La problematique de cette these repose sur la caracterisation de la qualite des abricots et leur ... more La problematique de cette these repose sur la caracterisation de la qualite des abricots et leur aptitude a la transformation industrielle. Trois axes principaux ont guide cette etude. Le premier consistait au depart a une caracterisation morphometrique globale des pieds clones des abricots marocains transplantes vers une station experimentale de l’INRA Marrakech puis suivie par l’analyse de la diversite genetique. 92 accessions, issus de differentes regions geographiques, ont ete genotypes en utilisant 21 marqueurs microsatellites. En effet, la collection analysee a ete caracterisee par un polymorphisme eleve et une diversite genetique reduite. Au total, 120 alleles ont ete identifies avec une moyenne de 5,71 alleles par locus.Toutes les preuves statistiques (analyse hierarchique, ACP et analyse de structure) montrent que la structure genetique de l’abricot marocain peut etre subdivisee en deux populations :une majeure population constituee de la plupart des accessions de groupes g...
The softening of apricot fruit results from significant changes in the cell wall which occurs dur... more The softening of apricot fruit results from significant changes in the cell wall which occurs during maturation. These modifications are essentially the result of enzyme activity modifying the cell walls composition and are involved in the detachment of the cell wall, which promotes tissue extension and growth. In this work, the activities of important pectinolytic enzymes involved in the degradation of the cell wall, and consequently the loss of firmness, namely pectin methylesterase , polygalacturonase and β-Galactosidase, were monitored during two ripening stages in 10 apricot clones. The overall results suggested that the maturation of the apricots was coordinated by the three pectinolytic enzyme activities, since PME, PG and β-Gal activities increased during ripening while fruit flesh firmness decreased. In addition, the results showed that apricot softening was more controlled by β-galactosidase and PME.
Changes in cell wall composition during ripening of nectarine fruit (Prunus persica var nectarina... more Changes in cell wall composition during ripening of nectarine fruit (Prunus persica var nectarina, Ait. Max, cv. “Caldesi 2000”) after harvest or after cold storage were investigated. Cell wall materials were prepared from nectarine fruits after harvest, after 2, 4 and 6 weeks of cold storage (0C) and after additional ripening at room temperature (20C) for 1 and 5 days, respectively. The materials were analyzed for neutral sugars and cellulose content. Incidence of chilling injury (CI) symptoms, expressed as woolliness and gaseous emissions of CO2 and ethylene evolution, were also monitored. A significant decrease in arabinose and galactose contents as the woolliness symptoms became more intense was observed. After 6 weeks of cold storage and an additional 5 days at room temperature, arabinose and galactose contents decreased up to 63 and 34%, respectively. In addition, as the cold storage period increased, a linear decrease of total neutral sugars (r = 0.9832, P < 0.01) and arab...
Background The theoretical, but especially the practical values of identifying the biochemical co... more Background The theoretical, but especially the practical values of identifying the biochemical compounds from the Rosa canina L. fruits are of present interest, this aspect being illustrated by the numerous researches. It was reported that the Rosa canina L. fruit, with its high ascorbic acid, phenolics and flavonoids contents, have antioxidant, antimutagenic and anticarcinogenic effects. This study was performed on order to evaluate the amount of the main phytochemicals (vitamin C, total polyphenols, and total flavonoids) content and their antioxidant activity. Results The results obtained revealed that the average amounts of vitamin C within the studied genotypes were: 360.22 mg/100 g frozen pulp (var. transitoria f. ramosissima, altitude 1250 m) and 112.20 mg/100 g frozen pulp (var. assiensis, altitude 440 m), giving a good correlation between the vitamin C content of the rosehip and the altitude. The total polyphenols content varied from 575 mg/100 g frozen pulp (var. transitori...
