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This study aims to develop a simplified bioink preparation method that can be applied to most hydrogel bioinks used in extrusion-based techniques.

The parameters of the bioprinting process significantly affect the printability of the bioink and the viability of cells. In turn, the bioink formulation and its physicochemical properties may influence the appropriate range of printing parameters. In extrusion-based bioprinting, the rheology of the bioink affects the printing pressure, cell survival and structural integrity. Three concentrations of alginate-gelatin hydrogel were prepared and printed at three different flow rates and nozzle gauges to investigate the print parameters. Other characterizations were performed to evaluate the hydrogel structure, printability, gelation time, swelling and degradation rates of the bioink and cell viability. An experimental design was used to determine optimal parameters. The analyses included live/dead assays, rheological measurements, swelling and degradation.

The experimental design results showed that the hydrogel flow rate substantially influenced printing accuracy and pressure. The best hydrogel flow rate in this study was 10 ml/h with a nozzle gauge of 18% and 4% alginate. Three different concentrations of alginate-gelatin hydrogels were found to exhibit shear-thinning behavior during printing. After seven days, 46% of the structure in the 4% alginate-5% gelatin sample remained intact. After printing, the viability of skin fibroblast cells for the optimized sample was 91%.

This methodology offers a straightforward bioink preparation method applicable to the majority of hydrogels used in extrusion-based procedures. This can also be considered a prerequisite for cell printing.

In this paper the aim is that Aramid/alginate blended nonwoven fabrics were prepared, and the flame retardancy of the blended nonwoven fabrics was studied by thermogravimetric analysis, vertical flame test, limiting oxygen index (LOI) and cone calorimeter test.

The advantages of different fibers can be combined by blending, and the defects may be remedied. The study investigates whether incorporating alginate fibers into aramid fibers can enhance the flame retardancy and reduce the smoke production of prepared aramid/alginate blended nonwoven fabrics.

Thermogravimetric analysis indicated that alginate fibers could effectively inhibit the combustion performance of aramid fibers at a higher temperature zone, leaving more residual chars for heat isolation. And vertical flame test, LOI and cone calorimeter test testified that the incorporation of alginate fibers improved the flame retardancy and fire behaviors. When the ratio of alginate fibers for aramid/alginate blended nonwoven fabrics reached 80%, the incorporation of alginate fibers could notably decreased peak-heat release rate (54%), total heat release (THR) (29%), peak-smoke production rate (93%) and total smoke production (86%). What is more, the lower smoke production rate and lower THR of the blends vastly reduced the risk of secondary injury in fires.

This study proposes to inhibit the flue gas release of aramid fiber and enhance the flame retardant by mixing with alginate fiber, and proposes that alginate fiber can be used as a biological smoke inhibitor, as well as a flame retardant for aramid fiber.

The use of Spirulina sp. in food is limited by its bitter flavour and low absorption in the gastrointestinal system. The purpose of this study is to develop encapsulated Spirulina-alginate beads and to determine the physicochemical properties, the release efficiency in the simulated gastrointestinal fluid and the sensory acceptance of the beads when added into a rose syrup beverage.

Spirulina-alginate beads were prepared based on 3 × 3 factorial experiments consisting of three concentrations (1%, 2% and 3%) of plain sodium alginate and three concentrations (1, 3 and 5%) (w/v) of Spirulina. Encapsulated Spirulina-alginate beads were evaluated for their encapsulation effectiveness, size, texture, morphology, colour, in vitro release rate and sensory properties.

Sample H (3% sodium alginate + 1% Spirulina) had higher encapsulation efficiency (82.3%) but less protein (38.2 ppm) than Sample J (3% sodium alginate + 5% Spirulina) which produced more protein (126.4 ppm) but had lower encapsulation efficiency (54.5%). Alginate was the primary factor affecting bead size, and the texture became harder at 3% sodium alginate but softer at 5% Spirulina. As the concentration of Spirulina increased, the intensity of the green colour diminished. The encapsulated samples released test was better than the control samples, and Sample B (1% sodium alginate + 1% Spirulina) was preferred by the panellists in the sensory study.

This newly developed encapsulated Spirulina will improve the beverage acceptability, minimize the bitterness and increase the release percentage of Spirulina in simulated gastrointestinal.

The purpose of this study is to evaluate the effectiveness of alginate as a vehicle to protect coenzyme Q10 in liposomes.

Encapsulation efficiency and stability were conducted at varying temperatures (20, 30, 40°C) for 5 d and at exposure to simulated gastric conditions (pH 2) for 2 h. The content of coenzyme Q10 was determined using HPLC (LC/MS). Cytotoxicity and phagocytosis of mouse macrophages (RAW264.7) was determined.

