Alginate Hydrogel Beads Research Articles

Green synthesis of benzimidazole derivatives using copper(II)-supported on alginate hydrogel beads

The study addresses the challenge of developing sustainable and efficient catalytic systems for the synthesis of benzimidazole derivatives, which are of significant importance in the field of medicinal chemistry due to their diverse biological activities. The objective is to develop a recyclable and environmentally friendly catalyst utilizing copper(II)-loaded alginate hydrogel beads, which can facilitate the synthesis of these compounds while minimizing environmental impact. The preparation process entails crosslinking sodium alginate with copper(II) ions to form hydrogel beads, which are then washed and characterized through techniques such as scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Inductively coupled plasma (ICP), and Zeta potential to analyses the morphology, composition and porosity of the beads. The catalytic performance is evaluated through recycling tests, which demonstrate the catalyst's ability to maintain selectivity and activity over multiple reaction cycles. The Cu(II)-Alg hydrogel beads were used for synthesizing substituted benzimidazole derivatives in a water-ethanol solvent at room temperature. This method offers significant advantages, including extremely mild reaction conditions, short reaction times (<1 h), high yields (70–94 %), and ease of processing. The most significant results indicate that the Cu(II)-alginate catalyst exhibits a high loading capacity and retains its catalytic efficiency for at least 3 cycles, thereby highlighting its potential for sustainable applications in organic synthesis.

Enhanced catalytic efficiency and ionic liquid tolerance of entrapped cellulase for single-step mixed cabbage residue saccharification

This study explores the enhancement of catalytic efficiency and 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) tolerance in the single-step saccharification of mixed cabbage residue (MCR) biomass using entrapped cellulase. Entrapping cellulase in calcium alginate hydrogel beads achieved an entrapment efficiency of 75.90 ± 1.83 %. In hydrolysis systems with 2 % and 10 % [Emim][OAc], the entrapped cellulase demonstrated 5.3 % and 6.5 % higher activity than free cellulase, respectively. After five cycles, the entrapped cellulase retained 93 % and 87 % of its initial activity in 0 % and 2 % [Emim][OAc] hydrolysis systems, respectively. Remarkably, cumulative glucose yields with entrapped cellulase were 3.51 and 3.10 times greater than those with free cellulase in 0 % and 2 % [Emim][OAc] hydrolysis systems, respectively. These results highlight the superior performance of entrapped cellulase in maintaining enzyme activity and improving glucose yields. Notably, while [Emim][OAc] is effective in separate pretreatment stages, its addition is unnecessary for the single-step saccharification of MCR biomass. This study underscores the promising potential of entrapped cellulase as a catalyst in enhancing the efficiency of biomass saccharification processes.

Covalent organic framework composite hydrogel sorbent beads for vortex-assisted dispersive miniaturized solid phase extraction of parabens and synthetic phenolic antioxidants in foodstuffs

A covalent organic framework composite hydrogel sorbent beads was fabricated for the vortex-assisted dispersive miniaturized-solid phase extraction and determination of parabens and synthetic phenolic antioxidants from food matrices. The covalent organic framework was entrapped into alginate hydrogel beads. This composite sorbent effectively adsorbs analytes through hydrophobic, π-π and hydrogen bonding interactions. Under optimal extraction conditions, the developed method demonstrated good linearity from 1.00 to 100 µg kg−1 for methyl paraben and 2.00 to 100 µg kg−1 for tertiary butylhydroquinone, propyl paraben, butyl paraben and butylated hydroxyanisole. Limits of detection ranged from 0.25 to 0.50 µg kg−1. The developed sorbent was applied to the extraction of parabens and synthetic phenolic antioxidants from tomato paste, mayonnaise, infant milk powder and coffee creamer samples. The analytes were separated and quantified by high-performance liquid chromatography, achieving recoveries ranging from 89 to 98 % with RSDs lower than 7 %. The vortex-assisted extraction approach was efficient, and the fabricated sorbent could be reused for up to eight cycles. The greenness of the methodology was also evaluated.

Alginate-Based Hydrogel Bead Reinforced with Montmorillonite Clay and Bacterial Cellulose-Activated Carbon as an Effective Adsorbent for Removing Dye from Aqueous Solution.

