Application Of Sodium Alginate Research Articles

Polyelectrolyte complex formation of alginate and chito oligosaccharide is influenced by their proportion and alginate molecular weight

Sodium alginate (SA) and chito oligosaccharide (COS) are widely used food additives in the food industry, and exploring their interaction to form polyelectrolyte complexes (PECs) may provide insights into food development. In the present study, the effects of viscosity-average molecular weight (Mv) and relative amounts of SA on the formation of sodium alginate/chito oligosaccharide polyelectrolyte (SCP) complexes were investigated. The results showed that the electrostatic interaction between -COOH and -NH2 and the hydrogen bonding between OH, were attributed to the formation of the SCP complexes. Then the formation and properties of SCP complexes were greatly dependent on the Mv and the relative amount of SA. SA with Mv of ≥2.16 × 106 Da could form spherical SCP complexes, while the SA/COS ratio (w/w) ≥ 0.8 was not conducive to the formation of SCP complexes. Moreover, the SCP complexes were more stable in the gastric environment than in the intestinal condition. In addition, 1.73 × 107 Da was the optimal Mv of SA for SCP complexes formation. This study contributed to a comprehensive understanding of the interaction between SA and COS, and shed light on the potential application of SA and COS formulation to develop new food products.

Preparation of recyclable magnetic palladium nanocatalysts by dispersion strategy based on sodium alginate for reduction of p-nitrophenol and Suzuki-Miyaura coupling

Palladium (Pd) has excellent catalytic performance, its application is seriously limited by low atomic utilization and weak recovery capacity. To solve these problems, we report a universal palladium nanocatalysts preparation strategy by taking advantage of the rich chemistry of sodium alginate (SA). SA units not only self-assemble into a cross-linked porous carboxyl and hydroxyl framework but also can coat different substrates. Benefiting from the distinguished chelation of SA, metallic nanocatalysts can be achieved. As a proof-of-concept demonstration, Pd loading on nano-Fe3O4 modified with SA and investigated their catalytic capabilities. The catalyst was Fe3O4 nanoparticles encapsulated by SA film loaded with 0.4 wt% of Pd. It has a particle size around 100 nm and has good superparamagnetism with a saturation strength of 76.26 emu/g. It exhibited good catalytic activity at TOF = 660 h−1 and TOF = 4311 h−1 in typical Suzuki-Miyaura coupling reaction and the reduction of p-nitrophenol, respectively, and showed appreciable recyclability in the test of recyclability. Thus, our findings demonstrate that recyclable magnetic palladium nanocatalysts have several attractive features, such as easy preparation, outstanding catalytic activity and reusability. This work lays the foundation for the preparation of palladium nanocatalysts and the potential application of SA in the field of catalysts.

Study of polysaccharide gels at Prof. Nishinari's laboratory

Studies performed at Prof. Katsuyoshi Nishinari's laboratory are overviewed. The gelation and gel properties of gellan gum were investigated by rheological and thermal analyses. The change in the elastic modulus of gellan gum gels due to the temperature or immersion in salt solutions was interpreted from the model that Prof. Nishinari proposed. The fracture behavior of the large deformation of gellan gum gels was also explained by this model. The gel of xyloglucan from tamarind seed, in particular, a thermoreversible cold-setting gel that formed in the presence of epigallocatechin gallate or Na-type gellan, was studied. As examples of recent collaborative works with Prof. Nishinari, the gelation of β-glucan extracted from Sparassis crispa, an edible mushroom, and the application of sodium alginate and low methoxy pectin to rice noodles are also described.

‘Efficacy of sodium alginate, xanthan gum, and diatomite admixtures in improving the strength and shrinkage behaviour of EPS lightweight concrete’

The aim of this study is to demonstrate the effectiveness of cement admixtures in improving the shrinkage and strength resistance of EPS lightweight concretes (ELCs). A group of EPS mixtures containing 0.5, 1 and 2% of sodium alginate, 0.1, 0.3 and 0.5% of xanthan gum and 2, 5 and 8% of diatomite was used. The results of the study showed that increasing the dose of each admixture significantly improved the strength and shrinkage resistance of ELC. Although the application of sodium alginate, xanthan gum and diatomite as cement admixtures decreased the water loss ratio of EPS concrete compared to the reference mix, the increase in their contents increased the water loss ratio of EPS concrete. The increase in sodium alginate, xanthan gum and diatomite content improved the EPS concrete pore structure stability and performance of the interface of transition zones (ITZ) between the cement slurries and EPS aggregates, which had a positive role in improving the strength and shrinkage behaviour of ELC. Application of 2% sodium alginate, 0.5% of xanthan gum and 8% of diatomite can be recommended as the preferred dose of cement admixtures to improve the strength and shrinkage performance of ELC.

