Hajar EL BASETT - Academia.edu (original) (raw)

Papers by Hajar EL BASETT

Research paper thumbnail of Production and Identification of N-Glucosylrubropunctamine and N-Glucosylmonascorubramine from Monascus ruber and Occurrence of Electron Donor-Acceptor Complexes in These Red Pigments

Applied and Environmental Microbiology, 1997

The filamentous fungus Monascus ruber produces water-soluble red pigments in a submerged culture ... more The filamentous fungus Monascus ruber produces water-soluble red pigments in a submerged culture when grown in a chemically defined medium containing glucose as a carbon source and monosodium glutamate as a nitrogen source. Two new molecules with polyketide structures, N-glucosylrubropunctamine and N-glucosylmonascorubramine, constituting under some conditions 10% of the total extracellular coloring matter when glucose as a carbon source was in excess (20 g/liter), were isolated and structurally characterized by high-pressure liquid chromatography, Dionex methods, (sup1)H and (sup13)C nuclear magnetic resonance spectroscopy, and mass spectrometry. The occurrence of the electron donor-acceptor complex effect was demonstrated by UV spectroscopy, polarography, and thin-layer voltammetry. The use of n-butanol as an extraction solvent stabilized the pigments against the effects of daylight for several months, promoting the stability of this type of complex.

Research paper thumbnail of Cholesterol-lowering properties of Ganoderma lucidum in vitro, ex vivo, and in hamsters and minipigs

Lipids in Health and Disease, 2004

INTRODUCTION: There has been renewed interest in mushroom medicinal properties. We studied choles... more INTRODUCTION: There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl), a renowned medicinal species. RESULTS: Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC) 9.8%, and HDL 11.2%. Gl (2.5 and 5%) had effects on

Research paper thumbnail of Molecular and biochemical characterization of patulin producing and non-producing Penicillium species in apples fruits from Morocco

Research paper thumbnail of Adsorptive performance of a synthesized Mg-Al Hydrotalcite compound for removal of malachite green: kinetic, isotherm, thermodynamic, and mechanism study

International Journal of Environmental Analytical Chemistry

Research paper thumbnail of Aspergillus oryzae produces compounds inhibiting cholesterol biosynthesis downstream of dihydrolanosterol

FEMS Microbiology Letters, 2005

Research paper thumbnail of Effect of 26-Oxygenosterols from Ganoderma lucidum and Their Activity as Cholesterol Synthesis Inhibitors

Applied and Environmental Microbiology, 2005

Ganoderma lucidum is a medicinal fungus belonging to the Polyporaceae family which has long been ... more Ganoderma lucidum is a medicinal fungus belonging to the Polyporaceae family which has long been known in Japan as Reishi and has been used extensively in traditional Chinese medicine. We report the isolation and identification of the 26-oxygenosterols ganoderol A, ganoderol B, ganoderal A, and ganoderic acid Y and their biological effects on cholesterol synthesis in a human hepatic cell line in vitro. We also investigated the site of inhibition in the cholesterol synthesis pathway. We found that these oxygenated sterols from G. lucidum inhibited cholesterol biosynthesis via conversion of acetate or mevalonate as a precursor of cholesterol. By incorporation of 24,25-dihydro-[24,25- 3 H 2 ]lanosterol and [3- 3 H]lathosterol in the presence of ganoderol A, we determined that the point of inhibition of cholesterol synthesis is between lanosterol and lathosterol. These results demonstrate that the lanosterol 14α-demethylase, which converts 24,25-dihydrolanosterol to cholesterol, can be ...

Research paper thumbnail of Characterization of the Biochemical Potential of Moroccan Onions (Allium cepa L.)

International Journal of Food Science

Allium cepa L. remains the most cultivated Allium species in Morocco and around the world. With t... more Allium cepa L. remains the most cultivated Allium species in Morocco and around the world. With the purpose of making the first biochemical characterization of Moroccan onions, several biochemical components have been measured in eleven onion ecotypes. Onions were collected as seeds from different geographical origins and cultivated in the same environment, to eliminate the influence of the environment on biochemical expression. Moisture, total phenols, flavonoids, antioxidant activity, total and reducing sugars, and sulfur dioxide were the biochemical properties of interest. Except for moisture, the eleven onion ecotypes revealed a highly significant variation in terms of the studied biochemical characters. The total phenol and flavonoid content ranged from 5.94 to 11.22 mg equivalent gallic acid/g dry weight and 0.67 to 1.52 mg equivalent quercetin/g dry weight, respectively. The antioxidant activity of the studied onions showed a strong correlation with the polyphenols ( R 2 = 0....

