Browsing by Author "Halla, Noureddine"
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- Bacterial cellulose biosynthesis in the presence of raw moist olive pomace: A green sustainable approach that enhances biopolymer production and propertiesPublication . Crugeira, Pedro; Khelifa, Halima; Barreira, Luísa; Halla, Noureddine; Barreiro, Filomena; Rodrigues, Paula; Peres, António M.; Schreiner, Tatiana B.; Schreiner, Tatiana B.In this study, the biosynthesis of bacterial cellulose (BC) by Komagataeibacter intermedius strain isolated from Kombucha tea in the presence of raw moist olive pomace (MOP) (concentration up to 40 % in the fermentation media) was studied. The BC membranes were characterized by their antioxidant activity, structural character- istics, crystallinity, thermal stability, and mechanical behavior. Using raw MOP activated the inherent activity of the phenolic compounds, leading to cellular adaptation under unfavorable conditions and increased BC pro- duction for all tested MOP concentrations (p < 0.0001). This led to a 166.61 % increase for the 20 % MOP group compared to the control (HS medium). For this sample, enhanced antioxidant activity (~40-fold higher than the control) was found, which might be associated with the molecular interactions established between hydroxyls of BC and phenolic compounds. Moreover, an increase of 603.03 % in strain capacity, and a 376.01 % improvement in stress at break compared to the control was observed. The study confirmed that BC can be synthesized using MOP in its natural state, supporting a sustainable circular economy while enhancing the biosynthesis of a value- added product. By reducing synthetic media and utilizing MOP, a greener bioprocess can be achieved, and BC’s applicability can be expanded.
- Chemical profile and bioactive properties of the essential oil isolated from Ammodaucus leucotrichus fruits growing in Sahara and its evaluation as a cosmeceutical ingredientPublication . Halla, Noureddine; Heleno, Sandrina A.; Costa, Patrícia; Fernandes, Isabel P.; Calhelha, Ricardo C.; Boucherit, Kebir; Rodrigues, Alírio; Ferreira, Isabel C.F.R.; Barreiro, M.F.Ammodaucus leucotrichus is a medicinal plant commonly used in Algeria by the indigenous populations, especially due to its therapeutic effects. In this context, the aim of the present study was to chemically characterize the essential oil of A. leucotrichus fruits (EOALF) growing in Algerian Sahara, and to evaluate its bioactive properties (antimicrobial, antioxidant and anti-inflammatory). Considering the interest of the cosmetic industry for natural ingredients, and taking into account the obtained biological properties, the essential oil was also evaluated by incorporation in a base cosmetic (cream). The essential oil was extracted with a yield of 2.58 ± 0.17%, being perilla aldehyde identified as the main component, accounting for 85.6% of the total composition. Concerning the tested bioactivities, EOALF presented antioxidant potential, a strong anti-inflammatory activity, and was effective against the tested microbial strains (Staphylococcus aureus, Eschericia coli and Pseudomonas aeruginosa), being S. aureus the most sensitive bacteria. After incorporation in a base cosmetic, the developed formulation was able to preserve the EOALF bioactivities along 28 days under storage. The obtained results, with relevance for the strong-anti-inflammatory activity, pointed out the interest to exploit this essential oil as a cosmeceutical ingredient in the cosmetic industry.
- Development of chitosan microspheres through a green dual crosslinking strategy based on tripolyphosphate and vanillinPublication . Correa, Rodolpho Fagundes; Colucci, Giovana; Halla, Noureddine; Pinto, João A.; Santamaria-Echart, Arantzazu; Blanco, Silvia Priscila; Fernandes, Isabel P.; Barreiro, M.F.Microencapsulation procedures have recently focused attention on designing novel mi-crospheres via green synthesis strategies. The use of chitosan (CS) as an encapsulating material has increased interest due to its unique bioactive properties and the various crosslinking possibilities offered by their functional groups. The consolidation of the microspheres by physical crosslinking using sodium tripolyphosphate (TPP) combined with chemical crosslinking using vanillin (VA) open new opportunities in the framework of green dual crosslinking strategies. The developed strategy, a straightforward technique based on an aqueous medium avoiding complex separa-tion/washing steps, offers advantages over the processes based on VA, mostly using water-in-oil emulsion approaches. Thus, in this work, the combination of TPP crosslinking (3, 5, and 10 wt.%) via spray-coagulation technique with two VA crosslinking methods (in situ and post-treatment using 1 wt.% VA) were employed in the preparation of microspheres. The microspheres were characterized concerning morphology, particle size, physicochemical properties, thermal stability, and swelling behavior. Results revealed that the combination of 5 wt.% TPP with in situ VA crosslinking led to microspheres with promising properties, being an attractive alternative for natural bioactives encapsulation due to the green connotations associated with the process.
- Microencapsulation of ammodaucus leucotrichus essential oil using chitosan/ TPP/vanillin chemical systemPublication . Halla, Noureddine; Fernandes, Isabel P.; Heleno, Sandrina A.; Calhelha, Ricardo C.; Costa, Patrícia; Rodrigues, Alírio; Boucherit, Kebir; Ferreira, Isabel C.F.R.; Barreiro, M.F.A. leucotrichus (Coss. & Dur.) Coss. & Dur., known in Algeria as “Kammûnes-sofi”, is a medicinal plant that finds culinary use by indigenous populations. Among others, it is used against stomach pain, indigestion, diarrhea, vomiting, fever, and to combat high blood pressure. In this work, the essential oil of A. leucotrichus, obtained by steam distillation (3h) from fruits collected in March 2015 from Tassili n'Ajjer, a vast plateau in south-east Algeria (25°30'0" N and 9°0'0" E), was chemically and biologically characterized and thereafter microencapsulated using a chitosan/TPP/vanillin system.