Abstract Dates are known to have a wide range of biological properties due to their bioactive com... more Abstract Dates are known to have a wide range of biological properties due to their bioactive compounds and antioxidant activities. The majority of Moroccan varieties and clones are not characterised for their bioactive compounds and their contribution to the total antioxidant activity. The aim of this research was to investigate the biochemical properties and antioxidant activities of 17 dates varieties and clones from Drâa oasis (southern Morocco) which have not been characterised yet. The results indicated that the total phenolic content was found between 101.06 and 478.37 mg of gallic acid equivalent (GAE)/100 g of dry matter (DM), the total flavonoids levels are between 1.79 and 216.12 mg of quercetin equivalent (QE)/100 g of dry matter (DM), and condensed tannins values range is between 5.29 and 152.15 mg of catechin equivalent (CE)/100 g dry matter (DM), and the antioxidant activity ranged between 0.219 and 2.028 mg/ml for FRAP IC50, 2.411 and 9.738 mg/ml for DPPH IC50. This study showed that date fruit is a veritable source of functional nutrients and natural antioxidants. Therefore, Moroccan dates can be used as a food or functional ingredient in food products.
Date fruit is known to be the staple food in the Arab countries. It provides a lot of potential h... more Date fruit is known to be the staple food in the Arab countries. It provides a lot of potential health benefits and can be the essential source of nutrients. The majority of Moroccan varieties are not characterized for their chemical, biochemical and quality properties. The aim of this work was to assess the chemical composition of 17 varieties of Moroccan date fruits (Phoenix dactylifera L.) and to determine their nutritive components. The analysis showed that the dates are rich in sugars (51.80-87.98%), they contain low concentration of proteins (1.09-2.80%) and lipids (0.16-0.39%). The predominant mineral is potassium (1055.26-1604.10 mg/100 g DW). Moreover, they contain high concentrations of malic acid (69.48-495.58 mg/100 g (DW)), oxalic acid (18.47-233.35 mg/100 g DW) and tartaric acid (115.70-484.168 mg/100 g DW). These results suggest that the date fruit are nutritious and can be an excellent source for human nutrition and health benefits.
Apricot is among the most important fruits in Morocco. This study aimed to determine the main phy... more Apricot is among the most important fruits in Morocco. This study aimed to determine the main physical, physicochemical, and biochemical quality criteria of three principal apricot cultivars in Morocco, namely, “Maoui,” “Canino,” and “Delpatriarca.” Different physicochemical and biochemical methods have been improved and adapted for the assessment of the apricot’s quality. Fruit of “Canino” has shown a good organoleptic quality due to interesting biometrics, richness of carotenoids (up to 113.67 μg of β-carotene g−1 of fresh weight (FW)), and an important content of soluble solids (SS) that reached 17.20 °Bx. “Delpatriarca” is rich in organic acids (27.35 g/kg FW for total acids) while “Maoui” has high water content (83.77%) and a SS content of 16.03 °Bx. The association of the total acidity and soluble solids determination with the use of the HPLC for determining the organic acids was very practical and effective in determining the organoleptic quality of the fruit. High correlatio...
In association with a desirable balance of sugars and organic acids, volatile compounds contribut... more In association with a desirable balance of sugars and organic acids, volatile compounds contribute to the important sensory attributes of apricots. This study assessed the biochemical, aromatic, and sensory qualities of ten Moroccan apricot clones at two maturity stages (M1: commercial stage and M2: consumption stage). Sucrose (1.84–7.09 g/100 g of fresh weight (FW)) and citric acid (0.56–2.25 g/100 g FW) were the main sugar and organic acid in fresh apricots, respectively. The principal identified volatile compounds classes were aldehydes, alcohols, and acetates. The major apricot volatile compounds, hexanal (15.43–696.35 μg/kg FW), 2-hexenal (9.04–404.72 μg/kg FW), β-linalool (8.49–880.50 μg/kg FW), and 1-hexanol (3.35–86.00 μg/kg FW), were previously reported to be major contributors to apricot flavor. Multivariate analysis revealed a significant impact of the ripening stage on the perception of sensory quality related to biochemical parameters. At the commercial stage, apricots ...