Effect of Sodium Alginate in Combination with Zataria multiflora Boiss. on Phenolic Compounds, Antioxidant Activity, and Browning Enzymes of Fresh In-Hull Pistachio (Pistacia vera L.)

The color of fresh pistachio is used as a postharvest quality indicator. The present study was performed to investigate the chemical properties of fresh pistachios coated with different sodium alginate concentrations (1 and 1.5%), various amounts of Shirazi thyme essential oil (0.3 and 0.5%), and their combination during storage (2 ± 1°C and 85 ± 5% RH). Over the storage duration, chemical parameters were measured on days 13, 26, and 39. The results showed that although the application of sodium alginate in combination with thyme essential oil decreased polyphenol oxidase activity in comparison with other treatments, the highest total phenolics and phenylalanine ammonia lyase activity were found in pistachios coated with alginate (1%) + thyme essential oil (0.3% and 0.5%). In general, it was proven that treatments containing 1% alginate + 0.3% essential oil had the ability to maintain the quality of fresh pistachio fruit approximately over 39 days of storage.

海藻酸钠在中性高钙乳中的应用研究

海藻酸钠在中性高钙乳中的应用研究

Improving Shelf Life of Strawberry Through Application of Sodium Alginate and Ascorbic Acid Coatings

In the present study, effects of edible coatings using sodium alginate (SA) and sodium alginate in combination with ascorbic acid (AA) on the shelf-life extension of strawberries at 4±1°C was studied. A factorial experiment was performed based on a randomized complete block design with four replications. The treatments included control (distilled water), SA (1%, 2%, 3% w/v), SA in combination with AA (1% w/v) and the storage periods (7 and 14 days). The results showed that lightness (L*), chroma, firmness, total acidity, vitamin C, phenols, and antioxidant activity decreased during storage, but coating improved them in the sold-stored strwberries. SA2%+AA1% coating was the best treatment in maintaining the fruit quality. Firmness, weight loss, fruit L*, fruit chroma, sepal L*, sepal chroma, total phenolics, and polyphenol oxidase activity were decreased by 15%, 1.95%, 16.7%, 2.66%, 10.23%, 16%, 19.47% and 2.5%, respectively for SA2%+AA1% samples at the end of the 14th day, which was lower than the untreated fruits. The results suggested that postharvest application of SA2%+AA1% has the potential to extend the storage life of strawberry fruits by reducing water loss and maintaining fruit quality.

Application of sodium alginate as a coagulant aid for mitigating membrane fouling induced by humic acid in dead-end ultrafiltration process

Ultrafiltration (UF) is one of the most promising technologies for surface water treatment, but severe membrane fouling is a significant obstacle for its widespread application. In this study, sodium alginate (SA) was used as a coagulant aid of polyaluminum chloride (PAC) in a pre-coagulation process prior to UF to mitigate UF membrane fouling. The influence of SA addition on water treatment efficiency, flocs characteristics and membrane fouling were examined. Results showed that SA dosed after PAC improved coagulation and UF efficiency due to its bridge role and gel network formation. UV254 and DOC removal from UF effluent were over 97% and 70%, respectively, when SA dosage ≥0.3 mg/L. In addition, UF membrane normalized flux was improved from 0.19 to 0.47. The membrane fouling alleviating mechanism of SA application was the formation of a porous cake layer by flocs with looser structures. In addition, these flocs were much larger than membrane pores (flocs sizes >450 μm), which also alleviate pore blocking degree of UF membrane.

Parameter optimization and mechanism research of enhanced coagulation treatment for Yuquan River water

Abstract As one of the drinking water sources for Xuzhou city, Yuquan River has been polluted seriously in recent years. In this paper, enhanced coagulation technology was selected and various parameters (coagulant species, dosage, solution pH and coagulant aid species) were optimized for Yuquan River water treatment. Turbidity and UV254 removal rate were calculated to assess coagulation efficiencies, and meanwhile floc generation kinetics, zeta potential and scanning electron microscope (SEM) spectra were measured to study the coagulation mechanism. Results indicated that the coagulation effect of polyaluminium chloride (PAC) on Yuquan River water was better than that of aluminium sulphate (AS), and its optimal dosage was 20 mg/L. Flocs produced by PAC also exhibited larger size and faster growth velocity than those of AS. Moreover, the applicable initial pH range for Yuquan River was 6.0–9.0, and the optimal coagulation efficiency was observed at pH 7.0. When PAC or AS was selected as coagulant, the application of sodium alginate (SA) could improve turbidity and UV254 removal due to its adsorption bridging role. In addition, coagulation efficiency could be enhanced in an AS coagulation system when polyacrylamide (PAM) was dosed as coagulant aid.