Research paper thumbnail of Monascus ruber Production in the Filamentous Fungus Medium-Chain Fatty Acids Affect Citrinin

Research paper thumbnail of Svojstva za snižavanje holesterola Ganoderma lucidum in vitro, ex vivo i kod hrčaka i minijaturnih svinja

Research paper thumbnail of Effect of carbon, nitrogen and physico-chemical factors on patulin production in Penicillium expansum

Environmental and nutritional factors play important roles in regulating production of mycotoxins... more Environmental and nutritional factors play important roles in regulating production of mycotoxins. Few studies have been reported on the biosynthesis of patulin mycotoxin and the mechanisms that involve its biosynthesis in Penicillium expansum. Here, we investigated the effects of two culture media, pH, temperature, carbon and nitrogen sources and effect of carbon/nitrogen ratio on mycotoxin biosynthesis by P. expansum isolated from Moroccan cereals. It was found that pH and temperature had great influence on patulin production. Results also showed that carbon and nitrogen sources influ-enced patulin biosynthesis significantly in this strain. L-glutamate was optimized as important nitrogen source in synthetic culture medium. Effect of carbon/nitrogen ratio was evaluated which indicated the dependence of patulin production on this ratio. These results will provide useful information to better understand the regulatory mechanisms of patulin biosynthesis, and be helpful in developing e...

Research paper thumbnail of Isolation, screening and identification of ligno-cellulolytic fungi from northern central Morocco

BASE

Description of the subject. Extracellular enzymes from filamentous fungi are increasingly used in... more Description of the subject. Extracellular enzymes from filamentous fungi are increasingly used in eco-friendly biotransformation processes. Their relevant technological role and their stability towards extreme process conditions make of them the first sustainable solution for the elaboration of bio-based products from biomass conversion. Objectives. This paper describes the isolation of filamentous fungi from decaying plant material in the region of Meknes (northern central Morocco) and the assessment of their ability to breakdown lignocellulose. The objective is to select performant fungi with enzymatic machinery adapted to local environment and with potential for the breakdown of the regional specific lignocellulosic by-products into potentially high-value molecules. Method. Cereals, decaying wood, olive-pomace and -pulp and their composts were used to isolate lignocellulolytic fungi. One hundred twenty-seven pure strains were isolated and screened at 25 °C on selective media with...

Research paper thumbnail of In Vitro Evaluation of the Antifungal Activity of Ghassoul-Based Formulations with Oregano and Thyme Essential Oils against Penicillium sp

Journal of Chemistry

The essential oils from aromatic plants are today considered a suitable tool to protect stored gr... more The essential oils from aromatic plants are today considered a suitable tool to protect stored grains from fungal attacks. The purpose of this work is to study the effect of formulations of thyme and oregano essential oil (EO) adsorbed on purified (Gh-P) and sulfuric acid-activated (Gh-A) ghassoul on the biological activity of fungal pathogens. Purified and activated ghassoul were characterized by XRD and FTIR, and EOs used in this study were issued from two medicinal plants known in Morocco and commercially available. Their chemical compositions were analyzed by the GC-MS technique. The main constituents of thyme EO were thymol (67.13%), ρ-cymene (4.85%), Z-caryophyllene (1.77%), and γ-terpinene (2.74%). Oregano EO contained carvacrol (59.82%), γ-terpinene (10.85%), and α-pinene (9.89%). This work focused on the study of the antifungal activity of EOs mixed with purified and sulfuric acid-activated ghassoul, in order to look for new natural bioactive products and assess their antif...

