Nadia Chammem - Academia.edu (original) (raw)
Papers by Nadia Chammem
International Journal of Food Properties, 2019
Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis... more Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis) as affected by the effects of rootstocks and viroid infection,
Une analyse microbiologique de la microflore intestinale du tractus digestif de poulets de chair ... more Une analyse microbiologique de la microflore intestinale du tractus digestif de poulets de chair commercialises dans le marche tunisien a ete effectuee. Le denombrement de la microflore mesophile aerobie totale (MMAT) et des coliformes a donne des concentrations bacteriennes variant respectivement entre 10 5 et 10 8 UFC/g et 10 et 10 5 UFCIg. Les bacteries lactiques constituent une population assez importante variant entre 10 4 et 10 7 UFCIg de contenu intestinal. L'identification biochimique et physiologique de ces bacteries a montre qu'elles appartiennent aux genres : Lactobacillus, Lactococcus et Enterococcus. Les Lactobacilles isoles appartiennent aux especes suivantes : Lactobacillus brevis, Lactobacillus casei ssp rhamnosus, Lactobacillus coprophilus et Lactobacillus plantarum et les Lactocoques appartiennent a l'espece : Lactococcus lactis.
Des olives de table vertes de la variete tunisienne « Meski » ont ete soumises au processus d'... more Des olives de table vertes de la variete tunisienne « Meski » ont ete soumises au processus d'elaboration du type espagnol. L'effet des concentrations des solutions de soude utilisees pour la desamerisation (1,5; 2; 2,5 % PN) ainsi que celles des saumures de fermentations (teneur en sel: 6; 9;12 % PN) sur les bacteries lactiques du genre Lactobacillus a ete evalue. 36 souches isolees a partir des differents essais realises ont ete identifiees par des tests morphologiques, biochimiques et physiologiques revelant 5 especes: Lb. plantarum, dominante avec un taux de 38,9 %, suivie de Lb. pentosus avec 27,8 %, puis de Lb. rhamnosus avec 16,7 %, ensuite de Lb. paracasei avec 11,1% et enfin de Lb. ssp avec 5,5 %.
International Journal of Food Properties, 2019
Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis... more Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis) as affected by the effects of rootstocks and viroid infection,
Experimental Parasitology, 2017
Acanthamoeba species are free-living amoebae widely distributed in the environment and which caus... more Acanthamoeba species are free-living amoebae widely distributed in the environment and which cause serious human infections. The treatment of Acanthamoeba infections is always very difficult and not constantly effective. More efficient drugs against Acanthamoeba must be developed and medicinal plants can be useful in this case. Our research focused on the examination of the anti-Acanthamoeba activity of the essential oil and the ethanolic-aqueous extract from Thymus capitatus L. The essential oil showed best activity with an IC of 2.73 µg/ml. The conducted Bio-guided fractionation of thyme extract result to the identification of two active compounds against the trophozoite stage of Acanthamoeba: thymol and 2,3dihydroxy-p-cymene. The results have clearly shown that the investigated products may be successfully used against Acanthamoeba infections. These molecules that are found in plants may be an alternative for the development of new drugs.
Biodegradation, 2017
Table olive processing wastewaters constitute a dangerous environmental problem in the Mediterran... more Table olive processing wastewaters constitute a dangerous environmental problem in the Mediterranean countries because of their large volumes, high organic matter and salt concentration. The quantity and the characteristics of wastewaters produced, and thus, their environmental impact, varied depending on the season, varieties, soil and process employed. Several chemicals, biological and combined technologies have proven effective at bringing down organic pollution and toxicity of these effluents. Advanced oxidation processes have recognized as highly efficient treatments for the degradation of organic matter. Nonetheless, complete mineralization is generally expensive without salt removal. Biological processes are the most environmentally compatible and least-expensive treatment methods, but these operations do not always provide satisfactory results. This article surveys the current available technologies and suggests an effective, cheaper alternative for the recycling and the valorization of green table olives wastewaters. Keywords Table olive wastewaters Á Advanced oxidation process Á Biological treatment Á Combined technologies Á Recycling
Journal of the science of food and agriculture, Jan 15, 2016
Oxidation taking place during the use of oil leads to the deterioration of both nutritional and s... more Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybean oil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. Results showed that bioactive compounds are effective i...