La problematique de cette these repose sur la caracterisation de la qualite des abricots et leur ... more La problematique de cette these repose sur la caracterisation de la qualite des abricots et leur aptitude a la transformation industrielle. Trois axes principaux ont guide cette etude. Le premier consistait au depart a une caracterisation morphometrique globale des pieds clones des abricots marocains transplantes vers une station experimentale de l’INRA Marrakech puis suivie par l’analyse de la diversite genetique. 92 accessions, issus de differentes regions geographiques, ont ete genotypes en utilisant 21 marqueurs microsatellites. En effet, la collection analysee a ete caracterisee par un polymorphisme eleve et une diversite genetique reduite. Au total, 120 alleles ont ete identifies avec une moyenne de 5,71 alleles par locus.Toutes les preuves statistiques (analyse hierarchique, ACP et analyse de structure) montrent que la structure genetique de l’abricot marocain peut etre subdivisee en deux populations :une majeure population constituee de la plupart des accessions de groupes g...
The softening of apricot fruit results from significant changes in the cell wall which occurs dur... more The softening of apricot fruit results from significant changes in the cell wall which occurs during maturation. These modifications are essentially the result of enzyme activity modifying the cell walls composition and are involved in the detachment of the cell wall, which promotes tissue extension and growth. In this work, the activities of important pectinolytic enzymes involved in the degradation of the cell wall, and consequently the loss of firmness, namely pectin methylesterase , polygalacturonase and β-Galactosidase, were monitored during two ripening stages in 10 apricot clones. The overall results suggested that the maturation of the apricots was coordinated by the three pectinolytic enzyme activities, since PME, PG and β-Gal activities increased during ripening while fruit flesh firmness decreased. In addition, the results showed that apricot softening was more controlled by β-galactosidase and PME.
Changes in cell wall composition during ripening of nectarine fruit (Prunus persica var nectarina... more Changes in cell wall composition during ripening of nectarine fruit (Prunus persica var nectarina, Ait. Max, cv. “Caldesi 2000”) after harvest or after cold storage were investigated. Cell wall materials were prepared from nectarine fruits after harvest, after 2, 4 and 6 weeks of cold storage (0C) and after additional ripening at room temperature (20C) for 1 and 5 days, respectively. The materials were analyzed for neutral sugars and cellulose content. Incidence of chilling injury (CI) symptoms, expressed as woolliness and gaseous emissions of CO2 and ethylene evolution, were also monitored. A significant decrease in arabinose and galactose contents as the woolliness symptoms became more intense was observed. After 6 weeks of cold storage and an additional 5 days at room temperature, arabinose and galactose contents decreased up to 63 and 34%, respectively. In addition, as the cold storage period increased, a linear decrease of total neutral sugars (r = 0.9832, P < 0.01) and arab...
Background The theoretical, but especially the practical values of identifying the biochemical co... more Background The theoretical, but especially the practical values of identifying the biochemical compounds from the Rosa canina L. fruits are of present interest, this aspect being illustrated by the numerous researches. It was reported that the Rosa canina L. fruit, with its high ascorbic acid, phenolics and flavonoids contents, have antioxidant, antimutagenic and anticarcinogenic effects. This study was performed on order to evaluate the amount of the main phytochemicals (vitamin C, total polyphenols, and total flavonoids) content and their antioxidant activity. Results The results obtained revealed that the average amounts of vitamin C within the studied genotypes were: 360.22 mg/100 g frozen pulp (var. transitoria f. ramosissima, altitude 1250 m) and 112.20 mg/100 g frozen pulp (var. assiensis, altitude 440 m), giving a good correlation between the vitamin C content of the rosehip and the altitude. The total polyphenols content varied from 575 mg/100 g frozen pulp (var. transitori...