Research paper thumbnail of Consolidated bioethanol production from olive mill waste: Wood-decay fungi from central Morocco as promising decomposition and fermentation biocatalysts

Research paper thumbnail of Adsorption of Thymol onto Natural Clays of Morocco: Kinetic and Isotherm Studies

Journal of Chemistry

The present work aims to study the affinity of a component of the thyme essential oil “thymol” to... more The present work aims to study the affinity of a component of the thyme essential oil “thymol” to natural Moroccan clay “Rhassoul” using the adsorption technique. The physicochemical characterizations of the purified and modified clay were carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DTA/TGA, and SEM-EDX. Thymol adsorption tests on the purified Rhassoul (Rh-P) and the modified one by CTAB (Rh-CTAB) were followed by UV-visible spectroscopy. They show that the adsorption isotherms can be described by the Freundlich model and that the kinetics of adsorption is in accordance with the pseudo-second-order model for the two clays. Adsorption capacities obtained were of the order of 6 mg/g for the purified Rhassoul and 16 mg/g for the modified Rhassoul by cetyltrimethylammonium bromide (CTAB). These values show that the modified Rhassoul has a better adsorption capacity compared to the purified Rhassoul.

Research paper thumbnail of Molecular Cloning and Expression of Candida antarctica lipase B in Corynebacterium genus

Microbiology and Biotechnology Letters

This study, for the first time, reports the functional expression of lipase B derived from the ye... more This study, for the first time, reports the functional expression of lipase B derived from the yeast Candida antarctica (CALB) in Corynebacterium strain using the Escherichia coli plasmid PK18. The CALB gene fragment encoding a 317-amino-acid protein was successfully obtained from the total RNA of C. antarctica. CALB was readily produced in the Corynebacterium strain without the use of induction methods described in previous studies. This demonstrated the extracellular production of CALB in the Corynebacterium strain. CALB produced in the Corynebacterium MB001 strain transformed with pEC-CALB recombinant plasmid exhibited maximum extracellular enzymatic activity and high substrate affinity. The optimal pH and temperature for the hydrolysis of 4-nitrophenyl laurate by CALB were 9.0 and 40℃, respectively. The enzyme was stable at pH 10.7 in the glycine-KOH buffer and functioned as an alkaline lipase. The CALB activity was inhibited in the presence of high concentration of Mg2+, which indicated that CALB is not a metalloenzyme. These properties are key for the industrial application of the enzyme.

Research paper thumbnail of Proanthocyanidins and anthocyanins contents, chromatic and antioxidant properties of red grape pomaces from morocco

Journal of Food Measurement and Characterization

Proanthocyanidins (PAs) and anthocyanins contents of four different red grape pomaces (GPs) from ... more Proanthocyanidins (PAs) and anthocyanins contents of four different red grape pomaces (GPs) from Morocco were analysed using chromatographic methods. The GP skin pigments characteristics were determined using spectroscopic methods while their antioxidant activities were determined using both spectroscopic methods as ABTS and DPPH radical cations, ferric reducing/antioxidant power (FRAP) and electrochemical technique: cyclic Voltammetry (CV). The PA of seeds extracts varied significantly among the types of GP and ranged from 56.1 ± 0.3 mg g−1 dry weight (DW) in Cot to 88.4 ± 2.3 mg g−1 DW in non-fermented Cabernet Sauvignon (CSNF). The skins of CSNF contained the highest levels of PAs (22.1 ± 0.3 mg g−1 DW). The PAs average degree of polymerization distribution ranged from 2 to 45 subunits for the skins and from 2 to 12 subunits for the seeds. The maximum anthocyanins amounts and antioxidant activities were measured in Cot skin extracts (32.8 mg g−1 DW, DPPH: 0.23 mmol Trolox mg g−1 DW; ABTS: 0.38 mmol Trolox mg g−1 DW and CV: 1.73 × 10−3mA V) followed by Arinarnoa skin extracts which had the maximum corrected pigments (14.8 ± 0.1) and color power (152.4 ± 4.6 Unit color). The principal components analysis (PCA) of GP skins showed three different groups relevant to anthocyanins, PAs content, color and antioxidant properties.

