Encapsulation Of Α-tocopherol Research Articles

Encapsulation of Folic Acid and α-Tocopherol in Lysozyme Particles and Their Bioaccessibility in the Presence of DNA.

Protein particles have been reported as the potential carriers for the co-encapsulation of bioactive components. In this study, lysozyme, a basic protein, was used to simultaneously encapsulate folic acid and α-tocopherol at pH 4.0. The encapsulation efficiency and loading capacity of folic acid or α-tocopherol increased with its respective concentration. Folic acid had no influence on the encapsulation of α-tocopherol. However, the encapsulation of folic acid was improved by α-tocopherol below 40 μg/mL but reduced by α-tocopherol at higher concentrations. The encapsulation by lysozyme shielded folic acid, α-tocopherol, or both partially from the attack of 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation. No masking effect of lysozyme encapsulation on α-tocopherol was found in DPPH antioxidant activity assay. Furthermore, the DNA coating was used to improve the dispersion of lysozyme with folic acid and α-tocopherol. The lysozyme/DNA particles with folic acid and α-tocopherol showed a homogenous size distribution of 180-220 nm with ζ-potential values between -33 and -36 mV. The release and bioaccessibility of folic acid in lysozyme/DNA with α-tocopherol were similar to that of folic acid alone, while the release of α-tocopherol was delayed and its bioaccessibility was improved by encapsulation in lysozyme/DNA with folic acid. The data gathered here would provide guidance for the use of lysozyme-based co-encapsulating carriers in the development of functional foods.

Encapsulation of α-tocopherol in large-ring cyclodextrin containing 26 α-D-glucopyranose units: A molecular dynamics study

α-Tocopherol is the most biologically active form of vitamin E (VE) exhibiting various biological activities such as strong antioxidant activity, antitumor properties and antiaging effects. However, the low water solubility of α-tocopherol has limited its prospective use in food, cosmetic and pharmaceutical industry. One of the promising strategies to tackle such issue is the use of a supramolecular complex with cyclodextrins (CDs). In this study, the encapsulation of α-tocopherol with six different initial un-complexed states into the large-ring CD containing 26 α-D-glucopyranose units (CD26) was studied by means of 400-ns molecular dynamics (MD) simulations to investigate their host–guest association process and the preferential binding efficiency upon complexation at low concentration of α-tocopherol. The MD results show that α-tocopherol spontaneously interacted with CD26 within 20 ns and formed a stable inclusion complex during 150–400 ns. From all six independent simulations, the inclusion complexes can be divided into two groups, which were fully and partly encapsulated inside the cavity of CD26. The α-tocopherol of the first group was covered by 13–14 subunits of CD26, while α-tocopherol in another group was attached by 6–10 subunits of CD26. In addition, α-tocopherol was surrounded by one- or two-turn helix of one half-ring of CD26, leaving the rest of cavities for forming complexation with a larger number of α-tocopherol molecules. Therefore, CD26 can be used as a solubility and stability enhancer for α-tocopherol through inclusion complexation.

Encapsulation of α-tocopherol in whey protein isolate/chitosan particles using oil-in-water emulsion with optimal stability and bioaccessibility

The aim of this study was to develop an oil-in-water (O/W) emulsion using whey protein isolate (WPI)-chitosan (CN) complex to encapsulate α-tocopherol and to characterize their stability and bioaccessibility in vitro. The O/W emulsions prepared under the optimal conditions (mass ratio of WPI:CN = 1: 1, corn oil containing 5 g/100 g of α-tocopherol) exhibited a monomodal distribution (d = 803.3 ± 6.9 nm) with encapsulation rate of 86.3 ± 2.3%. The emulsions were stable under NaCl (0–150 mmol/L), sugar (0–5 g/100 g), 55 °C for 30 min, pH 5–6.5, even storage for 20 d at 4 °C and 25 °C. During gastric digestion, WPI situated at the surface of emulsion particles can be digested into small molecular peptides by pepsin, but the structure of the core-shell particles remained due to the cross-linking with CN. During intestinal digestion, the structure of the particles disintegrated over the digestion time, and the inner-oil phase was released. Release profiles of the α-tocopherol and free fatty acids showed a burst effect followed by slow release. These results suggest that the WPI-CN complex could be used to achieve a controlled and sustainable release of liposoluble bioactive compounds from O/W emulsions.

Encapsulation of α-tocopherol and β-carotene in concentrated oil-in-water beverage emulsions stabilized with whey protein isolate

ABSTRACTThe stabilization of flavor emulsions is a challenge for the industry of functional beverages. In this work, whey protein isolate was used as the stabilizing agent in concentrated orange oil-in-water emulsions. A 23 factorial design was performed, varying the ratio of orange oil/water (30–60%), the concentration of whey protein (1–15%), and the concentration of the surfactant dioctyl sulfosuccinate sodium (0–100 mg L−1). Analyses of surface tension, film formation, zeta potential, particle size, and turbidity were performed. Stable emulsions containing 60% of oil phase were prepared. β-Carotene and α-tocopherol were successfully encapsulated, without affecting the emulsion's stability.

Photostability enhancement by encapsulation of α-tocopherol into lipid-based nanoparticles loaded with a UV filter

The aim of this study was to develop some sunscreen formulations able to maintain their photoprotection when exposed to UV radiation. In this context, the influence of the antioxidant α-tocopherol on the photostability of lipid-based nanoparticles, namely solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), encapsulated with a UVA filter, has been investigated. The nanoparticles co-encapsulated with both actives exhibited dimensions smaller than 200 nm and zeta potentials of –45 mV. The photoprotection of the creams based on lipid nanoparticles was evaluated in terms of two protection factors, SPF and erythemal UVA–PF. By exposing the creams to UV radiation, it was observed that tocopherol results in obtaining quite stable formulations, but it does not improve the overall photoprotection much. However, by adding the antioxidant to the formulation confers a double action: protection of the skin against reactive oxygen species and the photostabilization of the UVA filter into lipid nanoparticles.

Encapsulation of α-tocopherol in protein-based delivery particles

Abstract Two types of proteins, including β-lactoglobulin (BLG) and hen egg white protein (HEW), were examined for their ability to encapsulate α-tocopherol (α-TOC) after salt-induced gelation of the proteins. Parameters affecting encapsulation efficiency were investigated including the type of salt, as well as concentrations of salt, protein, and α-TOC. Concentrations of protein and α-TOC revealed to have an influence on encapsulation efficiency. The optimum preparation condition of BLG-encapsulated α-TOC was as follows: BLG of 0.5% (w/v); α-TOC of 100 mM; and CaCl2 of 25 mM. The optimum preparation condition of HEW-encapsulated α-TOC was as follows: HEW of 4.0% (w/v); α-TOC of 50 mM; and ZnCl2 of 25 mM. With the selected preparation conditions, encapsulation efficiency by BLG aggregates was approx. 20% and that by HEW was approx. 32%. From the in vitro estimation, the release of α-TOC was nearly 100% in simulated gastric condition. Alginate was therefore used for coating of these encapsulated particles to prolong the release of α-TOC till simulated intestinal condition. The α-TOC of approx. 55% and 38% were retained and released in the simulated intestinal condition from BLG- and HEW-encapsulated particles, respectively.