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- Natural antioxidants in emulsions O/WPublication . EL-GEUNDOUZ, Soukaina; Azza, S.; Dandlen, Susana Anahi; MAJDOUB, Nesrine; Lyoussi, Badiaa; Raposo, Sara; Gomes, Vera; Bankova, Vassya; Popova, Milena; Antunes, Maria Dulce; Miguel, Maria GracaThis study compared the capacity of propolis extract (PE) and thyme waste extract (TWE) to prevent the oxidation of oil in water (O/W) emulsion, as well as their impact on emulsion apparent viscosity (AV) in the presence of wheat germ and almond oils as lipid phase. For this, central composite design (CCD) and principal component analysis (PCA) were performed. Oxidation process was monitored by evaluating the formation of primary and secondary lipid oxidation products, at the same time the AV behavior was determined evaluating consistency index and flow behavior index. The results revealed that the increase of PE% and TWE% decreases TBARS (Thiobarbituric Acid Reactive Substances) and hydroperoxides formation. Viscosity increases with the rise of TWE% over (0.04%), whereas lower concentrations of PE% decreases it. Those results have been confirmed in the PCA analysis. TWE showed higher resistance to oxidation, although PE was more effective as antioxidant than TWE.
- Leaf mineral element content and soil characteristics on in vitro antioxidant and enzymatic inhibitory activities of aqueous fennel extractsPublication . MAJDOUB, Nesrine; EL-GEUNDOUZ, Soukaina; Carlier, Jorge; Clara Costa, Maria; Guerrero, Carlos; Duarte, João; Miguel, Mariahis study was conducted to evaluate the biochemical characterization of three harvested Foeniculum vulgare plants collected from two bioclimatic zones in order to investigate the soil growing conditions effect. The results showed a great variability of the phenolic amounts and biological properties of samples rely on localities. FvSEN contained the highest amounts of phenolic compounds. These amounts were accompanied by the greatest antioxidant ability through almost studied assays. FvSEN and FvZO were significantly different. In addition, the samples exhibited a significant and variable enzymatic inhibition activity with values ranging from 30 to 50 mu g/mL for lipoxygenase assay. But these extracts did not revealed significant differences on their tyrosinase abilities. On the other hand, the levels of mineral elements were also estimated. These contents varied depending on sample and locality. The growing soil conditions of samples in terms of different parameters is likely related to their antioxidant and enzyme inhibition potentialities added to their mineral composition which settled by Spearman's correlation. These data may confirm the interesting potential of F. vulgare as a valuable source for natural antioxidant molecules but the growing soil conditions can affect all the potentialities of these plants set for human consumption and other uses.
- Insight into the chemical composition and biological properties of Mediterranean royal jellyPublication . EL-GEUNDOUZ, Soukaina; Lyoussi, Badiaa; Miguel, Maria da GraçaRoyal jelly (RJ) is a secretion of the hypopharyngeal and mandibular glands of young Apis mellifera worker bees. It is privileged for the queen bee as exclusive nourishment for her entire life. This bee hive product was used in traditional and folk medicine for human health care. Recently, there have been several research studies on RJ highlighting their therapeutic properties. It was found that it exhibits a large spectrum of biological and pharmacological potential including antibacterial, antioxidant, anti-inflammatory, immunomodulatory and antitumor activities among others, which might be of high importance in modern medicine for the development of new drugs. Even if RJ is known since ancient times; research papers concerning its investigation are not this much developed as compared to the other bee hive, products such as honey or propolis. In this review, we summarize our understanding of data found in literature about the chemical composition and biological properties of RJ, in particular, that which originates from Mediterranean countries to stimulate future studies. More attention should be given to this natural product for better comprehension of its mechanism of action in vitro and in vivo, for possible standardization and achievement of new formulations.
- Zn treatment effects on biological potential of fennel bulbs as affected by in vitro digestion processPublication . Majdoub, Nesrine; Kaab, Leila Bettaieb Ben; Vieira, Ana Isabel; Faleiro, Maria Leonor; EL-GEUNDOUZ, Soukaina; Miguel, MariaZn treatment effects on the stability of polyphenols, MDA (malondialdehyde) content, antioxidant and lipoxygenase inhibition activities of two varieties of fennel bulbs were studied by using an in vitro gastrointestinal digestion model. Likewise, the effect of Zn on viability cells of E. coli was also performed. The results revealed that high amounts of total phenolic and flavonoid compounds were released during the digestion process, especially after the intestinal phase. Additionally, the antioxidant and lipoxygenase inhibitory activity were affected by the gastrointestinal digestion process and seems to be correlated with total phenol contents. On the other hand, the viability of E. coli was not affected by the activity of our tested bulbs during passage through the artificial digestion model, but the treated bulbs activity contribute relatively to the inhibition growth of bacteria. The survival of E. coli in fennel bulbs was challenged with simulated gastrointestinal fluids and the results showed that the E. coli strains, despite having experienced a viability reduction at the intestinal phase, were able to overcome the exposure to the gastrointestinal synthetic fluids. This E. coli ability reinforces the need for good hygienic measures to assure safe fresh produce, even for those that are rich in antibacterial compounds.
- Chemical characterization and biological properties of royal jelly samples from the mediterranean areaPublication . EL-GEUNDOUZ, Soukaina; Machado, Alexandra M.; AAZZA, Smail; Lyoussi, Badiaa; Miguel, Maria; Mateus, Maria; Figueiredo, A. CristinaRoyal jelly (RJ) is a bee product that has high nutritional value and is beneficial for the human health, earning importance as a functional food. Thus, the characterization of its main biological properties is with high importance. In this work, 6 RJ samples obtained in Morocco, Portugal, and Spain were evaluated in terms of total phenol and flavone/flavonol contents; total protein; 10-hydroxy-2-decenoic acid (10-HDA); volatiles composition; antioxidant and anti-inflammatory properties; and inhibition of tyrosinase, xanthine oxidase (XO), and acetylcholinesterase (AChE) activities. Total phenolic content ranged from 3 to 9 mg gallic acid equivalent/g RJ, and flavone/flavonol content from 0.1 to 0.5 mg quercetin equivalent/g RJ. 10-Hydroxy-2-decenoic acid content varied from 0.9% to 1.2% and total protein from 5.5% to 29.7%. Gas chromatography-flame ionization detector and gas chromatography-mass spectrometry analysis showed RJ volatiles dominated by linolenic acid, 2-decenoic acid, and octanoic acid in variable amounts. The antioxidant activity was monitored through nitric oxide (NO) scavenging activity and hydrogen peroxide (H2O2) scavenging capacity, where the IC50 ranged from 2.3 to 3.4 and 0.2 to 1.5 mg/mL, respectively. Anti-AChE activity IC50 ranged from 0.7 to 4.6 mg/mL, while XO inhibition IC50 ranged from 3.3 to 11.9 mg/mL. The results showed that phenols and flavonoids highly contributed to the RJ biological properties in contrast to 10-HDA and proteins.