Research paper thumbnail of Synthesis and characterization of crude hydrotalcite Mg–Al–CO3: study of thymol adsorption

Research on Chemical Intermediates

The study of the adsorption of thymol on a hydrotalcite of synthesis Mg3Al–CO3 (HT3) of molar rat... more The study of the adsorption of thymol on a hydrotalcite of synthesis Mg3Al–CO3 (HT3) of molar ratio Mg/Al = 3 and on its counterpart enabled at 500 °C (HT3-C) was conducted in hexane at a concentration of 40 mg L−1 of thymol. Hydrotalcite HT3 was prepared via coprecipitation at a constant pH of 10 and characterized by X-ray diffraction, infrared spectroscopy, nitrogen adsorption–desorption methods and thermal analysis (TGA/DTA). The adsorption of the thymol tests were monitored by UV–visible spectroscopy. The results show that the calcined hydrotalcite (HT3-C) has a capacity of adsorption of thymol (8 mg g−1) much greater than that of HT3 (4 mg g−1), and the experimental points are described by the isotherm model of the Freundlich of both materials.

Research paper thumbnail of Micro-Oxygenation and Fining Agent Treatments: Impact on Color of Moroccan Red Press Wine

Journal of Food Chemistry and Nanotechnology

Red press wine is collected after pressing solid parts (seed and skin) of grapes pomaces. Higher ... more Red press wine is collected after pressing solid parts (seed and skin) of grapes pomaces. Higher pressure induces more colorful, astringent, bitter and rustic wines. This is caused by the presence of undesirable phenolic compounds. To overcome this problem, the most common practice used in wine industry is the oenological treatment which enhances the clarity, stability and the wine taste. In the present work, press wines were separately submitted to four different treatments: micro-oxygenation and the addition of three fining agents: gelatin, polyvinylpolypyrrolidone (PVPP) and pea protein. The phenolic total index decreased (8%) significantly (P<0.05) for gelatin treatment, the PVPP based formulation treatment led to the largest loss (8%) in color intensity, (12%) in redness (a*), (9%) in polymeric pigments and increasing to 9% lightness (L*). Unlike micro-oxygenation which has decreased (5%) the color intensity. For the monomeric anthocyanins, the greatest reduction of acylated and coumaroylated anthocyanins at bottling and glucoside anthocyanidins after five months of storage was observed for both basic PVPP and gelatin.

Research paper thumbnail of Phenolic compounds of Moroccan red press wines: Influence of fining agents and micro-oxygenation treatments

LWT - Food Science and Technology, 2017

Abstract To improve the sensory quality of Moroccan red press wines, press wines were separately ... more Abstract To improve the sensory quality of Moroccan red press wines, press wines were separately submitted to micro-oxygenation and three fining agents (gelatin, Polyvinylpolypyrrolidone (PVPP) based formulation and pea protein) treatments at the winery Château Roslane, Morocco. The results showed that each treatment has a distinct behavior in relation with interactions and precipitation monomeric flavan-3-ol and fractions apparent and total condensed tannins. The fining agent corresponding to the vegetable protein has a greater affinity with the fraction of oligomeric condensed tannins with apparent aDP: 3.2. However, gelatin and PVPP based fining agent have an affinity with the catechin and epicatechin as well as with the fraction of polymeric tannins (apparent aDP: 6.6). For the structural parameters of proanthocyanidins, no significant differences were found out in global aDP and percentage of prodelphinidin between the different treatments. The global percentage of galloylation appeared slightly affected, while the global percentage of oxidized proanthocyanidins increased (9%) significantly (P

Research paper thumbnail of Cholesterol-lowering agent

Introduction: There has been renewed interest in mushroom medicinal properties. We studied choles... more Introduction: There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl), a renowned medicinal species. Results: Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC) 9.8%, and HDL 11.2%. Gl (2.5 and 5%) had effects on several fecal neutral sterols and bile acids. Both Gl doses reduced hepatic microsomal ex-vivo HMG-CoA reductase activity. In minipigs, 2.5 Gl decreased TC, LDL-and HDL cholesterol 20, 27, and 18%, respectively (P < 0.05); increased fecal cholestanol and coprostanol; and decreased cholate. Conclusions: Overall, Gl has potential to reduce LDL cholesterol in vivo through various mechanisms. Next steps are to: fully characterize bioactive components in lipid soluble/insoluble fractions; evaluate bioactivity of isolated fractions; and examine human cholesterol lowering properties. Innovative new cholesterol-lowering foods and medicines containing Gl are envisioned.

