Abstract

The main objective of the present work was to study the aptitude to drying of Pulicaria odora L. leaves pre-coated in functional gels. This involves drying in the open air leaves of P.odora pre-coated in a carrageenan gel, a carrageenan-based gel added to Z. jujuba Mill peel powder. In addition, the evaluation of certain properties (physicochemical, rheological and biological) of the obtained powders was carried out.

The obtained results show that coating has a very positive effect on the rheological properties of P. odora leaves powder (small grain size, good flow, and little swelling). It also promotes the conservation and release of bioactive substances (polyphenols and flavonoids). Indeed, the best extraction rates were obtained for the powder from the leaves coated in carrageenan gel based Z. jujuba Mill peel powder with levels of 1099.996 ± 8.545 mg EAG /g d.b and 141.336 ± 0.89 mg quercetin / g d.b) respectively for total polyphenols and flavonoids. Finally, the test for the antimicrobial activity of the total polyphenol extracts of the obtained powders reveals that they are effective against Gram-positive bacteria (S.aureus ATCC 25923) and Gram-negative bacteria (E.coli ATCC 25322) and yeast (C.albicans). The ethanolic extract of the powder from the leaves coated in the carrageenan gel based Z.jujuba Mill peel powder has an inhibition diameter of 24.5 ± 0.15 mm with respect to C.albicans.