototype of a conductometric acrylamide biosensor based on such a bioselective agent was developed. The most preferred method for storing immobilized cells was freezing at temperatures from –20 to –80°C; long-term storage is also possible wet at 4–25°C. It was shown that these cells were most preferable for the biodetection of acrylamide A. faecalis 2, immobilized in an agarose gel structure. An agarose gel with bacterial cells immobilized in its structure had greater mechanical strength and stability during successive cycles of conversion of acrylamide into acrylic acid compared to barium alginate gel. The mechanical strength of barium alginate gel can be enhanced by the addition of carbon nanomaterials during cell immobilization. Growing biofilms on carbon materials used for manufacturing electrodes is also promising. Biofilms of R. erythropolis 11-2 on TEG are capable of converting acrylamide into acrylic acid in more than 20 reaction cycles while maintaining at least 50% amidase activity.

A novel nCP-PVA@ACA composite with core–shell structure for efficient formaldehyde removal from air

Removing formaldehyde from indoor environments is crucial for the health of residents. However, developing a highly efficient and cost-effective material that is safe and stable and capable of continuously removing formaldehyde from ambient air is challenging. In this study, an environmentally friendly plant composite active calcium alginate gel (nCP-PVA@ACA) was prepared by fixing slow-release nanosized calcium peroxide (nCP-PVA) and active components from cactus stems into a three-dimensional network structure of a calcium alginate gel. The microscopic morphology, chemical composition, and structure of nCP-PVA@ACA were characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and Brunauer-Emmett-Teller. In the purification column, nCP-PVA@ACA was used as a filler, which effectively removed formaldehyde from the airflow. The results indicate that nCP-PVA was well dispersed and encapsulated by the calcium alginate gel. The formaldehyde removal efficiency of nCP-PVA@ACA ranged from 90.56 % to 98.51 % when the formaldehyde concentration in the air was in the range of 0.146–0.984 mg·m−3, with a maximum removal capacity of 89.31 mg·kg−1 (based on the dry weight of Na alginate). After 3.0 h of continuous purification, the formaldehyde concentration in the treated airflow was reduced to 0.020–0.053 mg·m−3, which was significantly lower than the recommended limit of 0.08 mg·m−3 of formaldehyde in ambient air. The synergistic effects of plant active components and slow-release nCP are key to effective formaldehyde removal. This study highlights the potential of calcium peroxide for air pollution control, providing new insights and theoretical support for their applications.

Curcumin-Loaded Liposomes in Gel Protect the Skin of Mice against Oxidative Stress from Photodamage Induced by UV Irradiation.

Prolonged exposure to ultraviolet (UV) irradiation can cause oxidative stress in the skin, accompanied by rapid immunosuppressive effects, resulting in a peroxidation reaction throughout the body. Curcumin (Cur), as the bioactive compound of turmeric, is a natural polyphenol with potent antioxidant properties but is often overlooked due to its poor solubility and low bioavailability. In this study, curcumin-loaded liposomes in a sodium alginate gel complex preparation were designed to improve the bioavailability of curcumin and to study its preventive effect on photodamage. Cur-loaded liposomes (Cur-L), Cur-loaded gel (Cur-G) based on an alginate matrix, and curcumin-loaded liposomes in gel (Cur-LG) were prepared, and their antioxidant effects and drug diffusion abilities were evaluated. The antioxidant capacity of Cur, Cur-L, Cur-G, and Cur-LG was also studied in a mouse model of photodamage. Cur had the highest antioxidant activity at about 4 mg/mL. Cur-LG at this concentration showed antioxidant effects during 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and H2O2 experiments. During the UV light damage test, Cur-LG demonstrated the ability to effectively neutralize free radicals generated as a result of lipid peroxidation in the skin, serum, and liver, thereby enhancing the overall activity of superoxide dismutase (SOD). In conclusion, using Cur-LG may protect against epidermal and cellular abnormalities induced by UV irradiation.

A New Method for Obtaining Monospecies and Binary Cultures of Staphylococcus spp. in Alginate Gel and the Study of the Action of Active Compounds on These Cultures on the Example of Catecholamines.

A simple and efficient method for obtaining monospecies and binary Staphylococcus aureus and Staphylococcus epidermidis cultures in sodium alginate gel matrix mimicking the natural microenvironment of the nasal cavity was proposed. The cultures were used for studying the effect of norepinephrine on monospecies and binary communities of two types of bacteria, S. aureus (invasive strain) and S. epidermis (commensal strain). After 24-h incubation, S. aureus predominated in the binary community, but later it was replaced by S. epidermis. Norepinephrine at higher concentrations accelerated this process without principally changing it. The model can be used to develop more effective complex antimicrobial drugs.

