Alginate Solution Research Articles

Synthesis and Exfoliation of Calcium Organophosphonates for Tailoring Rheological Properties of Sodium Alginate Solutions: A Path toward Polysaccharide-Based Bioink.

Layered nanoparticles with surface charge are explored as rheological modifiers for extrudable materials, utilizing their ability to induce electrostatic repulsion and create a house-of-cards structure. These nanoparticles provide mechanical support to the polymer matrix, resulting in increased viscosity and storage modulus. Moreover, their advantageous aspect ratio allows for shear-induced orientation and decreased viscosity during flow. In this work, we present a synthesis and liquid-based exfoliation procedure of phenylphosphonate-phosphate particles with enhanced ability to be intercalated by hydrophilic polymers. These layered nanoparticles are then tested as rheological modifiers of sodium alginate. The effective rheological modification is proved as the viscosity increases from 101 up to 103 Pa·s in steady state. Also, shear-thinning behavior is observed. The resulting nanocomposite hydrogels show potential as an extrudable bioink for 3D printing in tissue engineering and other biomedical applications, with good shape fidelity, nontoxicity, and satisfactory cell viability confirmed through encapsulation and printing of mouse fibroblasts.

Macroscopic Pattern Formation of Alginate Gels in a Two-Dimensional System.

Macroscopic spatial patterns were formed in calcium alginate gels when a drop of a calcium nitrate solution was placed on the center of a sodium alginate solution on a petri dish. These patterns have been classified into two groups. One is multi-concentric rings consisting of alternating cloudy and transparent areas observed around the center of petri dishes. The other is streaks extending to the edge of the petri dish, which are formed to surround the concentric bands between the concentric bands and the petri dish edge. We have attempted to understand the origins of the pattern formations using the properties of phase separation and gelation. The distance between two adjacent concentric rings was roughly proportional to the distance from where the calcium nitrate solution was dropped. The proportional factor p increased exponentially for the inverse of the absolute temperature of the preparation. The p also depended on the concentration of alginate. The pattern characteristics in the concentric pattern agreed with those in the Liesegang pattern. The paths of radial streaks were disturbed at high temperatures. The length of these streaks shortened with increasing alginate concentration. The characteristics of the streaks were similar to those of crack patterns resulting from inhomogeneous shrinkage during drying.

Experimental investigation of various energy-absorbing layer materials and sodium alginate viscosities on the jet formation in laser-induced-forward-transfer (LIFT) bioprinting

Laser-induced-forward-transfer (LIFT) bioprinting technology has been viewed as a regenerative medicine technology because of its high printing quality and good cell viability. To stabilize the jet to achieve high-quality printing, an energy-absorbing layer (EAL) can be introduced. In this study, three materials (graphene, gelatin, and gold) were utilized as the EAL. The effect of each EAL on the jet generation process was investigated. Besides, the effect of graphene EAL thickness was addressed for various experimental conditions. The jet generation process using sodium alginate solutions with different concentrations (1 and 2 wt. %) was also discussed to investigate the effect of viscosity. The time sequence images of the formed jets utilizing three EALs showed that both graphene EAL and gelatin EAL can promote the formation of jet flow. For the gold EAL, no jet flow was observed. This study provides experimental verifications that the interaction between laser and EAL materials can result in different jets due to various dominant interaction mechanisms. For example, strong absorption in the infrared range for the graphene EAL, strong scattering loss for the gelatin EAL, and strong absorption in the ultraviolet range but weak absorption in the infrared for the gold EAL. We also observed the holes left on the EAL after the printing was completed. The thermal effect is dominant to create regular and round shape holes for the graphene EAL, but it changes to the mechanical effect for the gold EAL because of the existence of irregular and unorganized holes. In addition, we identified the existence of an input laser energy threshold value for a certain thickness graphene EAL. More laser energy is required to break down thicker graphene EALs, which will result in a higher initial jet velocity. Furthermore, we explored the effect of sodium alginate (SA) solution's viscosity on the generated jet. We found that a high-viscosity SA solution can result in a low initial jet velocity, a short jet, and small droplets on the receiving substrate. The findings from this study help determine the mechanisms of EAL–laser interaction with different EAL materials in the LIFT process. This work aims to facilitate the development of new EAL and bioink to achieve stable jet formation and high printing quality in future LIFT bioprinting.