Food Chemistry, 2016
The aim of this study was to improve the oxidative stability of soybean oil by using aromatic pla... more The aim of this study was to improve the oxidative stability of soybean oil by using aromatic plants. Soybean oil flavored with rosemary (ROS) and soybean oil flavored with thyme (THY) were subjected to heating for 24 h at 180 °C. The samples were analyzed every 6 h for their total polar compounds, anisidine values, oxidative stability and polyphenols content. The tocopherols content was determined and volatile compounds were also analyzed. After 24 h of heating, the incorporation of these plants using a maceration process reduced the polar compounds by 69% and 71% respectively, in ROS and THY compared to the control. Until 6 h of heating, the ROS kept the greatest oxidative stability. The use of the two extracts preserves approximately 50% of the total tocopherols content until 18 h for the rosemary and 24 h for the thyme flavored oils. Volatile compounds known for their antioxidant activity were also detected in the formulated oils. Aromatic plants added to the soybean oil improved the overall acceptability of potato crisps (p<0.05) until the fifteenth frying.
African Journal of Biotechnology, Apr 10, 2012
Celiac disease (CD) results from damage to the small intestinal mucosa due to an inappropriate im... more Celiac disease (CD) results from damage to the small intestinal mucosa due to an inappropriate immune response to a cereal protein (wheat, rye, barley). The only treatment for CD is lifelong avoidance of gluten proteins. Gluten-free products are not widely available and usually more expensive. That is why; there is an urgent need to develop an alternative therapy. Enzymatic degradation of gluten among other approaches, abolishing its immunogenic and toxigenic activities, is an attractive alternative strategy for oral therapy in CD. Several proteases following different approaches were studied. This review focuses on enzymes (microbial or vegetal) designed to digest gluten. Also, recent biotechnological procedures that use microorganisms (cell factories for enzymes) as starter culture to eliminate gluten are reviewed in this manuscript.
Analytical Letters, 2015
ABSTRACT The olive tree historically provided economic benefits to the countries in Mediterranean... more ABSTRACT The olive tree historically provided economic benefits to the countries in Mediterranean basin as a source of products contributing to health promotion. Some of the health benefits attributed to olive tree leaves are related to phenolic composition. In this study, a 10-point augmented simplex-centroid design was used to formulate a three-component mixture system using water, ethanol, and methanol, adequate for the extraction of phenolics from olive leaves. Phenolic and flavonoid content, antioxidant activity with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), oleuropein, and luteolin7-O-glucoside concentrations were selected as responses. The optimal extraction mixture was: 12.7% water, 14.8% ethanol, and 72.5% methanol. The yields of total phenolic and flavonoid compounds, oleuropein, and luteolin-7-O-glucoside were 163.69 ± 6.35 mg gallic acid g−1, 114.69 ± 3.56 mg rutin g−1, 858.29 µg g−1, and 21.04 µg g−1 dry weight of olive leaves. The antioxidant capacity was 238.71 ± 4.35 mM equivalent Trolox per g−1 dry weight of olive leaves.
