Análise do flavonoide crisina por QuEChERS modificado e HPLC-DAD e co-encapsulação com probióticos

Abstract

The flavonoid chrysin has numerous bioactive effects. Despite being present in natural sources, most bioassays do not use natural sources to obtain chrysin. This is due to the lack of studies demonstrating the chrysin content in natural sources and adequate analytical methods. The first objective of this work was to adapt and validate a QuEChERS method (quick, easy, cheap, effective, rugged and safe), followed by analysis by high-performance liquid chromatography with diode array detector (HPLC-DAD) for the determination of chrysin in species of Passiflora, and apply this method to quantify chrysin in leaves, pulp and peel of Passiflora caerulea. The accuracy, precision and intermediate precision parameters showed adequate results, with a significant matrix effect for pulp and peel. The limit of quantification was 0.08, 0.01 and 0.014 mg kg-1 for leaf, pulp and peel, respectively. The leaves and green peel presented the highest chrysin content and the best antioxidant potential, and in vitro gastrointestinal digestion did not alter the bioaccessibility of chrysin. The second objective was to evaluate the feasibility of co-encapsulation of chrysin and Lactiplantibacillus plantarum (L. plantarum). Efforts were primarily focused on cataloging the methodologies used for chrysin encapsulation already documented in the literature. It was observed that there was no work associating probiotics and chrysin, and there was a lack of use of green and traditional techniques, such as external ionic gelation. From this, strains of L. plantarum were co-encapsulated at a concentration of 10 UFC mL-1 with chrysin at concentrations of 0.1, 0.25 and 0.5 %. The encapsulation efficiency for the probiotic was 90%, and for chrysin it was 54 to 84%. The microparticles were subjected to pasteurization and simulation of gastrointestinal digestion, obtaining satisfactory probiotic counts and chrysin levels. The stability of the capsules was evaluated for 120 days under 3 different temperature conditions (25, 8 and -18 °C). The stability of the probiotics was not affected by the concentration of chrysin, and the best stability of L. plantarum occurred at a temperature of -18 °C. The chrysin content was not substantially modified over the 120 days of study at any of the concentrations and temperatures. For the first time, a validated modified QuEChERS method followed by HPLCDAD analysis that can be applied for chrysin analysis in Passiflora species was demonstrated. It was observed that the leaves of Passiflora caerulea are excellent sources of chrysin and have antioxidant potential, followed by the green peel, and that the bioaccessibility of chrysin in these matrices is not altered by gastrointestinal digestion. The co-encapsulation of L. plantarum and chrysin proved to be viable, with chrysin not exerting acute or chronic toxicity in the probiotics, and encapsulation being beneficial for the stability of the encapsulated agents. As perspectives, it is envisioned to study the application of the leaves and green peel of Passiflora caerulea as a source of chrysin in co-encapsulation with probiotics and as a source of chrysin in nutraceutical or food formulations, as well as the study of the bioactive effect of microcapsules in in vitro and in vivo assays.