Limits...
Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads.

Lin SF, Chen YC, Chen RN, Chen LC, Ho HO, Tsung YH, Sheu MT, Liu DZ - PLoS ONE (2016)

Bottom Line: The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation.Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C.These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds.

View Article: PubMed Central - PubMed

Affiliation: Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering Taipei Medical University, Taipei, Taiwan (ROC).

ABSTRACT
There has been considerable interest in the biological functions of astaxanthin and its potential applications in the nutraceutical, cosmetics, food, and feed industries in recent years. However, the unstable structure of astaxanthin considerably limits its application. Therefore, this study reports the encapsulation of astaxanthin in calcium alginate beads using the extrusion method to improve its stability. This study also evaluates the stability of the encapsulated astaxanthin under different storage conditions. The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation. Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C. These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds.

No MeSH data available.


Related in: MedlinePlus

Comparison of astaxanthin encapsulated alginate beads with various formulations with different calcium chloride concentrations (2% and 10%).The word “ALG” denotes alginate. The asterisk indicates statistically significant difference (✽:p < 0.05, compared to 2%).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4836734&req=5

pone.0153685.g004: Comparison of astaxanthin encapsulated alginate beads with various formulations with different calcium chloride concentrations (2% and 10%).The word “ALG” denotes alginate. The asterisk indicates statistically significant difference (✽:p < 0.05, compared to 2%).

Mentions: The microencapsulation of astaxanthin was carried out by the extrusion method. In this method, spherical beads were obtained by dripping the polymer solution (alginate solution) into the calcium chloride solution. This instantly formed small beads that entrapped drugs within a tridimensional lattice. Preliminary tests summarized in Table 1 revealed the appropriate experimental parameters for preparing alginate beads. A comparison of stirring times while the alginate droplets were dripped in calcium chloride solution revealed no significant difference among treatments (15 min, 30 min, and 60 min) in terms of average size, microencapsulation yield, and loading efficiency. Hence, the stirring time was set at 15 min in this study. The optimum stirring rate was 150 rpm (Fig 3A) because a faster stirring rate resulted in deformed or irregularly-shaped beads (Fig 3B). This study further investigates the ideal experimental conditions for preparing astaxanthin encapsulated sodium alginate beads, including the concentration of calcium chloride solution, sodium alginate solution, and the surfactant Tween 20 (Table 2). Table 3 lists the average yield weight, microencapsulation yield, average size, and loading efficiency of astaxanthin encapsulated beads with various formulations. This table represents each formulation using a code name. For example, the code name “1A0.5T2C” denotes a formulation using 1% of alginate solution, 0.5% of Tween 20, and 2% of calcium chloride solution in the microencapsulation process. The microencapsulation yield and loading efficiency are both key aspects that must be considered in microencapsulation. The microencapsulation yield ranged from 97.94–25.83%, and the loading efficiency ranged from 100% to 82%. Considering the effect of experimental factors in this study, a higher concentration of sodium alginate led to greater average weight and size of alginate beads. This is because the drop size of alginate solution was expected to increase with increasing the viscosity of alginate solution resulting from higher alginate concentration. However, a higher concentration of calcium chloride led to lower microencapsulation yield no matter which alginate concentrations used (Fig 4). This is because calcium ions are capable of binding to the limited carboxylic groups of alginate, leading to the formation of a strong thermostable gel. Once the binding sites were fully occupied, the excess calcium ions were unable to incorporate into alginate beads. Hence, the more calcium chloride not entrapped the less microencapsulation yield would result. On the other hand, the addition of surfactant Tween 20 has no effect on the microencapsulation yield and loading efficiency.


Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads.

Lin SF, Chen YC, Chen RN, Chen LC, Ho HO, Tsung YH, Sheu MT, Liu DZ - PLoS ONE (2016)

Comparison of astaxanthin encapsulated alginate beads with various formulations with different calcium chloride concentrations (2% and 10%).The word “ALG” denotes alginate. The asterisk indicates statistically significant difference (✽:p < 0.05, compared to 2%).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4836734&req=5

pone.0153685.g004: Comparison of astaxanthin encapsulated alginate beads with various formulations with different calcium chloride concentrations (2% and 10%).The word “ALG” denotes alginate. The asterisk indicates statistically significant difference (✽:p < 0.05, compared to 2%).
Mentions: The microencapsulation of astaxanthin was carried out by the extrusion method. In this method, spherical beads were obtained by dripping the polymer solution (alginate solution) into the calcium chloride solution. This instantly formed small beads that entrapped drugs within a tridimensional lattice. Preliminary tests summarized in Table 1 revealed the appropriate experimental parameters for preparing alginate beads. A comparison of stirring times while the alginate droplets were dripped in calcium chloride solution revealed no significant difference among treatments (15 min, 30 min, and 60 min) in terms of average size, microencapsulation yield, and loading efficiency. Hence, the stirring time was set at 15 min in this study. The optimum stirring rate was 150 rpm (Fig 3A) because a faster stirring rate resulted in deformed or irregularly-shaped beads (Fig 3B). This study further investigates the ideal experimental conditions for preparing astaxanthin encapsulated sodium alginate beads, including the concentration of calcium chloride solution, sodium alginate solution, and the surfactant Tween 20 (Table 2). Table 3 lists the average yield weight, microencapsulation yield, average size, and loading efficiency of astaxanthin encapsulated beads with various formulations. This table represents each formulation using a code name. For example, the code name “1A0.5T2C” denotes a formulation using 1% of alginate solution, 0.5% of Tween 20, and 2% of calcium chloride solution in the microencapsulation process. The microencapsulation yield and loading efficiency are both key aspects that must be considered in microencapsulation. The microencapsulation yield ranged from 97.94–25.83%, and the loading efficiency ranged from 100% to 82%. Considering the effect of experimental factors in this study, a higher concentration of sodium alginate led to greater average weight and size of alginate beads. This is because the drop size of alginate solution was expected to increase with increasing the viscosity of alginate solution resulting from higher alginate concentration. However, a higher concentration of calcium chloride led to lower microencapsulation yield no matter which alginate concentrations used (Fig 4). This is because calcium ions are capable of binding to the limited carboxylic groups of alginate, leading to the formation of a strong thermostable gel. Once the binding sites were fully occupied, the excess calcium ions were unable to incorporate into alginate beads. Hence, the more calcium chloride not entrapped the less microencapsulation yield would result. On the other hand, the addition of surfactant Tween 20 has no effect on the microencapsulation yield and loading efficiency.

Bottom Line: The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation.Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C.These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds.

View Article: PubMed Central - PubMed

Affiliation: Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering Taipei Medical University, Taipei, Taiwan (ROC).

ABSTRACT
There has been considerable interest in the biological functions of astaxanthin and its potential applications in the nutraceutical, cosmetics, food, and feed industries in recent years. However, the unstable structure of astaxanthin considerably limits its application. Therefore, this study reports the encapsulation of astaxanthin in calcium alginate beads using the extrusion method to improve its stability. This study also evaluates the stability of the encapsulated astaxanthin under different storage conditions. The evaluation of astaxanthin stability under various environmental factors reveals that temperature is the most influential environmental factor in astaxanthin degradation. Stability analysis shows that, regardless of the formulation used, the content of astaxanthin encapsulated in alginate beads remains above 90% of the original amount after 21 days of storage at 25°C. These results suggest that the proposed technique is a promising way to enhance the stability of other sensitive compounds.

No MeSH data available.


Related in: MedlinePlus