Designing emulsion droplets of foods and beverages to enhance delivery of lipophilic bioactive components - a review of recent advances

Protein-Based Delivery Systems for the Nanoencapsulation of Food Ingredients

Many proteins possess functional attributes that make them suitable for the encapsulation of bioactive agents, such as nutraceuticals and pharmaceuticals. This article reviews the state of the art of protein-based nanoencapsulation approaches. The physicochemical principles underlying the major techniques for the fabrication of nanoparticles, nanogels, and nanofibers from animal, botanical, and recombinant proteins are described. Protein modification approaches that can be used to extend their functionality in these nanocarrier systems are also described, including chemical, physical, and enzymatic treatments. The encapsulation, retention, protection, and release of bioactive agents in different protein-based nanocarriers are discussed. Finally, some of the major challenges in the design and fabrication of protein-based delivery systems are highlighted.

Physicochemical stability, antioxidant properties and bioaccessibility of β-carotene in orange oil-in-water beverage emulsions: influence of carrier oil types

The bioaccessibility of β-carotene in beverage emulsions was enhanced by modifying the lipid composition of the dispersed phase.

Formulation and characterization of O/W nanoemulsions encapsulating high concentration of astaxanthin

This study evaluates the effect of modified lecithin (ML) and sodium caseinate (SC) on the formulation, stability and bioaccessibility of astaxanthin (AXT) loaded oil-in-water (O/W) nanoemulsions. These nanoemulsions were formulated using high-pressure homogenization in four passes at 100MPa. The volume mean diameter (d_4,3) of nanoemulsions produced by ML and SC were 163±5 and 144±12 nm, respectively. The physiochemical stability of nanoemulsions was recorded at 25°C. The nanoemulsions prepared by ML were stable for 30 minutes against a wide range of pH and heating temperatures (60-120 °C). However, ML-stabilized nanoemulsions showed droplet growth when treated at high NaCl concentrations. In comparison, droplet growth was observed in SC-stabilized nanoemulsions at pH4 and at high temperature treatment. However, SC-stabilized nanoemulsions were stable at high NaCl concentration (500 mM). The SC-stabilized nanoemulsions showed good physical and chemical stability (>70%) after 30 days of storage. The bioaccessibility of AXT in nanoemulsions was significantly higher in ML (33%) than in SC-stabilized nanoemulsions (6%), indicating a strong influence of emulsifier on bioaccessibility. These findings provide valuable information in designing nutritional products such as aqueous based AXT fortified beverages.

Formulation and characterization of monodisperse O/W emulsions encapsulating astaxanthin extracts using microchannel emulsification: Insights of formulation and stability evaluation

The study used straight-through microchannel emulsification (MCE) to encapsulate different extracts of astaxanthin (AXT) in oil-in-water (O/W) emulsion droplets. We used silicon microchannel plates (WMS 11-1) containing 13,752 discrete 10×104μm microslots, connected to a circular microhole with a diameter of 10μm. Two different AXT extracts (AstaReal (AR) and Zenthin^® (ZR)) based upon concentration and without purification was used as encapsulants in the dispersed phase, while different emulsifiers (1% (w/w) SDS, ML-750, MO-7S, Na-Cs and ML) with different stabilizing mechanisms were used as the continuous phase. The MCE was conducted at a dispersed phase flow rate of 1mLh^-1. Successful emulsification was conducted with a Sauter mean diameter of 35-37μm and relative span factor <0.25. The emulsification was highly depended on the type of emulsifiers and the extract type used during emulsification. Better droplet productivity was achieved with AR extract with 1% (w/w) ML-750 as the optimized emulsifier in Milli-Q Water. The O/W emulsion droplets remained stable at 25°C with encapsulation efficiency of over 98% during 15days of storage period.

Formulation, Characterization and Properties of Hemp Seed Oil and Its Emulsions

The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of Cannabis sativa L. in refined and unrefined form was characterized using iodine, saponification, acid values, and gas chromatography, and was employed for the preparation of stable oil-in-water emulsions. The emulsions were prepared using pairs of non-ionic surfactants (Tween, Span). The effects of the emulsification method (spontaneous emulsification vs. high-intensity stirring), hydrophilic lipophilic balance (HLB), type and concentration of surfactant, and oil type on the size and distribution of the emulsion particles were investigated. It was found that the ability to form stable emulsions with small, initial particle sizes is primarily dependent on the given method of preparation and the HLB value. The most efficient method of emulsification that afforded the best emulsions with the smallest particles (151 ± 1 nm) comprised the high-energy method, and emulsions stable over the long-term were observed at HBL 9 with 10 wt % concentration of surfactants. Under high-intensity emulsification, refined and unrefined oils performed similarly. The oils as well as their emulsions were tested against the growth of selected bacteria using the disk diffusion and broth microdilution methods. The antibacterial effect of hemp seed oil was documented against Micrococcus luteus and Staphylococcus aureus subsp. aureus. The formulated emulsions did not exhibit the antibacterial activity that had been anticipated.