Research paper thumbnail of Production and Identification of N-Glucosylrubropunctamine and N-Glucosylmonascorubramine from Monascus ruber and Occurrence of Electron Donor-Acceptor Complexes in These Red Pigments

Applied and Environmental Microbiology, 1997

The filamentous fungus Monascus ruber produces water-soluble red pigments in a submerged culture ... more The filamentous fungus Monascus ruber produces water-soluble red pigments in a submerged culture when grown in a chemically defined medium containing glucose as a carbon source and monosodium glutamate as a nitrogen source. Two new molecules with polyketide structures, N-glucosylrubropunctamine and N-glucosylmonascorubramine, constituting under some conditions 10% of the total extracellular coloring matter when glucose as a carbon source was in excess (20 g/liter), were isolated and structurally characterized by high-pressure liquid chromatography, Dionex methods, (sup1)H and (sup13)C nuclear magnetic resonance spectroscopy, and mass spectrometry. The occurrence of the electron donor-acceptor complex effect was demonstrated by UV spectroscopy, polarography, and thin-layer voltammetry. The use of n-butanol as an extraction solvent stabilized the pigments against the effects of daylight for several months, promoting the stability of this type of complex.

Research paper thumbnail of Cholesterol-lowering properties of Ganoderma lucidum in vitro, ex vivo, and in hamsters and minipigs

Lipids in Health and Disease, 2004

INTRODUCTION: There has been renewed interest in mushroom medicinal properties. We studied choles... more INTRODUCTION: There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl), a renowned medicinal species. RESULTS: Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC) 9.8%, and HDL 11.2%. Gl (2.5 and 5%) had effects on

Research paper thumbnail of Molecular and biochemical characterization of patulin producing and non-producing Penicillium species in apples fruits from Morocco

Research paper thumbnail of Adsorptive performance of a synthesized Mg-Al Hydrotalcite compound for removal of malachite green: kinetic, isotherm, thermodynamic, and mechanism study

International Journal of Environmental Analytical Chemistry

Research paper thumbnail of Aspergillus oryzae produces compounds inhibiting cholesterol biosynthesis downstream of dihydrolanosterol

FEMS Microbiology Letters, 2005

Research paper thumbnail of Effect of 26-Oxygenosterols from Ganoderma lucidum and Their Activity as Cholesterol Synthesis Inhibitors

Applied and Environmental Microbiology, 2005

Ganoderma lucidum is a medicinal fungus belonging to the Polyporaceae family which has long been ... more Ganoderma lucidum is a medicinal fungus belonging to the Polyporaceae family which has long been known in Japan as Reishi and has been used extensively in traditional Chinese medicine. We report the isolation and identification of the 26-oxygenosterols ganoderol A, ganoderol B, ganoderal A, and ganoderic acid Y and their biological effects on cholesterol synthesis in a human hepatic cell line in vitro. We also investigated the site of inhibition in the cholesterol synthesis pathway. We found that these oxygenated sterols from G. lucidum inhibited cholesterol biosynthesis via conversion of acetate or mevalonate as a precursor of cholesterol. By incorporation of 24,25-dihydro-[24,25- 3 H 2 ]lanosterol and [3- 3 H]lathosterol in the presence of ganoderol A, we determined that the point of inhibition of cholesterol synthesis is between lanosterol and lathosterol. These results demonstrate that the lanosterol 14α-demethylase, which converts 24,25-dihydrolanosterol to cholesterol, can be ...

Research paper thumbnail of Characterization of the Biochemical Potential of Moroccan Onions (Allium cepa L.)

International Journal of Food Science

Allium cepa L. remains the most cultivated Allium species in Morocco and around the world. With t... more Allium cepa L. remains the most cultivated Allium species in Morocco and around the world. With the purpose of making the first biochemical characterization of Moroccan onions, several biochemical components have been measured in eleven onion ecotypes. Onions were collected as seeds from different geographical origins and cultivated in the same environment, to eliminate the influence of the environment on biochemical expression. Moisture, total phenols, flavonoids, antioxidant activity, total and reducing sugars, and sulfur dioxide were the biochemical properties of interest. Except for moisture, the eleven onion ecotypes revealed a highly significant variation in terms of the studied biochemical characters. The total phenol and flavonoid content ranged from 5.94 to 11.22 mg equivalent gallic acid/g dry weight and 0.67 to 1.52 mg equivalent quercetin/g dry weight, respectively. The antioxidant activity of the studied onions showed a strong correlation with the polyphenols ( R 2 = 0....