Desalination and Water Treatment, 2015
ABSTRACT
The main idea of this work was to study the stability to autoxidation of refined oils with the ad... more The main idea of this work was to study the stability to autoxidation of refined oils with the addition of three essential oils. First, antioxidative activity of the essential oils which are isolated by water distillation from three plants (Thymus Capitatus Hoffmanns, Salvia officinalis L and Rosemarinus officinalis L.), was evaluated by using a β-carotene/linoleic acid system. Peroxidation of the linoleic acid was effectively inhibited by the three essential oils. In fact, they showed strong antioxidative properties when compared to BHT and BHA. Second, the stability to autooxidation of refined oils is evaluated using the Rancimat method. This method provides the induction time for decomposition of hydroperoxydes, produced by fat oxidation. This stability was also evaluated by the determination of the Peroxides Value (PV). As a result, it can be suggested that the stability of refined oils was improved with the addition of the essential oils, which possess antioxidant activities. T...
Therapeutic methods against several protozoa diseases caused by the genus Acanthamoeba strains na... more Therapeutic methods against several protozoa diseases caused by the genus Acanthamoeba strains namely, Granulomatous Amoebic Encephalitis (AGE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to chemical and physical agents. Recently several researches have been studying the amoebicidal activity of medicinal plants namely the Origanum, the Thymus sipyleus and the Olea europea [1-3]. This activity could be correlated to the presence of several molecules such as the flavonoids. The aim of this study was to evaluate the activity of the flavone on Acanthamoebae castellanii Neff. In fact, the flavone or the 2-phenylchoromone is the flavonoid parent compound [4]. Both form cyst and trophozoïte have been inhibiting by the Flavone with an IC50 about 25µg/ml against the vegetative form of the tested parasite. The action mode of this compound was studied by detecting changes in the phosphatidylserine (PS) exposur...
Industrial Crops and Products, 2015
The effect of rosemary extract (Rosemarinus officinalis L.), a natural antioxidant, on stability ... more The effect of rosemary extract (Rosemarinus officinalis L.), a natural antioxidant, on stability of frying oil during heat treatment and on sensorial quality of fried potato was studied. A mixture of soybean and sunflower oils in an equal proportions and containing 0.08% of rosemary extract was evaluated for thermo-oxidation at 180 • C for 30 h. This evaluation was carried out comparatively to an oil mixture without antioxidant. Results showed a significant difference (p < 0.05) between oils according to the measured parameters especially at the end of treatment. The addition of the rosemary extract in the mixture of soybean and sunflower oil reduce the peroxide value by 38% after 30 h of heating. This oil resists to oxidation and conserves the higher amount of unsaturated fatty acids even after 30 h of heating. The evolution of saturated fatty acid composition is estimated at 5.5% and 25% in the oil with and without extract, respectively, at the end of the heating treatment. Sensorial analysis carried out showed that the fried potato prepared in oil with rosemary extract had the best crispiness and taste until the fifteenth frying. The oil with rosemary extract showed an enhanced stability and therefore a best quality compared to the oil without rosemary extract.
Parasitology Research, 2013
The olive tree (Olea europaea, Oleaceae) has historically provided huge economic and nutritional ... more The olive tree (Olea europaea, Oleaceae) has historically provided huge economic and nutritional benefits to the Mediterranean basin. In fact, olive leaf extracts have also been used by native people of this area in folk medicine to treat fever and other diseases such as malaria. Recently, several studies have focused on the extraction of high-added-value compounds from olive leaves. However, no previous studies have been developed in order to evaluate the activity of these extracts against Acanthamoeba. In the present work, olive leaf extracts from five different Tunisian varieties of olive trees (Chemlali Tataouine, Zarrazi, Toffehi, Dhokkar, and Limouni) were obtained by using three different solvents, and their activity against the trophozoite stage of Acanthamoeba castellanii Neff was screened. The IC50/96 h (50% parasite growth inhibition) was chosen as the appropriate and comparable data to give as previously described. It could be observed that the amoebicidal activity was dose dependent. Trophozoite growth was inhibited by all the tested extracts with IC50 ranging from 8.234 ± 1.703 μg/ml for the alcoholic mixture of the Dhokkar extract to 33.661 ± 1.398 μg/ml for the methanolic extract of the Toffehi variety. The activity in fact was affected especially by the tested variety and not by the solvent extraction, the Dhokkar variety being the most active one as mentioned above.