According to environmental concerns related to water pollution, this study aims to develop a novel hydrogel bead as a biocompatible and efficient adsorbent by integrating bacterial cellulose-activated carbon (BCAC) and montmorillonite (MT) in alginate hydrogel (ALG). The ionotropic gelation method was applied to the fabrication of BCAC/MT/ALG hydrogel beads. The BCAC/MT/ALG hydrogel bead exhibited significantly higher tensile strength, Young's modulus, and thermal stability, with ~1.4 times higher adsorption uptake of methylene blue (MB) from aqueous solution as compared to the pristine ALG bead. The textural properties, including specific surface area and porosity, were beneficial to accommodate the size of cationic MB as the target molecule. This resulted in a remarkable MB adsorption uptake of 678.2 mg/g at pH 7 and 30 °C. The adsorption isotherm showed the best fit for the nonlinear Redlich-Peterson isotherm model. Experimental adsorption data were well-described by the pseudo-second order kinetic model, with R2 values reaching 0.997. In addition, the adsorbent bead demonstrated easy regeneration with high reusability with approximately 75% of MB removal after being used for six cycles. Therefore, BCAC/MT/ALG bead represents an eco-friendly, cost-effective, and highly efficient adsorbent for MB removal from water and could potentially be used for removal of a wide range of cationic dye pollutants from wastewater.

Adsorption behavior of solids incorporated in alginate hydrogel beads using herbicides 2,4-D and paraquat as test molecules

This study investigates the behavior of adsorbent solids within three-dimensional networks of biopolymers. Two chemically different herbicides, 2,4-D and paraquat (PQ) were employed as test molecules. Alginate (ALG) hydrogels in bead form were synthesized, incorporating activated carbon (PSCA) and montmorillonite clay (MMT) simultaneously and in varying proportions, resulting in multicomponent beads. The Langmuir isotherm parameters, KL (L mmol−1) and qmax (mmol g−1), in the adsorption of herbicides on beads with an increasing amount of montmorillonite (MMT) were as follows: For PQ, KL values were 10.709, 61.951, 162.33, 223.27, and qmax values were 0.0711, 0.1484, 0.2135, 0.2497. For 2,4-D, KL values were 13.360, 8.3234, 7.4126, 5.4308, and qmax values were 0.9529, 0.7096, 0.6534, 0.5881. The values clearly demonstrates that, even when solids are mixed in the hydrogel network, their reactive sites remain exposed, interacting with molecules to which they have greater affinity. Adsorption was also investigated on identical materials using binary mixtures of herbicides, revealing trends similar to those observed for individual solutions. Moreover, it was demonstrated that the adsorption capacity of multicomponent beads is equivalent to that achieved by proportionally mixing beads synthesized exclusively with clay or activated carbon. This suggests the tangible possibility of creating on-demand adsorbents by synthesizing distinct hydrogels, each incorporating a specific solid. Subsequently, drying, storing, and mixing them based on the target contaminant for retention are feasible. Finally, a column was packed with a proportional mixture of beads and successfully retained PQ and 2,4-D using a flow-through system.

Stability and Bioaccessibility of Carotenoids from Sea Buckthorn Pomace Encapsulated in Alginate Hydrogel Beads.

Carotenoids, the natural pigments that confer the bright orange color of sea buckthorn berries, are also associated with several health benefits, such as antioxidant activity and skin and eye protection. Due to their lipophilic nature and localization, carotenoids are largely retained in the sea buckthorn pomace (SBP) resulting from juice production. Carotenoids from SBP (70.03 mg/100 g DW), extracted and characterized by HPLC-PDA, contained zeaxanthin (free and esterified) and beta-carotene as major compounds. The SBP carotenoids-enriched sunflower oil was further encapsulated in Ca-alginate hydrogel beads (98.4% encapsulation efficiency) using ionotropic gelation. The hydrogel beads were characterized by confocal laser scanning microscopy and scanning electron microscopy. Fairly good stability (>64%) of the encapsulated carotenoids in the alginate hydrogel beads during storage (30 days, 4 °C and 25 °C) was found, with zeaxanthin esters being the most stable compounds, for all the experimental conditions. The bioaccessibility of the total carotenoids (INFOGEST protocol) was 42.1 ± 4.6% from hydrated, and, respectively, 40.8 ± 4% from dehydrated SBP alginate hydrogel beads. The addition of yogurt to the dehydrated hydrogel beads had a positive effect on the bioaccessibility of free and esterified zeaxanthin, but not on that of the carotenes. In conclusion, SBP is a valuable source of carotenoids which can be protected by encapsulation in alginate hydrogel beads, thus still retaining a good bioaccessibility.