Injectable hydrogel combining alginate and Rhodomyrtus tomentosa medicine with antibacterial, anti-inflammatory and cellular proliferation properties as potential wound dressing material

BackgroundAlginate hydrogels have been widely used as wound healing materials because of their high water content, biocompatibility, and easy fabrication. However, it is still challenging to improve their bioactivities due to the inherently bioinert properties of alginate. Herein, we report a simple and effective method to fabricate a multifunctional alginate hydrogel (Alg@Rt) with anti-inflammatory and antibacterial activities, by combining the advantages of alginate and Rhodomyrtus tomentosa leaves extract (Rt). MethodsThe hydrogel is prepared by simply mixing the solutions of alginate and Rt, using CaO2 as the crosslinker. The porous structure of hydrogel is evidenced by the scanning electron microscope. The swelling of the hydrogel was determined by comparing the difference in mass of samples immersed in physiological pH. The polyphenol release was determined by using the Folin-Ciocalteu method. The in vitro anti-inflammatory and antibacterial activities of the Alg@Rt hydrogel were evaluated and compared with the pure Alg hydrogel. The biocompatibility of hydrogels was evaluated towards fibroblasts. Significant findingA new injectable Alg@Rt hydrogel was developed to facilitate the wound healing process. Compared to the pure Alg hydrogel, Alg@Rt hydrogel significantly enhanced the anti-inflammatory, antibacterial and cell proliferative activities, which is beneficial in wound treatment and tissue regenerative applications.

Size Tunable Fabrication of Magnetic Alginate Microparticles Using Flow Focusing Microfluidics

AbstractThe size tunable formulation of magnetic alginate microparticles (MAMs) using a 3D flow‐focusing microfluidic device is reported. The droplet phase consists of iron oxide nanoparticles (IONPs) in an alginate solution and the continuous phase consists of fluorocarbon oils. The stability of IONP colloids in alginate and calcium ethylenediamine tetraacetic acid solutions using optical microscopy, dynamic light scattering, and zeta potential measurements is studied. These studies suggest that IONPs coated with polyethylene glycol (PEG) are most stable. MAMs using the PEG‐coated IONP colloid are then formulated and it is studied how MAM the average size and coefficient of variance vary as a function of droplet and continuous phase flow rates and viscosities. Droplet and MAM size decrease when the carrier flow rate or viscosity increases, and droplet and MAM size increase when droplet flow rate or viscosity increases. Crosslinking and drying of droplets result in MAMs whose diameter is ≈44% less than the original droplets while maintaining a population coefficient of variance below 8%. Conditions are identified that enable fabrication of MAMs with diameters between 30 and 60 µm with coefficients of variance of ≈6–7%. These results may guide future work exploring the role of MAM size on various applications.

Alginate-modulated continuous assembly of iron/tannic acid composites as photothermally responsive wound dressings for hemostasis and drug resistant bacteria eradication

Multifunctional dressing materials are highly required to combat multidrug resistant bacteria in wound infections. Here an alginate-based aerogel dressing is reported that combines photothermal bactericidal activity, hemostatic property, and free radical scavenging for skin wound disinfection and accelerated wound healing. The aerogel dressing is facilely constructed by immersing a clean nail (Fe) in a mixed solution of sodium alginate (Alg) and tannic acid (TA), followed by freezing, solvent replacement, and air drying. The Alg matrix plays an essential role in modulating the continuous assembly process between TA and Fe to allow the homogenous distribution of TA-Fe metal-phenolic networks (MPN) in the resulting composite, without forming aggregates. The photothermally responsive Nail-TA/Alg aerogel dressing is successfully applied in a murine skin wound model infected with Methicillin-resistant Staphylococcus aureus (MRSA). This work provides a facile strategy to integrate MPN with the hydrogel/aerogel matrix through in situ chemistry, which is promising for developing multifunctional biomaterials and biomedicine.