Experimental Parasitology, 2014
Leishmaniasis is one of the neglected tropical diseases in terms of drug discovery and developmen... more Leishmaniasis is one of the neglected tropical diseases in terms of drug discovery and development. Furthermore, the chemotherapy used to treat this disease has been proved to be highly toxic and to present resistance issues. As consequent, the need for novel leishmanicidal molecules has notably increased in the recent years. In the present work an attempt was made to evaluate the antioxidant and leishmanicidal activities besides presence of compounds in leaf extracts of 5 different Tunisian olive tree varieties, used as traditional medicine in this country. The concentration of extracts needed to inhibit 50% of the parasitic growth (IC50) was estimated using different Leishmania strains. All tested extracts showed an inhibitory effect on the parasite growth with IC50 ranging from 2.130±0.023 to 71.570±4.324μg/ml, respectively for the methanolic extracts of Limouni and Zarrazi against Leishmania donovani. In fact, this activity was significantly affected by the olive cultivar and the tested Leishmania strain. Furthermore, the activities against both Leishmania tropica and major species were correlated to the total phenolic compounds. These results could suggest that olive leaf extract could carry potential new compounds for the development of novel drugs against Leishmaniasis.
Bioresource Technology, 2005
Green olives of the Tunisian variety ''Meski'' were treated according to a Spanish-style green ol... more Green olives of the Tunisian variety ''Meski'' were treated according to a Spanish-style green olive preservation process by using an alkaline treatment (1.5, 2 and 2.5% (w/v) NaOH) to eliminate bitterness, combined with different brine concentrations (6, 9 and 12% (w/v) NaCl). A spontaneous fermentation by the environmental microflora took place. Results showed that 2% NaOH solution and 9% sodium chloride brine was an optimal combination inducing the best growth of Lactobacillus species (10 8 CFU/ml) and acidity of 0.726 g lactic acid/100 ml brine. In all trials and independently of the treatment, Lb. plantarum was the most dominant strain of Lactobacillus. Moreover, pretreatment with lye and lactic fermentation of olives contributed to coliform elimination.
Annals of Microbiology, 2011
Bacteria belonging to the genus Enterococcus spp.-a member of the lactic acid bacteria group-are ... more Bacteria belonging to the genus Enterococcus spp.-a member of the lactic acid bacteria group-are natural inhabitants of various environments, including vegetable products. Although some strains show pathogenic determinants, overall these bacteria may have some protechnological features. Some enterococci have been described as potential starter or protective cultures in the dairy industry, since they contribute to the organoleptic and quality characteristics of dairy products. Although several fermented vegetable products have a long history in human nutrition, studies regarding autochthonous enterococci and their application to fermented vegetable foods are much less numerous than those concerning dairy foods. In this review, after a general overview of enterococci, their presence and role in fermented vegetable foods (including table olives, sauerkraut, kimchi, tomato juice, French beans, caper berries and cereal-based products) will be covered.
Foods are the vehicle and the support of a wide variety of macronutrients, micronutrients and min... more Foods are the vehicle and the support of a wide variety of macronutrients, micronutrients and minor compounds that are responsible for the nutritional and sensorial properties. Mediterranean Diet is abundant in plant-based (nutrient-dense, seasonal and low-energy) foods, and despite including industrial products, it does not have place to ultraprocessed foods, which are energetically dense and low in nutrients; the first type of foods (including fresh produce as well as foodstuffs) is grounded on agro-biodiversity and respectful of the environment, while the second class of foods (sodas, fast-food) is responsible for the rise in obesity and other non-communicable diseases. Products of the second food category generally have a high carbon footprint, contribute to deforestation, to the reduction of biodiversity, and generally do not bring any social benefit. This chapter emphasizes the important involvement of polyphenols of natural origin specifically in connection with organoleptic ...