Improved nitrate removal by polyvinyl alcohol/sodium alginate hydrogel beads entrapping salt-tolerant composite bioagent AHM M3

The effective removal of nitrate from mariculture wastewater remains challenging. Here, novel polyvinyl alcohol (PVA)/sodium alginate (SA) hydrogel beads entrapping the salt-tolerant composite bioagent AHM M3 (PVA/SA&AHM-M3) were prepared. The effects of dosage, pH, and temperature on nitrate removal by PVA/SA&AHM-M3 were investigated in batch experiments, and the improved nitrate removal and bacterial community shifts by PVA/SA&AHM-M3 were investigated in moving bed biological reactors (MBBRs). The results showed that the optimal preparation conditions for PVA/SA&AHM-M3 were PVA 10 % (m/v), SA 2 % (m/v), CaCl2 2 % (m/v), and 48 h crosslinking. The nitrate was completely removed within 48 h, with little accumulation of nitrite in the batch experiments at a PVA/SA&AHM-M3 dosage of 2 % (w/v), pH 7.0, and 30 °C. The MBBR system with PVA/SA&AHM-M3 completely removed nitrate and 88.0 % of total nitrogen. Additionally, Zobellella sp. MAD-44 and Halomonas alkaliphila HRL-9 were successfully enriched in the MBBR, confirming the contributions of PVA/SA&AHM-M3.

Preparation and characterization of agarose-sodium alginate hydrogel beads for the co-encapsulation of lycopene and resveratrol nanoemulsion

In the study, lycopene and resveratrol nanoemulsion hydrogel beads were prepared by using agarose‑sodium alginate as a carrier and the semi-interpenetrating polymer network technique, characteristics and morphologies were evaluated by scanning electron microscopy, fluorescence microscopy, rheological measurement. The synergistic antioxidant effect of lycopene and resveratrol was confirmed, the best synergistic antioxidant performance is achieved when the ratio of 1:1. To increase the solubility and improve the stability, the lycopene was prepared as solid dispersion added to the nanoemulsion. The encapsulation rate of lycopene and resveratrol reached 93.60 ± 2.94 % and 89.30 ± 1.75 %, respectively, and the cumulative release showed that the addition of agarose slowed down the release rate of the compound, which improves the applicability of lycopene and resveratrol and development of carriers for the delivery of different bioactive ingredients.

Fabrication of a reusable Ti3C2Tx MXene/ZnO@zinc alginate hydrogel for highly efficient and selective phosphate removal

Nano-Zinc oxide (ZnO) shows great potential for phosphate adsorption, but its tendencies to aggregate and lack of selectivity significantly impact adsorption efficiency. The synthesis of Ti3C2Tx MXene/ZnO complexes efficiently disperses ZnO, thereby enhancing selectivity, while encountering challenges in recovery. In this study, Ti3C2Tx MXene/ZnO-embedded zinc crosslinked alginate hydrogel beads (MXZA) were synthesized by solution-phase and ionic cross-linking methods as a highly efficient, selective, and reusable phosphate adsorbent. MXZA exhibited a maximum adsorption capacity of up to 86.67 mg/g of phosphate, and showed excellent adsorption selectivity in complex solutions (e.g., Cl-, NO3–, and SO42-). In short, the MXZA gel adsorbent has a wide application perspective in the effective and selective removal of phosphate from wastewater.

Building blocks toward sustainable biofertilizers: variation in arbuscular mycorrhizal spore germination when immobilized with diazotrophic bacteria in biodegradable hydrogel beads.

We investigated whether there was interspecies and intraspecies variation in spore germination of 12 strains of arbuscular mycorrhizal fungi when co-entrapped with the diazotrophic plant growth-promoting bacteria, Azospirillum brasilense Sp7 in alginate hydrogel beads. Twelve Rhizophagus irregularis, Rhizophagus intraradices, and Funneliformis mosseae strains were separately combined with a live culture of Azospirillum brasilense Sp7. Each fungal-bacterial consortia was supplemented with sodium alginate to a 2% concentration (v/v) and cross-linked in calcium chloride (2%w/v) to form biodegradable hydrogel beads. One hundred beads from each combination (total of 1200) were fixed in solidified modified Strullu and Romand media. Beads were observed for successful spore germination and bacterial growth over 14 days. In all cases, successful growth of A. brasilense was observed. For arbuscular mycorrhizal fungi, interspecies variation in spore germination was observed, with R. intraradices having the highest germination rate (64.3%), followed by R. irregularis (45.5%) and F. mosseae (40.3%). However, a difference in intraspecies germination was only observed among strains of R. irregularis and F. mosseae. Despite having varying levels of germination, even the strains with the lowest potential were still able to establish with the plant host Brachypodium distachyon in a model system. Arbuscular mycorrhizal spore germination varied across strains when co-entrapped with a diazotrophic plant growth-promoting bacteria. This demonstrates that hydrogel beads containing a mixed consortium hold potential as a sustainable biofertilizer and that compatibility tests remain an important building block when aiming to create a hydrogel biofertilizer that encases a diversity of bacteria and fungi. Moving forward, further studies should be conducted to test the efficacy of these hydrogel biofertilizers on different crops across varying climatic conditions in order to optimize their potential.