Results showed that thermostability was strongly improved by alginate complex formation with liposomes. Moreover, alginate could maintain coenzyme Q10 at a significantly higher level in simulated gastric pH for at least 2 h (p<0.00).

This allowed a higher amount of coenzyme Q10 remaining to be absorbed in the small intestine. Alginate not only showed no toxic effect on mouse macrophages but also activated their proliferation and phagocytosis ability.

As a consequence, alginate could be applied as an aid to encapsulation stability and immunostimulating potency.

This paper aims to present a solid freeform fabrication-based in situ three-dimensional (3D) printing method. This method enables simultaneous cross-linking alginate at ambient environmental conditions (temperature and pressure) for 3D-laden construct fabrication. The fabrication feasibility and potentials in biomedical applications were evaluated.

Fabrication feasibility was evaluated as the investigation of fabrication parameters on strut formability (the capability to fabricate a cylindrical strut in the same diameter as dispensing tip) and structural stability (the capability to hold the fabricated 3D-laden construct against mechanical disturbance). Potentials in biomedical application was evaluated as the investigation on structural integrity (the capability to preserve the fabricated 3D-laden construct in cell culture condition).

Strut formability can be achieved when the flow rate of alginate suspension and nozzle travel speed are set according to the dispensing tip size, and extruded alginate was cross-linked sufficiently. A range of cross-linking-related fabrication parameters was determined for sufficient cross-link. The structural stability and structural integrity were found to be controlled by alginate composition. An optimized setting of the alginate composition and the fabrication parameters was determined for the fabrication of a desired stable scaffold with structural integrity for 14 days.

This paper reports that in situ 3D printing is an efficient method for 3D-laden construct fabrication and its potentials in biomedical application.

Particles are of the controlled release delivery systems. Also, topically applied olive oil has a protective effect against ultraviolet B (UVB) exposure. Due to its sensitivity to oxidation, various studies have investigated the production of olive oil particles. The purpose of this study was to use chitosan and sodium alginate as the vehicle polymers for olive oil.

The gelation method used to prepare the sodium alginate miliparticles containing olive oil and particles were coated with chitosan. Morphology and size, zeta potential, infrared spectrum of olive oil miliparticles, encapsulation efficiency and oil release profile were investigated. Among 12 primary fabricated formulations, formulations F₅ (olive oil loaded alginate miliparticles) and F₁₁ (olive oil loaded alginate miliparticles + chitosan coat) were selected for further evaluations.

The size of the miliparticles was in the range of 1,100–1,600 µm. Particles had a spherical appearance, and chitosan coat made a smoother surface according to the scanning electron microscopy. The zeta potential of miliparticles were −30 mV for F₅ and +2.7 mV for F₁₁. Fourier transform infrared analysis showed that there was no interaction between olive oil and other excipients. Encapsulation efficiency showed the highest value of 85% in 1:4 (olive oil:alginate solution) miliparticles in F₁₁. Release study indicated a maximum release of 68.22% for F₅ and 60.68% for F₁₁ in 24 h (p-value < 0.016). Therefore, coating with chitosan had a marked effect on slowing the release of olive oil. These results indicated that olive oil in various amounts can be successfully encapsulated into the sodium-alginate capsules cross-linked with glutaraldehyde.

To the best of the authors’ knowledge, no study has used chitosan and sodium alginate as the vehicle polymers for microencapsulation of olive oil.

The sensory quality and yield of mozzarella cheese deteriorate as the fat content in milk is reduced. This study aims to evaluate the efficacy of sodium alginate as a fat replacer in low-fat buffalo mozzarella cheese on the basis of processing and storage (4 ± 1°C) quality.

Five treatments of buffalo mozzarella cheese, viz., control full-fat cheese (6.0 per cent milk fat; CFFC), control low-fat cheese (<0.5 per cent milk fat) without sodium alginate (CLFC), low-fat cheese with 0.1 per cent sodium alginate (LFC-1), 0.2 per cent sodium alginate (LFC-2) and 0.3 per cent sodium alginate (LFC-3), were comparatively evaluated.

Increase in the level of sodium alginate increased the percent yield of treated low-fat cheese than CLFC. Addition of sodium alginate to low-fat cheese resulted in decrease in hardness (p = 0.023) and chewiness than CLFC. Meltability was significantly decreased (p = 0.03) in low-fat cheese than CFFC. It was recorded as 1.5 ± 0.14 cm for CFFC to 0.2 ± 0.08 cm in LFC-3. Sensory panellists awarded LFC-3 highest and lowest to LFC-1; however, treated products at all selected levels were superior to CLFC. Oxidative stability and microbial stability were improved in LFC-3 than CFFC during storage.