International Journal of Food Properties, 2019
Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis... more Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis) as affected by the effects of rootstocks and viroid infection,
Une analyse microbiologique de la microflore intestinale du tractus digestif de poulets de chair ... more Une analyse microbiologique de la microflore intestinale du tractus digestif de poulets de chair commercialises dans le marche tunisien a ete effectuee. Le denombrement de la microflore mesophile aerobie totale (MMAT) et des coliformes a donne des concentrations bacteriennes variant respectivement entre 10 5 et 10 8 UFC/g et 10 et 10 5 UFCIg. Les bacteries lactiques constituent une population assez importante variant entre 10 4 et 10 7 UFCIg de contenu intestinal. L'identification biochimique et physiologique de ces bacteries a montre qu'elles appartiennent aux genres : Lactobacillus, Lactococcus et Enterococcus. Les Lactobacilles isoles appartiennent aux especes suivantes : Lactobacillus brevis, Lactobacillus casei ssp rhamnosus, Lactobacillus coprophilus et Lactobacillus plantarum et les Lactocoques appartiennent a l'espece : Lactococcus lactis.
Des olives de table vertes de la variete tunisienne « Meski » ont ete soumises au processus d'... more Des olives de table vertes de la variete tunisienne « Meski » ont ete soumises au processus d'elaboration du type espagnol. L'effet des concentrations des solutions de soude utilisees pour la desamerisation (1,5; 2; 2,5 % PN) ainsi que celles des saumures de fermentations (teneur en sel: 6; 9;12 % PN) sur les bacteries lactiques du genre Lactobacillus a ete evalue. 36 souches isolees a partir des differents essais realises ont ete identifiees par des tests morphologiques, biochimiques et physiologiques revelant 5 especes: Lb. plantarum, dominante avec un taux de 38,9 %, suivie de Lb. pentosus avec 27,8 %, puis de Lb. rhamnosus avec 16,7 %, ensuite de Lb. paracasei avec 11,1% et enfin de Lb. ssp avec 5,5 %.
International Journal of Food Properties, 2019
Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis... more Chammem (2019) Essential oil components of Citrus cultivar'MALTAISE DEMISANGUINE' (Citrussinensis) as affected by the effects of rootstocks and viroid infection,
Experimental Parasitology, 2017
Acanthamoeba species are free-living amoebae widely distributed in the environment and which caus... more Acanthamoeba species are free-living amoebae widely distributed in the environment and which cause serious human infections. The treatment of Acanthamoeba infections is always very difficult and not constantly effective. More efficient drugs against Acanthamoeba must be developed and medicinal plants can be useful in this case. Our research focused on the examination of the anti-Acanthamoeba activity of the essential oil and the ethanolic-aqueous extract from Thymus capitatus L. The essential oil showed best activity with an IC of 2.73 µg/ml. The conducted Bio-guided fractionation of thyme extract result to the identification of two active compounds against the trophozoite stage of Acanthamoeba: thymol and 2,3dihydroxy-p-cymene. The results have clearly shown that the investigated products may be successfully used against Acanthamoeba infections. These molecules that are found in plants may be an alternative for the development of new drugs.
Biodegradation, 2017
Table olive processing wastewaters constitute a dangerous environmental problem in the Mediterran... more Table olive processing wastewaters constitute a dangerous environmental problem in the Mediterranean countries because of their large volumes, high organic matter and salt concentration. The quantity and the characteristics of wastewaters produced, and thus, their environmental impact, varied depending on the season, varieties, soil and process employed. Several chemicals, biological and combined technologies have proven effective at bringing down organic pollution and toxicity of these effluents. Advanced oxidation processes have recognized as highly efficient treatments for the degradation of organic matter. Nonetheless, complete mineralization is generally expensive without salt removal. Biological processes are the most environmentally compatible and least-expensive treatment methods, but these operations do not always provide satisfactory results. This article surveys the current available technologies and suggests an effective, cheaper alternative for the recycling and the valorization of green table olives wastewaters. Keywords Table olive wastewaters Á Advanced oxidation process Á Biological treatment Á Combined technologies Á Recycling
Journal of the science of food and agriculture, Jan 15, 2016
Oxidation taking place during the use of oil leads to the deterioration of both nutritional and s... more Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybean oil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. Results showed that bioactive compounds are effective i...