Research paper thumbnail of Monascus ruber Production in the Filamentous Fungus Medium-Chain Fatty Acids Affect Citrinin

Research paper thumbnail of Svojstva za snižavanje holesterola Ganoderma lucidum in vitro, ex vivo i kod hrčaka i minijaturnih svinja

Research paper thumbnail of Effect of carbon, nitrogen and physico-chemical factors on patulin production in Penicillium expansum

Environmental and nutritional factors play important roles in regulating production of mycotoxins... more Environmental and nutritional factors play important roles in regulating production of mycotoxins. Few studies have been reported on the biosynthesis of patulin mycotoxin and the mechanisms that involve its biosynthesis in Penicillium expansum. Here, we investigated the effects of two culture media, pH, temperature, carbon and nitrogen sources and effect of carbon/nitrogen ratio on mycotoxin biosynthesis by P. expansum isolated from Moroccan cereals. It was found that pH and temperature had great influence on patulin production. Results also showed that carbon and nitrogen sources influ-enced patulin biosynthesis significantly in this strain. L-glutamate was optimized as important nitrogen source in synthetic culture medium. Effect of carbon/nitrogen ratio was evaluated which indicated the dependence of patulin production on this ratio. These results will provide useful information to better understand the regulatory mechanisms of patulin biosynthesis, and be helpful in developing e...

Research paper thumbnail of Isolation, screening and identification of ligno-cellulolytic fungi from northern central Morocco

BASE

Description of the subject. Extracellular enzymes from filamentous fungi are increasingly used in... more Description of the subject. Extracellular enzymes from filamentous fungi are increasingly used in eco-friendly biotransformation processes. Their relevant technological role and their stability towards extreme process conditions make of them the first sustainable solution for the elaboration of bio-based products from biomass conversion. Objectives. This paper describes the isolation of filamentous fungi from decaying plant material in the region of Meknes (northern central Morocco) and the assessment of their ability to breakdown lignocellulose. The objective is to select performant fungi with enzymatic machinery adapted to local environment and with potential for the breakdown of the regional specific lignocellulosic by-products into potentially high-value molecules. Method. Cereals, decaying wood, olive-pomace and -pulp and their composts were used to isolate lignocellulolytic fungi. One hundred twenty-seven pure strains were isolated and screened at 25 °C on selective media with...

Research paper thumbnail of In Vitro Evaluation of the Antifungal Activity of Ghassoul-Based Formulations with Oregano and Thyme Essential Oils against Penicillium sp

Journal of Chemistry

The essential oils from aromatic plants are today considered a suitable tool to protect stored gr... more The essential oils from aromatic plants are today considered a suitable tool to protect stored grains from fungal attacks. The purpose of this work is to study the effect of formulations of thyme and oregano essential oil (EO) adsorbed on purified (Gh-P) and sulfuric acid-activated (Gh-A) ghassoul on the biological activity of fungal pathogens. Purified and activated ghassoul were characterized by XRD and FTIR, and EOs used in this study were issued from two medicinal plants known in Morocco and commercially available. Their chemical compositions were analyzed by the GC-MS technique. The main constituents of thyme EO were thymol (67.13%), ρ-cymene (4.85%), Z-caryophyllene (1.77%), and γ-terpinene (2.74%). Oregano EO contained carvacrol (59.82%), γ-terpinene (10.85%), and α-pinene (9.89%). This work focused on the study of the antifungal activity of EOs mixed with purified and sulfuric acid-activated ghassoul, in order to look for new natural bioactive products and assess their antif...

