Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer méditerranée bie... more Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer méditerranée bien répandues le long des côtes Tunisiennes et non exploitées. Il ressort de cette étude que ces algues pourraient être utilisées comme une source d’ingrédients fonctionnels d’origine naturelle pour la production de burgers à base de chair de poissons d’eau douce (Barbus barbus). De plus, ces travaux ont conduit à l’obtention d’un fucoïdane (CCF) et un alginate de sodium (CCSA) comme polysaccharides matriciels de C. compressa. CCF (1,05 × 105 g/mol) est un hétérogalactofucane sulfaté (14,65 %) composé d’une chaîne principale de α-(1,3 ; 1,4)-l-Fucp ramifiée (31,84 %) en positions O-4 et O-3 par des monosaccharides terminaux et des chaînes latérales. CCSA (Mw = 1 × 105 g/mol) est composé de 56 % de α-l-GulA (G) et 44 % de β-d-ManA (M) (M/G = 0,77). Ce polyuronide est constitué de 93 % d’homoblocs (FGG = 53 % et FMM = 40 %) et de 6 % d’hétéroblocs (FMG = 3 % et FGM = 3 %). Les analyses rhéol...
Polysaccharides are complex macromolecules long regarded as energetic storage resources or as com... more Polysaccharides are complex macromolecules long regarded as energetic storage resources or as components of plant and fungal cell walls. They have also been described as plant mucilages or microbial exopolysaccharides. The development of glycosciences has led to a partial and difficult deciphering of their other biological functions in living organisms. The objectives of glycobiochemistry and glycobiology are currently to correlate some structural features of polysaccharides with some biological responses in the producing organisms or in another one. In this context, the literature focusing on bioactive polysaccharides has increased exponentially during the last two decades, being sometimes very optimistic for some new applications of bioactive polysaccharides, notably in the medical field. Therefore, this review aims to examine bioactive polysaccharide, taking a critical look of the different biological activities reported by authors and the reality of the market. It focuses also o...
Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer mediterranee bie... more Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer mediterranee bien repandues le long des cotes Tunisiennes et non exploitees. Il ressort de cette etude que ces algues pourraient etre utilisees comme une source d’ingredients fonctionnels d’origine naturelle pour la production de burgers a base de chair de poissons d’eau douce (Barbus barbus). De plus, ces travaux ont conduit a l’obtention d’un fucoidane (CCF) et un alginate de sodium (CCSA) comme polysaccharides matriciels de C. compressa. CCF (1,05 × 105 g/mol) est un heterogalactofucane sulfate (14,65 %) compose d’une chaine principale de α-(1,3 ; 1,4)-l-Fucp ramifiee (31,84 %) en positions O-4 et O-3 par des monosaccharides terminaux et des chaines laterales. CCSA (Mw = 1 × 105 g/mol) est compose de 56 % de α-l-GulA (G) et 44 % de β-d-ManA (M) (M/G = 0,77). Ce polyuronide est constitue de 93 % d’homoblocs (FGG = 53 % et FMM = 40 %) et de 6 % d’heteroblocs (FMG = 3 % et FGM = 3 %). Les analyses rheol...
Polysaccharides from marine algae are one novel source of plant defense elicitors for alternative... more Polysaccharides from marine algae are one novel source of plant defense elicitors for alternative and eco-friendly plant protection against phytopathogens. The effect of exopolysaccharides (EPS) produced by Porphyridium sordidum on elicitation of Arabidopsis thaliana defense responses against Fusarium oxysporum was evaluated. Firstly, in order to enhance EPS production, a Box–Behnken experimental design was carried out to optimize NaCl, NaNO3 and MgSO4 concentrations in the culture medium of microalgae. A maximum EPS production (2.45 g/L) higher than that of the control (0.7 g/L) was observed for 41.62 g/L NaCl, 0.63 g/L NaNO3 and 7.2 g/L MgSO4 concentrations. Structurally, the EPS contained mainly galactose, xylose and glucose. Secondly, the elicitor effect of EPS was evaluated by investigating the plant defense-related signaling pathways that include activation of Salicylic or Jasmonic Acid-dependent pathway genes. A solution of 2 mg/mL of EPS has led to the control of fungal grow...