Food Chemistry, 2016
The aim of this study was to improve the oxidative stability of soybean oil by using aromatic pla... more The aim of this study was to improve the oxidative stability of soybean oil by using aromatic plants. Soybean oil flavored with rosemary (ROS) and soybean oil flavored with thyme (THY) were subjected to heating for 24 h at 180 °C. The samples were analyzed every 6 h for their total polar compounds, anisidine values, oxidative stability and polyphenols content. The tocopherols content was determined and volatile compounds were also analyzed. After 24 h of heating, the incorporation of these plants using a maceration process reduced the polar compounds by 69% and 71% respectively, in ROS and THY compared to the control. Until 6 h of heating, the ROS kept the greatest oxidative stability. The use of the two extracts preserves approximately 50% of the total tocopherols content until 18 h for the rosemary and 24 h for the thyme flavored oils. Volatile compounds known for their antioxidant activity were also detected in the formulated oils. Aromatic plants added to the soybean oil improved the overall acceptability of potato crisps (p<0.05) until the fifteenth frying.
African Journal of Biotechnology, Apr 10, 2012
Celiac disease (CD) results from damage to the small intestinal mucosa due to an inappropriate im... more Celiac disease (CD) results from damage to the small intestinal mucosa due to an inappropriate immune response to a cereal protein (wheat, rye, barley). The only treatment for CD is lifelong avoidance of gluten proteins. Gluten-free products are not widely available and usually more expensive. That is why; there is an urgent need to develop an alternative therapy. Enzymatic degradation of gluten among other approaches, abolishing its immunogenic and toxigenic activities, is an attractive alternative strategy for oral therapy in CD. Several proteases following different approaches were studied. This review focuses on enzymes (microbial or vegetal) designed to digest gluten. Also, recent biotechnological procedures that use microorganisms (cell factories for enzymes) as starter culture to eliminate gluten are reviewed in this manuscript.
Analytical Letters, 2015
ABSTRACT The olive tree historically provided economic benefits to the countries in Mediterranean... more ABSTRACT The olive tree historically provided economic benefits to the countries in Mediterranean basin as a source of products contributing to health promotion. Some of the health benefits attributed to olive tree leaves are related to phenolic composition. In this study, a 10-point augmented simplex-centroid design was used to formulate a three-component mixture system using water, ethanol, and methanol, adequate for the extraction of phenolics from olive leaves. Phenolic and flavonoid content, antioxidant activity with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), oleuropein, and luteolin7-O-glucoside concentrations were selected as responses. The optimal extraction mixture was: 12.7% water, 14.8% ethanol, and 72.5% methanol. The yields of total phenolic and flavonoid compounds, oleuropein, and luteolin-7-O-glucoside were 163.69 ± 6.35 mg gallic acid g−1, 114.69 ± 3.56 mg rutin g−1, 858.29 µg g−1, and 21.04 µg g−1 dry weight of olive leaves. The antioxidant capacity was 238.71 ± 4.35 mM equivalent Trolox per g−1 dry weight of olive leaves.
