Thermal protection and pH-gated release of folic acid in microparticles and nanoparticles for food fortification.

Encapsulation provides efficient approaches to increase stability and delivery of poorly soluble bioactive components, predominantly for fortification of beverages and similar liquid-based foods. In this study, folic acid was encapsulated within conventional and emulsion-templated alginate-pectin hydrogels, proliposomes, and a combination thereof. The stability of these systems was examined under various environmental conditions (pH 1.2-9.0, 25-85 °C, dark/light). The techniques demonstrated efficient and relatively straightforward production of well-defined microparticles and nanoparticles (350 nm to 250 µm). Dispersed folic acid provided a delivery system with unique pH-responsive features, which offered prolonged stability during food storage, and indicated increased release at the site of absorption upon ingestion. This formulation had no limitation due to particle size, while at the same time it allowed high encapsulation efficiencies (80%-100%), as compared to the low encapsulation efficiency achieved by solubilisation (6%). At the low pH that is expected in the stomach, leaching of the dispersed folic acid was prevented, while at the pH that is expected in the intestine, there was complete release via solubilisation and carrier swelling. Overall, the optimum for food processing and storage was pH 3.0, where ≥70% of 50% to 200% of the recommended daily allowance of folic acid remained in the alginate-pectin beads after 6 months at room temperature in the dark. The thermal properties were enhanced by emulsion-templated alginate-pectin beads and proliposomes. In this way, 30% to 75% retention of folic acid was achieved at temperatures ≤90 °C, where the proliposomes reinforced within a polysaccharide network achieved the highest level of protection.

Encapsulation of (-)-epigallocatechin gallate into liposomes and into alginate or chitosan microparticles reinforced with liposomes.

BACKGROUND: (-)-Epigallocatechin gallate (EGCG) was encapsulated into liposomes that were further incorporated into alginate and chitosan microparticles. The stability of free and encapsulated EGCG in all three systems was evaluated at different pH values and in fruit nectar. Furthermore, the interactions between EGCG and the compounds of the microparticles were studied using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). RESULTS: All three encapsulation systems showed high encapsulation efficiency (>97%) and sustained release; in 14 days, no more than 15% of EGCG was released. The encapsulation systems successfully protected EGCG against degradation at alkaline pH. For non-encapsulated EGCG, >70% was degraded after 14 days, while there was no significant degradation of encapsulated EGCG in these three systems. In fruit nectar, >30% of non-encapsulated EGCG was degraded in 14 days, while only 6% of EGCG encapsulated into liposomes or chitosan microparticles reinforced with liposomes was degraded at that time. The DSC and FTIR analyses showed that the main interactions occurred between the liposomes and the EGCG. CONCLUSION: This study demonstrates that liposomes as well as alginate and chitosan microparticles reinforced with liposomes have the potential to enhance EGCG stability in food products during storage. © 2016 Society of Chemical Industry.

Effect of in vitro digested cod liver oil of different quality on oxidative, proteomic and inflammatory responses in the yeast Saccharomyces cerevisiae and human monocyte-derived dendritic cells.

BACKGROUND: Upon oxidation of the polyunsaturated fatty acids in fish oil, either before ingestion or, as recently shown, during the gastro-intestinal passage, a cascade of potentially cytotoxic peroxidation products, such as malondialdehyde and 4-hydroxy-2-hexenal, can form. In this study, we digested fresh and oxidised cod liver oils in vitro, monitored the levels of lipid peroxidation products and evaluated oxidative, proteomic and inflammatory responses to the two types of digests in the yeast Saccharomyces cerevisiae and human monocyte-derived dendritic cells. RESULTS: Digests of cod liver oil with 22-53 µmol L(-1) malondialdehyde and 0.26-3.7 µmol L(-1) 4-hydroxy-2-hexenal increased intracellular oxidation and cell energy metabolic activity compared to a digested blank in yeast cells and the influence of digests on mitochondrial protein expression was more pronounced for oxidised cod liver oil than fresh cod liver oil. The four differentially expressed and identified proteins were related to energy metabolism and oxidative stress response. Maturation of dendritic cells was affected in the presence of digested fresh cod liver oil compared to the digested blank, measured as lower CD86 expression. The ratio of secreted cytokines, IL-12p40/IL-10, suggested a pro-inflammatory effect of the digested oils in relation to the blank (1.47-1.67 vs. 1.07). CONCLUSION: Gastro-intestinal digestion of cod liver oil increases the amount of oxidation products and resulting digests affect oxidation in yeast and immunomodulation of dendritic cells.