Design, Preparation, and Physicochemical Characterisation of Alginate-Based Honey-Loaded Topical Formulations.

Honey has widespread use as a nutritional supplement and flavouring agent. Its diverse bioactivities, including antioxidant, antimicrobial, antidiabetic, anti-inflammatory, and anticancer properties, have also made it an aspirant natural product for therapeutic applications. Honey is highly viscous and very sticky, and its acceptance as a medicinal product will require formulation into products that are not only effective but also convenient for consumers to use. This study presents the design, preparation, and physicochemical characterisation of three types of alginate-based topical formulations incorporating a honey. The honeys applied were from Western Australia, comprising a Jarrah honey, two types of Manuka honeys, and a Coastal Peppermint honey. A New Zealand Manuka honey served as comparator honey. The three formulations were a pre-gel solution consisting of 2-3% (w/v) sodium alginate solution with 70% (w/v) honey, as well as a wet sheet and a dry sheet. The latter two formulations were obtained by further processing the respective pre-gel solutions. Physical properties of the different honey-loaded pre-gel solutions (i.e., pH, colour profile, moisture content, spreadability, and viscosity), wet sheets (i.e., dimension, morphology, and tensile strength) and dry sheets (i.e., dimension, morphology, tensile strength, and swelling index) were determined. High-Performance Thin-Layer Chromatography was applied to analyse selected non-sugar honey constituents to assess the impacts of formulation on the honey chemical composition. This study demonstrates that, irrespective of the honey type utilised, the developed manufacturing techniques yielded topical formulations with high honey content while preserving the integrity of the honey constituents. A storage stability study was conducted on formulations containing the WA Jarrah or Manuka 2 honey. The samples, appropriately packaged and stored over 6 months at 5, 30, and 40 °C, were shown to retain all physical characteristics with no loss of integrity of the monitored honey constituents.

Cultivation of cells in alginate drops as a high-performance method of obtaining cell spheroids for bioprinting

Purpose of the study. Testing the protocol of obtaining cell spheroids of breast cancer cell cultures for bioprinting by growing in alginate drops.Materials and methods. Cells of breast cancer cell lines BT-20 and MDA-MB-453 were cultured in DMEM medium supplemented with 10 % FBS. Next, the cells were removed from the plastic using a trypsin-V ersene solution and resuspended in a sterile 2 % alginate solution in DPBS to the concentration of 105 cells/ml. Then the alginate solution with the cells was slowly dripped through a 30G needle into a sterile cooled solution of calcium chloride (100 mM) from a height of 10 cm. After polymerization, alginate drops were washed in DMEM and cultured for two weeks in DMEM with the addition of 10 % FBS at 37 °C and 5.0 % CO2.The spheroids formed in the alginate were photographed on the 3rd, 7th, 10th, and 14th days of cultivation, after which they were removed from the alginate by keeping in 55 mM sodium citrate solution with the addition of 20mM ethylenediaminetetraacetic acid (EDTA) and embedded in paraffin blocks according to the standard method, followed by histological examination.Results. Cellular spheroids were formed in both cell cultures already on the 3rd day of cultivation. From the 3rd to the 10th day in both cultures, a uniform growth of cell spheroids was observed with a gradual slowdown in the increase in the size of spheroids by the 14th day of cultivation. On the 10th day the proportion of cells that formed clones (more than 500 μm2 in size) was 25.2 % ± 7.1 % (n = 25) in the BT-20 culture and 38.5 % ± 9.9 % (n = 25) in MDA-MB-453 culture. On the 14th day, BT-20 culture was characterized by spheroids varying little in size and shape, with an average area of 1652 ± 175 µm2, having a dense structure with smooth edges. The spheroids in MDA-MB-453 culture turned out to be more loose and easily deformed, their size and shape varied noticeably, the average area of the spheroids was 2785 ± 345 µm2.Conclusion. The production of spheroids in alginate drops is inferior in speed to the methods of forming cell conglomerates in hanging drops or on microwells, but it surpasses these methods in productivity, which is comparable to the production of spheroids by constant medium stirring on low-adhesive substrates. In addition, the clonal nature of the obtained spheroids leads to an increase in research costs and thus limits their scalability.