Bioactive compounds with diverse chemical structures play a significant role in disease preventio... more Bioactive compounds with diverse chemical structures play a significant role in disease prevention and maintenance of physiological functions. Due to the increase in industrial demand for new biosourced molecules, several types of biomasses are being exploited for the identification of bioactive metabolites and techno-functional biomolecules that are suitable for the subsequent uses in cosmetic, food and pharmaceutical fields. Among the various biomasses available, macroalgae are gaining popularity because of their potential nutraceutical and health benefits. Such health effects are delivered by specific diterpenes, pigments (fucoxanthin, phycocyanin, and carotenoids), bioactive peptides and polysaccharides. Abundant and recent studies have identified valuable biological activities of native algae polysaccharides, but also of their derivatives, including oligosaccharides and (bio)chemically modified polysaccharides. However, only a few of them can be industrially developed and open ...
A novel sulfated xylogalactan-rich fraction (JSP for J. adhaerens Sulfated Polysaccharide) was ex... more A novel sulfated xylogalactan-rich fraction (JSP for J. adhaerens Sulfated Polysaccharide) was extracted from the red Tunisian seaweed Jania adhaerens. JSP was purified using an alcoholic precipitation process and characterized by Attenuated Total Reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR), high-pressure size exclusion chromatography (HPSEC) with a multi-angle laser light scattering (MALLS), gas chromatography coupled to mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR, 1D and 2D). JSP was then evaluated regarding its physicochemical and rheological properties. Results showed that JSP was mainly composed of an agar-like xylogalactan sharing the general characteristics of corallinans. The structure of JSP was mainly composed of agaran disaccharidic repeating units (→3)-β-d-Galp-(1,4)-α-l-Galp-(1→)n and (→3)-β-d-Galp-(1,4)-3,6-α-l-AnGalp-(1→)n, mainly substituted on O-6 of (1,3)-β-d-Galp residues by β-xylosyl side chains, and less with sul...
Abstract Rheological characteristics of a sodium alginate and a fucoidan extracted from the brown... more Abstract Rheological characteristics of a sodium alginate and a fucoidan extracted from the brown seaweed Cystoseira compressa harvested from Kerkennah island (Sfax, Tunisia) were investigated. Steady-shear flow and dynamical viscoelasticity were evaluated to describe physicochemical properties of the GulA-rich alginate (ManA/GulA, M/G = 0.77) and highly-ramified fucoidan in semi-diluted media depending on polymer concentration, shear rate, temperature, added mono- (KCl and NaCl) and divalent (CaCl2) salts. Alginate solutions exhibited shear-thinning behavior, with a temperature-dependent behavior highly correlated to the power-law model and the Arrhenius relationship. The results showed strong thixotropic and polyelectrolyte properties, influenced by addition of monovalent and divalent cations. The dynamic rheological characteristics showed a fluid-like viscoelastic behavior (tan δ > 1) whereas the critical overlap concentration C* and specific polymer constant ks were respectively 11 g.L−1 and 4.4 using Williamson model. Fucoidan solutions displayed a shear-thinning behavior with a low viscoelasticity character influenced by temperature and monovalent salts. The flow and viscoelastic characteristics of polysaccharides were described by the Ostwald model.
In this paper, water-soluble polysaccharides (named as NRLP) were extracted from Nitraria retusa ... more In this paper, water-soluble polysaccharides (named as NRLP) were extracted from Nitraria retusa leaves. The main structural features of NRLP were determined by High-pressure size exclusion chromatography, Fourier transform infrared and Gas Chromatography/Mass Spectrometry-Electronic Impact analysis. The in vitro and in vivo biological potential of NRLP were evaluated by measuring its antioxidant (•OH and DPPH• scavenging, total antioxidant capacity), anti-α-amylase as well as anti-inflammatory and antinociceptive activities in a mice model. NRLP was composed of Rha (33.7%), Gal (18.1%), GalA (15.0%), Glc (13.3%), Ara (13.3%), Xyl (3.8%), and GlcA (2.8%) and showed a Molecular Weight (Mw) of 23.0 kDa and a polydispersity index (PDI) of 1.66. The investigations highlighted a significant antioxidant activity (IC50 = 2.4–2.6 mg/mL) and an inhibition activity against α-amylase (IC50 = 4.55 mg/mL) in a dose-dependent manner. Further, NRLP revealed interesting anti-edematous effects and a...
