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.

Stability of yerba mate extract, evaluation of its microencapsulation by ionic gelation and fluidized bed drying.

Studies show that yerba mate (Ilex paraguariensis) has high antioxidant capacity occasioned by its high contents of total phenolic compounds. Microencapsulation, specifically ionic gelation, since it does not use heating during process, is considered as an alternative for preserving and applying the extract. The purpose of this study was to evaluate general characteristics and stability of hydroalcoholic extract of yerba mate, conduct the extract microencapsulation by ionic gelation followed by microparticle fluidized bed drying. The extract was evaluated for color stability, total phenolic compounds, and antioxidant activity for nine weeks and at three temperatures (5, 15, and 25 °C). From the extract, a double emulsion (W/O/W), generation of microparticles (ionic gelation by dripping), and fluidized bed drying were conducted. The extract had 32912.55 mg GAE/100 g of phenolic compounds and 2379.49 µmol TE/g of antioxidant activity. The main compound observed was chlorogenic acid (5-CQA) with 0.35 ± 0.01 g/100 mL. In the stability study, the temperature was observed to influence in phenolic compounds reduction, as well as in total color difference of the extract. Double emulsion has shown to be stable and appropriate for use. The values of microparticles total phenolic compounds and antioxidant activity were 423.18 ± 8.60 mg GAE/100 g and 21.17 ± 0.24 µmol TE/g, respectively. After drying, the moisture of microparticles was reduced from 79.2% to 19%. The extract had high total phenolic compound content and high antioxidant activity. Storage at the lowest temperature (5 °C) assured better preservation of extract total phenolic compounds. The dried microparticles showed content of total phenolic compounds and antioxidant activity with potential for commercialization and future application in food matrices.

Release of anthocyanins from the hibiscus extract encapsulated by ionic gelation and application of microparticles in jelly candy.

Microparticles containing anthocyanin extract from Hibiscus sabdariffa L. (HE) were produced by the ionic gelation method by dripping-extrusion (D) and atomization (A). Double emulsion (HE/rapeseed oil/pectin) and a cross-linked solution (CaCl2) were used. The purpose of the study was to evaluate the release profile of anthocyanins under simulated gastrointestinal conditions, as well as microparticles application in pectin candy. Microparticles were incubated in simulated gastric and intestinal fluids and the release was evaluated by polyphenols, anthocyanin and color. Jelly candies were characterized and being tested for sensory acceptance (84 tasters). Samples were stored in the absence of light (25 °C/55% humidity) and evaluated for polyphenols, anthocyanin and color for 62-days. Microencapsulation of hibiscus anthocyanin resulted in improved enteric protection of bioactive compound, mainly in microparticles generated by dripping-extrusion. Application in jelly candy has shown to be technically feasible, with retention of up to 73% of bioactive compounds and mean sensorial acceptance of 70% tasters.

Encapsulating anthocyanins from Hibiscus sabdariffa L. calyces by ionic gelation: Pigment stability during storage of microparticles.

Hibiscus extract (HE) has a strong antioxidant activity and high anthocyanin content; it can be used as a natural pigment, also adding potential health benefits. The objective of this work was the microencapsulation of HE anthocyanin by ionic gelation (IG) using two techniques: dripping-extrusion and atomization, both by means of a double emulsion (HE/rapseed oil/pectin) and a cross-linked solution (CaCl2). Particles (77-83% moisture content) were conditioned in acidified solution at 5, 15 and 25°C, absence of light, and evaluated for anthocyanins and color for 50-days. The median diameter (D50) of the particles ranged from 78 to 1100µm and encapsulation efficiency ranged from 67.9 to 93.9%. The encapsulation caused higher temperature stability compared with the free extract. The half-life (t1/2) values of the particles ranged from 7 (25°C) to 180days (5°C) for anthocyanins and from 25 (25°C) to 462days (5°C) for Chroma value. The IG increased the stability of HE anthocyanin. Both the dripping-extrusion and the atomization have shown to be feasible techniques.