Visible-light-driven calcium alginate hydrogel encapsulating BiOBr0.75I0.25 for efficient removal of oxytetracycline from wastewater

Oxytetracycline (OTC), a widely used antibiotic, poses significant environmental risks due to its persistence in ecosystems. This study introduces a visible-light-driven photocatalytic hydrogel system for effectively removing OTC from wastewater. The system employs calcium alginate (CA) hydrogel beads encapsulating a BiOBr0.75I0.25 solid solution, which utilizes the synergistic effects of adsorption and visible-light-driven photocatalysis. The BiOBr0.75I0.25 solid solution photocatalyst was synthesized via a solvothermal method, while CA hydrogel beads encapsulating BiOBr0.75I0.25 were prepared through ionic gelation of sodium alginate with calcium chloride. The novel hydrogel, CA-BiOBr0.75I0.25, demonstrated rapid adsorption, capturing over 50 % of OTC within 30 min and achieving a 90.92 % degradation rate within 60 min under visible light. This performance is associated with the unique petal-like structure of BiOBr0.75I0.25 and the high surface area of the hydrogel, facilitating efficient charge separation and radical generation critical for photocatalytic activity. Additionally, the system showed excellent stability and reusability, maintaining an 83 % removal efficiency after five cycles. These findings highlight the potential of this novel hydrogel as a sustainable solution for advanced wastewater treatment technologies.

Preparation and Characterization of Silica-Coated Sodium Alginate Hydrogel Beads and the Delivery of Curcumin

In this study, to address the defects of sodium alginate (SA), such as its susceptibility to disintegration, silica was coated on the outer layer of sodium alginate hydrogel beads in order to improve its swelling and slow-release properties. Tetraethyl orthosilicate (TEOS) was used as the hydrolyzed precursor, and the solution of silica precursor was prepared by sol-gel reaction under acidic conditions. Then SA–silica hydrogel beads prepared by ionic crosslinking method were immersed into the SiO2 precursor solution to prepare SA–silica hydrogel beads. The chemical structure and morphology of the hydrogel beads were characterized by XRD, FTIR, and SEM, and the results showed that the surface of SA–silica beads was successfully encapsulated with the outer layer of SiO2, and the surface was smooth and dense. The swelling experiments showed that the swelling performance effectively decreased with the increase of TEOS molar concentration, and the maximum swelling ratio of the hydrogel beads decreased from 41.07 to 14.3, and the time to reach the maximum swelling ratio was prolonged from 4 h to 8 h. The sustained-release experiments showed that the SA–silica hydrogel beads possessed a good pH sensitivity, and the time of sustained-release was significantly prolonged in vitro. Hemolysis and cytotoxicity experiments showed that the SA-silica hydrogel beads were biocompatible when the TEOS molar concentration was lower than 0.375 M. The SA–silica-2 hydrogel beads had good biocompatibility, swelling properties, and slow-release properties at the same time.

W/O/W emulsion-filled sodium alginate hydrogel beads for co-encapsulation of vitamins C and E: Insights into the fabrication, lipolysis, and digestion behavior

In this study, vitamins C and E were simultaneously encapsulated in water-in-oil-in-water (W/O/W) emulsion-filled sodium alginate (SA) hydrogel beads, as well as the effects of SA concentrations (0.5%, 1.0%, 1.5%, and 2.0%) on the structures and lipolysis the of hydrogel beads were investigated. With increasing SA concentration, the beads showed larger sizes, denser structures and better textures. The droplets tightly penetrated the gel network at high SA concentrations. Digestion behavior revealed the disintegrated intramolecular structure at low SA concentrations. The beads with 0.5% SA were fragmented, losing the initial shape during digestion in the intestinal fluid. Additionally, lipid phases were released as W/O/W and O/W emulsion droplets after digestion. However, the high SA concentration-containing beads exhibited a well-preserved morphological structure after digestion, and the release profiles of lipid phase were mainly O/W emulsion droplets. Furthermore, vitamins C and E encapsulated in the beads exhibited high bioaccessibility (vitamin C: 90.20% and vitamin E: 95.19%).

