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The aim of this work was the characterization of four plant-based milks: oat, almond, hemp, and quinoa’s milk. The nutritional composition of each milk, as well as its physico-chemical characteristics, microbiologic stability, and antioxidant potential, were determined in order to investigate the effect of the first ingredient on the overall quality of the plant-based milk. Finally, a hedonic sensory analysis was conducted in order to determine the acceptability of these products. In terms of nutritional value, obtained results highlighted that oat’s milk has the highest carbohydrate, protein and fiber contents (23g/100ml, 5g/100ml and 3g/100ml, respectively). However, hemp’s milk has the highest fat and calcium content (7g/100ml and 37.5 mg/ 100 ml, respectively). The pH of tested plant-based milk, were all similar and close to neutrality. The WI values found were 21.46 for almond’s milk, 9.48 for oat’s milk, 34.97 for hemp’s milk, and 0.1 for quinoa’s milk. The antioxidant capacity assessment demonstrated that tested plant-based milk have an interesting potential. Measured inhibition capacities ranged from 78.34 % (quinoa’s milk) to 63.14 % (oat’s milk), and their total polyphenol content ranged from 0.310 mg EAG/g DM (oat’s milk) to 0.836 mg EAG/g DM (quinoa’s milk). The microbial stability results showed that quinoa’s milk had the best bacterial stability, with a maximum denomination of 56 *104 UFC/ml for the first 8 days of storage, while almond and oat’s milks had better fungal stability and were free of contaminants up to the eighth day of storage. During the hedonic sensory analysis, the almond’s milk was the most appreciated by the panelist. Gathered results suggest that plant-based milks are high in nutrients and phenolic compounds, and they deserve to be considered as “healthy aliment”.

Retama raetam is a medicinal and aromatic plant present in the humid to the arid bioclimatic regions of Tunisia. In this work, we investigated R. raetam shoots antioxidant and antimicrobial activities and its natural antioxidant contents obtained from four fractions (petroleum ether, acetone 60%, ethyl acetate and water). Results showed that the ethyl acetate fraction exhibits the highest antioxidant activity as compared to the other ones. In fact, IC50 values of ethyl acetate extract were equal to 33.5, 500 and 1380 μg/ml (DPPH and ABTS radicals scavenging activity and reducing power, respectively). Accordingly, this fraction presented the highest total polyphenol and flavonoid contents (401 mg GAE/g DR and 33.21 mg CE/g DR, respectively). Moreover, RP-HPLC analysis showed that syringic acid and coumarin were the major phenolic compounds. Furthermore, this moderately polar fraction showed considerable antibacterial properties against human pathogen strains especially against Escherichia coli and Bacillus cereus. Finally, fractionation allows the identification of R. raetam most active molecules and therefore the optimization of their utilization. Our findings pointed out the appropriate solvent for extracting R. raetam potent phenolics which might provide a rich and novel source of natural antioxidants as food additives replacing synthetic ones in food industry.

International audience; We investigated the relative contributions of the environment and development stage on total polyphenols, flavonoids and condensed tannins contents, as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide scavenging activities in four Tunisian Mentha pulegium. Shoot total phenolics and antioxidant capacities were significantly dependent on environment, development stage and their interaction. Environment effects were considerably larger than development stage effects for total phenolics, flavonoids, DPPH and superoxide scavenging capacities, whereas development stage was much stronger than environment for tannin content and, although small, interaction effects of the two factors (environment and development stage) were significant for all antioxidant properties analyzed. The highest antioxidant activities were related to high phenolic contents. Three behaviors were revealed; the best antioxidant capacities in Soliman at floral bud stage, followed by Takelsa and the lowest potentialities (Bouarada and Jdeida). These findings indicate that antioxidant properties of M. pulegium were respectively influenced by environment, development stage and their interaction.

In the present study, shoot extracts from edible halophytic Mesembryanthemum species were evaluated for their effects against O 2 - , DPPH, and ABTS radicals. The reducing power, chelating ability, inhibition of lipid peroxidation and of β-carotene bleaching were also evaluated. Moreover, the total phenolic, flavonoid, and condensed tannin contents were determined. In vitro biotests showed a significant difference in the antioxidant capacities of the species studied. Mesembryanthemum edule was found to exhibit the higher antioxidant activity, except for the iron-chelating test where M. crystallinum showed the best activity with the lowest EC50 value (2.13 mg ml−1). Accordingly, M. edule exhibited high phenolic levels, especially in total phenols (70 mg of gallic acid equivalents/g dry weight), while no significant difference was found between M. crystallinum and M. nodiflorum (1.4 and 1.7 mg GAE g−1DW, respectively). Due to its strong antioxidant activities and high levels of phenols, M. edule was further studied for its phenolic constituents. HPLC analysis revealed 12 compounds, mainly flavonoids, with phloretin, quercitrin, and avicularin as the most abundant (1, 0.84 and 0.66 mg g−1 DW, respectively). These results evidenced the great variability in antioxidant capacities of these halophytes and suggested that M. edule might be an important source of functional phenolic compounds.

International audience; In the present study, shoot extracts from edible halophytic Mesembryanthemum species were evaluated for their effects against View the MathML source, DPPH, and ABTS radicals. The reducing power, chelating ability, inhibition of lipid peroxidation and of β-carotene bleaching were also evaluated. Moreover, the total phenolic, flavonoid, and condensed tannin contents were determined. In vitro biotests showed a significant difference in the antioxidant capacities of the species studied. Mesembryanthemum edule was found to exhibit the higher antioxidant activity, except for the iron-chelating test where M. crystallinum showed the best activity with the lowest EC50 value (2.13 mg ml−1). Accordingly, M. edule exhibited high phenolic levels, especially in total phenols (70 mg of gallic acid equivalents/g dry weight), while no significant difference was found between M. crystallinum and M. nodiflorum (1.4 and 1.7 mg GAE g−1DW, respectively). Due to its strong antioxidant activities and high levels of phenols, M. edule was further studied for its phenolic constituents. HPLC analysis revealed 12 compounds, mainly flavonoids, with phloretin, quercitrin, and avicularin as the most abundant (1, 0.84 and 0.66 mg g−1 DW, respectively). These results evidenced the great variability in antioxidant capacities of these halophytes and suggested that M. edule might be an important source of functional phenolic compounds.

Cynara cardunculus L. (cardoon) is a medicinal plant widespread in arid and semi-arid regions where high salinity frequently occurs. Cardoon leaves are known for their high content of natural bioactive molecules, notably polyphenols, that exhibit pharmacological activities such as antioxidant, antibacterial, and metal chelating activity. We studied the effect of different salt concentrations on plant growth, phenolic content and superoxide scavenging activity in locally grown C. cardunculus L. leaves (El Jem locality). No significant effect on leaf growth (leaf biomass, length and number) was found at moderate salinity (25—50 mM NaCl). However, these parameters were severely reduced (-30 to -90% as compared to the control) at 150 mM NaCl. Leaf phenolic content was significantly increased at 25-50 mM NaCl, and decreased at 150 mM NaCl. The superox-ide anion scavenging capacity of leaf extracts was stimulated by salt treatment, with a maximum at the highest NaCl level. Our findings indicate that the two studied characteristics of C. cardunculus leaves (polyphenol content and O2- quenching capacity) were not modified in parallel with increasing salinity, and that only the polyphenol content was correlated with leaf growth.