Lab-on-a-bead: Polymeric natural deep eutectic solvents as a versatile platform for (bio)sensor design

Natural polymers offer not only low-cost, wide availability, biocompatibility, and biodegradability but also a rich chemical functionality towards custom modifications and new applications. Among those, sodium alginate (ALG) offers several competitive advantages, including the possibility to form beads by a simple process call spherification as well as their modification by a wide number of processes, including the possibility to mixing the alginate solution with deep eutectic solvents (DES). Thus, and considering the capacity of DES to stabilize enzymes, the main objective of this work was to design and fabricate a new polymeric DES (using ALG as one of the components, ALGPODES) and to deploy this material as a new phase to develop colorimetric biosensors. The formed beads displayed a narrow size distribution (2.9 ± 0.1 mm) and a permeable structure with large internal cavities (25–100 µm). The applicability of these beads towards analytical applications (lab-on-a-bead) was demonstrated by integrating three sensing platforms and by their application in real food samples.

Versatile magnetic hydrogel soft capsule microrobots for targeted delivery

Maintaining the completeness of cargo and achieving on-demand cargo release during long navigations in complex environments of the internal human body is crucial. Herein, we report a novel design of magnetic hydrogel soft capsule microrobots, which can be physically disintegrated to release microrobot swarms and diverse cargoes with almost no loss. CaCl2 solution and magnetic powders are utilized to produce suspension droplets, which are put into sodium alginate solution to generate magnetic hydrogel membranes for enclosing microrobot swarms and cargos. Low-density rotating magnetic fields drive the microrobots. Strong gradient magnetic fields break the mechanical structure of the hydrogel shell to implement on-demand release. Under the guidance of ultrasound imaging, the microrobot is remotely controlled in acidic or alkaline environments, similar to those in the human digestion system. The proposed capsule microrobots provide a promising solution for targeted cargo delivery in the internal human body.

Mosquito repellent microcapsules of nepeta essential oil were prepared by electro‐atomization complex coacervation

AbstractMicrocapsules containing nepeta essential oil (NEO) are prepared by electro‐atomization complex coacervation with sodium alginate and gelatin as wall materials. The effects of conditions such as sodium alginate solution concentration, core‐to‐wall ratio and emulsifier content on the release of essential oil and mosquito repellent properties of the microcapsules are studied. The microcapsules prepared under optimal preparation conditions have good performance and morphology, the encapsulation efficiency and loading capacity being 86.65% and 13.93%, respectively. The prepared microcapsules have adequate morphological characteristics observed using scanning electron microscopy. Fourier transform infrared spectra and thermogravimetric analysis show that NEO is successfully loaded in the microcapsules, and the thermal stability of NEO is improved. In addition, the results of release and repellent tests show that the NEO in the microcapsules could achieve stable release within 15 days and maintain an avoidance rate above 80% within 48 h, indicating the potential application of the microcapsules in the field of mosquito repellents. © 2023 Society of Industrial Chemistry.

In Situ Sprayed Difunctional Gel Avoiding Microenvironments Limitations to Treat Pressure Ulcers.

How to avoid the microenvironment limitations in the therapeutic process of pressure ulcers is still challenging. The development of a functional gel can kill bacteria and scavenge reactive oxygen species (ROS), which is urgently required in the therapeutic process of pressure ulcers. Herein, an in situ sprayed gel is developed with silver nanoparticles (AgNPs) and polydopamine (PDA) NPs (APG) to obviate microenvironment restrictions in treating pressure ulcers. The gel is constructed by spraying sodium alginate solution and CaCl2 solution. AgNPs serve as an antibacterial agent in the formed gel, which can effectively cause bacterial inactivation and show more than 5 log (>99.999%) bacterial killing efficiency against methicillin-resistant S. aureus (MRSA), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) in vitro. Meanwhile, PDA NPs serve as the antioxidative agent in the formed gel, which can facilitate the elimination of ROS to address the high ROS problem in wound microenvironment. Based on these features, it is demonstrated through cell and animal experiments that the AgNPs and PDA NPs incorporated gel can realize the effective treatment of MRSA-infected and hydrogen peroxide (H2 O2 )-sensitized pressure ulcers. It is believed that the designed system by a simple spray-coating approach can provide a new therapeutic strategy in biomedical areas.