Alginate gels and nanocomposites with prolonged release of drugs and plant protection agents

Alginate gels and nanocomposites with prolonged release of drugs and plant protection agents

The Study of Calcium Chloride Effect on Silver Nanoparticles Capping with Roselle Extract Granule against Aggregatibacter actinomycetemcomitans

Abstract Objectives The primary aim of this research is to investigate the influence of calcium chloride on the synthesis of silver nanoparticles coated with roselle extract and enclosed within alginate and calcium chloride (SNP-Ro-CaCl2) beads, designated as SNP-Ro-CaCl2 beads. Additionally, the study aims to assess their antimicrobial activity. Materials and Methods For the preparation of SNP-Ro-CaCl2 beads, SNPs and alginate gel were mixed, followed by dropping in three different concentrations of CaCl2 solution (1%, 3%, and 5% w/v). The morphological structure of the SNP-Ro-CaCl2 beads was analyzed using a stereoscope and scanning electron microscope (SEM). Over a period of 14 days, the release of SNPs was monitored using ultraviolet-visible (UV-Vis) spectroscopy. Additionally, the activity against Aggregatibacter actinomycetemcomitans was evaluated using the disk diffusion technique. Statistical Analysis The data for this experiment were analyzed using one-way analysis of variance (ANOVA) and Scheffe's method. Results The results revealed that varying concentrations of calcium chloride had distinct crosslinking effects on alginate, resulting in different voids and porosity within the SNP-Ro-CaCl2 beads. In the SNP-Ro-1% CaCl2 beads, the inner element exhibited higher porosity, facilitating faster activation and greater efficiency in releasing SNPs. Regarding activity against A. actinomycetemcomitans after 14 days, SNP-Ro-1% CaCl2 beads showed a larger inhibition zone diameter compared to other concentrations, while no statistically significant difference in the inhibition zone diameter was observed between SNP-Ro-3% CaCl2 and SNP-Ro-5% CaCl2 beads. Additionally, it was observed that the antimicrobial effectiveness diminished after 17 days through testing of the lifetimes of the three concentrations. Conclusions This study developed a method for depositing SNP-Ro into alginate gel and crosslinking it with CaCl2 to produce small beads for the sustained release of SNP-Ro in periodontal lesions. Consequently, the SNP-Ro-CaCl2 beads have the potential to be developed as adjunctive locally delivered antimicrobial agents in periodontal therapy.

Structure and Dynamics of Water in Polysaccharide (Alginate) Solutions and Gels Explained by the Core-Shell Model.

In both biological and engineered systems, polysaccharides offer a means of establishing structural stiffness without altering the availability of water. Notable examples include the extracellular matrix of prokaryotes and eukaryotes, artificial skin grafts, drug delivery materials, and gels for water harvesting. Proper design and modeling of these systems require detailed understanding of the behavior of water confined in pores narrower than about 1 nm. We use molecular dynamics simulations to investigate the properties of water in solutions and gels of the polysaccharide alginate as a function of the water content and polymer cross-linking. We find that a detailed understanding of the nanoscale dynamics of water in alginate solutions and gels requires consideration of the discrete nature of water. However, we also find that the trends in tortuosity, permeability, dielectric constant, and shear viscosity can be adequately represented using the "core-shell" conceptual model that considers the confined fluid as a continuum.

Effect of calcium concentration on metastasis of hepatocellular carcinoma cells cultured in alginate gel beads

Changes in sodium alginate and calcium ion concentrations have a considerable impact on the structural properties of calcium alginate gel (ALG) beads, consequently influencing the biological characteristics of the cells encapsulated within them. This study aimed to examine the effects of calcium on the metastatic potential of hepatocellular carcinoma (HCC) cells encapsulated in ALG beads. The results showed that the invasion ability of HCC cells significantly increased when they were encapsulated in beads prepared with a calcium concentration of 200 mM compared to those prepared with a calcium concentration of 50 mM. Furthermore, the expression levels of genes related to metastasis were significantly elevated in ALG beads prepared with a calcium concentration of 200 mM. Specifically, the expression of activated matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and urokinase-type plasminogen activator system proteins was found to be high. Conversely, the expression of phosphatase and tensin homolog deleted on chromosome 10 was observed to be significantly reduced. These findings indicate that manipulating the calcium ion concentration during the fabrication of ALG beads enables the generation of three-dimensional HCC cells with varying metastatic capacities. This model offers a valuable tool for investigating the mechanisms underlying liver cancer metastasis and screening potential therapeutic drugs.

Sweet potato protein hydrolysates solidified calcium-induced alginate gel for enhancing the encapsulation efficiency and long-term stability of purple sweet potato anthocyanins in beads

Based on the previous research, this work aimed to reveal the effect of sweet potato protein hydrolysates (SPPHs) with different molecular weights (1000, 3000, and 8000 Da) at 0.5 % on the gelation behavior of calcium-induced sodium alginate (SA), and the encapsulation efficiency and storage stability of purple sweet potato anthocyanins (PSPA) in calcium-induced alginate gel beads was determined. Results indicated that SPPHs with a molecular weight of 8000 Da formed hydrogen bonds and other interactions with SA, which strengthened the internal network connections of the gel, significantly enhanced the gel and effectively filled its pores. The highest encapsulation efficiency was achieved at 87.27 %, compared to 61.73 % without SPPHs. Additionally, stored at 37 °C for 21 days after commercial sterilization, the residual concentration of PSPA with SPPHs was 2.50 times higher than that without SPPHs. SPPHs can enhance the encapsulation efficiency of PSPA and retard their release in gel beads.