海藻酸钠在胡萝卜海藻香肠中的应用

海藻酸钠在胡萝卜海藻香肠中的应用

Reactivity enhancement of iron sulfide nanoparticles stabilized by sodium alginate: Taking Cr (VI) removal as an example

The widespread distribution of chromium(VI) in the environment leads to groundwater contamination. The use of iron sulfide (FeS) to remove Cr(VI) has therefore been proposed. However, aggregation is one of the main problems associated with the use of FeS nanoparticles prepared by traditional methods In this study, we used sodium alginate (SA) to stabilize FeS nanoparticles (FeS-SA). SA could prevent aggregation of FeS by the concurrent electrostatic repulsion and steric hindrance. Homogeneously dispersed FeS-SA nanoparticles 100nm in diameter were observed. FeS-SA showed high efficiency in Cr(VI) removal, corresponding to an enhancement of efficiency from 65% (7.50mmol Cr(VI) per g FeS) to 100% (11.54mmol Cr per g FeS) relative to that achieved with naked FeS. Analysis of reaction products by X-ray diffraction and X-ray photoelectron spectroscopy revealed the co-existence of α-FeOOH, S8, and Cr(OH)3 that apparently were introduced by Fe(II), S(−II), and Cr(VI), respectively. In-depth analysis of the removal mechanism revealed that reduction and adsorption respectively account for 82% and 18% of the Cr removal. In addition, higher pH and CaCl2 concentration resulted in lower removal efficiency. This study provides a promising application of SA in enhancing FeS reactivity for the remediation of groundwater pollution.

Application of sodium alginate in induced biological soil crusts: enhancing the sand stabilization in the early stage

Induced biological soil crust (IBSC) technology has proved to be an effective means for speeding up the recovery of biological soil crusts (BSC) in arid and semi-arid regions. This study aims at improving the IBSC technology by using sodium alginate (SA) due to its sand-stabilizing ability in the early development stage of IBSCs. Results showed that SA can easily form a thin film on the surface of soil and can significantly enhance the compressive strength of the topsoil. More importantly, no negative effects of SA on the development and physiological activity of IBSCs were observed, and SA could facilitate the colonization and growth of cyanobacteria on sand. Moreover, the application of SA was much cheaper than the straw checkerboard barriers which are widely used in desertification control. This study suggests that SA can promote and accelerate the formation of BSCs; thus, it can be applied in IBSC technology to enhance the sand-stabilizing property of BSCs in the early stage.

CuO nanoparticle–humic acid (CuONP–HA) composite contaminant removal by coagulation/ultrafiltration process: The application of sodium alginate as coagulant aid

In order to remove CuO nanoparticle–humic acid composite contaminant (CuONP–HA) and reduce the membrane fouling in coagulation/ultrafiltraion process, sodium alginate (SA) was used as a coagulant aid of polyaluminum chloride (PAC) to pre-treat CuONP–HA in synthetic water. The effect of SA on floc properties and membrane fouling was investigated by a laser diffraction instrument and ultrafiltration fouling model. The results showed that SA, as coagulant aid, could improve the removal efficiency of CuONP–HA by coagulation/ultrafiltration process. CuONP was completely removed, and the removal efficiency of HA was over 80% at PAC dosage=3.0mg/L and SA dosage≥0.2mg/L. Besides, PAC with SA (PAC+SA) could form larger flocs with better recoverability than PAC alone. The average size of CuONP–HA flocs formed by PAC+SA exceeded 1000um which was about 66% larger than flocs formed by PAC, and the small CuONP–HA aggregation also increased to about 280um. Moreover, membrane fouling was effectively reduced by pre-treating of SA, and membrane fouling index (MFI) was decreased with the dosage of SA increasing.

The role of sodium alginate in improving floc size and strength and the subsequent effects on ultrafiltration membrane fouling

Background: Dosing environment-friendly polymer as coagulant aids is an encouraging method in water treatment to obtain desirable floc characteristics. Sodium alginate (SA) was used as the coagulant aid for synthetic humic acid (HA) water treatment to investigate the effect on flocs characteristics and ultrafiltration (UF) membrane fouling. Results: When SA content was 0.3 mg L−1, the treatment of HA by polyaluminium chloride (PAC) plus SA (PAC/SA) yielded the maximum removal efficiency of 66.5%, which was higher than the maximum HA removal efficiency of PAC (58%). Moreover, the HA flocs size of PAC would grow from 269 to 367 μm after SA was added. Strength factor and recovery factor of PAC/SA were larger than those of PAC. These resulted in the improvement in subsequent UF membrane performance. The membrane fouling decreased in the following order: the raw water>PAC coagulated water>PAC/SA coagulated water. Conclusion: The study showed that the application of SA as coagulant aids resulted in larger and stronger flocs, which would improve treatment efficiency of the coagulation process. And the flocs formed by PAC/SA contributed to the restriction of the fouling of UF membrane, which would decrease the cost of advanced water treatment.