Warped Product Semi-Slant Submanifolds of a Sasakian Manifold

2000 Mathematics Subject Classification: 53C40, 53C25.In the present note, it is proved that there donot exist warped product semi-slant submanifolds in a Sasakian manifold other than contact CR-warped product submanifolds and thus the results obtained in [8] are generalized

Hemi-Slant Warped Product Submanifolds of Nearly Kaehler Manifolds

Hemi-slant warped product submanifolds of nearly Kaehler manifolds are studied and some interesting results are obtained. Moreover, an inequality is established for squared norm of second fundamental form and equality case is also discussed. The results obtained are also true if ambient manifold is replaced by a Kaehler manifold. These results generalize several known results in the literature

Encapsulation of Natural Bioactive Compounds: Nanoemulsion Formulation to Enhance Essential Oils Activities

The microencapsulation technology consists of a trap of a compound inside a tiny sphere known as microsphere. The microencapsulation concerns many different active materials such as bioactive compounds, drugs, vitamins, enzymes, flavors, and pesticides. This technology has gained real interest in numerous fields such as agriculture, cosmetic, pharmaceutical, textile, and food. This chapter highlights the encapsulation of essential oils into nanoemulsion-based delivery system as a model for the encapsulation of natural bioactive compounds. Moreover, an investigation of different parameters affecting the stability of produced nanoemulsion was conducted, in addition to the study of the effect of the nanoencapsulation of essential oils on their antibacterial activity. Finally, an enumeration of the advantages of encapsulating essential oils into nanoemulsion-based delivery systems in order to provide a natural food preservatives has been provided

Ultrasound-Assisted Extraction: Effect of Extraction Time and Solvent Power on the Levels of Polyphenols and Antioxidant Activity of Mesembryanthemum edule L. Aizoaceae Shoots

Purpose: To investigate the influence of extraction conditions assisted by ultrasound on the quality of extracts obtained from Mesembryanthemum edule shoots.Methods: The extraction procedure was carried out in an ultrasonic bath. The effect of two solvents (methanol and ethanol) and two extraction times (5 and 10 min) were evaluated on the basis of the phenolic content and antioxidant activity of the plant extract.Results: Significant variability in phenolic content and antioxidant activity, depending on the solvent (S), and to a lesser degree, extraction duration (D) and their interaction (S/D) were found. Methanol extract was significantly richer in total polyphenols than ethanol extract, their levels being 104.7 and 74.2 mg GAE.g-1DW, respectively. For the two solvents used, longer extraction duration yielded higher polyphenol content. The ethanol extract exhibited higher antioxidant activity than the methanol extract. Moreover, Also, the longer sonication duration (10 min) yielded extracts with higher antioxidant activities.Conclusion: The antioxidant capacity of M. edule is strongly influenced by the nature of the extracting solvent and the duration of sonication extraction.Keywords: Antioxidant activity, Extraction duration, Mesembryanthemum edule, Polyphenols, Sonicatio

Upshot of the ripening time on biological activities, phenol content and fatty acid composition of Tunisian Opuntia ficus-indica fruit

Total phenol content and the antioxidant activities of three cultivars of Opuntia ficus-indica (L.) Mill. were evaluated. The results show that the ecotypes were significantly different according to their fatty acid composition, antioxidant and antibacterial activity, as well as their polyphenol profiles. Rossa fruit collected in August exhibited the higher phenolic content (15.48 mg GAE g−1 DW) with a stronger antioxidant activity. Bianca fruit collected in August exhibited a lower phenolic content (3.13 mg GAE g−1 DW) together with the stronger antiradical activity (96.14%). The advantage of this ecotype was more discernible as compared to positive controls butylated  hydroxytoluene (BHT, 79.75%). Likewise, CpG chromatogram identification revealed also an important difference between the ecotypes on oleic and linoleic acids.Keywords: Opuntia ficus-indica, variability, phenol content, fatty acid, antioxidant activity.African Journal of Biotechnology Vol. 12(40), pp. 5875-588

Phenolic nature, occurrence and polymerization degree as marker of environmental adaptation in the edible halophyte Mesembryanthemum edule

AbstractMesembryanthemum edule is an edible medicinal halophyte traditionally used to treat several human diseases. In this study, particular importance was attached to the influence of environmental conditions on phenolic composition and antioxidant activities of two M. edule provenances from contrasting climatic regions (Djerba and Monastir sampled from arid and superior semi-arid bioclimatic stages, respectively). Shoot phenolic content was evaluated using colorimetric method and its composition was identified by HPLC analysis with or without thiolysis. Antioxidant activities were assessed by five in vitro antioxidant systems. Results showed that the two M. edule provenances were significantly different according to their antioxidant activity as well as their polyphenol profiles. Indeed, plants from Djerba (lack of rainfall and long light hour periods) exhibited stronger antioxidant activity together with higher phenolic content. For instance, Djerba provenance shoots showed much lower IC50 (4.8μgml−1) and EC50 (80μgml−1) values for DPPH and Fe-reducing tests, respectively. In addition, the superiority of this provenance (Djerba) was more marked as compared to positive controls (BHT, BHA, and VitC). HPLC identification revealed also an important difference between the two provenances on major flavonoid components. This difference was confirmed by the mean degrees of tannin polymerization (DPn) which was higher in Djerba plants. These data suggest that M. edule adaptation to environmental stresses proceeds through induced particular phenol quality and DPn for the improvement of their antioxidant capacities to protect plant tissues against oxidative stress