Results concluded that 0.3 per cent sodium alginate is optimum for the development of extended shelf-life functional/low-fat/low-calorie buffalo mozzarella cheese.

Processing interventions can be successfully used to develop low-fat/low-calorie mozzarella cheese with acceptable sensory attributes and longer storage life.

This study aims to protect Lactobacillus plantarum and Enterococcus faecium encapsulated in alginate beads during stress treatments, such as high temperatures and concentrations of sodium chloride (NaCl) and sodium nitrite (NaNO₂).

Free and encapsulated probiotics were subjected to 70 and 80°C during 5, 10, 20 and 30 min. In addition, the probiotics were subjected to concentrations of 0.5, 1.0, 2.5 and 5.0 per cent NaCl and 0.5 and 1.0per cent of NaNO₂.

Free Lactobacillus plantarum was more resistant to heat than free Enterococcus faecium. Alginate-encapsulated Lactobacillus plantarum (ALP) also was more resistant to heat treatments than alginate-encapsulated Enterococcus faecium (AEF). After 30 min at 70°C, ALP showed levels about 6.9 log CFU/g while AEF presented 4.3 log CFU/g (p = 0.005). However, at 80°C, ALP maintained levels higher than 6 log CFU/g for up to 10 min, while AEF was able to maintain those levels only for approximately 5 min (p = 0.003). Encapsulation process provided adequate protection for both probiotics against NaCl. In relation to NaNO₂ concentrations, 0.5 and 1.0 per cent reduced viability of both probiotics (p = 0.014), either as free cells or as alginate-encapsulated forms.

Alginate beads containing probiotics is an interesting alternative for application in foods such as cooked meat products.

Alginate beads elaborated with milk powder, inulin and trehalose were effective to protect probiotics in stress situations similar to those can be found in the processing of foods, such as cooked meat products.

Alginate fiber with a breaking tenacity of up to 2.32 cN/dtex is prepared by spinning a sodium alginate solution in a coagulating solution of CaCl₂ aqueous solution followed by multi-roller drawing. Preparation parameters such as sodium alginate concentration, coagulant concentration and coagulation temperature, which affect the fiber tenacity, are investigated with an orthogonal test design, and the best spinning process is found with a coagulating 5% sodium alginate solution in 4% CaCl₂ at 40°C. The morphology, degree of crystallinity, thermal stability and the combustion performance of this alginate fiber are investigated by scanning electron microscopy (SEM), infrared (IR), X-ray diffraction (XRD), Thermo gravimetric Analysis (TGA) and Cone Calorimeter. Using the centrifugal dewatering method, the absorption capacity of this alginate fiber is determined, and has a capacity of 13.01 grams of man-made blood per gram. The test results show that fibers have an irregular cross-section without a thicker cortex and uniform longitudinal surface with grooves. The combustion property results demonstrate that the fiber has a self-flameretarding property.

The purpose of this study was to prepare alginate and chitosan-based edible coatings incorporating Schinus terebinthifolia and Piper nigrum essential oils. The prepared films were applied on minimally processed pineapple to study the microbial inhibition of Gram + and Gram – bacteria and fungi and to evaluate the shelf life of the minimally processed fruit.

In this study alginate and chitosan-based edible coating were prepared and applied on minimally processed pineapple. The edible coatings were evaluated microscopically, by the power of reducing microbial contamination, by the shelf-life improvement.

This study demonstrates that the incorporation of the essential oils P. nigrum and S. terebinthifolia contributed to the inhibition of all the microorganisms studied and improved the shelf life of minimally processed pineapple. This is especially true for P. nigrum in the chitosan-based edible coating, where the shelf life was improved by 45 days.

Because of the pandemic, it was not possible to perform the sensory analyses of the antimicrobial alginate and chitosan-based edible coatings prepared.

From the results obtained, it is possible to state that the antimicrobial alginate and chitosan-based edible coatings incorporating S. terebinthifolia and P. nigrum essential oils can be used on minimally processed fruits and prolong their shelf life.

Due to the lifestyle of modern consumers, who demand speed and practicality and the need to consume fruits for health and quality of life, minimally processed fruits covered with edible coatings incorporating natural antimicrobial additives can provide a practical solution.

To the best of the authors’ knowledge, this is the first time that alginate and chitosan-based edible coatings that incorporate P. nigrum and S. terebinthifolia applied on minimally processed fruit, have been studied.