International Journal of Biological Macromolecules
A water-soluble polysaccharide (PSPC) was extracted from the seeds of Plantago ciliata Desf., a s... more A water-soluble polysaccharide (PSPC) was extracted from the seeds of Plantago ciliata Desf., a spontaneous Algerian Saharan plant by a hot aqueous extraction then purified by successive ethanolic precipitations. The final extraction yield for PSPC was close to 18.6% (w/v). PSPC was then investigated regarding its global composition, structural features and rheological properties. PSPC is a neutral arabinoxylan, composed of a β-(1,3)/β-(1,4)-D-xylan backbone with side chains of Xylp, and Araf residues attached in O-2 and O-3 positions. The macromolecular characteristics of PSPC in water was determined by SEC/MALLS, with a high molecular weight (Mw) of 700 kDa, a low polydispersity index (PDI) of 1.47 and an intrinsic viscosity (η) close to 157 mL/g. PSPC showed a pseudoplastic behavior in semi-dilute media and the critical overlay concentration (C*) was estimated around 0.32-0.37% (w/v). This current research has supplied original structural information on a new arabinoxylan which could be particularly useful as a novel source of soluble fiber belonging to psyllium.
Microalgae have been used as natural ingredients to produce functional and nutritional food produ... more Microalgae have been used as natural ingredients to produce functional and nutritional food products. The impact of the addition of Chlorella minutissima, Isochrysis galbana, and Picochlorum sp. at concentrations of 0.5, 1, and 1.5% w/v on the texture and sensory attributes of canned burgers were investigated. The results show that carp formulations containing 1% microalgae show significantly better classification performance for many textural and sensory parameters compared to the rest of the formulations. Also, these treatments had higher swelling ability as well as water and oil holding capacities, thanks to the important dietary fiber and polysaccharide contents found in microalgae. Moreover, microalgae-supplemented burgers were characterized as having low a* and b* values, which made the color appear to be pale orange. Additionally, thanks to its richness in pigments and polysaccharides, microalgae considerably ameliorated the antioxidant activities of the new prepared fish bur...
Abstract Microalgae have been used as natural ingredients in popular fish-based products to incre... more Abstract Microalgae have been used as natural ingredients in popular fish-based products to increase their nutritional value. The impact of the addition of Chlorella minutissima, Isochrysis galbana, Picochlorum sp. at concentrations of 0.5, 1, and 1.5% w/v on the texture and sensory attributes of canned burgers were investigated. Compared to controls, fish burgers containing 0.5% of C. minutissima, 1% of I. galbana and 1% of Picochlorum sp. had better texture and sensory properties (p
International Journal of Biological Macromolecules
The structure, antioxidant and anti-hyperlipidemic activities of polysaccharides from Nitraria re... more The structure, antioxidant and anti-hyperlipidemic activities of polysaccharides from Nitraria retusa fruits (named as NRFP) were investigated. The NRFP fraction, with a molecular weight of 66.5 kDa, was composed of a β-(1 → 3)-glucan, containing neutral sugars (69.1%) but also uronic acids up to 23.1% due to pectin structure. The monosaccharide composition highlighted a polymer composed of glucose (41.4%), galacturonic acid (30.5%), galactose (12.6%), arabinose (11.8%) and rhamnose (3.70%). In the antioxidant assays, NRFP exhibited effective total antioxidant capacity (IC50 = 7.82 mg/ml), scavenging activities on DPPH radical (IC50 = 0.87 mg/ml) and hydrogen peroxide (IC50 = 2.03 mg/ml). In addition, NRFP proved protective effects on H2O2 induced hemolysis (IC50 = 66.2 μg/ml). In vivo NRFP reduced the hyperlipidemia, hepatotoxicity, cardiovascular and coronary diseases induced by Triton X-100.
International Journal of Biological Macromolecules
Optimal conditions for maximal biomass and starch production by the marine red microalgae Porphyr... more Optimal conditions for maximal biomass and starch production by the marine red microalgae Porphyridium marinum were investigated. Box-Behnken Design was used to model the effect of light intensity, NaNO3 concentration and salinity on the growth of microalgae but also on their starch and protein contents. These three factors increased biomass production by 13.6% in optimized conditions. A maximum starch production (140.21 μg·mL-1), 30.6% higher than that of the control, was attained at a light intensity of 100 μmol photons·m-2·s-1, a NaNO3 concentration of 1 g·L-1 and a NaCl concentration of 20 g·L-1. FT-IR spectroscopy was used to estimate the biochemical composition (carbohydrate accumulation) of P. marinum and revealed significant changes (P < 0.05) depending on culture conditions. FT-IR analysis highlighted also that the culture conditions leading to highest starch production by P. marinum corresponded to lowest sulfated polysaccharide and protein contents.
Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer méditerranée bie... more Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer méditerranée bien répandues le long des côtes Tunisiennes et non exploitées. Il ressort de cette étude que ces algues pourraient être utilisées comme une source d’ingrédients fonctionnels d’origine naturelle pour la production de burgers à base de chair de poissons d’eau douce (Barbus barbus). De plus, ces travaux ont conduit à l’obtention d’un fucoïdane (CCF) et un alginate de sodium (CCSA) comme polysaccharides matriciels de C. compressa. CCF (1,05 × 105 g/mol) est un hétérogalactofucane sulfaté (14,65 %) composé d’une chaîne principale de α-(1,3 ; 1,4)-l-Fucp ramifiée (31,84 %) en positions O-4 et O-3 par des monosaccharides terminaux et des chaînes latérales. CCSA (Mw = 1 × 105 g/mol) est composé de 56 % de α-l-GulA (G) et 44 % de β-d-ManA (M) (M/G = 0,77). Ce polyuronide est constitué de 93 % d’homoblocs (FGG = 53 % et FMM = 40 %) et de 6 % d’hétéroblocs (FMG = 3 % et FGM = 3 %). Les analyses rhéol...
Polysaccharides are complex macromolecules long regarded as energetic storage resources or as com... more Polysaccharides are complex macromolecules long regarded as energetic storage resources or as components of plant and fungal cell walls. They have also been described as plant mucilages or microbial exopolysaccharides. The development of glycosciences has led to a partial and difficult deciphering of their other biological functions in living organisms. The objectives of glycobiochemistry and glycobiology are currently to correlate some structural features of polysaccharides with some biological responses in the producing organisms or in another one. In this context, the literature focusing on bioactive polysaccharides has increased exponentially during the last two decades, being sometimes very optimistic for some new applications of bioactive polysaccharides, notably in the medical field. Therefore, this review aims to examine bioactive polysaccharide, taking a critical look of the different biological activities reported by authors and the reality of the market. It focuses also o...
Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer mediterranee bie... more Cystoseira compressa et Jania adhaerens sont deux macro-algues marines de la mer mediterranee bien repandues le long des cotes Tunisiennes et non exploitees. Il ressort de cette etude que ces algues pourraient etre utilisees comme une source d’ingredients fonctionnels d’origine naturelle pour la production de burgers a base de chair de poissons d’eau douce (Barbus barbus). De plus, ces travaux ont conduit a l’obtention d’un fucoidane (CCF) et un alginate de sodium (CCSA) comme polysaccharides matriciels de C. compressa. CCF (1,05 × 105 g/mol) est un heterogalactofucane sulfate (14,65 %) compose d’une chaine principale de α-(1,3 ; 1,4)-l-Fucp ramifiee (31,84 %) en positions O-4 et O-3 par des monosaccharides terminaux et des chaines laterales. CCSA (Mw = 1 × 105 g/mol) est compose de 56 % de α-l-GulA (G) et 44 % de β-d-ManA (M) (M/G = 0,77). Ce polyuronide est constitue de 93 % d’homoblocs (FGG = 53 % et FMM = 40 %) et de 6 % d’heteroblocs (FMG = 3 % et FGM = 3 %). Les analyses rheol...
Polysaccharides from marine algae are one novel source of plant defense elicitors for alternative... more Polysaccharides from marine algae are one novel source of plant defense elicitors for alternative and eco-friendly plant protection against phytopathogens. The effect of exopolysaccharides (EPS) produced by Porphyridium sordidum on elicitation of Arabidopsis thaliana defense responses against Fusarium oxysporum was evaluated. Firstly, in order to enhance EPS production, a Box–Behnken experimental design was carried out to optimize NaCl, NaNO3 and MgSO4 concentrations in the culture medium of microalgae. A maximum EPS production (2.45 g/L) higher than that of the control (0.7 g/L) was observed for 41.62 g/L NaCl, 0.63 g/L NaNO3 and 7.2 g/L MgSO4 concentrations. Structurally, the EPS contained mainly galactose, xylose and glucose. Secondly, the elicitor effect of EPS was evaluated by investigating the plant defense-related signaling pathways that include activation of Salicylic or Jasmonic Acid-dependent pathway genes. A solution of 2 mg/mL of EPS has led to the control of fungal grow...
