Agarase is a promising biocatalyst that catalyze the hydrolysis of agar or agarose and produce oligosaccharides with several biotechnological applications. Agarase production by Dendryphiella arenaria was optimized using a natural low-cost medium composed of the red alga Palisada perforata and natural seawater. The results showed that seaweed biomass and seawater concentrations were the most important factors influencing agarase production. After optimization, the agarase activity was enhanced to 2.5 ± 0.3 U/mL. The crude agarase exhibited a wide pH (4‒10) stability with residual activity more than 75%. The enzyme showed high thermostability at 40 °C, and a moderate thermostability at 50, 60, 70 °C. Several parameters of thermal inactivation kinetics and thermodynamics were calculated, and suggested that the enzyme would be thermostable. Enzymatic saccharification of alkali extracted polysaccharides from the red macroalgal biomass was also optimized with respect to substrate concentration, enzyme dosage, and temperature and proceeded optimally at 0.15% substrate, 40 °C with enzyme dosage 0.9 mL/mL substrate. Under these conditions, the enzymatic saccharification yielded 647.96 mg reducing sugars/g substrate. This study therefore describes an improved, effective, and low-cost process for agarase and fermentable sugar production from seaweed biomass.

Agarase is a promising biocatalyst that catalyze the hydrolysis of agar or agarose and produce oligosaccharides with several biotechnological applications. Agarase production by Dendryphiella arenaria was optimized using a natural low-cost medium composed of the red alga Palisada perforata and natural seawater. The results showed that seaweed biomass and seawater concentrations were the most important factors influencing agarase production. After optimization, the agarase activity was enhanced to 2.5 ± 0.3 U/mL. The crude agarase exhibited a wide pH (4‒10) stability with residual activity more than 75%. The enzyme showed high thermostability at 40 °C, and a moderate thermostability at 50, 60, 70 °C. Several parameters of thermal inactivation kinetics and thermodynamics were calculated, and suggested that the enzyme would be thermostable. Enzymatic saccharification of alkali extracted polysaccharides from the red macroalgal biomass was also optimized with respect to substrate concentration, enzyme dosage, and temperature and proceeded optimally at 0.15% substrate, 40 °C with enzyme dosage 0.9 mL/mL substrate. Under these conditions, the enzymatic saccharification yielded 647.96 mg reducing sugars/g substrate. This study therefore describes an improved, effective, and low-cost process for agarase and fermentable sugar production from seaweed biomass.

Alginate and fucoidan extracted from the brown macroalga Sargassum latifolium and chitosan derived from the filamentous fungus Aspergillus niger were used for the development of edible films with natural antioxidant properties. The incorporation of fucoidan and/or Ca2þ into the alginate-chitosan films decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The developed films showed good barrier properties against ultraviolet light. The interactions between film components were investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Film moisture content at equilibrium was increased by fucoidan blending. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's second law. The developed films exhibited good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the subsequent antioxidant activity of the films.

Alginate and fucoidan extracted from the brown macroalga Sargassum latifolium and chitosan derived from the filamentous fungus Aspergillus niger were used for the development of edible films with natural antioxidant properties. The incorporation of fucoidan and/or Ca2þ into the alginate-chitosan films decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The developed films showed good barrier properties against ultraviolet light. The interactions between film components were investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Film moisture content at equilibrium was increased by fucoidan blending. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's second law. The developed films exhibited good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the subsequent antioxidant activity of the films.

Alginate and fucoidan extracted from the brown macroalga Sargassum latifolium and chitosan derived from the filamentous fungus Aspergillus niger were used for the development of edible films with natural antioxidant properties. The incorporation of fucoidan and/or Ca2þ into the alginate-chitosan films decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The developed films showed good barrier properties against ultraviolet light. The interactions between film components were investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Film moisture content at equilibrium was increased by fucoidan blending. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's second law. The developed films exhibited good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the subsequent antioxidant activity of the films.

Alginate and fucoidan extracted from the brown macroalga Sargassum latifolium and chitosan derived from the filamentous fungus Aspergillus niger were used for the development of edible films with natural antioxidant properties. The incorporation of fucoidan and/or Ca2þ into the alginate-chitosan films decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The developed films showed good barrier properties against ultraviolet light. The interactions between film components were investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Film moisture content at equilibrium was increased by fucoidan blending. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's second law. The developed films exhibited good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the subsequent antioxidant activity of the films.

Alginate and fucoidan are unique polysaccharides present in brown algae and widely used in food and medical technologies. Alginate and fucoidan were sequentially extracted from Sargassum latifolium and used for the preparation of alginate and alginate-fucoidan blend films with or without Ca-crosslinking. The incorporation of fucoidan and Ca2þ decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The films showed good properties against ultraviolet light, however, incorporation of fucoidan and/or Ca2þ decreased the color parameter L* value and increased the a* and b* values of the films. The interaction of Ca2þ and fucoidan with alginate was investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Ca2þ crosslinking decreased initial moisture sorption and increased the maximum sorption capacity of the films. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's law. The developed films showed good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the antioxidant activity of the films.

Alginate and fucoidan are unique polysaccharides present in brown algae and widely used in food and medical technologies. Alginate and fucoidan were sequentially extracted from Sargassum latifolium and used for the preparation of alginate and alginate-fucoidan blend films with or without Ca-crosslinking. The incorporation of fucoidan and Ca2þ decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The films showed good properties against ultraviolet light, however, incorporation of fucoidan and/or Ca2þ decreased the color parameter L* value and increased the a* and b* values of the films. The interaction of Ca2þ and fucoidan with alginate was investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Ca2þ crosslinking decreased initial moisture sorption and increased the maximum sorption capacity of the films. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's law. The developed films showed good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the antioxidant activity of the films.

Alginate and fucoidan are unique polysaccharides present in brown algae and widely used in food and medical technologies. Alginate and fucoidan were sequentially extracted from Sargassum latifolium and used for the preparation of alginate and alginate-fucoidan blend films with or without Ca-crosslinking. The incorporation of fucoidan and Ca2þ decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The films showed good properties against ultraviolet light, however, incorporation of fucoidan and/or Ca2þ decreased the color parameter L* value and increased the a* and b* values of the films. The interaction of Ca2þ and fucoidan with alginate was investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Ca2þ crosslinking decreased initial moisture sorption and increased the maximum sorption capacity of the films. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's law. The developed films showed good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the antioxidant activity of the films.

Alginate and fucoidan are unique polysaccharides present in brown algae and widely used in food and medical technologies. Alginate and fucoidan were sequentially extracted from Sargassum latifolium and used for the preparation of alginate and alginate-fucoidan blend films with or without Ca-crosslinking. The incorporation of fucoidan and Ca2þ decreased water solubility, but increased film thickness, water vapor permeability and oxygen permeability. The films showed good properties against ultraviolet light, however, incorporation of fucoidan and/or Ca2þ decreased the color parameter L* value and increased the a* and b* values of the films. The interaction of Ca2þ and fucoidan with alginate was investigated using FTIR analysis which confirmed the presence of hydrogen bonded interaction. Kinetics of moisture sorption and polyphenol release exhibited a good fit to Peleg's model. Ca2þ crosslinking decreased initial moisture sorption and increased the maximum sorption capacity of the films. Additionally, the water vapor diffusion and polyphenol release were expressed in terms of effective diffusion coefficient based on simplified Fick's law. The developed films showed good antioxidant properties as measured by total antioxidant assay, ferric reducing antioxidant power and hydroxyl radical scavenging activity. Both film type and the type of the food simulant markedly affected the polyphenol release and the antioxidant activity of the films.