Dados do Trabalho

Título

Adsorption of phenolic compounds from biohybrid propolis extract in bentonite: Kinetic models, physicochemical characterization, and functional properties

Introdução

Phenolic compounds from propolis have promising food applications because of their antioxidant and antimicrobial properties. However, the main limitation of propolis is due to its low bioavailability, low permeability, and deficiency during human digestion, reducing the use of propolis in food formulations.

Material e Métodos

The current research aimed to stabilize the phenolic compounds from propolis extract (PE) using a natural clay (bentonite) and to characterize the physicochemical and antioxidant properties of bentonite stabilizing phenolic compounds from PE the resulting biohybrid (BH). PE (2.85 % w/v) was obtained after propolis dispersion in absolute ethanol. Extraction was performed using a Shaker at 30 °C and agitation at 120 rpm for 24 h. The PE was centrifuged at 4000 rpm for 10 min, filtered on filter paper, and stored in amber bottles at -24 °C without light until use. Adsorption test was carried out using different masses of bentonite and times at 20 ºC and pH of 6.03. Bentonite and BH were characterized concerning their color (CIELab scale), antioxidant properties (ABTS), and chemical composition (FTIR and Raman).

Resultados e Discussão

The maximum adsorption capacity was 1.80 mg of phenolic compound per gram of bentonite and it was completed in the first five minutes of the test. Bentonite had a brown color and after its use in the adsorption process, the color of the resulting BH changed to green. Furthermore, bentonite did not have antioxidant properties, but the stabilization of phenolic compounds from PE on bentonite produced BH with antioxidant properties. FTIR and Raman results suggest that the interaction between the phenolic compound from PE and bentonite is stabilized mainly through hydrogen bonds and physical interactions. Bentonite did not have antioxidant properties. In contrast, the BH had an ABTS value of 246.86 ± 0.03 μmol TROLOX/mL, which is higher than those reported in the literature for phenolic compounds from propolis extracts. The current research reports for the first time an alternative to producing a powder containing phenolic compounds from PE with promissory food applications as a natural additive.