Bioactive compounds with diverse chemical structures play a significant role in disease preventio... more Bioactive compounds with diverse chemical structures play a significant role in disease prevention and maintenance of physiological functions. Due to the increase in industrial demand for new biosourced molecules, several types of biomasses are being exploited for the identification of bioactive metabolites and techno-functional biomolecules that are suitable for the subsequent uses in cosmetic, food and pharmaceutical fields. Among the various biomasses available, macroalgae are gaining popularity because of their potential nutraceutical and health benefits. Such health effects are delivered by specific diterpenes, pigments (fucoxanthin, phycocyanin, and carotenoids), bioactive peptides and polysaccharides. Abundant and recent studies have identified valuable biological activities of native algae polysaccharides, but also of their derivatives, including oligosaccharides and (bio)chemically modified polysaccharides. However, only a few of them can be industrially developed and open ...
A novel sulfated xylogalactan-rich fraction (JSP for J. adhaerens Sulfated Polysaccharide) was ex... more A novel sulfated xylogalactan-rich fraction (JSP for J. adhaerens Sulfated Polysaccharide) was extracted from the red Tunisian seaweed Jania adhaerens. JSP was purified using an alcoholic precipitation process and characterized by Attenuated Total Reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR), high-pressure size exclusion chromatography (HPSEC) with a multi-angle laser light scattering (MALLS), gas chromatography coupled to mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR, 1D and 2D). JSP was then evaluated regarding its physicochemical and rheological properties. Results showed that JSP was mainly composed of an agar-like xylogalactan sharing the general characteristics of corallinans. The structure of JSP was mainly composed of agaran disaccharidic repeating units (→3)-β-d-Galp-(1,4)-α-l-Galp-(1→)n and (→3)-β-d-Galp-(1,4)-3,6-α-l-AnGalp-(1→)n, mainly substituted on O-6 of (1,3)-β-d-Galp residues by β-xylosyl side chains, and less with sul...
Abstract Rheological characteristics of a sodium alginate and a fucoidan extracted from the brown... more Abstract Rheological characteristics of a sodium alginate and a fucoidan extracted from the brown seaweed Cystoseira compressa harvested from Kerkennah island (Sfax, Tunisia) were investigated. Steady-shear flow and dynamical viscoelasticity were evaluated to describe physicochemical properties of the GulA-rich alginate (ManA/GulA, M/G = 0.77) and highly-ramified fucoidan in semi-diluted media depending on polymer concentration, shear rate, temperature, added mono- (KCl and NaCl) and divalent (CaCl2) salts. Alginate solutions exhibited shear-thinning behavior, with a temperature-dependent behavior highly correlated to the power-law model and the Arrhenius relationship. The results showed strong thixotropic and polyelectrolyte properties, influenced by addition of monovalent and divalent cations. The dynamic rheological characteristics showed a fluid-like viscoelastic behavior (tan δ > 1) whereas the critical overlap concentration C* and specific polymer constant ks were respectively 11 g.L−1 and 4.4 using Williamson model. Fucoidan solutions displayed a shear-thinning behavior with a low viscoelasticity character influenced by temperature and monovalent salts. The flow and viscoelastic characteristics of polysaccharides were described by the Ostwald model.
In this paper, water-soluble polysaccharides (named as NRLP) were extracted from Nitraria retusa ... more In this paper, water-soluble polysaccharides (named as NRLP) were extracted from Nitraria retusa leaves. The main structural features of NRLP were determined by High-pressure size exclusion chromatography, Fourier transform infrared and Gas Chromatography/Mass Spectrometry-Electronic Impact analysis. The in vitro and in vivo biological potential of NRLP were evaluated by measuring its antioxidant (•OH and DPPH• scavenging, total antioxidant capacity), anti-α-amylase as well as anti-inflammatory and antinociceptive activities in a mice model. NRLP was composed of Rha (33.7%), Gal (18.1%), GalA (15.0%), Glc (13.3%), Ara (13.3%), Xyl (3.8%), and GlcA (2.8%) and showed a Molecular Weight (Mw) of 23.0 kDa and a polydispersity index (PDI) of 1.66. The investigations highlighted a significant antioxidant activity (IC50 = 2.4–2.6 mg/mL) and an inhibition activity against α-amylase (IC50 = 4.55 mg/mL) in a dose-dependent manner. Further, NRLP revealed interesting anti-edematous effects and a...
