Publications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/13

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Author: search.filters.author.Kennas, AbderrezakSubject: search.filters.subject.Antioxidant activity

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    Evaluation of some biological activities of phenolic compounds obtained from two Algerian medicinal plants : mentha rotundifolia and satureja calamintha
    (2020) Benfares, Redhouane; Boudjema, Khaled; Behlali, Hadjira; Imedjdouben, Imene; Kennas, Abderrezak; Fazouane, Fethia; Jaroslava, Švarc-Gajić
    In this work phytochemical characterization of two medicinal plants from Lamiaceae family, Mentha rotundifolia and Satureja calamintha, has been carried out. Extracts obtained with different solvents were screened for different plant secondary metabolites and were biologically characterized by defining their antiradical and antibacterial activi-ties. Phytochemical screening of M. rotundifolia and S. calamintha confirmed their rich-ness in different secondary metabolites. The determination of phenolic compounds revea-led high polyphenols contents in water: methanol (30:70) extracts with concentrations of 20.64±1.74 mg EAG/g DW and 13.45±0.91 mg EAG/g DW for M. rotundifolia and S. calamintha, respectively. These extracts were also characterized by high concentrations of flavonoids (Mentha rotundifolia 12.33±1.58 mg EQ/g DW, Satureja calamintha 7.11±0.02 mg EQ/g DW). Furthermore, the water:methanol (30:70) extract of M. rotun-difolia was the most effective in inhibiting free radicals. Recorded inhibition diameters for both plant samples and tested microbial strains ranged from 6.66 mm to 13.66 mm. Presented results confirmed that tested indigenous Algerian plants are favorable sources of polyphenols with antioxidant and antimicrobial properties
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    Effect of pomegranate peel and honey fortification on physicochemical, physical, microbiological and antioxidant properties of yoghurt powder
    (King Saoud University, 2020) Kennas, Abderrezak; Amellal-Chibane, Hayat; Kessal, Fetta; Halladj, Fatima
    Consumers are focusing more and more on health benefits of functional products. The aim of this work is to formulate and characterize novel functional powder obtained by freeze-drying yoghurt supplemented concomitantly with pomegranate peel powder (0–10%) and honey (0–5%). In order to examine the powdered yoghurt, it was subjected to measurements of physicochemical, physical, microbiological and antioxidant properties. The experimental data of freeze-drying were fitted to four models and results showed that Page model was the most suitable thin-layer drying model according to R2 and RMSE as statistical comparison indexes. There was no significant difference (p > 0.05) among the powder samples in terms of moisture content and flow properties. The bulk and tapped densities values of yoghurt samples were slightly affected (p < 0.05) by the addition of pomegranate peel and honey. The results also demonstrated that powders particles exhibit an amorphous structure with mean diameter (D4.3) values that varied from 106.68 to 143.37 lm. Moreover, the addition of pomegranate peel and honey increased the glass transition temperature (Tg) value of yoghurt powder, and this could improve its stability during storage. Total lactic acid bacteria in all yoghurt powders remained over 107 cfu/g of dry matter after the freeze-drying. All the fortified yoghurt displayed higher phenolic contents and, consequently, exhibited higher antioxidant activities than control powder sample. It is concluded that, the freeze-drying of yoghurt with pomegranate peel and honey, at the fortification levels tested, is feasible, and the obtained powder has acceptable physicochemical and physical properties which could improve its shelf-life. Thus, the formulated yoghurt powder could be considered as a potential functional powder with antioxidant properties.