Design, preparation, and performance of different adsorbents based on carboxymethyl chitosan/sodium alginate hydrogel beads for selective adsorption of Cadmium (II) and Chromium (III) metal ions

Developing cost-effective and efficient adsorbents for heavy metals in multicomponent systems is a challenge that needs to be resolved to meet the challenges of wastewater treatment technology. Two adsorbents were synthesized, characterized, and investigated for the removal of Cd2+ and Cr3+ as model heavy metals in their single and binary solutions. The first adsorbent (ACZ) was a nanocomposite formed of O-Carboxymethyl chitosan, sodium alginate, and zeolite. While, the other (ACL) contained ZnFe layered double hydroxides instead of the zeolite phase. Adsorbents were characterized using XRD, FTIR, SEM, and swelling degree analysis. For single heavy metal adsorption isotherms, data for both adsorbents was best fitted and indicated a multilayer adsorption nature. For binary adsorption, Langmuir model with interacting parameters showed the best results compared to other models for both pollutants. For single system, Avrami model was found to be the best model representing the adsorption kinetics data, which indicates that the mechanism of adsorption follows multiple kinetic orders that may change during duration of adsorption process. Numerous interaction mechanisms can occur between the heavy metals and functional groups in the synthesized hydrogels such as NH2, COOH, and OH groups leading to efficient adsorption of metal ions.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

Novel colorimetric indicators based on alginate hydrogel beads containing anthocyanin for visual freshness monitoring of shrimp and minced chicken

Novel colorimetric indicators were developed by incorporating anthocyanins into alginate hydrogel beads through electrostatic extrusion for intelligent packaging. Two different sizes of hydrogel beads were produced and applied into shrimp and minced chicken packaging to visually detect freshness status during 4 °C storage. To assess the freshness of the products, the viable count of various types of bacteria (psychrotrophic, H2S-producing, mesophilic, and Pseudomonas spp.), total volatile basic nitrogen (TVB-N) content, pH, K-value, H-value, and biogenic amines level were analyzed. The indicators' color change (ΔE) was then correlated with these parameters. Color analysis of the indicators during storage indicated ΔE values below 10 and over 30 in the hydrogels incorporated into minced chicken and shrimp packaging, respectively. The color change of both indicators integrated into the shrimp package was strongly correlated with the change in viable counts, TVB-N, pH, K-value, and H-value (r ≥ 0.8, p < 0.016), as well as biogenic amines (r = 0.7, p < 0.05). The indicators applied to minced chicken packaging showed subtle color changes during storage, while those in shrimp packaging consistently reflected shelf-life variations. This innovative approach shows potential for improving food safety and quality monitoring, particularly in seafood packaging, where indicators have been effective in visually signaling product freshness.

Intestinal-specific oral delivery of lactoferrin with alginate-based composite and hybrid CaCO3-hydrogel beads

Sodium alginate hydrogel beads and sodium alginate/gellan gum composite hydrogel beads crosslinked by calcium chloride were prepared with different alginate concentrations (3–20 mg·mL−1). Additionally, a simple method for growing CaCO3in situ on the hydrogel to create novel inorganic-organic hybrid hydrogel beads was presented. FT-IR analysis revealed the involvement of hydrogen bonding and electrostatic interactions in bead formation. Swelling behavior in acidic conditions showed a maximum of 13 g/g for composite hydrogels and CaCO3-incorporated hybrid hydrogels. Lactoferrin encapsulation efficiency within these hydrogels ranged from 44.9 to 56.6%. In vitro release experiments demonstrated that these hydrogel beads withstand harsh gastric environments with <16% cumulative release of lactoferrin, achieving controlled release in intestinal surroundings. While composite sodium alginate/gellan gum beads exhibited slower gastrointestinal lactoferrin digestion, facile synthesis and pH responsiveness of CaCO3-incorporated hybrid hydrogel also provide new possibilities for future studies to construct a novel inorganic-organic synergetic system for intestinal-specific oral delivery.