Desalination and Water Treatment, 2015
ABSTRACT
The main idea of this work was to study the stability to autoxidation of refined oils with the ad... more The main idea of this work was to study the stability to autoxidation of refined oils with the addition of three essential oils. First, antioxidative activity of the essential oils which are isolated by water distillation from three plants (Thymus Capitatus Hoffmanns, Salvia officinalis L and Rosemarinus officinalis L.), was evaluated by using a β-carotene/linoleic acid system. Peroxidation of the linoleic acid was effectively inhibited by the three essential oils. In fact, they showed strong antioxidative properties when compared to BHT and BHA. Second, the stability to autooxidation of refined oils is evaluated using the Rancimat method. This method provides the induction time for decomposition of hydroperoxydes, produced by fat oxidation. This stability was also evaluated by the determination of the Peroxides Value (PV). As a result, it can be suggested that the stability of refined oils was improved with the addition of the essential oils, which possess antioxidant activities. T...
Therapeutic methods against several protozoa diseases caused by the genus Acanthamoeba strains na... more Therapeutic methods against several protozoa diseases caused by the genus Acanthamoeba strains namely, Granulomatous Amoebic Encephalitis (AGE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to chemical and physical agents. Recently several researches have been studying the amoebicidal activity of medicinal plants namely the Origanum, the Thymus sipyleus and the Olea europea [1-3]. This activity could be correlated to the presence of several molecules such as the flavonoids. The aim of this study was to evaluate the activity of the flavone on Acanthamoebae castellanii Neff. In fact, the flavone or the 2-phenylchoromone is the flavonoid parent compound [4]. Both form cyst and trophozoïte have been inhibiting by the Flavone with an IC50 about 25µg/ml against the vegetative form of the tested parasite. The action mode of this compound was studied by detecting changes in the phosphatidylserine (PS) exposur...
Industrial Crops and Products, 2015
The effect of rosemary extract (Rosemarinus officinalis L.), a natural antioxidant, on stability ... more The effect of rosemary extract (Rosemarinus officinalis L.), a natural antioxidant, on stability of frying oil during heat treatment and on sensorial quality of fried potato was studied. A mixture of soybean and sunflower oils in an equal proportions and containing 0.08% of rosemary extract was evaluated for thermo-oxidation at 180 • C for 30 h. This evaluation was carried out comparatively to an oil mixture without antioxidant. Results showed a significant difference (p < 0.05) between oils according to the measured parameters especially at the end of treatment. The addition of the rosemary extract in the mixture of soybean and sunflower oil reduce the peroxide value by 38% after 30 h of heating. This oil resists to oxidation and conserves the higher amount of unsaturated fatty acids even after 30 h of heating. The evolution of saturated fatty acid composition is estimated at 5.5% and 25% in the oil with and without extract, respectively, at the end of the heating treatment. Sensorial analysis carried out showed that the fried potato prepared in oil with rosemary extract had the best crispiness and taste until the fifteenth frying. The oil with rosemary extract showed an enhanced stability and therefore a best quality compared to the oil without rosemary extract.
Parasitology Research, 2013
The olive tree (Olea europaea, Oleaceae) has historically provided huge economic and nutritional ... more The olive tree (Olea europaea, Oleaceae) has historically provided huge economic and nutritional benefits to the Mediterranean basin. In fact, olive leaf extracts have also been used by native people of this area in folk medicine to treat fever and other diseases such as malaria. Recently, several studies have focused on the extraction of high-added-value compounds from olive leaves. However, no previous studies have been developed in order to evaluate the activity of these extracts against Acanthamoeba. In the present work, olive leaf extracts from five different Tunisian varieties of olive trees (Chemlali Tataouine, Zarrazi, Toffehi, Dhokkar, and Limouni) were obtained by using three different solvents, and their activity against the trophozoite stage of Acanthamoeba castellanii Neff was screened. The IC50/96 h (50% parasite growth inhibition) was chosen as the appropriate and comparable data to give as previously described. It could be observed that the amoebicidal activity was dose dependent. Trophozoite growth was inhibited by all the tested extracts with IC50 ranging from 8.234 ± 1.703 μg/ml for the alcoholic mixture of the Dhokkar extract to 33.661 ± 1.398 μg/ml for the methanolic extract of the Toffehi variety. The activity in fact was affected especially by the tested variety and not by the solvent extraction, the Dhokkar variety being the most active one as mentioned above.
