Multilayer microparticles for programmed sequential release of phenolic compounds from Eugenia stipitata: Stability and bioavailability.

A co-delivery system based on multilayer microparticles was developed and characterized for the sequential release of phenolic compounds (PCs) using different encapsulation processes (spray drying: SD and drying-chilling spray: SDC) and wall materials to improve the stability and bioavailability of PCs. Samples were characterized in terms of process yield (PY%), phenolic retention efficiency (PRE%), chemical structure and crystallinity (NMR, FTIR, DXR), thermal stability (DSC and FT-IR), anti-radical capacity (ORAC and ABTS) and in vitro digestion. PRE% of samples by SD were higher (p < 0.05) than SDC due to the formation of PCs from CRF (cará-roxo flour). NMR, FTIR, DXR confirmed the presence of key components and interactions for the formation of the advanced co-delivery system. The SDC particles showed crystalline regions by XRD and were stable at ∼47 °C. All samples showed good release of PC in the intestinal phase, and antiradical capacity that reached 23.66 µmol TE g-1.

Nanoencapsulation and bioaccessibility of polyphenols of aqueous extracts from Bauhinia forficata link.

Bauhinia forficata Link is a plant rich in polyphenols that has been used mainly for its hypoglycemic activity, which is related to its antioxidant and anti-inflammatory potential. However, the beneficial effect of these bioactive compounds is directly dependent on their bioaccessibility and bioavailability, requiring processing techniques that can improve and preserve their biological activities. This work aimed to obtain nanocapsulated extracts from the infusion (ESIN) and decoction (ESDC) of B. forficata Link leaves, by spray drying. The encapsulating agents used were maltodextrin and colloidal silicon dioxide. The nanocapsules were characterized by HPLC-PDA-ESI-IT-MS n , evaluated the bioaccessibility of polyphenols after simulated digestion and their antioxidant activity. Additionally, an extensive physicochemical characterization of the nanocapsulated extracts was carried out and their stability and technological parameters were evaluated. The ESIN and ESDC extracts had yields of 57.3 % and 62.7 %, with average nanocapsules sizes of 0.202 µm and 0.179 µm, low humidity and water activity (<0.5), powder density and proper flow properties (Hausner ratio ≤ 1.25; Carr index 18-19 %). Scanning electron microscopy showed a spherical and amorphous morphology and low viscosity, which may have favored the solubility profile. The phenolic compounds of the nanocapsules degraded after 400 °C, showing high thermal stability. The infrared spectra identified the presence of maltodextrin and phenolic compounds and that there were no reactions between them. Chromatography confirmed the presence of phenolic compounds, mainly flavonols and their O-glycosylated derivatives, as well as carbohydrates, probably maltodextrin. Simulated in vitro digestion showed that polyphenols and flavonoids from ESIN and ESDC nanocapsules were bioaccessible after the gastric phase (49.38 % and 64.17 % of polyphenols and 64.08 % and 36.61 % of flavonoids) and duodenal (52.68 % and 79.06 % of polyphenols and 13.24 % and 139.03 % of flavoids), with a variation from 52.27 % to 70.55 % of the antioxidant activity maintained, by the ORAC method, after gastric digestion and still 25 %, after duodenal. Therefore, the nanoencapsulation of extracts of B. forficata is a viable option for the preservation of their bioactive compounds, making them bioaccessible and with antioxidant activity, which make them suitable for incorporation into various nutraceutical formulations, such as capsules, tablets and sachets.