Research paper thumbnail of Consolidated bioethanol production from olive mill waste: Wood-decay fungi from central Morocco as promising decomposition and fermentation biocatalysts

Research paper thumbnail of Adsorption of Thymol onto Natural Clays of Morocco: Kinetic and Isotherm Studies

Journal of Chemistry

The present work aims to study the affinity of a component of the thyme essential oil “thymol” to... more The present work aims to study the affinity of a component of the thyme essential oil “thymol” to natural Moroccan clay “Rhassoul” using the adsorption technique. The physicochemical characterizations of the purified and modified clay were carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DTA/TGA, and SEM-EDX. Thymol adsorption tests on the purified Rhassoul (Rh-P) and the modified one by CTAB (Rh-CTAB) were followed by UV-visible spectroscopy. They show that the adsorption isotherms can be described by the Freundlich model and that the kinetics of adsorption is in accordance with the pseudo-second-order model for the two clays. Adsorption capacities obtained were of the order of 6 mg/g for the purified Rhassoul and 16 mg/g for the modified Rhassoul by cetyltrimethylammonium bromide (CTAB). These values show that the modified Rhassoul has a better adsorption capacity compared to the purified Rhassoul.

Research paper thumbnail of Molecular Cloning and Expression of Candida antarctica lipase B in Corynebacterium genus

Microbiology and Biotechnology Letters

This study, for the first time, reports the functional expression of lipase B derived from the ye... more This study, for the first time, reports the functional expression of lipase B derived from the yeast Candida antarctica (CALB) in Corynebacterium strain using the Escherichia coli plasmid PK18. The CALB gene fragment encoding a 317-amino-acid protein was successfully obtained from the total RNA of C. antarctica. CALB was readily produced in the Corynebacterium strain without the use of induction methods described in previous studies. This demonstrated the extracellular production of CALB in the Corynebacterium strain. CALB produced in the Corynebacterium MB001 strain transformed with pEC-CALB recombinant plasmid exhibited maximum extracellular enzymatic activity and high substrate affinity. The optimal pH and temperature for the hydrolysis of 4-nitrophenyl laurate by CALB were 9.0 and 40℃, respectively. The enzyme was stable at pH 10.7 in the glycine-KOH buffer and functioned as an alkaline lipase. The CALB activity was inhibited in the presence of high concentration of Mg2+, which indicated that CALB is not a metalloenzyme. These properties are key for the industrial application of the enzyme.

Research paper thumbnail of Proanthocyanidins and anthocyanins contents, chromatic and antioxidant properties of red grape pomaces from morocco

Journal of Food Measurement and Characterization

Proanthocyanidins (PAs) and anthocyanins contents of four different red grape pomaces (GPs) from ... more Proanthocyanidins (PAs) and anthocyanins contents of four different red grape pomaces (GPs) from Morocco were analysed using chromatographic methods. The GP skin pigments characteristics were determined using spectroscopic methods while their antioxidant activities were determined using both spectroscopic methods as ABTS and DPPH radical cations, ferric reducing/antioxidant power (FRAP) and electrochemical technique: cyclic Voltammetry (CV). The PA of seeds extracts varied significantly among the types of GP and ranged from 56.1 ± 0.3 mg g−1 dry weight (DW) in Cot to 88.4 ± 2.3 mg g−1 DW in non-fermented Cabernet Sauvignon (CSNF). The skins of CSNF contained the highest levels of PAs (22.1 ± 0.3 mg g−1 DW). The PAs average degree of polymerization distribution ranged from 2 to 45 subunits for the skins and from 2 to 12 subunits for the seeds. The maximum anthocyanins amounts and antioxidant activities were measured in Cot skin extracts (32.8 mg g−1 DW, DPPH: 0.23 mmol Trolox mg g−1 DW; ABTS: 0.38 mmol Trolox mg g−1 DW and CV: 1.73 × 10−3mA V) followed by Arinarnoa skin extracts which had the maximum corrected pigments (14.8 ± 0.1) and color power (152.4 ± 4.6 Unit color). The principal components analysis (PCA) of GP skins showed three different groups relevant to anthocyanins, PAs content, color and antioxidant properties.