Experimental Parasitology, 2014
Leishmaniasis is one of the neglected tropical diseases in terms of drug discovery and developmen... more Leishmaniasis is one of the neglected tropical diseases in terms of drug discovery and development. Furthermore, the chemotherapy used to treat this disease has been proved to be highly toxic and to present resistance issues. As consequent, the need for novel leishmanicidal molecules has notably increased in the recent years. In the present work an attempt was made to evaluate the antioxidant and leishmanicidal activities besides presence of compounds in leaf extracts of 5 different Tunisian olive tree varieties, used as traditional medicine in this country. The concentration of extracts needed to inhibit 50% of the parasitic growth (IC50) was estimated using different Leishmania strains. All tested extracts showed an inhibitory effect on the parasite growth with IC50 ranging from 2.130±0.023 to 71.570±4.324μg/ml, respectively for the methanolic extracts of Limouni and Zarrazi against Leishmania donovani. In fact, this activity was significantly affected by the olive cultivar and the tested Leishmania strain. Furthermore, the activities against both Leishmania tropica and major species were correlated to the total phenolic compounds. These results could suggest that olive leaf extract could carry potential new compounds for the development of novel drugs against Leishmaniasis.
Bioresource Technology, 2005
Green olives of the Tunisian variety ''Meski'' were treated according to a Spanish-style green ol... more Green olives of the Tunisian variety ''Meski'' were treated according to a Spanish-style green olive preservation process by using an alkaline treatment (1.5, 2 and 2.5% (w/v) NaOH) to eliminate bitterness, combined with different brine concentrations (6, 9 and 12% (w/v) NaCl). A spontaneous fermentation by the environmental microflora took place. Results showed that 2% NaOH solution and 9% sodium chloride brine was an optimal combination inducing the best growth of Lactobacillus species (10 8 CFU/ml) and acidity of 0.726 g lactic acid/100 ml brine. In all trials and independently of the treatment, Lb. plantarum was the most dominant strain of Lactobacillus. Moreover, pretreatment with lye and lactic fermentation of olives contributed to coliform elimination.
Annals of Microbiology, 2011
Bacteria belonging to the genus Enterococcus spp.-a member of the lactic acid bacteria group-are ... more Bacteria belonging to the genus Enterococcus spp.-a member of the lactic acid bacteria group-are natural inhabitants of various environments, including vegetable products. Although some strains show pathogenic determinants, overall these bacteria may have some protechnological features. Some enterococci have been described as potential starter or protective cultures in the dairy industry, since they contribute to the organoleptic and quality characteristics of dairy products. Although several fermented vegetable products have a long history in human nutrition, studies regarding autochthonous enterococci and their application to fermented vegetable foods are much less numerous than those concerning dairy foods. In this review, after a general overview of enterococci, their presence and role in fermented vegetable foods (including table olives, sauerkraut, kimchi, tomato juice, French beans, caper berries and cereal-based products) will be covered.
Foods are the vehicle and the support of a wide variety of macronutrients, micronutrients and min... more Foods are the vehicle and the support of a wide variety of macronutrients, micronutrients and minor compounds that are responsible for the nutritional and sensorial properties. Mediterranean Diet is abundant in plant-based (nutrient-dense, seasonal and low-energy) foods, and despite including industrial products, it does not have place to ultraprocessed foods, which are energetically dense and low in nutrients; the first type of foods (including fresh produce as well as foodstuffs) is grounded on agro-biodiversity and respectful of the environment, while the second class of foods (sodas, fast-food) is responsible for the rise in obesity and other non-communicable diseases. Products of the second food category generally have a high carbon footprint, contribute to deforestation, to the reduction of biodiversity, and generally do not bring any social benefit. This chapter emphasizes the important involvement of polyphenols of natural origin specifically in connection with organoleptic ...