Monodispersed CaCO3@hydroxyapatite/magnetite microspheres for efficient and selective extraction of benzoylurea insecticides in tea beverages samples.

A novel monodispersed CaCO3@hydroxyapatite/magnetite microsphere (CaCO3 @HAP/Fe3O4) was prepared via an in-situ growth strategy, and applied as an adsorbent for efficient and selective adsorption of benzoylurea insecticides (BUs) in various tea beverages samples. The sorbent exhibited uniformity in particle size, good mono-dispersibility and excellent solvent stability. The adsorption equilibrium of BUs (100 ng/mL) in 10 mL of tea beverages samples was achieved on 20 mg of CaCO3 @HAP/Fe3O4 within 10 min. The adsorption followed pseudo-second-order kinetics and Langmuir models and the maximum adsorption capacities of 131.9-161.3 mg/g were accomplished via hydrophobic interactions, hydrogen bonding, and the affinity of F atom and Ca2+. Coupled with high performance liquid chromatography, the method offered wide linear ranges of 0.8-1000 ng/mL with correlation coefficients (r) ≥ 0.9995, low limits of detection of 0.2-0.3 ng/mL and large enrichment factors of 75.7-102. The recoveries ranged from 75.7%- 102% with intra- and inter-day precisions of 1.9%- 9.3% and 1.6%- 11.8%, respectively. In addition, CaCO3 @HAP/Fe3O4 could be easily regenerated and reused at least 10 times with no significant loss of recovery. These results revealed an alternative strategy for fast and convenient determination of BUs in tea beverages samples and proved the great feasibility of CaCO3 @HAP/Fe3O4 in the application for the selective adsorption of BUs.

Gastrointestinal Fate of Fluid and Gelled Nutraceutical Emulsions: Impact on Proteolysis, Lipolysis, and Quercetin Bioaccessibility.

Fluid and gelled nutraceutical emulsions were formulated from quercetin-loaded caseinate-stabilized emulsions by the addition of gellan gum with or without acidification with glucono-δ-lactone. Gellan gum addition increased the viscosity or gel strength of the fluid and gelled emulsions, respectively. The behavior of the nutraceutical emulsions in a simulated gastrointestinal tract depended upon their initial composition. Fluid emulsions containing different gellan gum levels (0-0.2%) had similar protein and lipid hydrolysis rates as well as similar quercetin bioaccessibility (∼51%). Conversely, proteolysis, lipolysis, and quercetin bioaccessibility decreased with an increasing gellan gum level in the gelled emulsions. In comparison to gelled emulsions, fluid emulsions were digested more rapidly and led to higher quercetin bioaccessibility. There was a good correlation between quercetin bioaccessibility and the lipolysis rate. These findings are useful for designing nutraceutical-loaded emulsions that can be used in a wide range of food products with different rheological properties.

Pluronics modified liposomes for curcumin encapsulation: Sustained release, stability and bioaccessibility.

The present work evaluated the feasibility of different pluronics (F127, F87 and P85) utilized as modifiers to improve the stability and bioaccessibility of curcumin liposomes (cur-Lps). Pluronics modified curcumin liposomes (cur-pluronic-Lps) were prepared by thin film evaporation combined with dynamic high pressure microfluidization. The particle size and polydispersity index of cur-pluronic-Lps was significantly lower than cur-Lps. Fourier transform infrared spectroscopy analysis revealed that curcumin was loaded in liposomes successfully and X-ray diffraction suggested that curcumin in the liposomes was in an amorphous state. In vitro release studies demonstrated that 73.4%, 63.9%, 66.7% and 58.9% curcumin released from cur-Lps, cur-F127-Lps, cur-F87-Lps and cur-P85-Lps, respectively. Compared with cur-Lps, cur-pluronic-Lps showed a slower release rate and lower cumulative release percentage for curcumin. Non-Fickian transport was the main release mechanism for cur-Lps, cur-F127-Lps and cur-F87-Lps, and typically the first-order model fitted cur-P85-Lps release. Stability studies (exposure to solutions of different pH and heat treatment) indicated that pluronics modification could enhance their pH stability and thermal stability. In vitro simulated gastrointestinal tract studies suggested that pluronics modification could significantly improve the absorption of cur-Lps. Bioaccessibility of curcumin liposomes increased in the following order: cur-Lps < cur-F87-Lps < cur-P85-Lps < cur-F127-Lps. These results may guide the potential application of pluronics modified liposomes as carriers of curcumin in nutraceutical and functional foods.

Enhancement of Curcumin Bioavailability by Encapsulation in Sophorolipid-Coated Nanoparticles: An in Vitro and in Vivo Study.

There is great interest in developing colloidal delivery systems to enhance the water solubility and oral bioavailability of curcumin, which is a hydrophobic nutraceutical claimed to have several health benefits. In this study, a natural emulsifier was used to form sophorolipid-coated curcumin nanoparticles. The curcumin was loaded into sophorolipid micelles using a pH-driven mechanism based on the decrease in curcumin solubility at lower pH values. The sophorolipid-coated curcumin nanoparticles formed using this mechanism were relatively small (61 nm) and negatively charged (-41 mV). The nanoparticles also had a relatively high encapsulation efficiency (82%) and loading capacity (14%) for curcumin, which was present in an amorphous state. Both in vitro and in vivo studies showed that the curcumin nanoparticles had an appreciably higher bioavailability than that of free curcumin crystals (2.7-3.6-fold), which was mainly attributed to their higher bioaccessibility. These results may facilitate the development of natural colloidal systems that enhance the oral bioavailability and bioactivity of curcumin in food, dietary supplements, and pharmaceutical products.