Micropropagation of Pterocarpus marsupium Roxb. through synthetic seeds and its novel antibiofilm activities against ESKAPE pathogens

Pterocarpus marsupium, an endangered medicinal tree, desists long distance transportation of its recalcitrant propagules, eclipsing the mass vegetative propagation and hindering the pharmaceutical application. Therefore, the present study attempted to develop synthetic seeds by encapsulating the nodal segments using sodium alginate and calcium chloride solutions. A concentration of 100 mM calcium chloride and 3 % sodium alginate proved optimum for preparing uniform synthetic seeds. The highest 76.7 % conversion response of synthetic seed into 8.16 shoots with mean shoot length (4.35 cm) was obtained on Murashige and Skoog (MS) medium containing meta-topolin (5.0 µM) and α-naphthalene acetic acid (1.0 µM) after 12 weeks of culture. However, the shoots failed to induce a rooting response on the aforementioned optimized medium. Therefore, a two-step in vitro rooting procedure was developed. Synthetic seeds of this plant retained their germination potential after storage at 4 ᵒC for eight weeks. Analysis of glutathione-S-transferase (GST) activity indicated that the in vitro culture of synthetic seed on the above medium experienced the lowest physiological stress. The regenerated plantlets were successfully acclimatized to the natural environment, where they showed more than a 90 % survival rate after three months. The heartwood aqueous extract of the tree displayed novel antibiofilm activities against multi-drug resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobcter spp.) pathogens. This study facilitates the multiplication, conservation, and production of novel bioactive compounds.

Gelation in Alginate-Based Magnetic Suspensions Favored by Poor Interaction among Sodium Alginate and Embedded Particles

Alginate gels are extensively tested in biomedical applications for tissue regeneration and engineering. In this regard, the modification of alginate gels and solutions with dispersed magnetic particles gives extra options to control the rheo-elastic properties both for the fluidic and gel forms of alginate. Rheological properties of magnetic suspensions based on Na-alginate water solution with embedded magnetic particles were studied with respect to the interfacial adhesion of alginate polymer to the surface of particles. Particles of magnetite (Fe3O4), metallic iron (Fe), metallic nickel (Ni), and metallic nickel with a deposited carbon layer (Ni@C) were taken into consideration. Storage modulus, loss modulus, and the shift angle between the stress and the strain were characterized by the dynamic mechanical analysis in the oscillatory mode. The intensity of molecular interactions between alginate and the surface of the particles was characterized by the enthalpy of adhesion which was determined from calorimetric measurements using a thermodynamic cycle. Strong interaction at the surface of the particles resulted in the dominance of the “fluidic” rheological properties: the prevalence of the loss modulus over the storage modulus and the high value of the shift angle. Meanwhile, poor interaction of alginate polymer with the surface of the embedded particles favored the “elastic” gel-like properties with the dominance of the storage modulus over the loss modulus and low values of the shift angle.

Characterization and optimization of bioluminescent bacterial cells immobilization process in calcium alginate hydrogel tablets.