International Journal of Biological Macromolecules
A water-soluble polysaccharide (PSPC) was extracted from the seeds of Plantago ciliata Desf., a s... more A water-soluble polysaccharide (PSPC) was extracted from the seeds of Plantago ciliata Desf., a spontaneous Algerian Saharan plant by a hot aqueous extraction then purified by successive ethanolic precipitations. The final extraction yield for PSPC was close to 18.6% (w/v). PSPC was then investigated regarding its global composition, structural features and rheological properties. PSPC is a neutral arabinoxylan, composed of a β-(1,3)/β-(1,4)-D-xylan backbone with side chains of Xylp, and Araf residues attached in O-2 and O-3 positions. The macromolecular characteristics of PSPC in water was determined by SEC/MALLS, with a high molecular weight (Mw) of 700 kDa, a low polydispersity index (PDI) of 1.47 and an intrinsic viscosity (η) close to 157 mL/g. PSPC showed a pseudoplastic behavior in semi-dilute media and the critical overlay concentration (C*) was estimated around 0.32-0.37% (w/v). This current research has supplied original structural information on a new arabinoxylan which could be particularly useful as a novel source of soluble fiber belonging to psyllium.
Microalgae have been used as natural ingredients to produce functional and nutritional food produ... more Microalgae have been used as natural ingredients to produce functional and nutritional food products. The impact of the addition of Chlorella minutissima, Isochrysis galbana, and Picochlorum sp. at concentrations of 0.5, 1, and 1.5% w/v on the texture and sensory attributes of canned burgers were investigated. The results show that carp formulations containing 1% microalgae show significantly better classification performance for many textural and sensory parameters compared to the rest of the formulations. Also, these treatments had higher swelling ability as well as water and oil holding capacities, thanks to the important dietary fiber and polysaccharide contents found in microalgae. Moreover, microalgae-supplemented burgers were characterized as having low a* and b* values, which made the color appear to be pale orange. Additionally, thanks to its richness in pigments and polysaccharides, microalgae considerably ameliorated the antioxidant activities of the new prepared fish bur...
Abstract Microalgae have been used as natural ingredients in popular fish-based products to incre... more Abstract Microalgae have been used as natural ingredients in popular fish-based products to increase their nutritional value. The impact of the addition of Chlorella minutissima, Isochrysis galbana, Picochlorum sp. at concentrations of 0.5, 1, and 1.5% w/v on the texture and sensory attributes of canned burgers were investigated. Compared to controls, fish burgers containing 0.5% of C. minutissima, 1% of I. galbana and 1% of Picochlorum sp. had better texture and sensory properties (p
International Journal of Biological Macromolecules
The structure, antioxidant and anti-hyperlipidemic activities of polysaccharides from Nitraria re... more The structure, antioxidant and anti-hyperlipidemic activities of polysaccharides from Nitraria retusa fruits (named as NRFP) were investigated. The NRFP fraction, with a molecular weight of 66.5 kDa, was composed of a β-(1 → 3)-glucan, containing neutral sugars (69.1%) but also uronic acids up to 23.1% due to pectin structure. The monosaccharide composition highlighted a polymer composed of glucose (41.4%), galacturonic acid (30.5%), galactose (12.6%), arabinose (11.8%) and rhamnose (3.70%). In the antioxidant assays, NRFP exhibited effective total antioxidant capacity (IC50 = 7.82 mg/ml), scavenging activities on DPPH radical (IC50 = 0.87 mg/ml) and hydrogen peroxide (IC50 = 2.03 mg/ml). In addition, NRFP proved protective effects on H2O2 induced hemolysis (IC50 = 66.2 μg/ml). In vivo NRFP reduced the hyperlipidemia, hepatotoxicity, cardiovascular and coronary diseases induced by Triton X-100.
International Journal of Biological Macromolecules
Optimal conditions for maximal biomass and starch production by the marine red microalgae Porphyr... more Optimal conditions for maximal biomass and starch production by the marine red microalgae Porphyridium marinum were investigated. Box-Behnken Design was used to model the effect of light intensity, NaNO3 concentration and salinity on the growth of microalgae but also on their starch and protein contents. These three factors increased biomass production by 13.6% in optimized conditions. A maximum starch production (140.21 μg·mL-1), 30.6% higher than that of the control, was attained at a light intensity of 100 μmol photons·m-2·s-1, a NaNO3 concentration of 1 g·L-1 and a NaCl concentration of 20 g·L-1. FT-IR spectroscopy was used to estimate the biochemical composition (carbohydrate accumulation) of P. marinum and revealed significant changes (P < 0.05) depending on culture conditions. FT-IR analysis highlighted also that the culture conditions leading to highest starch production by P. marinum corresponded to lowest sulfated polysaccharide and protein contents.
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