Abstract Dates are known to have a wide range of biological properties due to their bioactive com... more Abstract Dates are known to have a wide range of biological properties due to their bioactive compounds and antioxidant activities. The majority of Moroccan varieties and clones are not characterised for their bioactive compounds and their contribution to the total antioxidant activity. The aim of this research was to investigate the biochemical properties and antioxidant activities of 17 dates varieties and clones from Drâa oasis (southern Morocco) which have not been characterised yet. The results indicated that the total phenolic content was found between 101.06 and 478.37 mg of gallic acid equivalent (GAE)/100 g of dry matter (DM), the total flavonoids levels are between 1.79 and 216.12 mg of quercetin equivalent (QE)/100 g of dry matter (DM), and condensed tannins values range is between 5.29 and 152.15 mg of catechin equivalent (CE)/100 g dry matter (DM), and the antioxidant activity ranged between 0.219 and 2.028 mg/ml for FRAP IC50, 2.411 and 9.738 mg/ml for DPPH IC50. This study showed that date fruit is a veritable source of functional nutrients and natural antioxidants. Therefore, Moroccan dates can be used as a food or functional ingredient in food products.
Date fruit is known to be the staple food in the Arab countries. It provides a lot of potential h... more Date fruit is known to be the staple food in the Arab countries. It provides a lot of potential health benefits and can be the essential source of nutrients. The majority of Moroccan varieties are not characterized for their chemical, biochemical and quality properties. The aim of this work was to assess the chemical composition of 17 varieties of Moroccan date fruits (Phoenix dactylifera L.) and to determine their nutritive components. The analysis showed that the dates are rich in sugars (51.80-87.98%), they contain low concentration of proteins (1.09-2.80%) and lipids (0.16-0.39%). The predominant mineral is potassium (1055.26-1604.10 mg/100 g DW). Moreover, they contain high concentrations of malic acid (69.48-495.58 mg/100 g (DW)), oxalic acid (18.47-233.35 mg/100 g DW) and tartaric acid (115.70-484.168 mg/100 g DW). These results suggest that the date fruit are nutritious and can be an excellent source for human nutrition and health benefits.
Apricot is among the most important fruits in Morocco. This study aimed to determine the main phy... more Apricot is among the most important fruits in Morocco. This study aimed to determine the main physical, physicochemical, and biochemical quality criteria of three principal apricot cultivars in Morocco, namely, “Maoui,” “Canino,” and “Delpatriarca.” Different physicochemical and biochemical methods have been improved and adapted for the assessment of the apricot’s quality. Fruit of “Canino” has shown a good organoleptic quality due to interesting biometrics, richness of carotenoids (up to 113.67 μg of β-carotene g−1 of fresh weight (FW)), and an important content of soluble solids (SS) that reached 17.20 °Bx. “Delpatriarca” is rich in organic acids (27.35 g/kg FW for total acids) while “Maoui” has high water content (83.77%) and a SS content of 16.03 °Bx. The association of the total acidity and soluble solids determination with the use of the HPLC for determining the organic acids was very practical and effective in determining the organoleptic quality of the fruit. High correlatio...
In association with a desirable balance of sugars and organic acids, volatile compounds contribut... more In association with a desirable balance of sugars and organic acids, volatile compounds contribute to the important sensory attributes of apricots. This study assessed the biochemical, aromatic, and sensory qualities of ten Moroccan apricot clones at two maturity stages (M1: commercial stage and M2: consumption stage). Sucrose (1.84–7.09 g/100 g of fresh weight (FW)) and citric acid (0.56–2.25 g/100 g FW) were the main sugar and organic acid in fresh apricots, respectively. The principal identified volatile compounds classes were aldehydes, alcohols, and acetates. The major apricot volatile compounds, hexanal (15.43–696.35 μg/kg FW), 2-hexenal (9.04–404.72 μg/kg FW), β-linalool (8.49–880.50 μg/kg FW), and 1-hexanol (3.35–86.00 μg/kg FW), were previously reported to be major contributors to apricot flavor. Multivariate analysis revealed a significant impact of the ripening stage on the perception of sensory quality related to biochemical parameters. At the commercial stage, apricots ...
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