Whole-cell biosensors (WCB) are increasingly utilized in various applications. These platforms integrate cells with a signal measurement device. One of the main challenges in the development of such platforms is the immobilization matrix that is used to keep the cells stable, which also affects the portability of the device. In this study, a portable and simple immobilization of bioluminescent bacterial cells in calcium alginate hydrogel was examined. The effects of several physical parameters were investigated (e.g. calcium alginate solution volume, drying, incubation time, mixing procedure, bacterial concentration, and tablet location within the cylinder). An alginate solution volume of 3mL was preferred as well as the addition of 400µL solution after the 15 minute of compressing step and before the polymerization step. Also, a stirring mixing mode is favored over vortexing due to the creation of better homogenized tablets, as well as a bacterial concentration of 0.15 OD600nm that produced a high light response while maintaining lower variance. Lastly, the findings showed a significantly higher response (Induction Factor (IF)) in the tablets using the optimized immobilization protocol (IF=8.814) than the old one (IF=1.979). To conclude, bacterial cells immobilization in calcium alginate tablets provides improved sensitivity and storability.

Development of air-assisted atomization device for the delivery of cells in viscous biological ink prepared with sodium alginate

Skin wounds, especially large-area skin trauma, would bring great pain and even fatal risk to patients. In recent years, local autologous cell transplantation has shown great potential for wound healing and re-epithelialization. However, when the cell suspension prepared with normal saline is delivered to the wound, due to its low viscosity, it is easy to form big drops in the deposition and lose them from the wound bed, resulting in cell loss and uneven coverage. Here, we developed a novel air-assisted atomization device (AAAD). Under proper atomization parameters, 1% (w/v) sodium alginate (SA) solution carrier could be sprayed uniformly. Compared with normal saline, the run-off of the SA on the surface of porcine skin was greatly reduced. In theory, the spray height of AAAD could be set to achieve the adjustment of a large spray area of 1–12 cm2. In the measurement of droplet velocity and HaCaT cell viability, the spray height of AAAD would affect the droplet settling velocity and then the cell delivery survival rate (CSR). Compared with the spray height of 50 mm, the CSR of 100 mm was significantly higher and could reach 91.09% ± 1.82% (92.82% ± 2.15% in control). For bio-ink prepared with 1% (w/v) SA, the viability remained the same during the 72-h incubation. Overall, the novel AAAD uniformly atomized bio-ink with high viscosity and maintained the viability and proliferation rate during the delivery of living cells. Therefore, AAAD has great potential in cell transplantation therapy, especially for large-area or irregular skin wounds.

Food encapsulation plant

This article shows an installation for encapsulating food products. Ensuring food security, the constant satisfaction of the population's needs for basic foodstuffs, is one of the main directions of ensuring the national security of any state. There is still an open question of obtaining high-quality capsules with properties and characteristics that dissolve in the desired environment, retain the therapeutic effect and at the same time meet the requirements of the consumer (ease of use, efficiency, reasonable cost). An installation for producing microcapsules was made of such parts: they are Mercury ATX Switching Power Supply-450W power supply; aquarium tube; glass washer pump; variable resistor with 10K switch; DC-dc DC voltage stabilizer, LM2596S module; gelatin, sodium alginate solution; electromagnetic mixer; plastic sprayer for spraying water (nozzle); calcium chloride solution. There are many technologies of the encapsulation process. Capsules can be obtained by drip, disk spraying methods. In this work, sodium alginate and gelatin were selected as the encapsulating material. A gelatin solution with the addition of sodium alginate was used as an aqueous solution of the gel-forming mixture. The best option is the composition of capsules containing 0.5% alginate and gelatin, the solution should be used at a temperature of 40° C. Capsules were obtained by the drip method. Capsules obtained from 0.5% sodium alginate were soft, with a smooth surface, with an average size of 2,0×10-3м.