Research paper thumbnail of Synthesis and characterization of crude hydrotalcite Mg–Al–CO3: study of thymol adsorption

Research on Chemical Intermediates

The study of the adsorption of thymol on a hydrotalcite of synthesis Mg3Al–CO3 (HT3) of molar rat... more The study of the adsorption of thymol on a hydrotalcite of synthesis Mg3Al–CO3 (HT3) of molar ratio Mg/Al = 3 and on its counterpart enabled at 500 °C (HT3-C) was conducted in hexane at a concentration of 40 mg L−1 of thymol. Hydrotalcite HT3 was prepared via coprecipitation at a constant pH of 10 and characterized by X-ray diffraction, infrared spectroscopy, nitrogen adsorption–desorption methods and thermal analysis (TGA/DTA). The adsorption of the thymol tests were monitored by UV–visible spectroscopy. The results show that the calcined hydrotalcite (HT3-C) has a capacity of adsorption of thymol (8 mg g−1) much greater than that of HT3 (4 mg g−1), and the experimental points are described by the isotherm model of the Freundlich of both materials.

Research paper thumbnail of Micro-Oxygenation and Fining Agent Treatments: Impact on Color of Moroccan Red Press Wine

Journal of Food Chemistry and Nanotechnology

Red press wine is collected after pressing solid parts (seed and skin) of grapes pomaces. Higher ... more Red press wine is collected after pressing solid parts (seed and skin) of grapes pomaces. Higher pressure induces more colorful, astringent, bitter and rustic wines. This is caused by the presence of undesirable phenolic compounds. To overcome this problem, the most common practice used in wine industry is the oenological treatment which enhances the clarity, stability and the wine taste. In the present work, press wines were separately submitted to four different treatments: micro-oxygenation and the addition of three fining agents: gelatin, polyvinylpolypyrrolidone (PVPP) and pea protein. The phenolic total index decreased (8%) significantly (P<0.05) for gelatin treatment, the PVPP based formulation treatment led to the largest loss (8%) in color intensity, (12%) in redness (a*), (9%) in polymeric pigments and increasing to 9% lightness (L*). Unlike micro-oxygenation which has decreased (5%) the color intensity. For the monomeric anthocyanins, the greatest reduction of acylated and coumaroylated anthocyanins at bottling and glucoside anthocyanidins after five months of storage was observed for both basic PVPP and gelatin.

Research paper thumbnail of Phenolic compounds of Moroccan red press wines: Influence of fining agents and micro-oxygenation treatments

LWT - Food Science and Technology, 2017

Abstract To improve the sensory quality of Moroccan red press wines, press wines were separately ... more Abstract To improve the sensory quality of Moroccan red press wines, press wines were separately submitted to micro-oxygenation and three fining agents (gelatin, Polyvinylpolypyrrolidone (PVPP) based formulation and pea protein) treatments at the winery Château Roslane, Morocco. The results showed that each treatment has a distinct behavior in relation with interactions and precipitation monomeric flavan-3-ol and fractions apparent and total condensed tannins. The fining agent corresponding to the vegetable protein has a greater affinity with the fraction of oligomeric condensed tannins with apparent aDP: 3.2. However, gelatin and PVPP based fining agent have an affinity with the catechin and epicatechin as well as with the fraction of polymeric tannins (apparent aDP: 6.6). For the structural parameters of proanthocyanidins, no significant differences were found out in global aDP and percentage of prodelphinidin between the different treatments. The global percentage of galloylation appeared slightly affected, while the global percentage of oxidized proanthocyanidins increased (9%) significantly (P

Research paper thumbnail of Cholesterol-lowering agent

Introduction: There has been renewed interest in mushroom medicinal properties. We studied choles... more Introduction: There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl), a renowned medicinal species. Results: Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC) 9.8%, and HDL 11.2%. Gl (2.5 and 5%) had effects on several fecal neutral sterols and bile acids. Both Gl doses reduced hepatic microsomal ex-vivo HMG-CoA reductase activity. In minipigs, 2.5 Gl decreased TC, LDL-and HDL cholesterol 20, 27, and 18%, respectively (P < 0.05); increased fecal cholestanol and coprostanol; and decreased cholate. Conclusions: Overall, Gl has potential to reduce LDL cholesterol in vivo through various mechanisms. Next steps are to: fully characterize bioactive components in lipid soluble/insoluble fractions; evaluate bioactivity of isolated fractions; and examine human cholesterol lowering properties. Innovative new cholesterol-lowering foods and medicines containing Gl are envisioned.