Characterization of hydrogel beads constructed from gelatinized lotus rhizome starch and sodium alginate by calcium cross-linking

The purpose of this study was to construct calcium cross-linked gelatinized lotus rhizome starch (LRS)/sodium alginate (SA) hydrogel beads of adjustable quality and to reduce the digestibility of gelatinized starch. LRS was mixed with SA, gelatinized by heating and subsequently cross-linked with Ca2+ to form hydrogel beads. The digestibility of the gelatinized LRS could be adjusted by changing the dose of SA in the hydrogel beads. When the LRS/SA ratio was 4/6, the rapidly digested starch (RDS) content in the beads was reduced by 26.9% compared with gelatinized LRS alone, whereas the slowly digested starch (SDS) and resistant starch (RS) contents increased by 12.3-fold and 2.3-fold, respectively. In addition, the water distribution in the Ca2+-crosslinked LRS/SA hydrogel bead samples also showed an SA dose dependence. With increasing SA concentration, the ability of the hydrogel beads to immobilize water increased. The diffusion of Ca2+ into the interpenetrating polymer network that was prepared with gelatinized LRS and SA gradually resulted in gelation dominated by ion bonds, leading to the heterogeneous microstructure of the hydrogel beads, which also involved intermolecular hydrogen bond interactions. Overall, the present study suggested a strategy for developing novel LRS hydrogel bead systems for quality control and gelatinized starch digestibility downregulation by adjusting the SA dose, which provided insights for the innovation of personalized and convenient starchy products in the food industry.

Encapsulation of Antarctic krill oil and kaempferol co‐loaded nano‐liposomes in alginate‐chitosan hydrogel beads: improved stability and modified digestive behaviour

SummaryIn this study, alginate (NaAlg) and/or chitosan (CS) hydrogel beads were prepared to encapsulate Antarctic krill oil (AKO) and kaempferol (KL) co‐loaded nano‐liposomes. The SEM study confirmed that the hydrogel beads were spherical, in which nano‐liposomes was distributed evenly within the polymer network. The FTIR spectra indicated no evidence of any chemical interaction between nano‐liposomes and hydrogel beads. The hydrogel beads especially the NaAlg‐CS hydrogel beads caused decrease in the release of KL and AKO mostly own to the improved density of bead microstructure. Furthermore, the network structure in the hydrogel beads especially the NaAlg‐CS hydrogel beads successfully insulated oxygen to improve AKO oxidation stability and protected KL by preventing degradation under natural light, while maintaining its antioxidant capacity. Importantly, the hydrogel beads significantly reduced the release of free fatty acids during in vitro digestion compared to nano‐liposomes. In principle, these new delivery systems may combine the benefits of nano‐liposomes and hydrogel beads to encapsulate AKO and KL and broaden their applicability in food industry.

Kinetic and adsorption isotherm studies of Malachite Green dye onto surfactant-tailored alginate hydrogel beads: An influence of surfactant hydrophobicity

This study details the synthesis and characterization of surfactant-modified sodium alginate hydrogel beads crosslinked with Ba2+ ions through ionotropic gelation. Cationic surfactants such as, dodecyltrimethylammonium bromide (DTAB), didodecyldimethylammonium bromide (DDAB), and butanediyl-α,ω-bis-(dimethyldodecylammonium bromide) (GEM), were employed in the modification process. The surfactant-modified ALG-DTAB, ALG-DDAB, and ALG-GEM beads were investigated for the removal of cationic dye Malachite Green (MG) to elucidate the impact of hydrophobicity of amphiphiles on the adsorption process. The characterizations were carried out using Rheometry, Field Emission Scanning Electron Microscopy (FESEM), Infrared Spectroscopy (IR), and Energy Dispersive X-ray Spectroscopy (EDX). Under optimized conditions, ALG-GEM and ALG-DDAB demonstrated highest maximum adsorption capacity (Qmax > 700 mgg−1). The adsorption data fitted well to pseudo-second order kinetic and Langmuir adsorption models, suggesting the involvement of chemisorption phenomena with notable contributions from pore diffusion. The effects of pH, initial dye concentration, adsorbent dose, temperature, and competing ions on the removal of MG were investigated. Interestingly, ALG-GEM beads exhibited an increase in adsorption capacity with rising pH and a subsequent decrease with increasing temperature, showcasing optimal adsorption at pH 7.0 and 25 °C. The study proposes that ALG beads modified with cationic surfactants with higher hydrophobicity could offer a promising avenue in wastewater treatment processes.