Гибридный гель для замены твердых жиров в кондитерских изделиях

The World Health Organization recommends reducing the intake of saturated fatty acids. However, a direct replacement of solid fats with liquid oils affects the technological and consumer properties of food. The research objective was to develop a hybrid gel with a dense structure based on oleogel and hydrogel to replace saturated fats in semi-finished confectionery products.
 The study featured samples of oleogel from sunflower oil and beeswax at a concentration of 10, 15, and 20% and hybrid gels prepared by mixing the oleogel with a 2% aqueous solution of sodium alginate at ratios of 99:1, 95:5, and 90:10. The samples were tested for strength, adhesive power, viscosity index, consistency, and Young modulus using a TA-XT Plus texture analyzer (Stable Micro Systems Ltd., UK). The water activity was studied using a water activity analyzer LabMaster (Novasina, Lab Master, Switzerland).
 The oleogel samples with wax concentrations of 20 and 15% demonstrated good adhesive strength. The best hybrid gel was the oleogel with 20% wax at the ratio of 95:5 to hydrogel. This ratio resulted in a considerable gel strength (≤ 408.222) while maintaining a dense and uniform texture (Young modulus ≤ 17.05) for a long time. The oleogels had low moisture content (Aw = 0.6 ± 0). The shelf life at 4–10°C was 6 months. The samples had good sensory properties, i.e., clear taste and smell, strong uniform structure and consistency, etc. The paper introduces a formulation for a semi-finished confectionery product with a hybrid gel instead of 30% cocoa butter substitute.
 Hybrid gels can be recommended as a substitute for cocoa butter or confectionery fats to reduce the amount of saturated and trans fatty acids. Such a replacement improves the consumer properties of semi-finished and finished products.

Effect of Environment on Acetylated Cellulose Nanocrystal-Reinforced Biopolymers Films.

Cellulose nanocrystals (CNCs) were acetylated to the various parametrised degrees of substitution (DS), determined through attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and incorporated into alginate (ALG) and chitosan (CH) film-forming solutions. An investigation of morphology with scanning electron microscopy (SEM) revealed increased chemical compatibility with the CH matrix after acetylation, producing a smooth surface layer, while ALG mixed better with pristine CNCs. The ATR-FTIR analysis of films demonstrated inter-diffusional structural changes upon the integration of pristine/modified CNCs. Films were evaluated in terms of water contact angle (WCA), which decreased upon CNC addition in either of the biocomposite types. The H2O barrier assessed through applicative vapour transmission (WVT) rate increased with the CNC esterification in CH, but was not influenced in ALG. To evaluate the relationship between environmental humidity and mechanical properties, conditioning was applied for 48 h under controlled relative humidity (33%, 54% and 75%) prior to the evaluation of the mechanical properties and moisture content. It was observed that tensile strength was highest upon specimens being dry (25 ± 3 MPa for ALG, reinforced with neat CNCs, or 16 ± 2 MPa in the CH with CNCs, reacting to the highest DS), lowering with dewing, and the elongation at break exhibited the opposite. It is worth noting that the modification of CNCs improved the best base benchmark stress-strain performance. Lastly, (thermal) stability was assessed by means of the thermogravimetric analysis (TGA) technique, suggesting a slight improvement.

Extraction of dietary fiber and phytochemicals from bottle gourd seeds (Lagenaria siceraria), its physicochemical properties and application in food model

This research aimed to extract dietary fiber and phytochemicals from matured bottle gourd (Lagenaria siceraria) seeds and use as ingredients in the preparation of cookies. Extraction of dietary fiber was performed using alkaline (AEDF), enzymatic (EEDF), and ultrasound-assisted alkali extraction (UAE). UAE gives a higher yield of 75.81% dietary fiber where the optimized conditions are solute: solvent; 1: 23.90 mg/ml, time; 27.20 min and amplitude; 47.76%. Comparison of physicochemical and functional properties of extracted dietary fiber was done and ultrasound-assisted alkaline extracted dietary fiber (UDF) was found to be the best. Extraction of phytochemicals using ultrasound-assisted alkaline extraction under the condition of 70% amplitude, 45 °C temperature, and duration of 15 min, and identification was done using RP-HPLC analysis and encapsulated using sodium alginate solution (2%) as the wall material. Fiber enriched cookies were developed by incorporating the extracted dietary fiber (3, 6, 9, 12 and 15%) and encapsulated phytochemicals beads (1, 1.5, 2, 2.5 and 3%) in 5 different formulations. The result of this study revealed that matured bottle gourd seeds can serve as a potential, inexpensive dietary fiber source and phytochemicals, which can further be used to develop functional foods.